Adsorption Properties

This study presents the synthesis of zeolite-NaX from rice husk using the hydrothermal method. The synthesized material exhibited the formation of zeolite-NaX as confirmed by X-ray diffraction (XRD) analysis. The substance was subjected to further modifications through the silver (Ag 0 ) nanoparticles and surfactant sodium dodecyl sulfate (SDS) to further investigate the adsorption properties of mercury and dyes in water. As a result of the ion exchange reaction and reduction by silver nanoparticles (AgNPs), the particle size was 15-16.4nm. Cationic methylene blue and mercury ion (Hg 2+ ) adsorption onto unmodified and modified zeolites was studied using a batch equilibration method. The sorbent modified with silver nanoparticles was investigated for its ability to purify water from mercury ions (Hg²⁺), resulting in an increased sorption capacity from qmax = 136.9 to 285.7 mg g⁻¹. The possibility of removing dyes from an aqueous medium at a neutral pH was also studied. The sorption capacity increased from 9.21 to 13.48 mg g⁻¹ when the SDS modified the sorbent. During 24 hours, preliminary results showed that the removal of mercury ions from the solution ranged from 27 to 76% and the removal of methylene blue from 18 to 87% of the initial concentration.

This paper describes the physico-chemical study of the adsorption of dysprosium (Dy3+) in aqueous solution onto two types of activated carbons synthesized from spent coffee ground. KOH activated carbon is a microporous material with a specific BET surface area of 2330 m2·g-1 and pores with a diameter of 3.2 nm. Carbon activated with water vapor and N2 is a solid mesoporous, with pores of 5.7 nm in diameter and a specific surface of 982 m2·g-1. A significant dependence of the adsorption capacity on the solution pH was found, while it does not depend significantly neither on the dysprosium concentration nor on the temperature. A maximum adsorption capacity of 31.26 mg·g-1 and 33.52 mg·g-1 for the chemically and physically activated carbons, respectively, were found. In both cases, the results obtained from adsorption isotherms and kinetic study were better fit to a Langmuir model and a pseudo-second-order kinetics. In addition, thermodynamic results indicate that dysprosium adsorption...

Electrocatalysts are mainly characterized by their intrinsic adsorption properties. However, the observed electrocatalytic activity ultimately results from the interplay between such properties and various additional interactions within the electrified solid-liquid interface. One of such phenomena is solvation, which can substantially affect the stability of adsorbates. The incorporation of solvation in computational electrocatalysis models can be fully implicit (inaccurate for H-bonded adsorbates), fully explicit (challenging computation of free energies), or embedded. Here we show that without any need for explicit or implicit media, a micro-solvation approach with just 3 water molecules captures the contribution of coadsorbed water to the adsorption energies of *OH and *OOH (two important adsorbates for oxygen reduction) on platinum nanoparticles of various sizes. The approach enables an accurate yet inexpensive explicit modeling of solvent-adsorbate interactions in nanoparticles, and the calculation of solvation corrections, estimated as 0.59 0.14 eV -± and 0.47 0.13 eV -± for *OH and *OOH adsorption on Pt.

The requirement to counter carbon emissions is becoming urgent. Zeolitic Imidazolate Frameworks (ZIFs) have been extensively investigated recently for storing and separating gases, especially carbon dioxide. The present review aims to summarise the state of the art of ZIFs for carbon dioxide capture focusing on the structure, mechanism, optimisation, and modelling. The methods utilised for carbon capture are briefly summarized. The morphology of ZIFs with different topologies, N 2 -CO 2 adsorption-desorption isotherms, X-ray diffraction patterns, thermo-gravimetric analysis (TGA) results are discussed to give insights into the textural properties, structure-activity relationship and structural-thermal stability of ZIFs. Finally, the experimental optimisation techniques, modelling and simulation studies for improving CO 2 capture by ZIFs are discussed. This review should provide a comprehensive and quick understanding of this research area. It is timely to summarize and review ongoing developments in this growing field to accelerate the research in the right direction.

