CN1312038C

CN1312038C - Large aperture capacity silicon oxide vesicle, foamed material and process for preparing the same

Info

Publication number: CN1312038C
Application number: CNB2005100268374A
Authority: CN
Inventors: 余承忠; 王红宁; 王韵华; 赵东元
Original assignee: Fudan University
Current assignee: Fudan University
Priority date: 2005-06-16
Filing date: 2005-06-16
Publication date: 2007-04-25
Anticipated expiration: 2025-06-16
Also published as: CN1730392A

Abstract

本发明属于介孔分子筛材料技术领域，具体为一种采用溶胶-凝胶的方法在温和的条件下合成出的具有大孔容(可达3cm³/g)，可控形貌(囊泡、泡沫等)、且孔径可调(10-200nm)的新型纳米多孔材料。制备方法包括囊泡、泡沫的制备、水热反应、干燥、去除模板剂等步骤。本发明反应条件温和，操作简便易行，无需加入助表面活性剂和助溶剂，最终材料价廉易得。通过改变原料比、反应温度、溶液pH值以及缓冲溶液离子浓度等条件可以调变材料的形貌、孔径及孔容等物理化学性质。这类大孔容纳米多孔材料在吸附、催化剂载体、药物缓释、分离、色谱、颜料、微反应器等领域具有广泛的应用前景。The invention belongs to the technical field of mesoporous molecular sieve materials, specifically a sol-gel method synthesized under mild conditions with large pore volume (up to 3cm ³ /g) and controllable morphology (vesicles, vesicles, Foam, etc.), and a new type of nanoporous material with adjustable pore size (10-200nm). The preparation method comprises the steps of preparing vesicles and foams, hydrothermal reaction, drying, removing template agents and the like. The invention has mild reaction conditions, simple and easy operation, no co-surfactant and co-solvent need to be added, and the final material is cheap and easy to obtain. Physical and chemical properties such as morphology, pore size and pore volume of the material can be adjusted by changing the raw material ratio, reaction temperature, solution pH value and buffer solution ion concentration and other conditions. This kind of macroporous porous material has broad application prospects in the fields of adsorption, catalyst carrier, drug sustained release, separation, chromatography, pigment, microreactor and so on.

Description

Large aperture capacity silicon oxide vesicle or foam materials and preparation method thereof

Technical field

The invention belongs to the meso-porous molecular sieve material technical field, be specifically related to a kind of vesica or foam and synthetic method thereof of large aperture capacity silicon oxide.

Background technology

Novel mesopore molecular sieve MCM-41 from 1992 by U.S. Mobil oil company synthetic first since, caused the very big concern of zeolite and catalysis circle, but its pore volume, aperture are less relatively.Stucky[Patrick Schmidt-Winkel, Galen D.Stucky ^*, et al.Chem.Mater.2000,12,686-696] and the mesoporous vesica (MCF) for preparing of co-workers, have than large pore volume and aperture, make organic expander but must add trimethylbenzene (TMB), TMB has destroyed the order of material when enlarging the material pore volume.In addition, TMB is toxic, and is unfriendly to environment; Volatile, be unsuitable for industrial mass production.Eisenberg[Kui Yu, Adi Eisenberg ^*, Macromolecules, 1996,29,6359-6361] and co-workers by changing the composition of high-molecular block copolymer, the concentration of segmented copolymer, use different solvents, change the composition of solvent, add additive (salt, acid, alkali, homopolymer), change the temperature of synthetic system, pH value of solution value etc. obtains organic vesica.Pinnavaia[S.S.Kim; T.J.Pinnavaia, Science 1998,282,1302-1305] and co-workers utilize the gemini tensio-active agent to obtain the vesica of the silicon-dioxide of pore size distribution broad (20-1400nm), but its pore volume＜1cm ³/ g, and to add organic solvent.Chen Yongming [Jianzhong Du and Yongming Chen, Macromolecules 2004,37,5710-5716] etc. utilize the material of the organic and inorganic compounding of the hydrophilic and hydrophobic segment of special synthetic different lengths, the content that changes water is realized by ball and bar-shaped, arrives stratiform, rod and vesica (on a small quantity), to vesica and stratiform, the transformation of arriving vesica again, its raw material (making silicon source and template simultaneously) is so expensive can't the preparation in a large number.The present invention adopts P123 (EO ₂₀PO ₇₀EO ₂₀) (EO oxyethylene; The PO propylene oxide) etc. as template, silicon oxide vesicle, the foam of preparation large pore volume under the low temperature in buffered soln, its aperture is at 10-200nm, and pore volume is at 1.0-3.0cm ³In/g the scope, adjustable.

