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Adsorption Behavior (adsorption + behavior)
Kinds of Adsorption Behavior Selected AbstractsAdsorption Behavior of Asymmetrical Triblock Copolymers at the Solid-Liquid Interface by Monte Carlo SimulationMACROMOLECULAR THEORY AND SIMULATIONS, Issue 8 2004Changjun Peng Abstract Summary: Monte Carlo simulation on a simple lattice model has been used to study the adsorption of asymmetrical triblock copolymers from a non-selective solvent at the solid-liquid interface. The size distributions of train, loop and tail configurations for those copolymers are obtained as well as other details of the adsorption layer microstructure. Also the influence of adsorption energy and the role of molecular symmetry are investigated. A segment-density profile, the adsorption amount, the surface coverage, and the adsorption layer thickness have been determined. Finally, it is shown that the adsorption behavior of an asymmetrical copolymer can be predicted from the symmetrical copolymer. Size distributions of the tail configuration for A8,kB20Ak. [source] Adsorption Behavior of Potassium Ion on Planting MaterialsCHINESE JOURNAL OF CHEMISTRY, Issue 9 2007Dechprasitthichokea Paunpassanan Abstract Characterization of planting materials used as adsorbent has been studied in order to compare potassium ion adsorption on two types of planting materials, which are a fired planting material (FPM) made from a mixture of 4 kinds of wastes (bottom ash, flue gas desulfurization (FGD) gypsum, paddy soil and sawdust) formed and fired at 850 °C and the commercial planting material called "hydroball" (HDB) bought from Jatujak market, Bangkok. The physical characteristics of both types of planting materials indicate that the FPM has a larger specific surface area than the HDB. The factors affecting potassium adsorption on both the planting materials such as an equilibration time and some solid/solution ratios were investigated. The suitable equilibration time for the adsorption to reach an equilibrium on the FPM and HDB is one and two hours, respectively. The highest amounts of potassium ion adsorbed on both the planting materials were obtained when the solid/solution ratio was 1:15. The adsorption behavior on both the planting materials tends to correspond with the Freundlich isotherm. [source] Optimization of activated carbon-based decontamination of fish oil by response surface methodologyEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 7 2007Åge Oterhals Abstract The effect of activated carbon (AC) adsorption on the reduction of persistent organic pollutants (POP) in fish oil was studied based on response surface methodology at a 5-g/kg AC inclusion level. Pretreatment of the oil by alkali refining and bleaching increased the POP levels. The tested process variables (contact time and temperature) affected the AC adsorption rate and significant first- and second-order response models could be established. Polychlorinated dibenzo- p -dioxins and dibenzofurans (PCDD/F) showed a very rapid adsorption behavior and the concentration and toxic equivalent (TEQ) level could be reduced by 99%. Adsorption of dioxin-like polychlorinated biphenyls (DL-PCB) was less effective and depended on ortho substitution, i.e. non- ortho PCB were adsorbed more effectively than mono- ortho PCB with a maximum of 87 and 21% reduction, respectively, corresponding to a DL-PCB-TEQ reduction of 73%. A common optimum for both PCDD/F and DL-PCB adsorption could not be identified. AC treatment had no effect on the level of polybrominated diphenyl ether flame retardants. The differences in adsorption patterns may be explained based on molecular conformation. No change in oil quality could be observed based on oxidation parameters. Compliance with present PCDD/F and DL-PCB legislation levels in fish oil can be achieved based on AC adsorption. [source] Nanotubes: A Closer Look Inside Nanotubes: Pore Structure Evaluation of Anodized Alumina Templated Carbon Nanotube Membranes Through Adsorption and Permeability Studies (Adv. Funct.ADVANCED FUNCTIONAL MATERIALS, Issue 15 2010Mater. In the "heart" of nanotubes. The internal morphology of carbon nanotubes (CNTs) is assessed by investigating the permeability and adsorption behavior of selected gases and vapors through CNTs that have been grown inside the channels of an anodized