Slow pyrolysis is widely used to convert biomass into useable form of energy. Ultrasound pre-treatment assisted pyrolysis is a recently emerging methodology to improve the physicochemical properties of products derived. Biochar, the solid residues obtained from pyrolysis, is getting considerable attention because of its good physicochemical properties. Various modification techniques have been implemented on biochars to enhance their properties. Ultrasonic pre-treated wood biochar has showcased efficient surface and adsorption properties. Iron impregnated biochar is interesting as it has potentially proved the efficiency as an efficient low-cost catalyst. In this study, by combining the advantages of ultrasonic pre-treatment and iron impregnation, we have synthesized a series of Fe-impregnated biochar from softwood chips. Pre- and post-pyrolysis methods using a lab-scale pyrolyser had been implemented to compare the pyrolysis product yields and degree of impregnation. Biochars deriv...

Physical and chemical modification on biochar is an interesting approach to enhance the properties and make them potential candidates in adsorption of heavy metals from water. Studies have shown that ultrasound treatments as well as alkali activations on biochar has positive impact on adsorption behaviour of the material. Base activation on biochar derived from ultrasound pre-treated woodchips were studied to understand the influence of ultrasound pre-treatment on chemical modification of biochar and the adsorption properties emerged from it. 40 and 170 kHz ultrasound pre-treated softwood woodchips were subjected to laboratory scale pyrolysis and the resulted biochars were treated with NaOH. The physicochemical properties were examined, and the adsorption experiments revealed that ultrasound pretreatment assisted biochars have better adsorption capacity as compared to untreated biochar samples after activation. 170 kHz pre-treated sample exhibited an equilibrium adsorption POSTPRINT VERSION. The final version is published here: Peter, A., Chabot, B. et Loranger, E. (2021) Enhanced activation of ultrasonic pre-treated softwood biochar for efficient heavy metal removal from water.

h i g h l i g h t s " Polymer/silica/PEI hollow fibers are proposed as sorbents for CO 2 capture. " CA/silica/PEI fibers are made via a post-spinning amine infusion technique. " Effects of synthesis conditions on CO 2 capacity are determined. " Multi-fiber module used to monitor CO 2 and water adsorption from simulated flue gas. " Amine-containing fibers may be useful in RTSA CO 2 capture process.

Sciences. She is an expert in transmission electron microscopy and develops hybrid nanomaterials for photovoltaic applications. She also applies nanomaterials to water remediation. She has 80 publications, 2 patents, 4 book chapters, 1 book, and an H-index of 22. She is also CEO of PRO-1 NANOSolutions, a startup company that applies nanotechnology to water remediation and nanomedicine.

Immobilization of 4-(methacryloylamino)phenyl-2-methylacrylate homopolymer on the silica gel surface has been carried out in situ. The structure and quantitative characteristics of immobilized polymer have been examined by IR spectroscopy, thermogravimetric analysis and mass spectrometry. Adsorption activity towards microquantities of Pb(II), Cu (II), Mn(II), Co(II), Ni(II) and Fe(III) ions in the range of pH 6-8,5 has been observed. Quantitative adsorption of traces of Pb(II) in neutral and slightly alkaline media is reported.

Amide-linked side-chains can substitute for esters in crystalline nanoporous steroidal ureas (NSPUs). This efficient conjugation method increases the versatility of NPSUs, and should aid the inclusion of complex functional units in the crystal channels.

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Molecular dynamics (MD) and Born-Oppenheimer MD simulations (BOMD) were employed to investigate adsorption of aqueous triethylene glycol (TEG) on a hydrated {1014} calcite surface at 298K. We analyzed the orientation of TEG adsorbed on calcite, as well as the impact of TEG on water density and adsorption free energy. Adsorption energies of TEG, free energy profiles for TEG, the details of hydrogen bonding between water and adsorbed TEG, as well as dihedral angle distribution of adsorbed TEG were estimated. We found that while the first layer of water was mostly unaffected by presence of adsorbed TEG, the density of the second water layer was decreased by 71% at 75% surface coverage of TEG. TEG primarily attached to the calcite surface via two adjacent adsorption sites. Hydrogen bonds between water and adsorbed TEG in the second layer almost exclusively involved the hydroxyl oxygen of TEG. The adsorption energy of TEG on calcite in a vacuum environment calculated by classical MD amou...

