HK40006448A - Self-assembled surfactant structures - Google Patents

Description

Self-assembling surfactant structures

The application is a divisional application with the application date of 2011, 05 and 23, international application numbers PCT/US2011/037605 and national application number 201180035651.9 and the name of the invention is 'self-assembled surfactant structure'.

Cross Reference to Related Applications

The present application claims priority and benefit of U.S. provisional patent application serial No. 61/347,317 entitled "Self-Assembly of graded and/or multi-scale Materials Via physical constraints" filed on 21.5.2010 and U.S. provisional patent application serial No. 61/415,761 entitled "Free Standing graded Self-assembled Films" filed on 19.11.2010. The specification and claims of which are incorporated herein by reference.

Background

Technical Field

Embodiments of the invention employ biomimetic multi-scale self-assemblies and materials, such as membranes fabricated therefrom, that are fabricated in different configurations using batch and automated manufacturing to enable aqueous separation and concentration of solutes. Embodiments of the present invention also relate to methods of multi-scale self-assembly and materials made therefrom, wherein surfactant mesostructures self-assemble, preferably simultaneously, and incorporate one or more materials through physical confinement between two or more discrete surfaces and/or through physical confinement on two or more sides.

Background

It should be noted that the following discussion may refer to multiple publications by one or more authors and the year of disclosure, and that certain publications are not admitted to be prior art to the present invention due to recent publication dates. The discussion of these publications herein is presented to improve the background of the invention and is not to be construed as an admission that such publications are prior art for patentability determination purposes.

Membranes are used to separate ions, molecules and colloids. For example, ultrafiltration membranes can be used to separate water and molecules from colloids above 2 kdaltons; ion exchange membranes can be used to separate cations and anions; and the thin film composite membrane may be used to separate salt from water. These membranes all use the same separation physics. The permeability of the membrane to a particular one or more types of ions, molecules, colloids, and/or particles is much less than another type or types of ions, molecules, colloids, and/or particles. For example, ultrafiltration membranes have pores of a particular size that prevent the crossing of molecules and particles of a particular size. This technique is known as size exclusion. Reverse osmosis membranes use solubility differences to separate molecules. In a typical thin film composite membrane, water is three orders of magnitude more soluble than sodium chloride. The result is a material with a preference of water molecules to salt ions > 100: 1. In fact, this material filters water by blocking 99.7% of the sodium chloride.

For most separation membranes, the permeability of a membrane is defined as the ratio of the solvent flux through the membrane to the area of the membrane and the pressure applied to the membrane over a given period of time. The following is a formula for controlling flux through the membrane

Flux (Δ P- Δ π)

Where Δ P is the pressure across the membrane, Δ pi is the permeation pressure across the membrane and P is the membrane permeability. The permeability of a membrane is a function of the membrane structural parameters. The structural parameter is

Where S is the structural parameter, τ is the curvature, t is the thickness, and ε is the porosity of the film. Curvature is defined as the ratio of the distance between two points through the material to the minimum distance between the two points. Since the structural parameter is proportional to the permeability of the membrane, the curvature is proportional to the permeability.

Membranes for separation are used in many configurations. For Reverse Osmosis (RO) and Forward Osmosis (FO) applications, they are typically configured in a spiral wound configuration in which the membrane is wound around a hollow core. Water flows from the core into the membrane envelope and then back into the core. For Pressure Retarded Osmosis (PRO), the membrane may also be in a spiral wound configuration. In PRO, water flows under pressure into the membrane envelope and the osmotic gradient across the membrane pulls more water into the membrane envelope. Membranes for RO, FO and PRO can also be constructed as hollow fibers. In the hollow fiber, a hollow porous cylindrical membrane was manufactured. The water flows tangentially to the membrane surface and the pores in the fibres enable separation. Membranes can also be manufactured as cartridges typically used for concentration of proteins, viruses, bacteria, sugars and other biological materials. These membranes can be placed in cassettes that enable easy concentration of solutes.

For chlor-alkali processes, batteries and fuel cells, the anode and cathode are separated by an electrolyte. The electrolyte conducts cations or anions and blocks electrons, anolyte, and/or catholyte. In some devices, the electrolyte is an ion exchange membrane. Typically, an ion exchange membrane will allow either cations or anions, but not both, to pass through. The ion exchange membrane may be configured to allow passage of both monovalent and divalent ions or passage of only monovalent ions. The transport of undesirable solutes across the electrolyte fluid is known as Membrane cross over. Membrane exchange establishes an overpotential at the anode and/or cathode and reduces the current efficiency of the cell. Membrane exchange is a limiting factor in many devices such as direct methanol fuel cells, direct ethanol fuel cells, vanadium redox batteries, iron chromium batteries, flow batteries, and the like.

In biology, water drives the self-assembly of a class of surfactants called lipids in water, creating lipid bilayers that act as diffusion barriers to diffusion into cells. The permeability of the model cell membrane to water and various low molecular weight solutes was measured. A typical measurement of the selectivity of lipid bilayers is performed in aqueous suspension using osmosis (also known as forward osmosis). Also, the results of these experiments show that the lipid bilayer has greater permeability than commercial osmotic (also known as forward osmosis) membranes. Model cell membranes are phospholipids that self-assemble by water into structures called vesicles. Phospholipids have a hydrophilic head group and two fatty acid tails that are hydrophobic. Vesicles are spherical, hollow lipid bilayers between 30nm and 20,000nm in diameter. The lipid bilayer creates a physical barrier to the volume of water contained within the vesicle. A typical permeability experiment consists of two steps. The first step is to change the osmotic strength of the solute in the aqueous solution containing the vesicles. The second step is to measure the diffusion of solutes and/or solvents into or out of the vesicles across the lipid bilayer. The experiment is similar to a forward osmosis industrial process in which water is extracted through a membrane using a highly concentrated brine solution.

The results of these experiments show that the hydrophobic core of the bilayer separates different low molecular weight compounds. One mechanism is the sub-nano-porosity established by the gaps between the lipids in the bilayer and the hydrophobic core of the bilayer, enabling preferential selectivity in the above order for water, protons, uncharged below 100 molecular weight organics, and ions. Also, fluctuations in the molecular structure of the bilayer enable faster transport of water and protons than expected. Furthermore, these experiments show control of selectivity by the chemical structure of the lipids used. In particular, the separation properties of lipid bilayers depend on the length of the fatty acid tail of the lipid.

Disclosure of Invention

One embodiment of the invention includes a membrane comprising a stabilized surfactant mesostructure bound to a surface of a porous support. The stabilized surfactant mesostructure is preferably stabilized with a material that maintains the arrangement of the surfactant molecules. The material is optionally porous and the stabilized surfactant mesostructure optionally comprises flakes alternating with flakes comprising the porous material. Alternatively, the material is optionally non-porous and the stabilized surfactant mesostructure optionally comprises hexagonally packed columns comprising surfactant molecules in a circular arrangement, each of the columns being substantially surrounded by the non-porous material. The film preferably further comprises a material disposed between the stabilized surfactant mesostructure and the surface for maintaining a hydrogen bonding network between the surfactant in the stabilized surfactant mesostructure and the surface. The material preferably comprises a material selected from the group consisting of: silanes, organics, inorganics, metals, metal oxides, alkylsilanes, calcium, and silica. Preferably the surface is oxidized, melted and resolidified before the stabilized surfactant mesostructure binds to the surface; the average pore size at the resolidified surface in this case is preferably smaller than the average pore size in the bulk of the porous support. The pore size of the porous support is preferably small enough to prevent the precursor solution of the stabilized surfactant mesostructure from penetrating completely into the support prior to the formation of the stabilized surfactant mesostructure. The membrane optionally further comprises an additional porous structure disposed on the side of the porous support opposite the surface for mechanically or chemically stabilizing the porous support. The stabilized surfactant mesostructure optionally comprises a transporter. The membrane optionally comprises a second porous support, wherein the stabilized surfactant mesostructure is sandwiched between the porous support and the second porous support. The film preferably has a curvature of less than about 1.09. The stabilized surfactant mesostructure preferably has a pore size of about 0.3 angstroms to about 4 nm. The membrane preferably has a porosity greater than about 1%. The porous support preferably comprises plastic and/or cellulose. The porous support preferably mechanically stabilizes the stabilized surfactant mesostructure. The membrane optionally further comprises a second stabilized surfactant mesostructure bound to the porous support on a side opposite the surface. The film is optionally laminated with other identical films to form a multilayer film. The surface of the stabilized surfactant mesostructure is optionally modified. The membrane optionally comprises an ion-exchange membrane and/or a gas diffusion layer, the membrane comprising a membrane electrode assembly or an electrolyte.

Another embodiment of the present invention is a method for preparing a membrane, the method comprising: modifying the surface of the porous support; wetting the modified surface with a first solvent; placing a solution on the wetted surface, the solution comprising at least one surfactant and at least one second solvent, wherein the at least one surfactant is in a dispersed phase in the solution; confining the solution between two or more confining surfaces; and stabilizing the one or more surfactants to form a stabilized surfactant mesostructure on the surface of the porous support. The first solvent and/or the second solvent preferably comprise water. The solution optionally further comprises precursor solutes and/or transporters. The placing the solution and the limiting the solution are optionally performed substantially simultaneously. Confining the solution preferably comprises confining the solution between a surface of the porous support and at least one second surface. The at least one second surface is preferably selected from the group consisting of: slot sidewalls, rollers and blade edges. Modifying the surface preferably comprises an operation selected from the group consisting of: surface functionalization; surface grafting; covalent surface modification; surface adsorption; surface oxidation; surface ablation; rinsing the surface; depositing a material on the surface, the material selected from the group consisting of: silanes, organics, inorganics, metals, metal oxides, alkylsilanes, calcium, and silica; maintaining a network of hydrogen bonds between the surfactant in the stabilized surfactant mesostructure and the surface; and oxidizing, melting, and resolidifying the surface, and combinations thereof. The method is preferably performed as part of a mass production coating process. The method preferably further comprises controlling the thickness of the stabilized surfactant mesostructure. The solution optionally does not contain acids, bases or hydrophilic compounds. The at least one surfactant is preferably not removed from the solution after the solution is placed on the surface. The method is optionally performed on both sides of the porous support. The method optionally further comprises modifying the surface of the stabilized surfactant mesostructure, preferably with surface functionalization, altering the hydrophobicity of the surface of the stabilized surfactant mesostructure and/or methylating the surface of the stabilized surfactant mesostructure. The method may be repeated to form a multilayer film. The porous support preferably comprises plastic and/or cellulose. The method optionally further comprises placing a second porous support on the surface of the stabilized surfactant mesostructure, thereby sandwiching the stabilized surfactant mesostructure between the porous support and the second porous support.

Another embodiment of the invention is a forward osmosis membrane having a LM greater than about 15LM for a draw solution concentration of 10 wt% NaCl at 20 ℃^-2H^-1Permeability of (d). For a draw solution concentration of 10 wt% NaCl at 20 ℃, the permeability is preferably greater than about 20LM^-2H^-1And even more preferably greater than about 60LM for a draw solution concentration of 10 wt% NaCl at 20 deg.C^-2H^-1. The forward osmosis membrane preferably has a NaCl rejection greater than about 96%. The forward osmosis membrane preferably comprises one or more surfactants.

Another embodiment of the invention is a device for performing separations comprising an active layer comprising one or more surfactants. The active layer preferably comprises one or more transporters. The device is preferably selected from the group consisting of: forward osmosis membranes or modules, reverse osmosis membranes or modules, pressure retarded osmosis membranes or modules, hollow fiber membranes, spiral wound membranes or modules, cartridges, Tangential Flow Filter (TFF) cartridges, plate and frame modules, tubular membranes and bags. The device preferably comprises a porous support coated on both sides with the one or more surfactants. The one or more surfactants preferably form a mechanically stabilized membrane on one or more porous supports.

The objects, benefits and novel features, and further scope of applicability of the present invention will be set forth in part in the detailed description to follow, taken in conjunction with the accompanying drawings, and in part will become apparent to those skilled in the art upon examination of the following, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the appended claims.

Drawings

The accompanying drawings, which are incorporated in and form a part of the specification, illustrate several embodiments of the present invention and, together with the description, serve to explain the principles of the invention. The drawings are only for the purpose of illustrating one or more embodiments of the invention and are not to be construed as limiting the invention. In the drawings:

figure 1 illustrates how the gaps between surfactant molecules in the lamellar phase can be used for separation.

Figure 2 illustrates how the gaps between surfactant molecules in the hexagonal phase can be used for separation.

Figure 3 illustrates how the gaps between surfactant molecules in the hexagonal inversion phase can be used for separation.

Fig. 4 illustrates the process of self-assembly localization of surfactant mesophase thin films to the surface of porous materials. The result is a free standing surfactant mesogenic phase material attached to the porous material.

Fig. 5 shows an embodiment of a stabilized surfactant mesostructured film in which assembly is localized to the surface of a porous material.

FIG. 6 illustrates a physical confinement method for building the free-standing surfactant templated film shown.

Figure 7 is a schematic of biomimetic surfactant nanostructure assembly via physical confinement.

FIG. 8 illustrates various configurations of two-dimensional multi-scale self-assembly, according to an embodiment of the invention.