alumina template, as presented by G. E. Romanos, G. N. Karanikolos, and co-workers on page 2500. The cover illustrates template-free aligned CNTs in a heart-like configuration. Internal restrictions, surface roughness, hollow space narrowing, and other inside-tubes characteristics are determined that are crucial in CNT storage and flow-through applications. [source] Preparation of bimodal porous copolymer containing ,-cyclodextrin and its inclusion adsorption behaviorJOURNAL OF APPLIED POLYMER SCIENCE, Issue 4 2010Zhao-Yang Sun Abstract A novel insoluble bimodal porous polymer containing ,-cyclodextrin (,-CD) was prepared to adsorb aromatic amine compound. The process involved copolymerization of styrene and methyl methacrylate with a maleic acid derivative of ,-CD, subsequently, above formed copolymer was foamed by supercritical CO2. The chemical properties and physical structure of obtained copolymer was analyzed using Fourier transform infrared spectra, Thermal gravimetric analysis, X-ray diffraction, scanning electron microscope, and N2 adsorption techniques. The inclusion adsorption of aromatic amine compounds on ,-CD copolymer was carried out in a batch system. The quantities of aromatic amine compounds adsorbed on ,-CD copolymer reached equilibrium within 60 min. The adsorption kinetic could be fitted to a pseudo-second-order kinetic equation, and the linear correlation coefficients varied from 0.9828 to 0.9935. With the influence of molecular structure and hydrophobicity of the aromatic amine compound, the sequence of quantity of aromatic amine compounds adsorbed on ,-CD copolymer is p -toluidine > aniline > benzidine > o -toluidine. The adsorption equilibrium data of aromatic amine compound adsorbed on ,-CD copolymer were fitted to Freundlich and Langmuir models, respectively. The linear correlation coefficients of Langmuir model varied from 0.9516 to 0.9940, and the linear correlation coefficients of Freundlich varied from 0.9752 to 0.9976. It is concluded that Freundlich model fits better than Langmuir model, because the adsorption of aromatic amine compound on ,-CD copolymer is a chemical process. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source] Influence of the matrix porosity on the synthesis and adsorption behavior of dithiocarbamate styrenic resins toward zinc(II) and cadmium(II) ionsJOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2010Priscila A. da Costa Abstract The dependence of the adsorption behavior toward Zn2+ and Cd2+ on the synthesis conditions of dithiocarbamate styrenic resins was investigated. We synthesized styrene,divinylbenzene copolymers with different kinds of porous structures by varying the divinylbenzene (DVB)-to-styrene ratio and the dilution degree of the monomers with n -heptane. The porous structure of these materials was characterized. The introduction of the dithiocarbamate moiety on the copolymers followed a synthetic pathway based on the nitration reaction, reduction of the nitro group to the amino one, and finally, the addition of the amino group to CS2. All of the synthesis steps were monitored by Fourier transform infrared spectroscopy. Only the addition reaction to CS2 was greatly influenced by the copolymer porosity. The effect of the dilution degree on the reaction extension was more pronounced than the effect of the DVB content. The more porous materials with higher dithiocarbamate contents adsorbed a higher amount of ions in a faster way, with Zn2+ being preferable over Cd2+ ions. The difference between the Zn2+ and Cd2+ adsorption rates was enhanced with the copolymer porosity, and also enhanced was the difference between the amounts of ions adsorbed by the copolymer; this suggested that the selectivity toward these ions could be controlled by the copolymer porous structure. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source] Preparation and adsorption behavior of a cellulose-based, mixed-mode adsorbent with a benzylamine ligand for expanded bed applicationsJOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2008Dong Gao Abstract A novel mixed-mode expanded bed adsorbent with anion-exchange properties was explored with benzylamine as the functional ligand. The cellulose composite matrix, densified with stainless steel powder, was prepared with the method of water-in-oil suspension thermal regeneration. High activation levels of the cellulose matrix were obtained with allyl bromide because of the relative inertness of the allyl group under the conditions of the activation reaction. After the formation of the bromohydrin with N -bromosuccinimide and coupling with benzylamine, the activated matrix was derived to function as a mixed-mode adsorbent containing both hydrophobic and ionic groups. The protein adsorption capacity was investigated with bovine serum albumin as a model protein. The results indicated that the prepared adsorbent could bind bovine serum albumin with a high adsorption capacity, and it showed salt tolerance. Effective desorption was achieved by a pH adjustment across the isoelectric point of the protein. The interactions between the cell and adsorbent were studied, and the bioadhesion was shielded by the adjustment of the salt concentration above 0.1M. Stable fluidization in the expanded bed was obtained even in a 2% (dry weight) yeast suspension. The direct capture of target proteins from a biomass-containing feedstock without extra dilution steps could be expected with the mixed-mode adsorbent prepared in this work, and this would be especially appropriate for expanded bed adsorption applications. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Computational screening of biomolecular adsorption and self-assembly on nanoscale surfacesJOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 7 2010Hendrik Heinz Abstract The quantification of binding properties of ions, surfactants, biopolymers, and other macromolecules to nanometer-scale surfaces is often difficult experimentally and a recurring challenge in molecular simulation. A simple and computationally efficient method is introduced to compute quantitatively the energy of adsorption of solute molecules on a given surface. Highly accurate summation of Coulomb energies as well as precise control of temperature and pressure is required to extract the small energy differences in complex environments characterized by a large total energy. The method involves the simulation of four systems, the surface-solute,solvent system, the solute,solvent system, the solvent system, and the surface-solvent system under consideration of equal molecular volumes of each component under NVT conditions using standard molecular dynamics or Monte Carlo algorithms. Particularly in chemically detailed systems including thousands of explicit solvent molecules and specific concentrations of ions and organic solutes, the method takes into account the effect of complex nonbond interactions and rotational isomeric states on the adsorption behavior on surfaces. As a numerical example, the adsorption of a dodecapeptide on the Au {111} and mica {001} surfaces is described in aqueous solution. © 2009 Wiley Periodicals, Inc. J Comput Chem, 2010 [source] Simulation of binary mixture adsorption of methane and CO2 at supercritical conditions in carbonsAICHE JOURNAL, Issue 3 2006Yohanes Kurniawan Abstract Knowledge of the adsorption behavior of coal-bed gases, mainly under supercritical high-pressure conditions, is important for optimum design of production processes to recover coal-bed methane and to sequester CO2 in coal-beds. Here, we compare the two most rigorous adsorption methods based on the statistical mechanics approach, which are Density Functional Theory (DFT) and Grand Canonical Monte Carlo (GCMC) simulation, for single and binary mixtures of methane and carbon dioxide in slit-shaped pores ranging from around 0.75 to 7.5 nm in width, for pressure up to 300 bar, and temperature range of 308-348 K, as a preliminary study for the CO2 sequestration problem. For single component adsorption, the isotherms generated by DFT, especially for CO2, do not match well with GCMC calculation, and simulation is subsequently pursued here to investigate the binary mixture adsorption. For binary adsorption, upon increase of pressure, the selectivity of carbon dioxide relative to methane in a binary mixture initially increases to a maximum value, and subsequently drops before attaining a constant value at pressures higher than 300 bar. While the selectivity increases with temperature in the initial pressure-sensitive region, the constant high-pressure value is also temperature independent. Optimum selectivity at any temperature is attained at a pressure of 90-100 bar at low bulk mole fraction of