Immobilization of 4-(methacryloylamino)phenyl-2-methylacrylate homopolymer on the silica gel surface has been carried out in situ. The structure and quantitative characteristics of immobilized polymer have been examined by IR spectroscopy, thermogravimetric analysis and mass spectrometry. Adsorption activity towards microquantities of Pb(II), Cu (II), Mn(II), Co(II), Ni(II) and Fe(III) ions in the range of pH 6-8,5 has been observed. Quantitative adsorption of traces of Pb(II) in neutral and slightly alkaline media is reported.

The most important environmental challenge that the world is facing today is the control of the quantity of CO 2 in the atmosphere, because it causes global warming. Increase in the global temperature results in greenhouse gas emission, interruption of the volcanic activity, and climatic changes. The alarming rise of the CO 2 level impels to take some serious action to control these climatic changes. Various techniques are being utilized to capture CO 2. However, chemical absorption and adsorption are supposed to be the most suitable techniques for postcombustion CO 2 capture, but the main focus is on adsorption. The aim of this study is to provide a brief overview on the CO 2 adsorption by a novel class of adsorbents called the metal-organic framework. The metal-organic framework is a porous material having high surface area with high CO 2 adsorption capacity. The metal-organic frameworks possess dynamic structure and have large capacity to adsorb CO 2 at either low pressure or high pressure due to its cavity size and surface area. Adsorption of CO 2 in the metal-organic framework at various pressures depends upon pore volume and heat of adsorption correspondingly. In this review, different synthesis methods of the metal-organic framework such as slow evaporation, solvo thermal, mechanochemical, electrochemical, sonochemical, and microwave-assisted synthesis are briefly described as the structure of the metal-organic frameworks are mostly dependent upon synthesis techniques. In addition to this, different strategies are discussed to increase the CO 2 adsorption capacity in the metal organic-framework.

The aim of the study was to prepare resistant and spherical inorgano-organo pillared clays (GIOCs) granules for wastewater treatment using a new and simple method named high-shear wet granulation. To optimize the preparation method, the effects of the main process parameters, such as binder concentration, liquid to solid ratio and impeller speed on granule properties (size distribution, friability and disintegration tests) were investigated. Experimental results showed that the granulation of inorgano-organo pillared clays (PIOCs) with industrial Silicone is significantly influenced by the binder concentration, the liquid to solid ratio (H %) and the impeller speed (N). A modification of these parameters can greatly alter the characteristics of the granules. The impact of wet granulation on the kinetics and adsorption capacities of GIOCs was estimated using Basic Yellow 28 as model pollutant. Kinetic studies reveals that BY 28 adsorbed faster on PIOCs (k 1 = 7.40 × 10 −2 min −1) than on granular forms. Results best fitted the pseudo-first-order kinetic model. It was also found that the adsorption kinetic is directly related to the surface diffusion of prepared GIOCs. The adsorption equilibrium data were analyzed by the Langmuir and Freundlich models using non-linear regression. The best fit to the data was obtained with the Langmuir isotherm. The highest adsorption capacities (Q max = 514 mg/g; pH 6) for GIOCs were obtained for the finest forms (300-400 m).