Summary of the invention

The purpose of this invention is to provide a kind of silicon oxide vesicle of large pore volume or foam and preparation method thereof.

The vesica or the foam of the large aperture capacity silicon oxide that the present invention proposes are a kind of employing sol-gel method synthetic under mild conditions, have large pore volume, controllable appearance (vesica, foam etc.), and the adjustable novel nano porous material in aperture.The mol ratio in tensio-active agent that it is used and silicon source is 0.01～0.05: 1, and the aperture is at 10-200nm, and pore volume is at 1.0-3.0cm ³In/g the scope, adjustable.

Large aperture capacity silicon oxide vesicle of the present invention or foamy preparation method are as follows:

(1) vesica, foamy preparation

Certain amount of surfactant is dissolved in the buffered soln, under agitation add the silicon source by a certain percentage: methyl silicate (TMOS) or tetraethoxy (TEOS), continue to stir 3-10 minute, and left standstill or continued to stir 20-48 hour, its each mol ratio of forming is:

Tensio-active agent: silicon source=0.01～0.05: 1 buffered soln: silicon source=100～350: 1;

Temperature of reaction system is 15-70 ℃.

(2) hydro-thermal, the mother liquor that step (1) is made under 80-130 ℃ of temperature hydro-thermal 20-36 hour.

(3) drying, with the product suction filtration after step (2) hydro-thermal, washing, flush away inorganic salt, drying at room temperature.

(4) removal of tensio-active agent at 400-900 ℃ of following roasting 4-8 hour, is removed tensio-active agent with dried product, makes product of the present invention.

Aforesaid tensio-active agent is poly-oxyethylene (PEO) as hydrophilic block, the long chain alkane nonionic surface active agent as hydrophobic group, and carbon atom number is 8-20, and the polymerization degree of oxyethylene is 4-100; Perhaps poly-oxyethylene (PEO) is as hydrophilic block, poly-propylene oxide (PPO) or poly-epoxy butylene (PBO) the block macromolecular tensio-active agent as hydrophobic block, and its molecular formula is EO _nPO _mEO _n, n=10-140, m=5-100, or EO _nBO _mEO _n, n=10-200, m=10-100, or EO _nBO _m, n=10-100, m=5-60.

Aforesaid buffered soln is the NaAc-HAc of pH value between 3-8, or NaOH-NaH ₂PO ₄Buffered soln uses inorganic salt to regulate and control the total ion concentration of buffered soln, and ionic concn is between 0.05-1.00M.

The present invention compared with prior art has following advantage:

(1) raw material is cheap and easy to get, and the reaction conditions gentleness is easy to operation.

(2) by change raw material ratio, temperature of reaction, pH value of solution value and and condition such as buffered soln total ion concentration can the modulation vesica, physicochemical property such as foamy pattern, aperture and pore volume.

(3) silicon oxide vesicle of gained, foam have bigger pore volume, illustrate as accompanying drawing, and prove to have good adsorption, sustained release performance by experiment.Material of the present invention is with a wide range of applications in fields such as absorption, support of the catalyst, medicament slow release, separation, chromatogram, pigment, microreactors.

Description of drawings

Fig. 1 is the transmission electron microscope picture of silicon oxide vesicle.

Fig. 2 is silicon oxide vesicle nitrogen adsorption-desorption isotherm.

Fig. 3 is a silicon-dioxide foamy transmission electron microscope picture.

Fig. 4 is silicon-dioxide foam nitrogen adsorption-desorption isotherm.

Embodiment

Embodiment 1

1g P123 is added 30g pH=5, Ac ^-Total ion concentration is a 0.2mol/L NaAC-HAc buffered soln, stirs P123 is dissolved fully under 40 ℃ of temperature, adds 1.52g TMOS in system, continues to stir 5 minutes, left standstill 24 hours, in 100 ℃ of hydro-thermals 24 hours, suction filtration, washing, drying was 550 ℃ of roastings 5 hours.Obtain foam materials.Aperture 40nm, pore volume 2.50cm ³/ g.

