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Poly(ethylene glycol dimethacrylate-2-vinyl pyridine)-TiO2 [poly (EGDMA-2-VP)] - TiO2 microbeads were synthesized by suspension polymerization method for photocatalytic decolorization of textile dyes from aqueous solution. The synthesized cross-linked [poly (EGDMA-2-VP)] - TiO2 microbeads were characterized by scanning electron microscopy (SEM), X-ray Diffraction (XRD) and fourier transform infrared spectroscopy (FTIR). To investigate the usability of the obtained microbeads in dye decolorization, the paramreters such as pH, polymer amount, time, and dye concentration were examined both under sunlight and 366 nm UV light. Optimum conditions under which maximum photocatalytic decolorization of the dye were pH 3, polymer amount 0.05 g, dye concentration 30 mg /L and time 5 hours. [ABSTRACT FROM AUTHOR]

This paper reports synthesis of the poly(ethylene glycol dimethacrylate-n-vinyl imidazole) ([poly(EGDMA-VIM)]) microspheres by suspension polymerization for the removal of phenol from an aqueous solution. The synthesized [poly(EGDMA-VIM)] microspheres were characterized by various analysis techniques. The [poly(EGDMA-VIM)] microspheres possessed a high specific surface area (304.4 m² g-1). It was found that the pseudo-second-order kinetic and Freundlich isotherm models could well define the phenol adsorption process. The maximum capacity of the [poly(EGD- MA-VIM)] microspheres was calculated to be 34.7441 mg g-1 at 298 K and natural pH from Langmuir isotherm. The adsorption thermodynamics revealed that the adsorption of phenol was an exothermic and spontaneous process. The [poly(EGDMA-VIM)] microspheres were easily regenerated by using a 0.01 M NaOH solution, and were repeatedly used for at least 5 cycles without losing the adsorption capacity. The experimental results suggest that the [poly(EGDMA-VIM)]microspheres can be implemented as a promising adsorbent for phenol removal from wastewater. [ABSTRACT FROM AUTHOR]

The magnetic poly(ethylene glycol dimethacrylate-n-vinylimidazole) (Fe3O4@poly (EGDMA@VIM)) microspheres were prepared by suspension polymerization method using magnetite Fe3O4 nano-powder and the porosity, morphology, chemical composition and structure of the magnetic polymer microspheres were characterized. The specific surface area and swelling ratio of the Fe3O4@poly(EGDMA@VIM) microspheres were found to be 278.6 m2·g–1 and 48%, respectively. The Fe3O4@poly(EGDMA@VIM) microspheres were used as an adsorbent for phenol removal. The effects of the parameters such as adsorbent dosage, temperature, pH and initial concentration of phenol solutions on the adsorption were investigated. The experimental adsorption equilibrium data obtained were fitted with Langmuir, Freundlich and Dubinin-Radushkevich isotherms and the pseudo-first-order, pseudo-second-order and intra–particle diffusion kinetic models. The adsorption equilibrium data agreed well with the Freundlich isotherm and the pseudo-second-order kinetic model. The maximum capacity of the Fe3O4@poly(EGDMA@VIM) microspheres was calculated to be 33.83 mg·g–1 at 298 K and natural pH from Langmuir isotherm. The Fe3O4@poly(EGDMA@VIM) microspheres were found to be reusable for removal of phenol after desorption for several times. The result indicated that the Fe3O4@poly(EGDMA@VIM) microspheres are potential candidate for removal of phenol in wastewaters. [ABSTRACT FROM AUTHOR]

Magnetic vinylphenyl boronic acid microparticles, poly(ethylene glycol dimethacrylate-vinylphenyl boronic acid) [mpoly( EGDMA-VPBA)], produced by suspension polymerization, was found to be efficient solid acid catalyst for the esterification of methanol and propionic acid. Characterization techniques such as FT-IR, Elemental analyses, ICP-AES, ESR, SEM and N2 sorption showed that both of Fe3O4 and H2SO4 are bonded to the polymer successfully. Esterification was studied for different molar percentages of H2SO4 at temperature range of 50-70 °C. The apparent activation energy was found to be 28.4 kj.mol-1 for 10% H2SO4 doped m-poly(EGDMA-VPBA). Combining of strong acid H2SO4 with m-poly(EGDMA-VPBA), leads to materials with different functional properties. In addition, H2SO4 species could be introduced into the structure as acid centers, therefore this micro-dimensional catalyst has potential candidate for applications in the catalytic esterifications such as propionic acid with methanol. [ABSTRACT FROM AUTHOR]