While the magnetite stoichiometry (i.e., Fe(II)/Fe(III) ratio) has been extensively studied for the reductive transformation of chlorinated or nitroaromatic compounds, no work exists examining the influence of stoichiometry of magnetite on its binding properties. This study, for the first time, demonstrates that the stoichiometry strongly affects the capacity of magnetite to bind not only quinolone antibiotics such as nalidixic acid (NA) and flumequine (FLU), but also salicylic acid (SA), natural organic matter (humic acid, HA), and dissolved silicates. Fe(II)-amendment of nonstoichiometric magnetite (Fe(II)/Fe(III) = 0.40) led to similar sorbed amounts of NA, FLU, SA, silicates or HA as compared to the stoichiometric magnetite (i.e., Fe(II)/Fe(III) = 0.50). At any pH between 6 and 10, all magnetites exhibiting similar Fe(II)/Fe(III) ratio in the solid phase showed similar adsorption properties for NA or FLU. This enhancement in binding capability of magnetite for NA is still observ...

In this study, adsorption properties of cationized cellulose nanofibers (c-CNF) were examined for the removal of sulfate (SO 4 2-) ions from aqueous solutions under diverse experimental conditions. Nanofiber mats were fabricated through electrospinning and cationized with 3chloro-2-hydroxypropyl tri-methyl ammonium chloride (CHTAC). The resultant c-CNF with 0.134 mmol/g ammonium content showed the maximum adsorption capacity of 24.5 mg of SO 4 2per gram of sorbent using a Langmuir isotherm model. A pseudo-second order (PSO) kinetic model was fitted to the adsorption rate data, showing a faster adsorption rate of 0.0022 mg•g-1 min-1. The SEM (scanning electron microscope) micrographs revealed the average fiber diameter 280±10 nm with BET surface area of 5.04 m 2 /g analyzed through BET surface area and porosity analyzer. Fourier transform infrared (FTIR) spectroscopy confirmed the conversion of cellulose acetate (CA) to cellulose, and its subsequent cationization. Furthermore, the consequences of cationization were evaluated by Zeta potential and Thermogravimetric analysis (TGA).

We compared four types of ZIF-8 with varying sizes and shapes to determine their thermal-structural stability and derive appropriate thermal activation conditions and correlation between structural characteristics and adsorption properties. Under air, the ZIF-8 phase for all the samples was converted completely into the zinc oxide phase above ∼300°C , though thermalgravimetric analysis (TGA) indicated that the original structure was stable to ∼300−350°C. Longer exposures (∼30 d) suggested that thermal activation at ∼200°C was appropriate for the removal of guest and/or solvent molecules under air without structural damage. Despite no noticeable change in X-ray diffraction (XRD) patterns after activation at 250°C under air, the resulting BET surface areas and CO 2 adsorption amounts (at 1 bar and 30°C) of ZIF-8s were reduced to ∼44−54 and ∼72−87%, respectively, as compared to those of appropriately activated ZIF-8s. It appears that after the activation at 250°C under air, some Zn and N atoms were dissociated and converted to ZnOH and NOH, respectively, causing the partial structural damage of ZIF-8s.

The potential emergence of fluorescence-based techniques has propelled research towards developing probes that can sense trace metal ions specifically. Although luminescent metal-organic frameworks (MOFs) are well suited for this application, the role of building blocks towards detection is not fully understood. In this work, a systematic screening by varying number of Lewis basic (pyridyl-N atoms) sites is carried out in a series of isostructural, robust UiO-67 MOFs, and targeting a model metal ion-Fe 3 +. All the three fluorescent MOFs are seen to present quenching response towards Fe 3 + ions in water. However, UiO-67@N exhibits highly selective and sensitive response, whereas emission of both UiO-67 and UiO-67@NN is quenched by several metal ions. Detailed experimental and theoretical mechanistic investigation is carried out in addition to demonstration of UiO-67@N being able to sense trace amount of Fe 3 + ions in synthetic biological water sample. Further, UiO-67@N based mixed-matrix membrane (MMM) has been prepared and employed to mimic the real time Fe 3 + ions detection in water.