Fig. 9 illustrates the effect of surface chemistry preparation of membrane materials on flux and blocking levels of the resulting materials.

Figure 10 shows the effect of concentration polarization of methanol on flux through biomimetic surfactant nanostructures.

Figure 11 shows membrane thickness control via self-assembly solution solute concentration and its effect on permeability.

Fig. 12 shows film thickness control via physical limitation and its effect on permeability.

Fig. 13 is a schematic of an embodiment of an automated roll-to-roll process for making a film.

Figure 14 shows the effect of annealing on membrane permeability.

Figure 15 shows the difference between symmetric and asymmetric membranes.

Figure 16 is a graph comparing the back diffusion of salts of symmetric and asymmetric free-standing biomimetic surfactant nanostructures.

FIG. 17 shows the effect of surface functionalization chemistry on membrane hydrophobicity.

Fig. 18 shows the design of an embodiment of a filter cartridge using flat membranes for separation and concentration.

Figure 19 shows the design of an embodiment of an spiral filter cartridge for solute concentration.

Fig. 20 shows the design of an embodiment of a spiral filter cartridge for water purification.

Figure 21 illustrates the effect of pressure on the stopping level of an embodiment of a membrane according to the present invention.

Fig. 22 illustrates the effect of mechanical backing on the long term stability of embodiments of the film.

Fig. 23 illustrates the use of an embodiment of a membrane to concentrate methanol.

Figure 24 measures the effect of alcohol on different supports.

Figure 25 illustrates the effect of the lower support on ethanol separation.

Fig. 26 illustrates the use of an embodiment of a membrane to concentrate methanol.

Figure 27 illustrates NaCl rejection by an embodiment of the membrane.

FIG. 28 illustrates MgSO passing through an embodiment of the membrane₄And (4) preventing.

Fig. 29 shows a cross section of an embodiment of a multilayer film.

Fig. 30 shows ethanol block for an embodiment of a 3 BSNS layer film.

Fig. 31 shows butanol blockage of an embodiment of a 4 BSNS layer membrane.

Figure 32 shows the bottom plate penetration conductivity, methanol permeability, and biomimetic surfactant nanostructure stability.

Fig. 33 is a schematic of a multi-scale self-assembled film used in an electrochemical cell.

Detailed Description

Detailed Description

Definition of

The following terms used throughout the specification and claims are defined as follows:

by "amphiphilic" is meant a molecule having both solvent-preferred and solvent-repellent regions.

By "hydrophilic" is meant that water is preferred. Hydrophilic compounds and surfaces have high surface tension.

By "hydrophobic" is meant water repellent. Hydrophobic compounds and surfaces have low surface tension.

By "surfactant" is meant a type of amphiphile having at least one hydrophilic region and at least one hydrophobic region. A system designed to work with surfactants is likely to work with all amphiphiles.

"phospholipid" means the major component of a cell membrane. These molecules self-assemble into vesicles in water and exist as a dispersed phase in a low surface tension solvent.

"layered" is meant to encompass multiple layers or bilayers.

By "mesogenic phase" is meant a surfactant liquid crystal structure formed by the interaction between one or more solvents and one or more surfactants.

By "micellar phase" is meant a spherical phase of a surfactant in which the hydrophobic region of the surfactant is located within the micelle and hidden from the bulk solution.

By "critical micelle concentration" is meant the concentration above which the surfactant orders into micelles.

By "hexagonal phase" is meant a two-dimensional hexagonal arrangement of surfactant cylinders in which the hydrophobic regions of the surfactant are inside the cylinders.

By "trans" is meant a surfactant structure in which the hydrophilic region is on the inside of the structure. For example, surfactants in oils form reverse micelles in which the hydrophilic head is within the micelle and hidden from the bulk solution.

By "stabilized surfactant mesostructure" is meant a mesomorphic phase that retains its structure after removal of the solvent.

By "self-assembled surfactant film" is meant a film having a thickness typically less than or equal to ten microns, wherein one component of the film is a mesogenic phase.

By "biomimetic membrane" is meant a single phospholipid bilayer comprising a transporter.

"biomimetic surfactant nanostructure (" BSNS ")" means a lamellar stabilized surfactant mesostructure assembled on a porous support, which may or may not contain a transporter.

"transporter" means a molecule, complex of molecules, structure, protein, zeolite, ion channel, membrane protein, carbon nanotube, cyclodextrin, or any other structure that modulates the transport rate of a particular species of ion, molecule, complex of molecules, biological structure, and/or colloidal particle.

By "free-standing" is meant a surfactant templated thin film in which both sides of the film can reach solution and the film does not have to be bound by a physical barrier.

By "support" is meant a material assembled on a second material such that the second material imparts mechanical stability to the first material without eliminating all of its functionality.

"hollow fiber membrane" means a hollow porous cylindrical structure. It is similar to wheat straw, except that the material is porous. This material is typically used for aqueous separations.

By "membrane/semi-permeable membrane" is meant a material used to separate a particular type of ions, molecules, proteins, enzymes, viruses, cells, colloids, and/or particles from other types.

By "mechanical backing" is meant a solid or porous support for increasing the mechanical stability of the second material.

By "concentration polarization" is meant that the local concentration of the compound at the surface of the membrane is different from the bulk concentration of the compound during filtration.

"reverse osmosis" means a process that uses pressure to separate salt and water.

"Forward osmosis" means a process that uses an osmotic gradient to establish water flux.

"pressure retarded osmosis" means a process that uses an osmotic gradient and pressure to harvest energy from forward osmosis.

By "membrane exchange" is meant the transport of undesirable molecular or ionic species across the electrolyte.

By "overpotential" is meant the reduction in potential of the half-electrochemical cell from the theoretically expected value. Membrane exchange can be one cause of overpotential for semi-electrochemical cells.

Definition of Material preparation method

The following method was used to prepare the assembled surface for surfactant templated sol-gel films. Each material was rinsed in water, ethanol, and then dried before additional further preparation. All materials were stored in water prior to use. The UV light source is an ozone generating pen lamp (ozone generating pen lamp) from UVP.

Rinse only-the material was not further treated after rinsing.

"UV cleaning" -exposing the material to ozone-generating UV light from a pen lamp for more than 1 minute. After treatment, the material was stored in water.

"UV cleaning web" -exposing the material to ozone-generating UV light from a pen lamp for more than 1 minute. After treatment, the material was stored in water. A microporous screen is placed between the solid surface and the membrane in the physical confinement unit prior to deposition of the self-assembly solution.

“H₂O₂Boil "-the material was rinsed in hot (> 20 ℃) hydrogen peroxide for one hour.

“H₂O₂Boiling TEOS "-the material was rinsed in hot (> 20 ℃) hydrogen peroxide for one hour. Thereafter, the material was imbibed with a stock solution of silica, air dried for at least three hours, and finally cured at > 80 ℃ for more than three hours.

"UV TEOS" -exposing the material to ozone from a pen lamp generates UV light for more than 1 minute. Thereafter, the material was imbibed with a stock solution of silica, air dried for at least three hours, and finally cured at > 80 ℃ for more than three hours.

Surfactant mesostructure

Surfactant mesostructures may be used for separations according to embodiments of the invention. There are at least three independent mechanisms for mesostructure separation using surfactants. The first involves the use of gaps between surfactants in the mesostructure. The use of gaps for separation has several benefits including, but not limited to, low curvature, adjustable pore size, adjustable surface charge, and pores that are either non-polar or polar. Furthermore, the thickness of the surfactant in the mesostructure is easily controlled. The second mechanism is molecular transport through defects, making the membrane selective. These defects may be molecular (e.g., missing molecules or poorly matched molecules) and/or macroscopic (e.g., from wetting instability during deposition). The third mechanism is that the surfactant mesostructure itself can form pores via entrapment of solvent during formation. After formation, the solvent may be removed to enable transport or may be held similar to a water line in biology to enable transport. Although this embodiment of the invention is inspired by biological (e.g. cellular) membranes, it preferably does not comprise biomimetic membranes, as the invention requires material nanoscience to stabilize self-assembled surfactant thin films and integrate them with devices. This embodiment of the invention is also preferably not a surfactant templated sol-gel material, as it preferably uses the physical properties of the surfactant mesostructure to separate the compounds rather than using the surfactant to build a suitable sol-gel structure. In other words, embodiments of the present invention preferably employ a surfactant, rather than an inorganic sol-gel structure such as silica or titania, to form the structure of a stabilized surfactant mesostructure. Embodiments of the invention include stabilized surfactant mesostructures, including but not limited to lipid bilayers, for separation, including but not limited to osmosis.

The appropriate permeability and separation ability of the stabilized surfactant mesostructure is related to the simplest type of embodiment of the invention: one-dimensional crystals of surfactants assembled in lamellar phase. One particular embodiment in this class is a z-dimensional sheet of lipid bilayers. Lipid bilayers use the energy loss of molecules in the oil phase, consisting of a lipid tail, to create a solubility barrier, limiting transport across membranes. This mechanism can be simulated by a solubility diffusion model. Water and protons pass through the membrane through spontaneous pores formed in the membrane, as shown in fig. 1. FIG. 1A is a side cross-sectional view of a layered bilayer surfactant structure. The hydrophilic regions of the surfactant are indicated by stippling gray circles. The hydrophobic region of the surfactant is indicated by two black dotted lines. Arrows show the path of molecules between the surfactants. Figure 1B is a top view of a layered bilayer surfactant structure. The grey circles represent surfactants. The black dots represent the gaps between the surfactants that enable transport through the structure.

This embodiment differs from conventional biomimetic membranes that contain ion channels and/or additional transporters within the surfactant. In those systems, transmembrane transport is a function of the channel or transporter. This embodiment of the invention is a membrane that does not contain transporters or ion channels. Alternatively, other embodiments of the invention may comprise one or more transporters, but are preferably multilayer and thus not biomimetic membranes.

X-ray diffraction measurements determined the diameter of the lipid toAssuming that the lipids in a plane are locally close-packed and can be represented as circles, the circles marked between the lipids have a diameter ofFor reference, the bond length is typically aboutTo aboutThis enables the surfactant to functionSize exclusion separation can be performed at the atomic level. In this type of embodiment, X-ray experiments show that the distance between the two sides of a single bilayer is aboutThe maximum/minimum path length of a molecule through a single bilayer is aboutThe maximum path length occurs when one layer of lipid falls on the interstitium of another lipid layer. Thus, the curvature of the individual bilayers is about 1.09 to 1.00. In the smallest case for self-assembled mesophase, the curvature of the material is 1.00, which is possible by definition of the minimum curvature. The curvature of the membrane of the invention is preferably approximately close to the curvature of a single lipid bilayer. This enables the films of the present invention to have structural parameters preferably less than 0.5mm, and more preferably less than about 0.1 mm. The material science and technology preferably controls the number of z-dimensional sheets to be formed to be one to one thousand. The water transport effect of the sol-gel layer is negligible because of the high porosity, the thickness is several molecules, and the curvature is close to one.

In the layered type of embodiment, the porosity of the flakes can be controlled by using different sizes and shapes of surfactants and mixtures of surfactants. For example, when the surfactants were modeled as the planes of circles, the diameter of the interstitial pores between the surfactants was 15.5% of the diameter of the surfactants. For example, single chain surfactants have a smaller in-plane area than lipids. The result is a membrane comprising smaller pores. In one embodiment, sheets of lipid bilayers are assembled on a microporous support using various methods included in the invention. As expected, the stabilized surfactant mesostructure has a higher permeability to water when compared to current forward osmosis membranes. In this embodiment, the surfactant is a lamellar phase. This embodiment will be described in detail later. The results of this experiment are summarized in table 1. As can be seen, the stabilized surfactant mesostructure of the present embodimentIs about five times the permeability of a typical commercial FO membrane. Thus the present invention can have greater than 15LM at 20 ℃ for a draw solution concentration of 10 wt% NaCl^-2H^-1More preferably greater than 20LM^{- 2}H^-1And even more preferably greater than 60LM^-2H^-1Permeability of (d). Furthermore, the rejection of NaCl for these membranes was greater than about 96%.

Film	Permeability rate of penetration	Concentration of draw solution
			Commercial FO membranes	15LM-2H-1	10% by weight NaCl
Stabilized surfactant mesostructure	75.5LM-2H-1	10% by weight NaCl

TABLE 1

In cells, lipid membranes are used to enable selective transport into and out of cells without the use of external pressure. The following is a summary of experimentally measured permeabilities of water (table 2), ions (table 2) and small molecules (table 3) across the lipid bilayer. Without ion channels, water permeates the lipid bilayer faster than other ions and molecules. In the presence of gramicidin ion channels, water and monovalent ion permeability are increased, resulting in an increaseStrong water separation efficiency from molecules and reduced selectivity of water from monovalent ions. The permeability of the membrane containing gramicidin was calculated from the flux (ml/min) of gramicidin at a density of 10% in the lipid bilayer. For calculation, the area per lipid (solvent) was used, per 0.596nm²One molecule instead of the area of each gramicidin (solute). The area of gramicidin was 10% calculated as 10% of the molecules in the bilayer. The permeability of potassium through a membrane containing gramicidin was calculated by assuming an 8: 1 water to potassium ion metering ratio. Sodium transport was calculated from potassium transport using the well-known sodium to potassium conductivity ratio of 0.338.