CO2, decreasing to approximately 35 bar at high bulk mole fractions. © 2005 American Institute of Chemical Engineers AIChE J, 2006 [source] New ,-amino phenylalanine tetrazole ligand for immobilized metal affinity chromatography of proteinsJOURNAL OF SEPARATION SCIENCE, JSS, Issue 16-17 2008Genhu Lei Abstract A new chelating compound has been developed for use in the immobilized metal affinity chromatographic (IMAC) separation of proteins. The bidentate ligand, ,-amino phenylalanine tetrazole, 4, was synthesized via a five-step synthesis from N -fluorenylmethoxycarbonyl phenylalanine and then immobilized onto silica through the epoxide coupling procedure. The binding behavior of the resulting IMAC sorbent, following chelation with Zn2+ to a density of 183 ,mol Zn2+ ions/g silica, was characterized by the retention of proteins in the pH range of 5.0,8.0, and by the adsorption behavior of lysozyme with frontal chromatography at pH 6.0 and 8.0. The prepared column showed the separation ability to four test proteins and the retention time of these proteins increased with an increase in pH. From the derived isotherms, the adsorption capacity, qm, for the binding of lysozyme to immobilized Zn2+ -,-amino phenylalanine tetrazole,silica was found to be 1.21 ,mol/g at pH 6.0 and 1.20 ,mol/g sorbent at pH 8.0, respectively, whilst the dissociation constants KD at these pH values were 5.22×10,6 and 3.49×10,6 M, respectively, indicating that the lysozyme was retained more stable under alkaline conditions, although the binding capacity in terms of micromole protein per gram sorbent remained essentially unchanged. [source] Comparative Study of the Solid,Liquid Interface Behavior of Amphiphilic Block and Block-Like CopolymersMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 3-4 2009Nikolay Bulychev Abstract Amphiphilic block and "block-like" copolymers based on poly(isobornyl acrylate) and poly(acrylic acid) were used as stabilizers for hydrophilic (titanium dioxide) and hydrophobic (copper phthalocyanine) pigments. As reflected by the dispersion stabilities and electrokinetic sonic amplitude (ESA) measurements, the molecular architecture of the copolymer is of great importance for its interaction with the pigment surface. It was observed that irrespective of polymer composition, block-like copolymers exhibit lower stabilization ability and quite different adsorption behavior in comparison to block copolymers with sharp block boundaries. Models for the adsorption behavior of both block and block-like copolymers are proposed. [source] Adsorption Behavior of Asymmetrical Triblock Copolymers at the Solid-Liquid Interface by Monte Carlo SimulationMACROMOLECULAR THEORY AND SIMULATIONS, Issue 8 2004Changjun Peng Abstract Summary: Monte Carlo simulation on a simple lattice model has been used to study the adsorption of asymmetrical triblock copolymers from a non-selective solvent at the solid-liquid interface. The size distributions of train, loop and tail configurations for those copolymers are obtained as well as other details of the adsorption layer microstructure. Also the influence of adsorption energy and the role of molecular symmetry are investigated. A segment-density profile, the adsorption amount, the surface coverage, and the adsorption layer thickness have been determined. Finally, it is shown that the adsorption behavior of an asymmetrical copolymer can be predicted from the symmetrical copolymer. Size distributions of the tail configuration for A8,kB20Ak. [source] Adsorption of 6-mercaptopurine and 6-mercaptopurine-ribosideon silver colloid: A pH-dependent surface-enhanced Raman spectroscopy and density functional theory study.BIOPOLYMERS, Issue 6 2005Abstract Surface-enhanced Raman spectroscopy (SERS) has been applied to characterize the interaction of 6-mercaptopurine-ribose (6MPR), an active drug used in chemotherapy of acute lymphoblastic leukemia, with a model biological substrate at therapeutic concentrations and as function of the pH value. Therefore, a detailed vibrational analysis of crystalline and solvated (6MPR) based on Density Functional Theory (DFT) calculations of the thion and thiol tautomers has been performed. 