The potential of vinylferrocene Fc(CHCH 2) (1) as redox-active ene functional precursor for thiol−ene radical reaction has been successfully investigated for the first time. To this end, we initially studied thiol−ene model reactions of 1 with a variety of functionalized monothiols, including 2-mercaptoethanol, 1-thioglycerol, 3-mercaptopropionic acid, (3-mercaptopropyl)trimethoxysilane, 2-aminoethanethiol hydrochloride, dithiol 2,2′-(ethylenedioxy)diethanethiol, and the tetrafunctional thiol pentaerythritol tetrakis(3-mercaptopropionate) (PETMP). These reactions afforded the newly ferrocenyl-hydrothiolated smallmolecule models Fc(CH 2) 2 S(CH 2) 2 OH (2), Fc(CH 2) 2 S(CH 2) 2 COOH (3), Fc(CH 2) 2 S(CH 2)CH(OH)(CH 2)OH (4), Fc(CH 2) 2 S(CH 2) 3 Si(OMe) 3 (5), bimetallic Fc(CH 2) 2 S(CH 2) 2 O(CH 2) 2 O(CH 2) 2 S(CH 2) 2 Fc (6), and tetrametallic [Fc(CH 2) 2 S-(CH 2) 2 COOCH 2 ] 4 C (7) in relatively high yields. Furthermore, the hydrothiolation of the CC bond of vinylferrocene was successfully extended to the S−H-polyfunctionalized poly[(3-mercaptopropyl)methylsiloxane] (PMMS), which provided access to a new redox-active polysiloxane (Me 3 SiO){MeSi[(CH 2) 3 S(CH 2) 2 Fc]O} n (SiMe 3) (8) containing covalently attached electroactive ferrocenyl−thioether side groups. The thiol−vinylferrocene reactions have been initiated either thermally, in toluene solution with AIBN, or by UV light irradiation in THF in the presence of 2,2-dimethoxy-2-phenylacetophenone (DMPA) as photoinitiator. The outcomes of the hydrothiolation of vinylferrocene strongly depend on the thiol structure and on the experimental conditions. Thermogravimetric analysis (TGA) of 8 established that the incorporation of pendant thioether− ferrocenyl units within the Si−O−Si backbone significantly improves the thermal stability of polymethylsiloxane in comparison to the S−H-polyfunctionalized PMMS precursor. Electrochemical studies revealed that polysiloxane 8, containing sulfur-bridged ferrocenyl moieties attached along the main chain, exhibits unusual and excellent adsorption properties and spontaneously forms robust films on Pt and Au electrodes. The well-defined and persistent voltammetric waves of the surface-adsorbed 8 films display nearly ideal redox behavior and exhibit peak potential separations (ΔE peak) and full width at half-maximum (E fwhm) values close to those theoretically expected for stable, surface-immobilized electroactive layers.

We compared four types of ZIF-8 with varying sizes and shapes to determine their thermal-structural stability and derive appropriate thermal activation conditions and correlation between structural characteristics and adsorption properties. Under air, the ZIF-8 phase for all the samples was converted completely into the zinc oxide phase above ∼300°C , though thermalgravimetric analysis (TGA) indicated that the original structure was stable to ∼300−350°C. Longer exposures (∼30 d) suggested that thermal activation at ∼200°C was appropriate for the removal of guest and/or solvent molecules under air without structural damage. Despite no noticeable change in X-ray diffraction (XRD) patterns after activation at 250°C under air, the resulting BET surface areas and CO 2 adsorption amounts (at 1 bar and 30°C) of ZIF-8s were reduced to ∼44−54 and ∼72−87%, respectively, as compared to those of appropriately activated ZIF-8s. It appears that after the activation at 250°C under air, some Zn and N atoms were dissociated and converted to ZnOH and NOH, respectively, causing the partial structural damage of ZIF-8s.