TABLE 2

	Methanol	Ethanol	Butanol	Urea	Glycerol
						Permeability (cm/sec)	1.20×10-5	3.80×10-5	1.20×10-w	3.40×10-6	6.20×10-6
Permeability (LM)-2H-1)	0.432	1.37	43.2	0.122	0.223

TABLE 3

The transporters of interest include, but are not limited to, aquaporin (aquaporin) for rapid water permeation, chemically modified natural channels, some of which increase water permeability (e.g., desformamyl gramicidin), and/or chemically modified natural channels, some of which affect selectivity for specific ions and/or molecules (e.g., modified α hemolysin.) aquaporin and diethylsteryl gramicidin have an increased water flux of greater than 100 x compared to gramicidin a.

In another class of embodiments of the invention, the stabilized surfactant mesostructure is either a hexagonal phase or an inverse hexagonal phase. In the hexagonal phase, the surfactant self-assembles into a hexagonal lattice of cylinders, with the hydrophobic regions of the surfactant hidden from the hydrophilic gaps between the cylinders. This structure can be used for separation as shown in fig. 2. The hydrophilic regions of the surfactant are indicated by stippling gray circles. The hydrophobic regions of the surfactant are indicated by stippling the black lines. Fig. 2A is a top view of hexagonal packing of hexagonal phases. Figure 2B is a side cut view of the hexagonal phase of surfactant organized in a close-packed configuration. In both fig. 2A and 2B, the cross-hatched area preferably comprises a solid, non-porous stabilizing material, such as silica, an organic polymer, or polymerizable groups on some or all of the surfactants in the mesostructure. Figure 2C is a top plan view of a single surfactant cylinder in a hexagonal phase. The arrows show the path of the molecules between the surfactants. During the assembly of the material, the hydrophobic molecules may be solvated within the cylinder. After assembly, they may be retained or removed. Both methods enable transport through the material. Fig. 2D is a side cut view of one cylinder in a hexagonal phase. Arrows show the molecular path between the surfactants.

In the inverted hexagonal phase, they self-assemble into a hexagonal lattice of cylinders, with the hydrophilic regions of the surfactant facing inward and the hydrophobic regions of the surfactant facing outward, from the cylinders toward the hydrophobic gap. This phase can also be used for separation, as shown in fig. 3. The hydrophilic regions of the surfactant are indicated by stippling gray circles. The hydrophobic regions of the surfactant are indicated by stippling the black lines. Fig. 3A is a top view of a hexagonal packing of cylinders in an inverted hexagonal phase. Figure 3B is a side cut view of the reverse hexagonal phase of surfactant organized in a close-packed configuration. In both fig. 3A and 3B, the cross-hatched area preferably comprises a solid, non-porous stabilizing material, such as silica, an organic polymer, or polymerizable groups on some or all of the surfactants in the mesostructure. Figure 3C is a top view of a single surfactant cylinder in an inverted hexagonal phase. Arrows show the molecular path between the surfactants. During the assembly of the material, the hydrophilic molecules may be solvated within the cylinder. After assembly, they may be retained or removed. Both methods enable transport through the material. Fig. 3D is a side cut view of one cylinder in an inverted hexagonal phase. The arrows show the path of the molecules through the surfactant cylinders. Both the hexagonal and the inverted hexagonal structures allow for the separation of molecules using the inside of the hexagonal cylinder. The size of the hole in the hexagonal cylinder can be controlled by at least two mechanisms. The first mechanism is to select one or more surfactants to form the structure. The surfactant does not pack perfectly for the inverse hexagonal phase or the hexagonal phase, respectivelyPorosity is created in the interstitial spaces between the hydrophilic surfactant head or the hydrophobic surfactant tail. As a model for imperfect packing, the diameter of Cetrimide (CTAB) micelles is aboutBut the length of the individual molecules is aboutThis is shown to be as large in diameter asThe molecules of (a) are adapted to pass through the micelle. Since the flakes of surfactant cylinders in the hexagonal phase are two-dimensional micelles, they have the same porosity as three-dimensional micellesExamples of such molecules include straight chain molecules such as, but not limited to, alkanes, alkenes, ethers, and esters, as the terminal methyl group has aboutOf (c) is measured. In one embodiment, poor packing of hydrophobic regions may be established by using one or more surfactants having large hydrophilic regions or large and/or branched hydrophobic regions.

A second mechanism for controlling the size of the internal bore of a hexagonal cylinder is to solvate the solution of the cylinder within the structure (both hexagonal and inverted hexagonal) during self-assembly. The solution may or may not be withdrawn after self-assembly. Simple methods of extracting the solvent include, but are not limited to, evaporation or rinsing after assembly. The amount and chemical composition of the solution defines the pores within the cylinder. For hexagonal mesostructures, the hydrophobic solution will solvate the interior of the hexagonal cylinder. Examples of hydrophobic solutions are alkanes, esters and ethers. For an inverse hexagonal mesostructure, the hydrophilic solution will solvate the interior of the hexagonal cylinder. Examples of hydrophilic solutions are water, glycerol, ethylene glycol and other high surface tension solvents and any accompanying solutes.

A single surfactant or combination of surfactants can be selected to tailor surfactant mesostructure selectivity. For example, the chain length of phospholipids is shown to regulate transport across membranes. Similarly, cholesterol is known to affect the structure of biological membranes. For example, a one mole ratio one mole mixture of a single-chain cationic surfactant (e.g., CTAB) and an anionic surfactant (e.g., sodium dodecyl sulfate) will form a close-packed layered structure, as the enthalpy loss for packing all head groups is reduced due to charge balance. The result is a denser packing of surfactant within the lamellar layer compared to the lipid. Alternatively, a single surfactant or a mixture thereof may be used in cases where the head group is readily charged. The result is a looser packing of surfactant within the lamellar layer compared to the lipid. Size mismatch of surfactants can also be used to affect packing. For example, one surfactant (e.g., dimyristoylphosphatidylcholine) may have twice the area of the other surfactant (e.g., CTAB). Due to imperfect molecular dimensions, the resulting structure may not be able to achieve a close-packed structure. The result of the non-close-packed structure is a larger pore size of the voids between the surfactants, enabling greater flux and less selectivity compared to lipids. Many factors affect the final surfactant mesostructure including, but not limited to, the ratio of the diameters of the surfactants in the structure, the relative concentrations of each surfactant, the representative conical shape of the surfactant, the temperature, and the thermodynamics of the assembly of the structure. For example, the bulk density of lipids is modulated by the inclusion of cholesterol. Cholesterol is a planar molecule located in the interstices of the bilayer, reducing the void space between molecules. The result is a tighter packing of surfactants within the lamellar layer compared to the lipid.

Embodiments of the present invention include methods of generating macroscopic defects in surfactant nanostructures. In this type of embodiment, defects are created in the nanostructures during the assembly process. In one embodiment, the film is deposited too quickly, creating streak defects due to wetting instability. The size of these defects may be any value from about 1nm to about 10,000 nm.

Embodiments of the present invention include the use of surfactant mesophases that are distinct from lamellar, hexagonal, and inverse hexagonal mesophases for separation. A single surfactant may form several phases including, but not limited to lamellar phases, hexagonal phases, cubic phases, inverse cubic phases, tubular phases, and micellar phases. The surfactant may be represented as a conical portion. The surfactant has a shape resembling a pie piece, a wedge, and a cylinder. The shape and concentration of the surfactant or surfactants used directly affects the shape of the phase. Further, the mixture of surfactants may be selected such that the surfactants partition into specific phases. For example, cholesterol will partition preferentially into the saturated lipid phase, and reverse cone surfactants (e.g., didecyldimethylammonium bromide and dipalmitoylphosphatidylethanolamine) will partition preferentially into the cubic phase. The selection of mixtures of these can result in unique shapes and structures. The resulting surfactant phase may be lamellar, tubular, disordered, cubic, reverse cubic, or any other shape. Surfactants can be stabilized by a number of techniques. Sol-gel chemistry can be used to stabilize the surfactant. Stabilization chemistry includes silica, alumina, and titania formed from chemical precursors. The precursor may be an alkoxy precursor. For example, Tetraethylorthosilicate (TEOS) is a precursor to silicon dioxide. The surfactant may also be stabilized by a polymeric group attached to the surfactant. For example, surfactants containing epoxy groups can be crosslinked to stabilize mesostructures.

This embodiment of the present invention is preferably not a surfactant templated sol-gel material. Surfactant templated sol-gel materials use surfactant liquid crystal mesophases to create an inverse replica of the desired nanostructure. The surfactant is removed using a surfactant templated material, typically via calcination at 400 ℃. A large variety of materials (e.g., plastics) are damaged and/or destroyed by the extraction scheme required to remove the surfactant. Rather, this embodiment preferably uses the retained surfactant mesophase as an active layer enabling separation. This structure eliminates the need for high temperature, aggressive solvent extraction and/or oxidation steps to remove the surfactant, enabling the material of the present embodiment to be used with plastics.

This embodiment of the invention preferably uses a unique process to make self-assembled surfactant films. Typical surfactant templated sol-gel processes require a hydrophobic compound, a hydrophilic compound, a surfactant, and a mixture of water and alcohol as a solvent. The hydrophobic compound typically comprises a metal precursor, namely Tetraethylorthosilicate (TEOS). The hydrophilic compound is typically an acid or a base. In contrast, in embodiments of the present invention, the use of hydrophilic compounds is not required to form self-assembled surfactant films or stabilized surfactant mesostructures.

Free standing surfactant templated films

Self-assembled surfactant films are difficult to assemble on porous films. The challenge with self-assembly is that the energy difference between the ordered and disordered states is at most about 4.0-5.0kcal/mol, the energy of the hydrogen bonds. For comparison, the pi-bonds in the carbon-carbon double bonds (the bonds used in many polymer reactions) contain 63.5 kcal/mol. The thermodynamic differences in assembly therefore significantly affect the formation of the final structure. For example, three kelvin is one percent of the enthalpy of formation. An additional challenge is the assembly of the materials in solution phase. This presents a challenge when using porous materials, as the solution will penetrate into the material. Once the solution penetrates into the porous medium, the self-assembly of the surfactant may be disrupted. Embodiments of the invention include: the present invention relates to methods for the preparation of surfactant mesophases, methods for localizing the assembly of surfactant mesophases to prevent their destruction, methods for chemically preparing and/or modifying surfaces to enable the generation of surfactant mesophases on desired materials, and methods for enabling the assembly of surfactant mesophases to establish desired structures and materials for all applications including but not limited to separations.

While embodiments of the present invention include the use of stabilized surfactant mesostructures for separations, the mechanisms, methods, and applications described in the present invention are applicable to all self-assembled surfactant films, including biomimetic films, surfactant templated sol-gel materials, hybrid biomimetic sol-gel materials, sol-gel templated films, and block copolymers. The following is a description of other applicable self-assembled thin film chemistries.

Embodiments of the invention include: surfactant templated nanostructures self-assemble from solution under physical constraints through more than two discrete surfaces and/or on more than two sides, enabling the creation of a unique class of materials that preferably possess one or more of the characteristics of surfactant templated nanostructures. Example surfactant templated nanostructures can self-assemble via the physical limitations of templated solutions, similar to those described by Brinker et al (U.S. patent No. 6,264,741) and the references cited therein. The solution typically comprises at least one hydrophobic compound, one hydrophilic compound and at least one amphiphilic surfactant. Classically, as the solvent is removed, the solution can exceed the critical micelle concentration of the surfactant to induce the formation of nanostructures in a physically confined volume. The solution may contain an initiator triggered by an external electromagnetic field, temperature and/or aging. After formation, the material may be washed to remove excess solution or to extract surfactant. The surfactant may also be removed via calcination. In other words, as the solvent evaporates, the silica densifies around the surfactant structure, producing a three-dimensional inverse replica of the surfactant phase. This method enables control of the pore size, which is particularly useful for separation.

Structures formed from biosurfactants (e.g., phospholipids) (see, e.g., U.S. patent publication No. 2007/0269662) can be prepared in lamellar phases to block transport or via binding of transport-modulating molecules such as ion channels to define pores of the material, typically without removal of the surfactant. The structure is a biomimetic surfactant nanostructure ("BSNS") having a structure similar to the surfactant-defined structure of the surfactant templated nanostructure described previously, and optionally including the additional function of actively or passively modulating transport across the membrane of the partially or fully solvated surfactant phase ("transporter"). By co-assembling these membranes with or into the components of an electrochemical cell as an electrolyte, they have the potential to reduce the "exchange" of aqueous molecules and/or ions. By assembling these membranes between Nafion membranes, free-standing surfactant templated membranes can be built. Many molecules, macromolecular assemblies, polymers, proteins, etc. are solvated and can act as transporters in lipid bilayers. Any one or more surfactants may be used, including but not limited to natural lipids, including surfactants used for purification of proteins, membrane proteins, and ion channels. The simple nature of the process enables simple scale-up to commercial manufacturing and existing post-manufacturing film processing. The hierarchical structure manufactured according to the present invention has applications including: optical, separation, fuel cell, energy storage, energy conversion, chemical manufacturing, ion exchange, purification, electrochemical, surface coating, isolation, biological and/or environmental monitoring for medical diagnostics, chemical and biological warfare agent isolation and regulator development. Physical limitations may be used to integrate BSNS with size exclusion membranes, ion exchange membranes, gas diffusion layers, catalysts, and/or other materials used in electrochemical cells, optionally via multi-scale self-assembly.