Embodiment 2

1g P123 is added 30g pH=5, Ac ^-Total ion concentration is the NaAC-HAc buffered soln of 0.2mol/L, stirring under 50 ℃ of temperature dissolves P123 fully, in system, add 1.52g TMOS, continue to stir 5 minutes, left standstill 24 hours, in 100 ℃ of hydro-thermals 24 hours, suction filtration, washing, drying was 550 ℃ of roastings 5 hours. obtain foam materials.Aperture 50nm, pore volume 2.20cm ³/ g.

Embodiment 3

1g P123 is added 30g pH=5, Ac ^-Total ion concentration is the NaAC-HAc buffered soln of 0.2mol/L, stirs P123 is dissolved fully under 60 ℃ of temperature, adds 1.52g TMOS in system, continues to stir 5 minutes, left standstill 24 hours, in 100 ℃ of hydro-thermals 24 hours, suction filtration, washing, drying was 550 ℃ of roastings 5 hours.Obtain foam materials.Aperture 40nm, pore volume 2.10cm ³/ g.

Embodiment 4

1g P123 is added 30g pH=6, Na ⁺Total ion concentration is the NaOH-NaH of 0.2mol/L ₂PO ₄Buffered soln stirs under 40 ℃ of temperature P123 is dissolved fully, adds 1.52g TMOS in system, continues to stir 5 minutes, left standstill 24 hours, and in 100 ℃ of hydro-thermals 24 hours, suction filtration, washing, drying was 550 ℃ of roastings 5 hours.Obtain foam materials.Aperture 30nm, pore volume 2.80cm ³/ g.

Embodiment 5

1g P123 is added 30g pH=5, Ac ^-Total ion concentration is the NaAC-HAc buffered soln of 0.05mol/L, stirs P123 is dissolved fully under 40 ℃ of temperature, adds 1.52g TMOS in system, continues to stir 5 minutes, left standstill 24 hours, in 100 ℃ of hydro-thermals 24 hours, suction filtration, washing, drying is at 550 ℃ of roasting 5h.Be and obtain the vesica material.Aperture 20-130nm, pore volume 1.82cm ³/ g.

Embodiment 6

1g P123 is added 30g pH=5, Ac ^-Total ion concentration is the NaAC-HAc buffered soln of 0.2mol/L, stirs P123 is dissolved fully under 40 ℃ of temperature, adds 2.08g TEOS in system, continues to stir 5 minutes, left standstill 24 hours, in 100 ℃ of hydro-thermals 24 hours, suction filtration, washing, drying was 550 ℃ of roastings 5 hours.Obtain foam materials.Aperture 100nm, pore volume 2.05cm ³/ g.

Claims

1, a kind of preparation method of macroporous silicon dioxide vesicle or foam material, it is characterized in that concrete steps are as follows:

(1) Preparation of vesicles and foams

Dissolve the surfactant into the buffer solution, add the silicon source under stirring: methyl orthosilicate or ethyl orthosilicate, continue to stir for 3-10 minutes, stand still or continue to stir for 20-48 hours, the components The molar ratio is:

Surfactant: Silicon source = 0.01～0.05:1 Buffer solution: Silicon source = 100～350:1

The reaction temperature of the system is 15-70°C;

(2) hydroheating, the mother liquor prepared in step (1) is hydrothermally heated at a temperature of 80-130° C. for 20-36 hours;

(3) drying, suction filtering the product after step (2) hydroheating, washing with water, washing away inorganic salts, and drying at room temperature;

(4) Removal of the surfactant, the dried product is roasted at 400-900° C. for 4-8 hours, and the surfactant is removed to obtain the desired silica vesicle or foam with a pore size of 10-200 nm. The pore volume is 1.0-3.0cm ³ /g.

2. The method for preparing macroporous silica vesicles or foams as claimed in claim 1, characterized in that said surfactant is polyethylene oxide as a hydrophilic block and long-chain alkane as a hydrophobic group. Non-ionic surfactant, the number of carbon atoms is 8-20, the degree of polymerization of polyethylene oxide is 4-100; or polyethylene oxide as a hydrophilic block, polypropylene oxide or polybutylene oxide as a hydrophobic A block polymeric surfactant with a molecular formula of EO _n PO _m EO _n , n=10-140, m=5-100, or EO _n BO _m EO _n , n=10-200, m=10 -100, or EO _n BO _m , n=10-100, m=5-60.

3. The method for preparing large-volume silica vesicles or foams according to claim 1, characterized in that the buffer solution is NaAc-HAc or NaOH-NaH ₂ PO ₄ buffer solution with pH=3-8 , and use inorganic salts to regulate the ion concentration of the buffer solution, and the ion concentration is between 0.05-1.00M.