Electro-synthesis of Metal-Organic Frameworks types of MIL-100(Fe) (MIL = Material Institute of Lavoisier) in ethanol: water (1: 1) with electrolyte TBATFB 0.1 M has been optimized by varying voltage (12, 13, 14 and 15 Volt) and temperature (room temperature, 40, 60 and 80 °C). The product showed light brown powder which upon activation becomes dark brown. Optimum condition achieved during use voltage of 15 Volts and at a temperature of 40 °C with 33% yield. The obtained material was characterized by XRD and compared to CCDC 640536 simulated patterns to confirm the phase purity of the product. As comparison hydrothermal and reflux method have been carried out. Characterization by FTIR has also undertaken to ensure the coordination between the metal cation (Fe3+) and the BTC ligand (BTC = 1,3,5-Benzene Tri Carboxylate). Meanwhile pore analysis using SAA confirmed that MIL-100(Fe) obtained by electrolysis method has a BET surface area reached till 569.191 m²/g with a total pore volume...

The hybrid frameworks M 2 dobdc (dobdc 4-= 2,5-dioxidoterephthalate, M 2+ = Mg 2+ , Co 2+ , Ni 2+ , Cu 2+ and Zn 2+), commonly known as CPO-27 or MOF-74, are shown to be active catalysts in base-catalyzed reactions such as Knoevenagel condensations or Michael additions. Rather than utilizing Nfunctionalized linkers as a source of basicity, the intrinsic basicity of these materials arises from the presence of the phenolate oxygen atoms coordinated to the metal ions. The overall activity is due a complex interplay of the basic properties of these structural phenolates and the reactant binding characteristics of the coordinatively unsaturated sites. The nature of the active site and the order of activity among the different M 2 dobdc materials were rationalized via computational efforts; the most active material, both in theory and experiment, is the Ni-containing variant. The basicity of Ni 2 dobdc was experimentally proven by chemisorption of pyrrole and observation by IR spectroscopy.

Novel morphologies of activated carbons such as monolith, beads and fiber cloth can effectively capture organic vapors from industrial sources. These adsorbent materials are also unique because they can undergo direct electrothermal regeneration to recover the adsorbed organic vapors for potential re-use. This investigation compares and contrasts the properties of these adsorbents when using electrothermal-swing adsorption. The adsorption systems consisted of an organic vapor generation system, an electrothermal-swing adsorption vessel, a gas detection unit, and a data acquisition and control system. The activated carbon monolith (ACM) had the lowest pressure drop, highest permeability, highest electrical resistivity and lowest cost as compared to the activated carbon beads (ACB) and the activated carbon fiber cloth (ACFC). ACB had the largest throughput ratio and lowest length of unused bed as compared to the other adsorbents. However, ACFC had the largest adsorption capacity for toluene when compared to ACM and ACB. ACFC was also faster to regenerate and had a larger concentration factor than ACM and ACB. These results describe relevant physical, electrical, adsorption and cost properties for specific morphologies of the adsorbents to more effectively capture and recover organic vapors from gas streams.

We compared four types of ZIF-8 with varying sizes and shapes to determine their thermal-structural stability and derive appropriate thermal activation conditions and correlation between structural characteristics and adsorption properties. Under air, the ZIF-8 phase for all the samples was converted completely into the zinc oxide phase above ∼300°C , though thermalgravimetric analysis (TGA) indicated that the original structure was stable to ∼300−350°C. Longer exposures (∼30 d) suggested that thermal activation at ∼200°C was appropriate for the removal of guest and/or solvent molecules under air without structural damage. Despite no noticeable change in X-ray diffraction (XRD) patterns after activation at 250°C under air, the resulting BET surface areas and CO 2 adsorption amounts (at 1 bar and 30°C) of ZIF-8s were reduced to ∼44−54 and ∼72−87%, respectively, as compared to those of appropriately activated ZIF-8s. It appears that after the activation at 250°C under air, some Zn and N atoms were dissociated and converted to ZnOH and NOH, respectively, causing the partial structural damage of ZIF-8s.