While the use of natural lipids is exemplified for surfactant templated nanostructures comprising transporters, other surfactants may optionally be used. For example, surfactants that have been used to purify membrane proteins have the potential to simultaneously template the nanostructure and intercalate the ion channel. Other lipid-mimicking surfactants may be used to increase the stability, electrical resistance, or other physical properties of the resulting nanostructure. Examples of surfactants are Brij, sodium dodecyl sulphate, anionic surfactants such as sodium lauroyl sulphate, perfluorooctanoate, perfluorooctanesulphonate, or sodium dodecyl sulphate, cationic surfactants such as cetyltrimethylammonium bromide, or zwitterionic surfactants such as 1, 2-di-O-tetradecyl-sn-glycero-3-phosphorylcholine. Any zwitterionic surfactant is of particular interest, especially if the surfactant spontaneously self-assembles into vesicles.

The transporters of interest may comprise natural or synthetic channels. One or more channels may be included in the surfactant templated nanostructure as transporters to control permeability, transport, and convert molecular gradients into other forms of energy. The channels may be passive to allow passive selective membrane transport (e.g., gramicidin), may be active to allow membrane transport against free energy potential (e.g., rhodopsin), active to allow passive membrane transport under selective conditions (e.g., voltage-controlled channels), and/or active to allow molecular conversion using passive membrane transport (e.g., atpase). In addition, the delivery bodies may work in combination when activated by external stimuli including electromagnetic fields, pressure and chemical recognition. The transporter may actively drive transport against the free energy gradient. Materials with biomimetic surfactant nanostructures assembled between porous surfaces are of particular interest for dialysis, separations, electrochemical cells, fuel cells and batteries. These channels can create membranes with sub-nanometer pore sizes for a variety of electrolytic applications, including fuel cells. The non-biological transporter can be included in a biomimetic surfactant nanostructure including, but not limited to, carbon nanotubes. Many molecules, macromolecular assemblies, polymers, proteins, etc. are solvated within the lipid bilayer. This type of structure can control transport across the lipid membrane via selective modulation of passive diffusion or active modulation. Active enzymes or synthetic variants may be included in the membrane to produce high voltage batteries, chemical-to-electrical energy conversion, photo-chemical energy conversion and/or photo-to-electrical energy conversion.

Embodiments of the present invention employ surface functionalization chemistry to enable and/or enhance the assembly of surfactant mesophases. Surface functionalization chemically changes one or more surface properties of the material without changing bulk properties. One example of a surface functionalization chemistry is the chemistry to assemble self-assembled monolayers (SAMs) of octadecyltrichlorosilane on silicon wafers. The surface of the wafer becomes hydrophobic but the mechanical and optical properties remain the same. The interaction between the surfactant and the chemically modified surface drives self-assembly and imparts stability to the film after assembly. This is well studied in the assembly of self-assembled monolayers on solid surfaces. For example, a monolayer of octadecyltrichlorosilane may be assembled on a silicon wafer to render the surface hydrophobic. Previous studies on surfactant bilayers (i.e., supporting lipid bilayers) demonstrated the effect of substrate preparation on the physical properties of the final material. Embodiments of the present invention enable surfactant mesophase assembly on solid and porous supports. Typical surface functionalization chemistries include surface grafting, covalent surface modification, surface adsorption, surface oxidation, surface ablation, and surface rinsing. The chemicals may be deposited in the liquid and/or vapor phase. Molecules that can be covalently bound to the surface include, but are not limited to, silanes, organics, inorganics, metals, and metal oxides. Metal oxides are of interest because they can significantly increase the surface tension of the material. For example, the assembly of the alkylsilane may render the hydrophilic surface hydrophobic. Surface modification may also enable ordering and assembly of surfactants. For example, calcium may enable the assembly of surfactants; doping calcium into the support material can reduce defects in the surfactant mesomorphic phase. For another example, silica may stabilize the hydrogen bonding network of lipids. In one embodiment, surface functionalization chemistry is used to coat polyethersulfone ultrafiltration membranes with silica. The result is a prevention of solute enhancement by surfactant mesophase assembly, which is the result of improved assembly in ordered lamellar phases.

Embodiments of the present invention employ localization of surfactant mesostructure assembly, which is particularly useful for preventing porous surfaces from being wetted by self-assembly solutions. If the self-assembly solution wets the porous surface, the mesostructure may be destroyed. One localized mechanism is to drive the surfactant solution by phase change with the addition of solvent and/or solute at the interface where assembly occurs. In one embodiment, the porous material is first substantially saturated with an aqueous solution (solution 1). Thereafter, a self-assembly solution (solution 2) comprising TEOS, Dimyristoylphosphatidylcholine (DMPC), ethanol and water was deposited on the surface. DMPC is preferably in the gas phase in solution 2 when deposited on a surface. Solution 1 and solution 2 are mixed at the surface of the porous material. Due to the increase in water concentration, DMPC is urged into the lamellar phase. In this embodiment, the self-assembly of DMPC is preferably visualized by a rapid increase in the viscosity and opacity of the solution. The method enables rapid self-assembly and can be repeated to assemble multiple layers. For example, after deposition of solution 2, another coating of solution 1 may be applied, followed by a coating of solution 2.

This mechanism is illustrated in fig. 4. The porous support was wetted with solution (solution 1). The subsequent solution (solution N) was introduced. The surfactant in solution 1 or solution N is driven via a phase change by adding solution N and/or solution 1, respectively. After assembly with one or more levels of solute, a second set of solutions (solution 1 and solution N) may be introduced to repeat the process and/or add additional coatings. The surfactant mesophase self-assembly occurs at the interface between solution 1 and solution N. The final material is a free standing graded material, preferably attached to a support, which has some or all of the properties of both the self-assembled surfactant mesostructure and the support. This technique is particularly useful for assembly on porous supports. Examples of such properties that may be present in the resulting material include control of ion and molecular transport, increased film durability, and/or protection and/or encapsulation of the film with known antimicrobial nanoparticles.

In one embodiment, the porous membrane is wetted with a polar solvent. In this embodiment, the polar solvent is solution 1. The polar solvent may include water, ethylene glycol, glycerol, or mixtures thereof. The polar solvent may or may not be acidic or basic. Subsequently, an aliquot of the self-assembly solution in an organic solvent is deposited. In this embodiment, the organic solvent is solution N, which preferably comprises a surfactant. In this particular embodiment, solution N comprises 5 wt.% tetraethyl orthosilicate (TEOS), 1 wt.% DMPC in an organic solvent. The organic solvent may comprise, but is not limited to, one or more alcohols, alkanes, esters, ethers, or mixtures thereof. At the interface of the two solvents, the surfactant is driven by a phase change to form a surfactant mesostructure by the presence of solution 1. Finally, solvent evaporation drives the assembly of silica to stabilize the surfactant mesostructure at the interface between solution 1 and solution N. Fig. 5 illustrates a lamellar model of the structure, a schematic of the structure, and images of the hydrophilic teflon membrane before (left) and after (right) interfacial assembly.

The assembly within the self-assembled membrane and the assembly of the membrane with the porous surface make it a multi-scale self-assembled material, as shown in fig. 5, on a microscopic scale is the assembly of two membranes a and B, in this embodiment a is a nanostructured membrane and B is a porous membrane, on a nanoscale is the assembly of alternating sheets of silica and lipid bilayers shown both in a and in enlarged C, within the lipid bilayer is an optional ion channel, gramicidin (β band structure in C), in this photograph, the left side is the membrane before coating and on the right side is the membrane after coating, the membrane is hydrophilic PTFE with 0.1 micron pores and a nominal diameter of 47mm the yellow color of the right side membrane is from the natural color of Soy PC (95%) Lipids from Avanti Polar Lipids (Alabaster, AL) used in the above described embodiment.

Other methods may be used for localized self-assembly. Self-assembly may be induced by changing one or more thermodynamic variables, including temperature, pressure, volume, and/or number of molecules, and/or by application of an electromagnetic field. External stimuli, including light energy, ultraviolet light, electrophoretic fields, and/or alternating electric fields, can direct assembly to align molecules, pores, or channels. Both light and external electric fields can guide the assembly of the model, the colloid system.

Physical confinement manufacturing method

Embodiments of the present invention employ physical confinement of a surfactant self-assembly solution, which preferably simultaneously templates the membrane structure, drives membrane assembly, and assembles the thin film with the surface for physical confinement, thereby creating a single unique material. Both multi-scale assembly and hierarchical assembly can occur during self-assembly based on physical constraints. In embodiments of the present invention, there can be many scales of assembly, such as self-assembly on the nanometer scale within a nanostructured thin film and self-assembly on the macro scale between a nanostructured thin film and one or more surfaces for physical confinement. In embodiments of the invention, there may be many levels of assembly, including intramolecular assembly (e.g., surfactant-surfactant assembly), molecular assembly (e.g., silica condensation), material assembly (e.g., thin films assembled with surfaces), assembly based on the interaction of surfactants with solvents, and assembly based on the interaction of surfaces with self-assembly solutions.

The interplay of the physical and chemical topologies of the limiting surfaces, the method used to induce assembly, and the mixture of self-assembling solutions may all determine the final structure of the material. Unique types of surfaces can be combined with surfactant templated nanostructures via the present invention, including but not limited to surfaces having one or more of the following properties: solid, porous, chemically layered (e.g., self-assembled on a surface or a thin film chemically spun on a solid surface), physically layered (e.g., one or more surfaces on top of a solid surface), including macroscopic features, including microscopic features, including non-radially symmetric surfaces, being unable to form a stable meniscus, physical properties greater than two dimensions, and/or non-uniform surface chemistry. The surface used for assembly may be designed for modification and/or removal after assembly without destroying the remaining material, so that the surface can be removed after assembly without completely destroying the material. Embodiments of the present invention preferably include robust methods of rational design, simultaneous assembly, templating, and integration of surfactant templated nanostructures. The hierarchical assembly may produce materials in a single step, which will typically require multiple steps, such as a membrane electrode assembly, a sensor, or a switch.

Two important aspects of the assembly of self-assembling surfactant films on porous plastic supports are the surface-functional chemistry of the support and the interfacial polymerization process. These enable the formation of the final material, i.e. a self-assembled surfactant film on the surface of the porous plastic support, considered together with physical confinement methods.

Embodiments of the surfactant mesophases of the present invention can be isolated. The assembly method and resulting biomimetic surfactant nanostructure are shown in fig. 6. In this embodiment, two membranes or porous surfaces are prepared as supports for the self-assembly solution using one of the various protocols defined in "materials preparation" in the examples section. The focus of the protocol includes, but is not limited to, cleaning the surface with a solvent, surface oxidation, and/or surface chemical deposition. The material consists of two PES films combined with a bionic surfactant templated sol-gel film. Two Polyethersulfone (PES) membranes were immersed in 18.2M Ω water before being placed on two different flathead teflon sheets (for physical confinement). An aliquot (. about.500. mu.l) of 10% by weight DLPC: 1mol gramicidin in silica stock was dispensed via a micropipette onto one of the PES membranes. A second Nafion membrane backed by teflon was used to sandwich the BSNS solution between the two membranes as shown in fig. 6A. The sheets are allowed to be brought together in contact with each other. The sample was dried at room temperature for more than one hour, after which it was heated to 80 ℃ for more than 3 hours. Finally, to simulate the assembly of the membrane electrode assembly, some samples were heated to over 130 ℃ for 15 minutes. After slowly cooling the sample, the teflon material was removed to produce a free standing film, as shown in fig. 6B. In this embodiment, teflon is used for physical confinement. Alternatively, any solid surface may be used, including metal, plastic, ceramic, glass, and organic (e.g., wood). The membrane was 4cm by 4 cm. The confinement simultaneously drives the assembly and bonding of the resulting membrane to the physical confinement assembly.

Figure 7 is a schematic of the resulting biomimetic surfactant nanostructure structure in the structure in this embodiment, two supporting porous materials sandwich a layered nanostructure with alternating silica layers and lipid bilayers.the material is a multi-scale self-assembling material.the micro-scale assembly is an assembly of three membranes (A, B and C). in this embodiment, a and C are porous membranes and B is a nanostructured thin film.

Physical constraints can also use roll coating. The self-assembly solution is sandwiched between the porous support material and the cylindrical roller. The temperature of the rollers can be controlled to control the evaporation rate of the solution. The solution can be applied directly to the roll. The roller may apply the self-assembly solution to the porous material more than once. The rollers may push or pull the support material through one or more process steps. The sandwich enables uniform deposition of the material on the porous support material.

FIG. 8 shows several different physical limiting methods: prototype high-throughput devices and systems (C) that assemble many materials with unique chemistries simultaneously with two solid surface constraints (a), a self-assembly solution and two constraints of porous materials (B). The high-throughput device is a solid piece of teflon plate with holes in it and Nafion's teflon clips. A surfactant templating solution was added to each well followed by a Nafion membrane and a teflon sheet so that the Nafion was supported by the teflon. The material self-assembles within physical constraints using a multi-step drying protocol. After assembly, the apparatus is disassembled to retrieve new, free-standing film material. The intermediate images of fig. 8A-8C are of the system during assembly. The bottom image of fig. 8A-8C is an exploded structure after assembly of the materials.