6MPR adopts the thion tautomeric form in the polycrystalline state. The SERS spectra of 6MPR and 6-mercaptopurine (6MP) recorded on silver colloid provided evidence that the ribose derivative shows different adsorption behavior compared with the free base. Under acidic conditions, the adsorption of 6MPR on the metal surface via the N7 and possibly S atoms was proposed to have a perpendicular orientation, while 6MP is probably adsorbed through the N9 and N3 atoms. Under basic conditions both molecules are adsorbed through the N1 and possibly S atoms, but 6MP has a more tilted orientation on the silver colloidal surface while 6MPR adopts a perpendicular orientation. The reorientation of the 6MPR molecule on the surface starts at pH 8 while in the case of 6MP the reorientation starts around pH 6. Under basic conditions, the presence of the anionic molecular species for both molecules is suggested. The deprotonation of 6MP is completed at pH 8 while the deprotonation of the riboside is finished at pH 10. For low drug concentrations under neutral conditions and for pH values 8 and 9, 6MPR interacts with the substrate through both N7 and N1 atoms, possibly forming two differently adsorbed species, while for 6MP only one species adsorbed via N1 was evidenced. © 2005 Wiley Periodicals, Inc. Biopolymers 78: 298,310, 2005 This article was originally published online as an accepted preprint. The "Published Online" date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com [source] Purification of cell culture-derived modified vaccinia ankara virus by pseudo-affinity membrane adsorbers and hydrophobic interaction chromatographyBIOTECHNOLOGY & BIOENGINEERING, Issue 2 2010Michael W. Wolff Abstract A purification scheme for cell culture-derived smallpox vaccines based on an orthogonal downstream process of pseudo-affinity membrane adsorbers (MA) and hydrophobic interaction chromatography (HIC) was investigated. The applied pseudo-affinity chromatography, based on reinforced sulfated cellulose and heparin-MA, was optimized in terms of dynamic binding capacities, virus yield and process productivity. HIC was introduced as a subsequent method to further reduce the DNA content. Therefore, two screens were undertaken. First, several HIC ligands were screened for different adsorption behavior between virus particles and DNA. Second, elution from pseudo-affinity MA and adsorption of virus particles onto the hydrophobic interaction matrix was explored by a series of buffers using different ammonium sulfate concentrations. Eventually, variations between different cultivation batches and buffer conditions were investigated. The most promising combination, a sulfated cellulose membrane adsorber with subsequent phenyl HIC resulted in overall virus particle recoveries ranging from 76% to 55% depending on the product batch and applied conditions. On average, 61% of the recovered virus particles were infective within all tested purification schemes and conditions. Final DNA content varied from 0.01% to 2.5% of the starting material and the level of contaminating protein was below 0.1%. Biotechnol. Bioeng. 2010;107: 312,320. © 2010 Wiley Periodicals, Inc. [source] Surface-Treated Activated Carbon for Removal of Aromatic Compounds from WaterCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 5 2009B. Li Abstract Modifications of commercial activated carbons by chemical treatment with HNO3 or HCl and HF and the adsorption behavior of simple aromatic compounds (aniline, pyridine, phenol, and benzene) on activated carbon and modified activated carbon were investigated. The results show that the textural properties change a little after these modifications, but the surface acidity (mainly oxygen-containing groups) of activated carbon modified with HNO3 increases greatly. The effect of ash of activated carbon on adsorption of the organic compounds mentioned above is insignificant. However, addition of surface acidity (mainly surface oxygen-containing groups) decreases the adsorption capacity of compounds significantly. The adsorption uptake of compounds on activated carbon with oxidation of HNO3 is low possibly due to dispersive interaction, water cluster blocking, or competition between water and compounds adsorbed on activated carbon's surface because of hydrophilic increase of the activated carbon surface. The solubility of aromatic compounds in water has an important effect on the adsorption capacity of activated carbon. qm and KL (Langmuir adsorption parameters) for the aromatic compounds vary similarly. [source] Improving