In this study, adsorption properties of cationized cellulose nanofibers (c-CNF) were examined for the removal of sulfate (SO 4 2-) ions from aqueous solutions under diverse experimental conditions. Nanofiber mats were fabricated through electrospinning and cationized with 3chloro-2-hydroxypropyl tri-methyl ammonium chloride (CHTAC). The resultant c-CNF with 0.134 mmol/g ammonium content showed the maximum adsorption capacity of 24.5 mg of SO 4 2per gram of sorbent using a Langmuir isotherm model. A pseudo-second order (PSO) kinetic model was fitted to the adsorption rate data, showing a faster adsorption rate of 0.0022 mg•g-1 min-1. The SEM (scanning electron microscope) micrographs revealed the average fiber diameter 280±10 nm with BET surface area of 5.04 m 2 /g analyzed through BET surface area and porosity analyzer. Fourier transform infrared (FTIR) spectroscopy confirmed the conversion of cellulose acetate (CA) to cellulose, and its subsequent cationization. Furthermore, the consequences of cationization were evaluated by Zeta potential and Thermogravimetric analysis (TGA).

The aim of the study was to prepare resistant and spherical inorgano-organo pillared clays (GIOCs) granules for wastewater treatment using a new and simple method named high-shear wet granulation. To optimize the preparation method, the effects of the main process parameters, such as binder concentration, liquid to solid ratio and impeller speed on granule properties (size distribution, friability and disintegration tests) were investigated. Experimental results showed that the granulation of inorgano-organo pillared clays (PIOCs) with industrial Silicone is significantly influenced by the binder concentration, the liquid to solid ratio (H %) and the impeller speed (N). A modification of these parameters can greatly alter the characteristics of the granules. The impact of wet granulation on the kinetics and adsorption capacities of GIOCs was estimated using Basic Yellow 28 as model pollutant. Kinetic studies reveals that BY 28 adsorbed faster on PIOCs (k 1 = 7.40 × 10 −2 min −1) than on granular forms. Results best fitted the pseudo-first-order kinetic model. It was also found that the adsorption kinetic is directly related to the surface diffusion of prepared GIOCs. The adsorption equilibrium data were analyzed by the Langmuir and Freundlich models using non-linear regression. The best fit to the data was obtained with the Langmuir isotherm. The highest adsorption capacities (Q max = 514 mg/g; pH 6) for GIOCs were obtained for the finest forms (300-400 m).

We compared four types of ZIF-8 with varying sizes and shapes to determine their thermal-structural stability and derive appropriate thermal activation conditions and correlation between structural characteristics and adsorption properties. Under air, the ZIF-8 phase for all the samples was converted completely into the zinc oxide phase above ∼300°C , though thermalgravimetric analysis (TGA) indicated that the original structure was stable to ∼300−350°C. Longer exposures (∼30 d) suggested that thermal activation at ∼200°C was appropriate for the removal of guest and/or solvent molecules under air without structural damage. Despite no noticeable change in X-ray diffraction (XRD) patterns after activation at 250°C under air, the resulting BET surface areas and CO 2 adsorption amounts (at 1 bar and 30°C) of ZIF-8s were reduced to ∼44−54 and ∼72−87%, respectively, as compared to those of appropriately activated ZIF-8s. It appears that after the activation at 250°C under air, some Zn and N atoms were dissociated and converted to ZnOH and NOH, respectively, causing the partial structural damage of ZIF-8s.

Sciences. She is an expert in transmission electron microscopy and develops hybrid nanomaterials for photovoltaic applications. She also applies nanomaterials to water remediation. She has 80 publications, 2 patents, 4 book chapters, 1 book, and an H-index of 22. She is also CEO of PRO-1 NANOSolutions, a startup company that applies nanotechnology to water remediation and nanomedicine.

Hydrogen adsorption data on as-grown and heat-treated single walled carbon nanotubes (SWNTs) obtained by a volumetric procedure using a Quantachrome Autosorb-1 equipment are presented. The amounts of hydrogen adsorbed at atmospheric pressure reach approximately 0.01 wt.% at 298 K and 1 wt.% at 77 K. The isosteric heat of adsorption has been calculated for both samples from H 2 equilibrium adsorption data at three temperatures, having initial values of 7.42 and 7.75 kJ mol À1. Studies in porous structure by N 2 adsorption and density measurements in helium pycnometer are reported.