Fig. 8 illustrates several different examples of physical limitations of surfactant templated sol-gel solutions and the resulting materials. The surfactant templated sol-gel solution was deposited on a freshly oxidized silicon wafer. The solution was then sandwiched between two discrete surfaces using a silica cover sheet with a self-assembled monolayer of octadecyltrichlorosilane. Once drying is complete, the film remains on the surface after removal of the cover sheet. Fig. 8A shows hydrophobic and hydrophilic surfaces sandwiching a surfactant templated sol-gel solution. After drying the film, the hydrophobic surface is removed. The image is the film after removal.

Figure 8B shows a schematic of another embodiment of a physically constrained "sandwich". To assemble the membranes, two Nafion membranes were immersed in a silica precursor solution and then placed on two different pieces of eptfe. Aliquots (. about.100. mu.l) of 5 wt% BSNS solution were dispensed via micropipette onto a Nafion membrane. The BSNS solution was sandwiched between two membranes using a second Nafion membrane backed by teflon. (alternatively, in other embodiments, the membrane may be supported on a solid surface by any solid surface or Gas Diffusion Layer (GDL)) the surfaces are held together by spring clips. The sample was allowed to dry at room temperature for more than one hour, after which it was heated to 80 ℃ for more than 3 hours. Finally, to simulate the assembly of the membrane electrode assembly, some samples were heated to over 130 ℃ for 15 minutes. After slowly cooling the sample, the teflon surface was removed to make a free standing film.

The resulting film was stable to shear forces generated by rubbing the film with two fingers and to any deformation forces caused by peeling with tweezers. No precautions are required to prevent membrane damage during typical laboratory procedures of typical Nafion membranes. The center image is a typical sample film without surfactant in the template solution after assembly. The final material was translucent white. The bottom image is representative of free-standing BSNS after assembly with surfactant in template solution. The membrane has a yellow color that is unique to the lipids assembled into BSNS in physical limitations. Following a similar heat treatment, the lipids evaporated on the surface were not yellow. Due to the comparable periodicity of the surfactant templated nanostructures and the wavelength of visible light, the yellow color may be the result of scattering from the layered nanostructures. These membranes are stable, whether dehydrated or not, heat treated up to 130 ℃, and pressure treated via two solid surfaces and spring clamps.

Fig. 8C shows a modification of fig. 8B, illustrating a prototype high-throughput device and system that simultaneously assembles many materials with unique chemistries. A teflon plate with holes in it and a solid piece of teflon sandwiching a piece of Nafion. A surfactant templating solution was added to each well followed by a Nafion membrane and a teflon sheet so that the Nafion was supported by the teflon. The materials self-assemble within physical constraints using a multi-step drying protocol. After assembly, the apparatus is disassembled to retrieve new, free-standing film material. The center image is the system in the assembly process. The bottom image is the disassembled structure after the material is assembled.

The following embodiments of the invention illustrate how surface functionalization chemistry enhances surfactant mesostructure assembly, which can be observed by improved solute rejection. The surfactant mesophase acts as a reverse osmosis membrane to separate methanol from water. Figure 9 shows the effect of surface preparation technique on flux and methanol rejection of the membrane. Here, performance is defined by two metrics: methanol stop percentage and solution flux. The percent methanol hold-up is one minus the ratio of the permeate methanol concentration to the feed methanol concentration. The percent rejection of 25% v/v methanol (% rejection) as a function of the method of preparation of the porous surface used to support the free-standing surfactant-templated film is given in fig. 9A. Solution flux is the volume of solution passing through the membrane per unit time for a constant area, given in fig. 9B for each preparation method. Three representative methods were examined: chemical cleaning (rinse cleaning), surface oxidation (UV cleaning and H)₂O₂Boiling), chemical deposition (TEOS), and combinations thereof. In this embodiment, the self-assembly solution contains 10mol DLPC to 1mol gramicidin in 10% by weight of the silica stock solution. In this embodiment, the self-assembly solution is sandwiched by two 0.03 micron Polyethersulfone (PES) membranes. The effective area of the membrane is 1.13cm². The separation was performed at 5 PSI. No methanol separation was observed in the control experiment with the raw PES membrane. Methanol rejection was not expected because the pore size of the PES membrane (30nm) was much larger than the diameter of methanol (0.41 nm). Methanol stop (sample of FIG. 9: UV clean Net, H₂O₂Boiling, H₂O₂Boiling TEOS) shows the ability of surfactant mesophase membranes to perform reverse osmosis separation of small molecules.

In addition, fig. 10 compares the flux of 25 wt%/wt% methanol in pure water and water at 5-15 psi through a single free standing biomimetic surfactant mesomorphic membrane assembled from a 10 lipid wt% solution comprising 10: 1 DLPC and gramicidin between two PES membranes prepared using UV cleaning. A > 50% reduction in flux of a 25 wt%/wt% methanol solution versus pure water at all pressures is a result of concentration polarization, i.e., an increase in solute (methanol) concentration at the membrane surface due to the membrane's selectivity to water. Furthermore, because flux increases with pressure, the relative difference between the flux of the 25 wt%/wt% methanol solution and the pure solvent (18.2M Ω water) increases. This is expected because the effect of concentration polarization is a function of membrane flux; in other words, more methanol accumulates on the surface as the flux of solution through the membrane increases.

Embodiments of the present invention use conformal coating of self-assembling surfactant films on hollow fiber membranes. The ultrafiltration and microfiltration membranes can be configured as hollow cylinders. In the fiber wall are pores typically ranging in size from about 30nm to several hundred microns. In one embodiment, H is used₂O₂The boiling TEOS method coats the hollow fibers with silica. The fibers were then rinsed with water. The fibers are then filled with a surfactant self-assembly solution. After the fibers are filled with the surfactant self-assembly solution, they are sealed at both ends. The solvent is allowed to evaporate through the pores of the membrane. After heating in an oven at 80 ℃ for one day, the inside of the fiber is preferably rinsed with water. The inside of the fiber is coated with a surfactant self-assembled film.

Materials constructed according to embodiments of the present invention preferably integrate self-assembled nanostructures and/or films with a surface for confinement; the resulting material then preferably has some or all of the properties of both the self-assembled nanostructure and the surface. Examples of such surface properties that may be present in the resulting material include controlling ion and molecular transport, increasing film durability and/or protection and/or encapsulation of the film. The surfaces used for assembly can be removed or modified after assembly without destroying the material.

While theory suggests that surfactant templated nanostructures can produce structures that can be used for separation, the challenge of defect-free assembly has prevented them from being used as such. Surfactant templated nanostructure self-assembly solutions are typically physically confined using one or more membranes, and the resulting selectivity of the final material may be the result of the compounding of one or more integrated membranes and nanostructured thin films. In one embodiment, a biomimetic thin film with high conductivity and high selectivity can be assembled on a Nafion membrane. Because of the thin nature of the film, the conductivity of the film is negligible compared to Nafion. The structure of the membrane makes conduction of other ions more difficult. Biomimetic membranes are z-dimensional crystals of lipid bilayers and sol-gel silica. Within each lipid bilayer is an ion channel gramicidin. Short circuits through the film caused by pinhole defects in the biomimetic film are not possible because of the combined resistance of the resulting material. Furthermore, the final material may be free standing, e.g. it may be handled, moved, manipulated and applied without further need for specific techniques and/or instruments. The hierarchical structure manufactured in this method has applications in: optical, separation, fuel cell, electrochemical, surface coating, isolation, biosensing for medical diagnostics and/or environmental monitoring, chemical and biological warfare agent isolation and regulator development.

There are many different configurations to physically confine surfactant templated sol-gel solutions, such as those containing the self-assembly of model colloidal systems. One configuration of physical confinement is to introduce a surfactant self-assembly solution between two or more discrete surfaces. One example is a surfactant sol-gel solution sandwiched between two flat surfaces. One configuration of physical limitation is to introduce a surfactant self-assembly solution into a volume having more than two sides. One example is a single folded surface having three interior sides: a top surface, a bottom surface, and a folded surface. Another configuration is that the self-assembly solution is physically confined by a single surface with a three-dimensional topology, such as a surface with an axis of asymmetry, a molding surface, a microfabricated surface, or an etched surface. In this example, the sides of the single three-dimensional surface confine the surfactant templated sol-gel solution.

In fig. 11, BSNS membranes prepared from the starting material and the diluted self-assembly solution are compared. Stock membranes were prepared from a typical lipid solution of 10% by weight of 10mol DLPC to 1mol Brevibacterium peptide in a stock solution of silica. A typical lipid solution of 10% by weight DLPC: 1mol gramicidin diluted 1: 1% v/v with ethanol in a stock solution of silica was used to prepare diluted membranes. Two membranes were assembled between two PES membranes prepared via UV cleaning. The effective area of the membrane is 2cm². With a lower concentration of BSNS self-assembly solution and a constant area of support membrane and constant volume of self-assembly solution, less material is assembled into a BSNS membrane. The films made with the diluted self-assembly solution (UV cleaning dilution 1: 1) performed as thinner films compared to the films made with the stock self-assembly solution: it has less methanol rejection (FIG. 11A) and greater solution flux (FIG. 11B) than 10% by weight DLPC: 1mol gramicidin (standard biomimetic surfactant nanostructure) assembled in a silica stock solution between two PES membranes prepared via UV cleaning.

In one embodiment of the invention, the thickness of the resulting thin film is controlled by the physical limitations of the film in the tank. The one-dimensional cells are preferably configured to contain at least one linear slot extending along the length of the cell. The membrane preferably sits in a plane at the bottom of the tank. Preferably the film is first coated with water. Thereafter, a surfactant self-assembly solution is placed on the membrane. The volume of the solution is preferably chosen such that it exceeds the height of the tank. The excess volume is then preferably removed with a blade, ruler and/or roller. The final film thickness is determined by the depth of the groove and the solids content of the surfactant self-assembly solution. Fig. 12 shows that the self-assembled membrane decreases in permeability in physical confinement with linear grooves (grooves) compared to the self-assembled membrane in physical confinement between the roll and the teflon (no grooves) of the flat sheet. Two 20 wt% DLPC solutions were self-assembled on a UV clean 0.1 micron PES membrane. The solution is self-assembled using an interfacial method and by physically confining the solution between the roller and the porous membrane. A membrane is placed at the bottom of the tank prior to assembly. The depth of the groove is half a millimeter. The result is an increase in the volume of the self-assembly solution of the coating film. The membrane is loaded into a closed-end cartridge. Water permeability was measured at 5 PSI. When measuring water permeability, the material assembled in the grooves has a lower permeability than the material assembled on the flat surface. The increase in the confining volume of the membrane self-assembled in the tank produces a thicker stabilized surfactant mesostructured film. The increase in film thickness results in decreased film permeability.

One possible limitation scheme includes surfactant templated films assembled into complex three-dimensional geometries, such as self-assembly of colloids within the physical confines of a wafer in which one or more surfaces have an asymmetric three-dimensional topology (Yang et al, "proteolitic sheet: vertical growth of colloidal crystalline patterns within silicon wafers" (optical chips: vertical growth of colloidal crystalline patterns within silicon wafers), "chem. Commun.2000, 2507-. For example, the surface may be a molded Polydimethylsiloxane (PDMS) surface having a three-dimensional topology, or alternatively an etched silicon wafer. The surfactant templated nanostructure preferentially assembles in the grooves due to solvent evaporation from between the sides of the one or more three-dimensional solid surfaces. This approach templates and binds surfactant-templated nanostructures with three-dimensional surfaces. Some embodiments include localizing assembly within channels and/or nanoscale patterns for microfluidic and optical applications. This configuration preferably gives solid surface stability to the membrane and accessibility to the transport of penetrations, which is not possible with other assembly methods. The preferred result is a multi-scale self-assembled material, for which the surface is protected and the nanomaterial is held up and adds new functionality.

Another physical confinement scheme combines chemical patterning with physical confinement to enable self-assembly and patterning of surfactant templated nanostructures. This approach has been demonstrated for self-assembly and pattern model Colloidal systems (Brozell et al, "Formation of Spatially Patterned Colloidal Photonic Crystals through control of Capillary Forces and templated Recognition" (Formation of spatial Patterned Colloidal Photonic Crystals of Capillary Forces), Langmuir, 21, 2005, 11588-. In this scheme, the membrane assembly is driven by the physical constraints of both surfaces. One or more portions of one or more chemically patterned surfaces cause the film to be unstable. After assembly, the membrane is damaged in the unstable area. In one example, a thin film may be assembled between the patterned wettable surface and the hydrophilic surface. There are many ways to wet the surface of the pattern. One example is the use of hydrophobic self-assembling silanes followed by selective removal of the silanes with deep UV lithography to create a non-uniform hydrophobic surface. Two examples of hydrophobic silanes are octadecyltrichlorosilane (CH)₃(CH₂)₁₇SiCl₃OTS) (90% Aldrich) and fluoroalkyl trichlorosilane (CF)₃(CF₂)₁₀C₂H₄SiCl₃1, 1, 2, 2, tetramethylenefluorodecyltrichlorosilane, FDTS). The freshly oxidized surfaces are assembled by incubating them in a 2.5mM solution (100ml volume) preferably with anhydrous hexadecane (99% Sigma-Aldrich) or HPLC grade toluene (99% Sigma-Aldrich) as solvent. All silanization reactions are preferably carried out in glass containers under nominally dry ambient conditions (< 20% relative humidity). After 60 minutes incubation, the sample is preferably removed from the solution, the surface rinsed thoroughly with chloroform and acetone, and dried under a nitrogen stream. The silane is removed via a combination of short wavelength UV lithography (187, 254nm) preferably using an ozone generating medium pressure Hg lamp (UVP, Inc) enclosed in a quartz housing and having a chrome feature in a quartz lithography mask. Other methods for patterning wettability include microcontact printing. The patterned surfaces include those surfaces that display the pattern of electrodes.