MCM-41 as a Nitrosamines Trap through a One-Pot SynthesisCHEMISTRY - AN ASIAN JOURNAL, Issue 8 2007Jia Hui Xu Abstract Copper oxide was incorporated into MCM-41 by a one-pot synthesis under acidic conditions to prepare a new mesoporous nitrosamines trap for protection of the environment. The resulting composites were characterized by XRD, N2 adsorption,desorption, and H2 temperature-programmed reduction techniques, and their adsorption capabilities were assessed in the gaseous adsorption of N -nitrosopyrrolidine (NPYR). The adsorption isotherms were consistent with the Freundlich equation. The copper salt was deposited onto MCM-41 during the evaporation stage and was fixed on the host in the calcination process that followed. MCM-41 was able to capture NPYR in air below 373,K but not at 453,K. Loading of copper oxide on MCM-41 greatly improved its adsorption capability at elevated temperatures. The influence of the incorporation of copper into MCM-41 samples and the adsorption behavior of these samples are discussed in detail. [source] New Microporous Materials for Acetylene Storage and C2H2/CO2 Separation: Insights from Molecular SimulationsCHEMPHYSCHEM, Issue 10 2010Michael Fischer Abstract Force-field based grand-canonical Monte Carlo simulations are used to investigate the acetylene and carbon dioxide uptake capacity, as well as the C2H2/CO2 adsorption selectivity of three novel microporous materials: Magnesium formate, Cu3(btc)2, and cucurbit[6]uril. Because no comparable computational studies of acetylene adsorption have been reported so far, the study focuses on systems for which experimental data are available to permit a thorough validation of the simulation results. The results for magnesium formate are in excellent agreement with experiment. The simulation predicts a high selectivity for acetylene over CO2, which can be understood from a detailed analysis of the structural features that determine the affinity of Mg-formate towards C2H2. For Cu3(btc)2, preliminary calculations reveal the necessity to include the interaction of the sorbate molecules with the unsaturated metal sites, which is done by means of a parameter adjustment based on ab-initio calculations. In spite of the high C2H2 storage capacity, the C2H2/CO2 selectivity of this material is very modest. The simulation results for the porous organic crystal cucurbit[6]uril show that the adsorption characteristics that have been observed experimentally, particularly the very high isosteric heat of adsorption, cannot be understood when an ideal structure is assumed. It is postulated that structural imperfections play a key role in determining the C2H2 adsorption behavior of this material, and this proposition is supported by additional calculations. [source] Adsorption of 4,4,-thiobisbenzenethiol on silver surfaces: surface-enhanced Raman scattering studyJOURNAL OF RAMAN SPECTROSCOPY, Issue 3 2008Yuling Wang Abstract Adsorption of 4,4,-thiobisbenzenethiol (4,4,-TBBT) on a colloidal silver surface and a roughened silver electrode surface was investigated by means of surface-enhanced Raman scattering (SERS) for the first time, which indicates that 4,4,-TBBT is chemisorbed on the colloidal silver surface as dithiolates by losing two H-atoms of the SH bond, while as monothiolates on the roughened silver electrode. The different orientations of the molecules on both silver surfaces indicate the different adsorption behaviors of 4,4,-TBBT in the two systems. It is inferred from the SERS signal that the two aromatic rings in 4,4,-TBBT molecule are parallel to the colloidal silver surface as seen from the disappearance of ,CH band (3054 cm,1), which is a vibrational mode to be used to determine the orientation of a molecule on metals according to the surface selection rule, while on the roughened silver electrode surface they are tilted to the surface as seen from the enhanced signal of ,CH. The orientation of the C-S bond is tilted with respect to the silver surface in both cases as inferred from the strong enhancement of the ,CS. SERS spectra of 4,4,-TBBT on the roughened silver electrode with different applied potentials reveal that the enhancement of 4,4,-TBBT on the roughened silver electrode surface may be related to the chemical mechanism (CM). More importantly, the adsorption of 4,4,-TBBT on the silver electrode is expected to be useful