The adsorption of zinc, cadmium and mercury ions from aqueous solutions on an activated carbon cloth was studied as a function of their concentrations and solution pH. For that purpose, pertinent adsorption isotherm data was collected at different pH values. The amount of adsorbed zinc and cadmium ions increases while the amount of adsorbed mercury remains constant with an increase in the equilibrium pH of the solution. The adsorption mechanisms of metal ions on activated carbon cloth are discussed. Under the conditions investigated, these primarily involve adsorption of monovalent cations (Zn and Cd) or precipitation of metal hydroxides (Cd and Hg) on the activated carbon cloth tested.

Novel morphologies of activated carbons such as monolith, beads and fiber cloth can effectively capture organic vapors from industrial sources. These adsorbent materials are also unique because they can undergo direct electrothermal regeneration to recover the adsorbed organic vapors for potential re-use. This investigation compares and contrasts the properties of these adsorbents when using electrothermal-swing adsorption. The adsorption systems consisted of an organic vapor generation system, an electrothermal-swing adsorption vessel, a gas detection unit, and a data acquisition and control system. The activated carbon monolith (ACM) had the lowest pressure drop, highest permeability, highest electrical resistivity and lowest cost as compared to the activated carbon beads (ACB) and the activated carbon fiber cloth (ACFC). ACB had the largest throughput ratio and lowest length of unused bed as compared to the other adsorbents. However, ACFC had the largest adsorption capacity for toluene when compared to ACM and ACB. ACFC was also faster to regenerate and had a larger concentration factor than ACM and ACB. These results describe relevant physical, electrical, adsorption and cost properties for specific morphologies of the adsorbents to more effectively capture and recover organic vapors from gas streams.

Novel morphologies of activated carbons such as monolith, beads and fiber cloth can effectively capture organic vapors from industrial sources. These adsorbent materials are also unique because they can undergo direct electrothermal regeneration to recover the adsorbed organic vapors for potential re-use. This investigation compares and contrasts the properties of these adsorbents when using electrothermal-swing adsorption. The adsorption systems consisted of an organic vapor generation system, an electrothermal-swing adsorption vessel, a gas detection unit, and a data acquisition and control system. The activated carbon monolith (ACM) had the lowest pressure drop, highest permeability, highest electrical resistivity and lowest cost as compared to the activated carbon beads (ACB) and the activated carbon fiber cloth (ACFC). ACB had the largest throughput ratio and lowest length of unused bed as compared to the other adsorbents. However, ACFC had the largest adsorption capacity for toluene when compared to ACM and ACB. ACFC was also faster to regenerate and had a larger concentration factor than ACM and ACB. These results describe relevant physical, electrical, adsorption and cost properties for specific morphologies of the adsorbents to more effectively capture and recover organic vapors from gas streams.

Novel morphologies of activated carbons such as monolith, beads and fiber cloth can effectively capture organic vapors from industrial sources. These adsorbent materials are also unique because they can undergo direct electrothermal regeneration to recover the adsorbed organic vapors for potential re-use. This investigation compares and contrasts the properties of these adsorbents when using electrothermal-swing adsorption. The adsorption systems consisted of an organic vapor generation system, an electrothermal-swing adsorption vessel, a gas detection unit, and a data acquisition and control system. The activated carbon monolith (ACM) had the lowest pressure drop, highest permeability, highest electrical resistivity and lowest cost as compared to the activated carbon beads (ACB) and the activated carbon fiber cloth (ACFC). ACB had the largest throughput ratio and lowest length of unused bed as compared to the other adsorbents. However, ACFC had the largest adsorption capacity for toluene when compared to ACM and ACB. ACFC was also faster to regenerate and had a larger concentration factor than ACM and ACB. These results describe relevant physical, electrical, adsorption and cost properties for specific morphologies of the adsorbents to more effectively capture and recover organic vapors from gas streams.