The present invention enables techniques for assembling self-assembled films on many surfaces that cannot be used with standard techniques of dip coating and spin coating, including but not limited to stabilized surfactant mesostructured films and surfactant templated sol-gel films. Many surfaces may be used for physical confinement such as teflon, plastic, acrylic, Nafion, ceramic, silica, silicon, semiconductor, oxide, gold, glass, metal, polymer, poly-di-methyl siloxane (PDMS), molded polymer, membrane, polycarbonate membrane, size exclusion membrane, ion exchange membrane, or graphite. These surfaces may be planar, radially or spherically symmetrical (e.g., ball bearings), cylindrically symmetrical (e.g., rollers), have a two-dimensional physical and/or chemical topology, and/or have a three-dimensional physical and/or chemical topology. The surface may be a roll or a press used in manufacturing. The surface may be laminated, including one or more chemical and/or physical layers. Chemical layers include, but are not limited to, self-assembled layers, physical absorption layers, and deposition layers (e.g., Langmuir Blodgett assembled layers or spin-on coatings). The physical layer includes, but is not limited to: microporous surfaces, macroporous surfaces, layers with suitable electrical properties, and layers with suitable optical properties.

Porous surfaces such as Nafion (of any thickness, including but not limited to Nafion 117), ion exchange Membranes, carbon fiber felt, carbon fiber cloth, cellulose Membranes, polyamide Membranes, polyethylene based Membranes, polycarbonate Membranes, other Membranes, gas diffusion layers, gas diffusion electrodes, metals, teflon, plastics, silica gel, Nafion, carbon fiber cloth, ultrex (tm) (Membranes-International Ltd.),AHA film (Eurodia Industrie SA), size exclusion film and/or gas diffusion electrode. For porous materials, the physical and chemical topology of the material and its pore size typically define the final structure and function of the material. The pore size may be on a macro scale or a micro scale or both. The macro-scale pores allow penetration of the surfactant through the material, preferably assembling the surface within the membraneThe active agent templated nanostructure. The micro-scale pore structure typically prevents or limits the penetration of surfactants through the material, preferably assembling the surfactant templated nanostructures on or near the surface of the membrane. The pore size characteristics (macropore versus micropore) are preferably defined by the physicochemical properties of the surfactant, not the pore geometry. The surfactant has a uniform length. Thus, the material may have macro-scale pores for one surfactant solution and micro-scale pores for a different surfactant solution. For example, lipid vesicles at a concentration of 1mg/ml under aqueous conditions will self-assemble on top of colloidal crystals with 45nm pores, in which case the surface is microporous. Triton-X, a different surfactant, will penetrate into colloidal crystals with 45nm pores, in this case the surface is macroporous.

Particular embodiments of the present invention include the automated fabrication of surfactant self-assembled films comprising stabilized surfactant mesostructures, biomimetic surfactant mesostructures, and sol-gel templated mesostructures. The present invention includes a number of automated or mass production manufacturing techniques for these films including spray coating, painting, ink jet printing, roll coating, reverse roll coating, blade coating, gravure coating, gap coating, dip coating, curtain coating, metering rod coating, slot coating, air knife coating, and knife coating. FIG. 13 illustrates the construction of a representative, but non-limiting, automated system for fabricating self-assembled films on films and other materials. Each dot marked with letters a-H may or may not be included in the manufacturing system. Point a is where deposition of the self-assembly solution occurs. Points B and C are pre-and post-processing steps, respectively. In these steps, the material may be subjected to one, some or all of the following: changes in temperature, exposure to an oxidizing environment (e.g., ozone-generating UV light, ozone gas), deposition of chemicals (e.g., to promote adhesion), chemical rinsing or cleaning, addition or removal of materials, chemical etchants, pressure and/or tension, and the like. Point D is the material feed. The material may be any including, but not limited to, a membrane, PTFE membrane, PES membrane, PVP membrane, plastic, carbon fiber cloth, carbon fiber felt, or any other material. Prior to assembly, the material may be washed in water and/or other solvents, temperature treated, placed in an ultrasonic bath, and/or have other molecules deposited thereon. Point E is the final material. The material at this point may be, but is not limited to, a roll of film, a spiral membrane cartridge, or an intermediate point in a larger process. Point F is the material feed through the fabrication. Point G is the separated material fed to the final material at point E. Point H is the separated material that has undergone one, some, or all of the treatment of the material in point F and is fed into the material in point E. In some cases, material from point F or point G will cause physical limitations of the self-assembled material deposited on point F and rolled into point E. The orientation of the device is merely exemplary and the elements may be rearranged in any number of suitable orientations relative to the vertical for performing the method steps shown. Additional conventional supports, such as guides, rollers, and the like, may be used to support, stretch, rotate, and/or distort the feed film and biomimetic surfactant nanostructures.

Certain embodiments of the methods of the present invention include one or more annealing steps following deposition of the surfactant self-assembly solution. The addition of a particular solution allows some surfactant to escape from the ordered phase into the disordered phase. The solution is preferably selected based on a phase diagram of a multi-component mixture comprising at least two solvents and a surfactant. Subsequent addition and/or evaporation of the second particular solution drives some of the surfactant into the ordered phase. The second solution is also preferably selected from a multi-component phase diagram such that the surfactant is driven into the desired ordered phase. The ordered phase of the surfactant after any annealing treatment may be unique and the surfactant may be in another phase within the material. The process may repeat all three steps or any combination of steps one or more times. The treatment anneals the surfactant mesophase to remove defects and excess surfactant and/or adds additional surfactant phase. This annealing process is similar to the annealing of metal or glass to reduce the likelihood of material fracture. In fig. 14, the permeabilities of two membranes are compared, with the only difference being the annealing step. The membranes were 20 wt% 10: 1 DLPC to Brevibacterium peptide on UV cleaned 0.1 micron PES membranes. The permeability of the membrane was measured using a home-made cross-flow membrane test unit. The pressure drop across the unit was 55 PSI. The annealed membrane showed higher permeability without loss of rejection of the fluorescein salt.

Embodiments of the present invention allow for the deposition of material on both sides to produce a symmetric film. When an interfacial self-assembly method is used, an asymmetric membrane is obtained; in other words, a membrane with a thin film on one side only. The process of depositing the self-assembled surfactant film may be repeated on the other side of the porous material. A schematic comparing asymmetric and symmetric membranes is given in fig. 15. In one embodiment, a UV cleaned 20 wt% DLPC on 0.1 micron PES film was assembled. After curing the membrane at 80 ℃ for one day, the process was repeated on the other side of the PES membrane. The forward osmosis experiment was performed between two 10L buckets. The conductivity of the feed was less than 1. mu.S/cm. The conductivity of the brine was 110 mS/cm. The solute in the brine is NaCl. The pressure drop from the feed to the brine was 5 PSI. The membrane area was 3 square inches and it was tested in a home-made cross-flow test unit. As expected, the double-sided membrane exhibited a lower diffusion rate of salt from brine into the feed of the experiment, as shown in fig. 16.

Embodiments of the present invention include surface functionalization chemistry of the final material. The surfactant may be cationic, anionic or zwitterionic. For reverse osmosis this presents a challenge for salts, since according to the DLVO theory, salts in solution will form a bilayer on the membrane surface. The opposite is true for a hydrophobic surface in solution. There will be a reduced density of water at the surface resulting in a reduced density of dissolved ions. Surface functionalization chemistry can impart hydrophilicity or hydrophobicity (e.g., forward osmosis versus reverse osmosis) to a surface depending on the application.

In one embodiment of the invention, the surface of the material is treated with (CH)₃CH₂O)(CH₃)₃Si is methylated to render the material hydrophobic. The result is a sub-nanometer with a low surface tension liquid for extraction of, for example, alkanes and alcohols from waterA porous hydrophobic membrane. In fig. 17, several 10 μ Ι drops were placed on 20 wt% DLPC on a UV clean 0.1 micron PES membrane (left sample) and 20 wt% DLPC on a UV clean 0.1 micron PES membrane, the latter after assembly and curing was surface functionalized with methylated silane (in particular, 600 microliters of 10 wt% ethoxy (trimethyl) silane (right sample) — the resulting material was more hydrophobic than the original material, as shown by the smaller spread of water droplets on the treated hydrophobic membrane surface than on the untreated hydrophilic membrane surface.

Self-assembled membranes on porous supports can be used in many configurations for separations. Figure 18 illustrates one embodiment of a flat sheet membrane filter cartridge configuration. In this configuration, water flows perpendicular to the surface of the membrane. The water flowing through the membrane (permeate) has a lower solute concentration than the retentate (water retained in the cartridge). (A) Represents the flow of retentate and (B) represents the flow of permeate. (C) And (G) is a device or set of devices that hold the biomimetic surfactant nanostructures in place. (D) Is an optional porous material that supports and/or constitutes the biomimetic surfactant nanostructure. In some embodiments, the layer comprises a metal shelf, which is particularly important in applications where it is desirable to rinse the back side of the film and/or prevent leakage of the film. (E) Representing a biomimetic surfactant nanostructure and (F) is an optional porous material to increase the mechanical stability of the biomimetic surfactant nanostructure. (H) Is an optional outlet to allow the flow or drainage of the blocked solution. All data given for this configuration in this example were measured using a flat sheet membrane cartridge without bleed and/or stop flow.

Fig. 19 and 20 illustrate an embodiment of the invention used in a spiral wound membrane cartridge. In this configuration, the water flow is tangential to the membrane surface. For concentrated applications (fig. 19), the solution may be passed directly through the core onto which the membrane is wound. The retentate (solution within the core) is enriched as it travels down the core, and water selectively permeates tangentially through the spiral wound membrane. (A) Indicating the flow of retentate. (B) Is a spiral membrane cylinder. (C) Is the flow of water removed from the solution and (D) is the flow of concentrate. (E) Is a porous hollow core that allows tangential flow. (F) Representing a membrane spiral comprising one or more layers. These layers may comprise a single sheet or a plurality of sheets. Each layer may be the same or different. It is preferred to place a large pore sieve between the biomimetic surfactant nanostructure layers to distribute pressure evenly across the surface of the biomimetic surfactant nanostructure. (G) Is the direction of flow of the removed water. For water purification and concentration applications (fig. 20), the cartridge preferably includes a plug to prevent direct flow of the feed solution. (A) Indicating the flow of retentate. (B) Is a flow plug. (C) Is the flow of purified water. (D) And (I) a solid layer to prevent water loss from the cartridge. (E) Is the prevention of the flow of the solution and (F) is the flow of purified water. (G) Is a hollow core that allows tangential water flow with a direct flow plug. The hollow core preferably has a pore size greater than 0.03 microns. (H) Denotes a membrane spiral, which preferably comprises a plurality of layers. These layers may comprise a single sheet or a plurality of sheets. Each layer may be the same or different. It is preferred that large pore sieves be positioned between the biomimetic surfactant nanostructure layers to evenly distribute pressure across the surface of the biomimetic surfactant nanostructure. The water must flow through the membrane and return to the core behind the plug to be collected in the permeate. The stopped water falls outside the side.

Other configurations than those given may be preferred based on the particular application, including configurations with different material orientations, flow directions, additional chemical deposition, insertion of one or more electrodes, and/or addition of thin films. For example, for use of the biomimetic surfactant nanostructures for ion exchange applications or in fuel cells, it is typically necessary to insert electrodes on either side of the biomimetic surfactant nanostructure.

Hollow membrane fibers may be used for filter water. The fibers enable greater permeability per unit volume because the fibers have a greater surface area than the spiral wound element. Embodiments of the present invention use the ability of surfactant mesophases for separation, and the ability to form surfactant self-assembled films on porous supports, enabling surfactant self-assembled films to be assembled inside and outside of hollow fibers.For coating a hollow fiber membrane on the inside, H₂O₂The boiling TEOS protocol is preferred for preparing the surface. Microporous filtered water is preferred for rinsing and pre-wetting the fibers for interfacial assembly. The self-assembly solution is then rinsed through the inside of the fiber and preferably allowed to polymerize overnight. The ends of the fibers may optionally be blocked to prevent leakage of the self-assembly solution. To coat the outside of the fiber, the fiber is preferably subjected to the same H₂O₂Boiling TEOS scheme. The fibers are then rinsed with water, preferably coated. The outside of the fiber is then preferably coated with a self-assembling solution. One method of coating the outside of the fiber is to pull it through a round hole plate containing the self-assembly solution. The self-assembling solution is preferably allowed to polymerize overnight.