to covalently adsorb metal nanoparticles through the free SH bond to form two- or three- dimensional nanostructures. Copyright © 2007 John Wiley & Sons, Ltd. [source] Synthesis and characterization of dual-responsive micrometer-sized core-shell composite polymer particlesPOLYMERS FOR ADVANCED TECHNOLOGIES, Issue 3 2008M. Ashraful Alam Abstract Dual-responsive micrometer-sized core-shell composite polymer particles were prepared by dispersion polymerization followed by seeded copolymerization. Polystyrene (PS) particles prepared by dispersion polymerization were used as core particles. N-isopropyl acrylamide (NIPAM) and methacrylic acid (MAA) were used to induce dual-responsive that is thermo- and pH-responsive properties in the shell layer of composite polymer particles, prepared by seeded copolymerization with PS core particles. Temperature- and pH-dependent adsorption behaviors of some macromolecules on composite polymer particles indicate that produced composite polymer particles exhibit dual-responsive surface properties. Copyright © 2007 John Wiley & Sons, Ltd. [source] Adsorption properties of microwave synthesized inorgano,organo montmorilloniteASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 2 2010Miray Emreol Abstract The aim of this study is to determine the adsorption properties of microwave synthesized inorgano,organo montmorillonites. Microwave irradiation is preferred because of its low time and energy consumption properties, forming an advantage in industrial applications. In addition to the intercalation of Keggin and hexadecyltrimethylammonium (HDTMA+) cations, the aging process of pillaring solution was also carried out through the microwave irradiation. Both inorgano clays, namely the parents, and their inorgano,organo derivatives, were prepared by using the same amounts of aluminum by keeping the OH,/Al3+ and Al3+/clay ratios constant. The HDTMA+/clay ratio was changed in inorgano-organo clays (IOCs) during the preparation. The effects of these parameters on the surface properties and adsorption behaviors of the samples were investigated by conducting X-ray diffraction (XRD), Fourier transform infrared (FTIR) and simultaneous thermal analyses (STA), as well as batch adsorption experiments, in which phenol was used as a model pollutant. The results of XRD analyses reveal that the intercalation is successfully achieved. The existence of the Keggin and HDTMA+ cations was observed in FTIR spectra of the samples. Through the STA, it was determined that the existence of organic layer increases the dehydroxylation temperature and the thermal behavior of inorgano-organo montmorillonites strongly depends on the structure of the parent clay. An increase in the adsorption efficiencies with increasing HDTMA+/clay ratio was observed, except with the highest ratio. The behavior of this sample was explained by the formation of the second HDTMA+ layer leading to the hydrophilic surface formation. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd. [source] The investigation of protein adsorption behaviors on different functionalized polymers filmsBIOTECHNOLOGY JOURNAL, Issue 6 2007Zhi-Hong Zhang Dr. Abstract The adsorption of BSA and fibrinogen onto plasma-polymerized di-(ethylene glycol) vinyl ether, allylamine, and maleic anhydride films were investigated in detail by surface plasmon resonance spectroscopy (SPR). The chemical properties of the plasma polymers were initially determined by the plasma deposition conditions during the generation procedure. The analysis of the chemical structure of the films and the refractive index of plasma polymers in aqueous solution was carried out using Fourier transform infrared spectroscopy and waveguide mode spectroscopy, respectively. Using water contact angle measurement, the surface wettability of plasma polymers was also characterized. These properties have a critical influence on the behavior of protein adsorption on the surface of the plasma polymers. Protein adsorption was found to depend not only on the types of functionalized groups, but also on the plasma polymer thickness since the protein molecules penetrate into the plasma polymer network bulk. According to the size of protein molecules in aqueous solution and the amount of adsorbed proteins observed by SPR, the conformational changes of proteins could be deduced. [source] | ||||||||||||||||