Certain methods according to embodiments of the present invention stabilize the resulting film such that it better withstands mechanical deformation (stretching and/or compression). Both mathematical models and experimental results of lipid bilayer transport demonstrate that solute permeability across lipid bilayers decreases as membrane thickness increases. For example, a negative correlation between lipid chain length and bilayer permeability has been experimentally measured. There are many ways to vary the membrane thickness, including, but not limited to, lipid molecular structure (e.g., tail length, lipid species), mechanical stretching, chemical swelling, chemical bonding, and/or lipid interdigitation. The same is true for the stabilized surfactant mesostructured films. The stretching effect on biomimetic surfactant nanostructures induced by conventional surface pressure is shown in fig. 21A (effect of pressure on percent inhibition). Figure 21A is data for a single free standing biomimetic surfactant nanostructure assembled from a 5 wt% lipid solution comprising 10: 1 DLPC and gramicidin between two PES membranes prepared using UV cleaning. Figure 21B is data for a single free standing biomimetic surfactant nanostructure assembled from a 10 wt% lipid solution comprising 10: 1 DLPC and gramicidin between two PES membranes prepared using UV cleaning. The prevention of methanol by biomimetic surfactant nanostructures decreases with pressure because of the transverse stretching caused by solvent flow through the membrane. By inserting a mechanical backing, such as a porous screen (0.1 mm pores made by DelStar, El Cajon, CA) on a metal screen (5 mm pores) placed after a single free standing biomimetic surfactant nanostructure (assembled from a 10 lipid wt% solution containing 10: 1 DLPC with gramicidin cleaned with two PES membranes prepared using UV with a 20% wt/wt methanol concentration), the prevention of methanol reached steady state operation after approximately 40 minutes, as shown in fig. 22A. In addition, the flux of the solution through the membrane slowed as a function of time, as shown in fig. 22B, indicating the ability to concentrate methanol in the retentate.

Particular embodiments of the present invention provide for concentration of solutes across a membrane. Molecules, ions and particles stopped by the membrane may be concentrated in the solute. One example method includes configuring a membrane in a tangential flow device. Particular embodiments of the present invention may be used to concentrate methanol. As shown in figure 23, a volume (5.5ml) of 20 wt%/wt% methanol solution (25ml) was pumped through a single freestanding biomimetic surfactant nanostructure, assembled from a 10 lipid wt% solution containing 10: 1 DLPC and gramicidin between two PES membranes prepared using UV cleaning. The membrane backing has a millimeter-sized porous screen backed with a porous metal frame. A one inch metal stand was glued to the other side of the film with Devcon 5 minute epoxy. The flow rate was 0.074 ml/min and the average pressure was 11.4 PSI. The membrane area was 1.13cm². The membrane was perpendicular to the solution flow in the home-made membrane cartridge. The sides of the membrane are bonded to prevent leakage. The concentration of methanol in the retentate increased by 5.3%, as expected from the mass balance between the given initial methanol concentration of the feed solution and the measured methanol concentration of the permeate solution.

Certain embodiments of the present invention provide for the formation of biomimetic surfactant nanostructures using different types of porous materials. Rational design and incorporation of specific membrane supports for enhancing material stability is critical for separation of specific solutes, as limitations of the support materials include, but are not limited to, chemical stability in solutes, mechanical stability in solutes, pore size, pore shape, cost, separation efficiency, and system compatibility. One limitation of separation solvents such as alcohols, ketones, acetone or benzene is the chemical stability of the support membrane. For example, PES is soluble in many organic solvents including acetone and is mechanically unstable in alcohols. PES, HI-PTFE (hydrophilic) and HO-PTFE (hydrophobic) differ in their mechanical stability in alcohol. Here, the mechanical stability of the membrane is defined as the swelling of the material in the mixture of alcohols. FIG. 24A shows the swelling of a 5cm by 1cm piece of PES as a function of alcohol type and alcohol concentration. FIG. 24B shows the expansion of 5cm by 1cm pieces of HI-PTFE and HO-PTFE membranes as a function of PTFE membrane type, alcohol type, and alcohol concentration. Normalized to water, PES expands 6% in pure ethanol and pure butanol. Normalized to water, both HI-PTFE and HO-PTFE do not swell in pure ethanol and pure butanol. This makes both HI-PTFE and HO-PTFE ideal for use with small organic solvents. The expansion of the support causes lateral stretching on the biomimetic surfactant nanostructure, which reduces its performance.

FIG. 25 compares two particular embodiments of the invention separating 25ml of a 10 wt.%/wt.% aqueous ethanol solution from water. A single free-standing biomimetic surfactant nanostructure was assembled from a 10 lipid wt% solution containing 10: 1 DLPC and gramicidin between two HI-PTFE membranes prepared using UV cleaning. The membrane was backed by both a millimeter-sized porous screen and a porous metal frame. As shown in fig. 25B, this configuration shows a 17.5% increase in percent inhibition at comparable pressures versus a single free-standing biomimetic surfactant nanostructure assembled from a 10 lipid weight% solution containing 10: 1 DLPC and gramicidin between two PES membranes prepared using UV preparation methods (fig. 25A). Both embodiments have a mechanical backing of porous metal sheet to stabilize the membrane.

In certain embodiments of the invention, the ethanol may be concentrated. In fig. 26, the results of the ethanol concentration experiment are presented. A volume (7.4m1) of a 20.5 wt%/wt% ethanol solution (25ml) was pumped through a single freestanding biomimetic surfactant nanostructure assembled from a 10 lipid wt% solution containing 10: 1 DLPC and gramicidin between two HI-PTFE support membranes prepared using UV cleaning. The membrane consists of a millimeter-sized perforated screen backA liner further backed by a porous metal frame. A one inch metal stand was glued to the other side of the film with Devcon 5 minute epoxy. The membrane area was 1.13cm². Flow rate of 1.2X 10^-5m³/m²Second, with a pressure of 5 PSI. Flow rate for pressure normalization was 3.48 × 10^-10m³/m²second/Pa. The loss was 0.1 ml. The membrane was perpendicular to the solution flow in the home-made membrane cartridge. The sides of the membrane are glued to prevent leakage. The ethanol concentration of the retentate increased by 2.4% from the initial ethanol concentration as expected from the mass balance given by the measured ethanol concentration of the permeate.

In certain embodiments of the invention, aqueous NaCl may be separated from water, as shown in fig. 27. The material was 10 wt% Soy PC (95%) from Avanti Polar Lipids (Alabaster, AL) in a standard silica solution assembled between two UV cleaned PES membranes (0.030 micron pores). The NaCl solution had a volume of 233ml and a conductivity of 15.4 mS/cm. The conductivity was measured using a Horiba B-173 conductivity meter. The membrane was backed by both a millimeter-sized porous screen and a porous metal frame. The membrane area was 1.13cm². The pressure was 5 psi.

In certain embodiments of the invention, MgSO may be combined₄The aqueous solution was separated as shown in fig. 28. The membrane was 30 wt% SoyPC (95%) from AvantiPolar Lipids (Alabaster, AL) in a silica stock assembled between two UV cleaned PES membranes (0.030 micron pores). MgSO (MgSO)₄The volume of the solution was 13.2ml with an initial conductivity of 9.0 mS/cm. The final conductivity was 9.2 mS/cm. The conductivity was measured using a Horiba B-173 conductivity meter. The membrane was backed by both a millimeter-sized porous screen and a porous metal frame. The membrane area was 1.13cm². The pressure was 5 psi.

Multilayer film

Embodiments of the present invention include multilayer films. The multilayer film is preferably an alternating layered layer of self-assembling material and support material. An exemplary embodiment is shown in fig. 29. Two solid surfaces (A) sandwiching alternating layers of porous material (B) and surfactant templatingSol-gel self-assembly solution (C). In particular, HI-PTFE membranes are permeated through H₂O₂Boiled TEOS and rinsed in 18.2M omega water. After the HI-PTFE membrane was prepared, alternating layers of membrane and 400 microliters of BSNS solution were built on the solid surface, with the first final layer being H₂O₂Boiling the TEOS HI-PTFE film. The three laminated films were sandwiched by another solid surface, dried at room temperature for more than one hour, and then dried at 80 ℃ for more than three hours. The resulting film was glued to a mechanical backing. The restraint simultaneously drives the assembly and bonds the resulting membrane to the physical restraint assembly.

In one example of a multilayer film, three BSNS layer free standing biomimetic surfactant nanostructures were assembled using a 10 lipid weight% solution containing 10: 1 DLPC with gramicidin. The porous material is prepared by four UV preparation methods (H)₂O₂Boiling TEOS and rinsing in 18.2MQ water). After preparation, H is₂O₂Alternating layers of boiling TEOS HI-PTFE membrane and BSNS solution were placed on a solid surface, the last layer being H₂O₂Boiling the TEOS HI-PTFE film. The stack of membranes was sandwiched by another solid surface, dried at room temperature for more than one hour, and then dried at 80 ℃ for more than three hours. The resulting film was glued to a mechanical backing. The membrane area was 6.16cm². The separation of the 10% wt./wt.% ethanol solution was performed at 2.5 PSI. The multilayer film blocked ethanol at an average of 80.5% as shown in fig. 30, and exhibited a nearly constant water flux over 200 minutes as shown in fig. 30B.

The physical properties of embodiments of the multilayer film may be fundamentally and significantly different from a plurality of individual films stacked in series. The separation of the multilayer material showed improved performance over the calculated performance of a single layer of film material and three single layers of film in series. The following is a table comparing the rejection and flux of monolayers (monolayers), three monolayers in series (three monolayers), and triplets of multilayers (triplets of multilayers). For the calculation of three monolayers, the pressure was calculated by multiplying the pressure of one layer by the number of layers, the flux was calculated by dividing the flux of one layer by the number of layers, and the percentage of inhibition was calculated by adding one to the number of layers and then subtracting the obtained value by one. The pressure, flux and rejection of the multilayer film are better than calculated for the tandem films. This can be attributed to the difference in the assembled state between a single layer, in which each porous material has a solid surface on one side, and a multilayer, in which all but two of the porous materials do not have a solid surface on either side.

TABLE 4

In one embodiment of the multilayer film, four biomimetic layer films were assembled using a 10 wt% lipid solution containing 10: 1 DLPC and gramicidin. The porous material is prepared by five UV preparation methods (H)₂O₂Boiling TEOS and rinsing in 18.2M Ω water). After preparation, H is₂O₂Alternating layers of boiling TEOS HI-PTFE membrane and BSNS solution were placed on a Teflon sheet with the last layer being H₂O₂Boiling the TEOS HI-PTFE film. The stack of membranes was sandwiched by another solid surface, dried at room temperature for more than one hour, and then dried at 80 ℃ for more than three hours. After drying, the resulting film is glued to a mechanical backing. The sample area was 6.15cm². The separation of the 5% wt.%/wt.% butanol solution was performed at 25PSI and 10 PSI. The flux and blocking rate data are given in figure 31. The line with the diamond shape refers to the axis (flux) on the left. The line with squares refers to the axis on the right (percent block).

Electrochemistry and related applications

Table 5 compares the selectivity of Nafion membranes versus the calculation of free standing BSNS containing 10 mole% gramicidin transporters. The values listed for Nafion are from the literature. The values listed for BSNS are based on calculations parameterized by experimental measurements. Proton and methanol conductivities per lipid bilayer were measured using conductivity measurements from single channel gramicidin, respectivelyAnd large unilamellar vesicle ("GUV") experiments. The proton conductivity was determined to be 602.6S/cm²And the methanol permeability was determined to be 1.2 × 10 per bilayer^-5cm/sec. The BSNS equivalent circuit is an equivalent circuit of 100 lipid bilayers in parallel, approximately one micron thick material. Proton conductivity and methanol permeability were divided by the number of total layers according to the equivalent circuit model of the lipid bilayer. As such, these values represent an estimate of the performance of a Direct Methanol Fuel Cell (DMFC) using this BSNS configuration. Membrane exchange in a typical DMFC requires methanol dilution at the anode to 3M-4M and reduces fuel cell power density (W cm)^-2) About 50%. However, for the above-described BSNS, we predicted a 1733-fold reduction in methanol permeability versus Nafion and a 5.93 x 10 in multivalent cation permeability^-8And decreases. The resulting DMFC will be about 50% more efficient and can be operated on "clean" methanol.

	Nafion 117	Predicting BSNS	Ratio of BSNS to Nafion
				Thickness of	～100μm	～1μm	.001
Conductivity (S)	7.5S/cm2(Lee W et al)	6.026S/cm2	.803
				Permeability of methanol (P)	2.08×10-4cm/sec (Lee W, etc.)	1.2×10-7cm/sec	5.7×10-3
Permeability of multivalent cations	5.93×10-8cm2Second (Xia J et al)	＞10-16cm2Second/second	1.69×10-7

TABLE 5

Some biomimetic surfactant nanostructures containing gramicidin self-assemble between two Nafion membranes as depicted in figure 8. The BSNS self-assembly solution contained lipids (lipid 5, lipid 1, lipid 2, 5 wt% DLPC, 10 wt% DMPC), lipids and gramicidin (gramicidin 4, 10 wt% 10 DMPC: 1 gramicidin), or neither lipids nor gramicidin (silica, silica 1, silica 2). The transporter material is characterized by a breakthrough conductivity measurement. Conductivity of penetration by sandwiching the membrane between two-1 cm²The resistance was measured between the steel plates by an ohmmeter. The films and steel plates were stored in acid at a specified concentration for at least 2 minutes prior to measurement. Fig. 32A-32C compare the conductivity of control and three free-standing BSNS graded membranes with and without transporters. In fig. 32A, the penetration resistance of three types of membranes was compared at different sulfuric acid concentrations: silica (no lipid), lipid 5 (no transporter), and gramicidin 4 (including transporter). We measured a 6.375-fold increase in the resistance of the transporter-free BSNS membrane (lipid 5) relative to the transporter-containing BSNS membrane brevibacterium peptide 4. As expected from experiments with vesicles in solutionThe results show that inclusion of transporter gramicidin in BSNS increases the conductivity of biomimetic surfactant nanostructures. Furthermore, at 1M sulphuric acid, the resistance of the control membrane (silica) was comparable to that of BSNS (gramicidin 4) containing the transporter. The resistance is therefore film-limited, not transporter-limited. When compared to table 5, this indicates that the BSNS layer is less than 1 micron thick.

The stability of these materials in acidic and high concentrations of alcohols is important for fuel cell applications. The conductivity of the membrane remained for more than about one day, regardless of whether the sample was stored in pure (neat) methanol (fig. 32B) or 1M H2SO₄Middle (fig. 32C). As shown in fig. 32B, after day 1, the resistance increased significantly, indicating material failure. In fig. 32C, two surfactant-free materials (silica 1, silica 2) and one surfactant-containing material (5 wt% DLPC) were stored in 1M sulfuric acid. After three days, the resistance of the surfactant-containing material did not change significantly. This indicates that the material remains assembled despite the corrosive environment. This stability indicates that the material according to this embodiment can be used in electrolysis, separation and fuel cell applications.

For direct methanol fuel cells and molecular separations, a decrease in the permeability of methanol through the membrane is important. This embodiment, the free-standing BSNS, had a 4 x reduction in methanol permeability compared to Nafion. Methanol permeability was measured by filtering water and high concentration aqueous (18-23Brix) methanol solutions with Nafion 117 or free-standing BSNS at equal volumes of 18.2M Ω millipore. The methanol concentration of the initial pure water was measured as a function of time using an Atago 4436PAL-36S digital portable methanol refractometer. Permeability coefficient the following formula is used to relate flux to concentration gradient

Wherein J is the flux (cm)²Second of^-1) P is permeability (cm/sec), Δ C is concentration gradient (Brix), V is volume on one side, andand a is the interfacial area. The ratio of volume to area of the permeability cell was 0.3 cm. The concentration gradient (ac) over time (as shown in fig. 32D) was fitted to a single index with a rate coefficient k. The permeability was calculated using the following formula

Wherein P is permeability (cm/sec) and V is volume (cm) of one side³) A is the interfacial area (cm)²) And k (seconds)^-1) Is the rate constant obtained from the fitting. Methanol permeability was measured for three Nafion 117 membranes, a biomimetic nanostructured membrane without a transporter, and a biomimetic nanostructured membrane with a transporter. For the Nafion 117 membrane, the average methanol permeability coefficient for the three experiments was 1.2 × 10^-4cm second^-1. This is in good agreement with the Nafion 117 methanol permeability values in table 5. For the sample embodiment of the invention, the average methanol permeability was 0.3X 10^-5cm second^-1. Despite the inclusion of the transporter (10 wt% 10 DMPC: 1 Brevibacterium peptide) in the BSNS, the permeability coefficient was the same as for the transporter-free BSNS (10 wt% DMPC). As expected from experiments with vesicles in solution, this result shows that inclusion of gramicidin in BSNS does not increase methanol permeability of biomimetic surfactant nanostructures. The lipid structure is thus retained regardless of the inclusion of the transporter. The methanol permeability of the present invention is reduced by a factor of four compared to Nafion 117.

Embodiments of the invention may be used as an electrolyte for electrochemistry, a membrane electrode assembly or an electrochemical cell; one configuration is illustrated in fig. 33. The high conductivity and low exchange of biomimetic surfactant nanostructures makes them suitable as electrolytes for liquid-fed fuel cells and batteries. The biomimetic surfactant nanostructures 3330 are placed between the backing layer 3320 and the anode flow plate 3310 and the cathode flow plate 3340. Either or both of the flow plates optionally comprise a serpentine graphite plate. The plates may be different. To create a free standing membrane, the BSNS containing passive transporters, or alternatively a stabilized surfactant mesostructure, in combination with one or more Nafion membranes preferably has better selectivity than current industrial membranes. This has important applications for both fuel cells and batteries where membrane "exchange" of fuel or electrolyte reduces efficiency and energy storage capability. The biomimetic surfactant nanostructures 3330 may optionally comprise a multi-scale self-assembled Membrane Electrode Assembly (MEA), which may optionally include one or more of the following: catalyst, membrane, Gas Diffusion Layer (GDL), and/or carbon fiber paper. The sandwiched portion of the MEA is a surfactant templated nanostructure fabricated using physical constraints. The membrane may be supported by any solid surface or GDL on a solid surface. A complete Membrane Electrode Assembly (MEA) containing the catalytic layer on the GDL can be manufactured in a similar manner. Alternatively, if the GDL is replaced with a conductive ion exchange membrane, the device may contain an electrolyte for a battery.

Similarly, redox flow batteries, such as vanadium ion redox batteries (VRBs), have reduced efficiency due to membrane exchange of aqueous redox ions. Eliminating the exchange in redox flow batteries by using the above BSNS enables to obtain batteries with > 90% efficiency similar to lithium ion batteries, which are not plagued by electrolyte exchange.

Similar configurations can be used for separations such as urea removal, dialysis, desalination, distillation, alcohol purification, and chlor-alkali treatment.

Materials made according to embodiments of the present method may be suitable for use in: as a membrane in a membrane electrode assembly for a direct methanol fuel cell, as a membrane electrode assembly for a fuel cell, as a membrane in a membrane electrode assembly for a biofuel cell, as a membrane in a membrane electrode assembly for an electrochemical cell, in active devices and smart devices via cooperation of channels, in chlor-alkali cells, in electrochemistry, in chemical manufacturing and/or in enzymatic conversion of molecules.

While the invention has been described in detail with particular reference to the described embodiments, other embodiments can achieve the same results. Variations and modifications of the present invention will be obvious to those skilled in the art and it is intended to cover all such modifications and equivalents. The entire disclosures of all patents and publications cited above are hereby incorporated by reference.

Claims (48)

1. A membrane comprising a stabilized surfactant mesostructure bound to a surface of a porous support.

2. The film of claim 1, wherein the stabilized surfactant mesostructure is stabilized with a material that maintains the arrangement of surfactant molecules.

3. The membrane of claim 2, wherein the material is porous and the stabilized surfactant mesostructure comprises alternating lamellae with lamellae comprising the porous material.

4. The membrane of claim 2, wherein the material is non-porous and the stabilized surfactant mesostructure comprises hexagonally packed columns comprising surfactant molecules in a circular arrangement, each of the columns being substantially surrounded by the non-porous material.

5. The film of claim 1, further comprising a material disposed between the stabilized surfactant mesostructure and the surface for maintaining a hydrogen bonding network between the surfactant in the stabilized surfactant mesostructure and the surface.

6. The film of claim 5, wherein the material comprises a material selected from the group consisting of: silanes, organics, inorganics, metals, metal oxides, alkylsilanes, calcium, and silica.

7. The film of claim 1, wherein the surface has been oxidized, melted, and resolidified before the stabilized surfactant mesostructure is bound to the surface.

8. The membrane of claim 7, wherein the average pore size at the resolidified surface is less than the average pore size in the bulk of the porous support.

9. The membrane of claim 1, wherein the pore size of the porous support is small enough to prevent the precursor solution of the stabilized surfactant mesostructure from completely penetrating the support prior to the formation of the stabilized surfactant mesostructure.

10. The membrane of claim 1, further comprising an additional porous structure disposed on a side of the porous support opposite the surface for mechanically or chemically stabilizing the porous support.

11. The film of claim 1, wherein the stabilized surfactant mesostructure comprises a transporter.

12. The membrane of claim 1, further comprising a second porous support, wherein the stabilized surfactant mesostructure is sandwiched between the porous support and the second porous support.

13. The film of claim 1, having a curvature of less than about 1.09.

14. The membrane of claim 1, wherein the stabilized surfactant mesostructure has a pore size of about 0.3 angstroms to about 4 nm.

15. The membrane of claim 1, having a porosity greater than about 1%.

16. The membrane of claim 1, wherein the porous support comprises plastic and/or cellulose.

17. The membrane of claim 1, wherein the porous support mechanically stabilizes the stabilized surfactant mesostructure.

18. The membrane of claim 1, further comprising a second stabilized surfactant mesostructure bonded to the opposite side of the surface of the porous support.

19. The film of claim 1 laminated with other films of claim 1 to form a multilayer film.

20. The film of claim 1, wherein the surface of the stabilized surfactant mesostructure is modified.

21. The membrane of claim 1 comprising an ion-exchange membrane and/or a gas diffusion layer, the membrane comprising a membrane electrode assembly or an electrolyte.

22. A method for making a membrane, the method comprising:

modifying the surface of the porous support;

wetting the modified surface with a first solvent;

placing a solution on the wetted surface, the solution comprising at least one surfactant and at least one second solvent, wherein the at least one surfactant is in a dispersed phase in the solution;

confining the solution between two or more confining surfaces; and

stabilizing the one or more surfactants to form a stabilized surfactant mesostructure on the surface of the porous support.

23. The method of claim 22, wherein the first solvent and/or the second solvent comprises water.

24. The method of claim 22, wherein the solution further comprises precursor solutes and/or transporters.

25. The method of claim 22, wherein placing the solution and limiting the solution are performed substantially simultaneously.

26. The method of claim 22, wherein confining the solution comprises confining the solution between a surface of the porous support and at least one second surface.

27. The method of claim 26, wherein the at least one second surface is selected from the group consisting of: slot sidewalls, rollers and blade edges.

28. The method of claim 26, wherein modifying the surface comprises an operation selected from the group consisting of: surface functionalization; surface grafting; covalent surface modification; surface adsorption; surface oxidation; surface ablation; rinsing the surface; depositing a material on the surface, the material selected from the group consisting of: silanes, organics, inorganics, metals, metal oxides, alkylsilanes, calcium, and silica; maintaining a network of hydrogen bonds between the surfactant in the stabilized surfactant mesostructure and the surface; and oxidizing, melting and resolidifying the surface.

29. The method of claim 22, performed as part of a mass production coating process.

30. The method of claim 22, further comprising controlling the thickness of the stabilized surfactant mesostructure.

31. The method of claim 22, wherein the solution does not comprise an acid, a base, or a hydrophilic compound.

32. The method of claim 22, wherein the at least one surfactant is not removed from the solution after the solution is placed on the surface.

33. The method of claim 22, which is performed on both sides of the porous support.

34. The method of claim 22, further comprising surface modification of the stabilized surfactant mesostructure.

35. The method of claim 34, wherein modifying the surface of the stabilized surfactant mesostructure comprises: surface functionalization, altering the hydrophobicity of the surface of the stabilized surfactant mesostructure and/or methylation of the surface of the stabilized surfactant mesostructure is employed.

36. The method of claim 22, which is repeated to form a multilayer film.

37. The method of claim 22, wherein the porous support comprises plastic and/or cellulose.

38. The method of claim 22, further comprising placing a second porous support on the surface of the stabilized surfactant mesostructure, thereby sandwiching the stabilized surfactant mesostructure between the porous support and the second porous support.

39. A forward osmosis membrane having greater than about 15LM at 20 ℃ for a draw solution concentration of 10 wt% NaCl^-2H^-1Permeability of (d).

40. The forward osmosis membrane of claim 39, wherein the permeability at 20 ℃ for a draw solution concentration of 10 wt% NaCl is greater than about 20LM^-2H^-1。

41. The forward osmosis of claim 39A membrane, wherein the permeability at 20 ℃ for a draw solution concentration of 10 wt% NaCl is greater than about 60LM^-2H^-1。

42. The forward osmosis membrane of claim 39, having a NaCl rejection greater than about 96%.

43. The forward osmosis membrane of claim 39, comprising one or more surfactants.

44. A device for performing separations, said device comprising an active layer, said active layer comprising one or more surfactants.

45. The device of claim 44, wherein the active layer comprises one or more transporters.

46. The device of claim 44, selected from the group consisting of: forward osmosis membranes or modules, reverse osmosis membranes or modules, pressure retarded osmosis membranes or modules, hollow fiber membranes, spiral wound membranes or modules, cartridges, Tangential Flow Filter (TFF) cartridges, plate and frame modules, tubular membranes and bags.

47. The device of claim 44, comprising a porous support coated on both sides with the one or more surfactants.

48. The device of claim 44, wherein the one or more surfactants form a mechanically stabilized membrane on one or more porous supports.