The chemically modified multiwalled carbon nanotubes (MWCNT)/poly(1-vinyl-1,2,4-triazole) (PVTri) composites were prepared via in situ emulsion polymerization. The morphological and structural properties of the surface-modified MWCNT and the synthesized MWCNT/PVTri composites were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The electrical properties of the composite material were analyzed by conductivity measurements. The thermal analysis and the Tgvalue of the polymer were determined by differential scanning calorimetry technique. The obtained novel MWCNT/PVTri composites exhibited excellent solubility and possessed a slightly higher glass transition temperature than that of the pure polymer. [ABSTRACT FROM PUBLISHER]

A modified suspension polymerization was used for the preparation of the mesoporous magnetic-poly(divinylbenzene-co-vinylimidazole) (m-poly(DVB-VIM)) microbeads in size 53-212 [an of average diameter. The specific surface area and the DVB/VIM mol ratio of the microspheres were determined as 29.47 m²/g and 1:4 mol/mol with Fe3O4, respectively. The physicochemical studies of adsorption of Ni(II) ions from aqueous solutions such as pH, initial concentration, amount of mesoporous m-poly(DVB-VIM) microbeads, contact time, and temperature onto the m-poly(DVB-VIM) microspheres were carried out. The maximum adsorption capacities of the m-poly(DVB-VIM) microspheres towards Ni(II) ions were determined as 13.51, 20.14, 21.00 and 23.62 mg/g at 277 K, 298 K, 318 K, and 338 K, respectively. The dynamic and equilibrium adsorption behaviours of the system were adequately described by the pseudo-second-order kinetic and the Langmuir isotherm models, respectively. Various thermodynamic parameters, such as the Gibbs' free energy change (ΔG°), the standard enthalpy change (ΔH°) and the standard entropy change (ΔS°) were also determined. Morever, after use in the adsorption, the m-poly(DVB-VIM) microbeads with paramagnetic property was separated from the via the applied magnetic force. These results indicate that the material studied could be used as a purifier for the removal of Ni(II) ions from water and wastewater under magnetic field. [ABSTRACT FROM AUTHOR]

Abstract: In this paper we report the electrical characteristics of the Schottky diodes formed by surface polymerization of the Poly(ethylene glycol dimethacrylate-n-vinyl imidazole)/Single Walled Carbon Nanotubes on n-Si. The Single Walled Carbon Nanotubes were synthesized by CVD method. The main electrical properties of the Poly(ethylene glycol dimethacrylate-n-vinyl imidazole)/Single Walled Carbon Nanotubes/n-Si have been investigated through the barrier heights, the ideality factors and the impurity density distribution, by using current–voltage and reverse bias capacitance voltage characteristics. Electrical measurements were carried out at room temperature. Poly(ethylene glycol dimethacrylate-n-vinyl imidazole)/Single Walled Carbon Nanotubes/n-Si Schottky diode current–voltage characteristics display low reverse-bias leakage currents and average barrier heights of 0.61±0.02eV and 0.72±0.02eV obtained from both current–voltage and capacitance–voltage measurements at room temperature, respectively. [Copyright &y& Elsevier]

Abstract: Sulfonic acid functionalized poly (ethylene glycol dimethacrylate-1-vinyl-1,2,4-triazole), poly (EGDMA–VTAZ–SO3H) (average diameter 1.0–1.5mm), was found to be efficient solid acid catalyst for the esterification of methanol and propionic acid under heterogeneous reaction conditions. The pristine polymer, poly (EGDMA–VTAZ), was produced by suspension polymerization and then proton-conducting polymer was obtained by blending of poly (EGDMA–VTAZ) with different percentage of H2SO4 solutions. The protonation of aromatic heterocyclic rings was proved with Fourier-transform infrared spectroscopy (FT-IR). Thermo gravimetric (TG) analysis showed that the catalyst is thermally stable up to 573K. The surface morphology of the catalyst was characterized by scanning electron microscopy (SEM). Poly (EGDMA–VTAZ–SO3H) beads can be regenerated and reused, so this provides a potential application. It has a rate constant which exceeds that of Amberlyst-15 by a factor of about four at 333K. As for the reaction equilibrium constant (Ke ), which is independent of temperature ranging from 318 to 343K, was determined to be 3.16. The apparent activation energy was found to be 41.6kJmol−1 for poly (EGDMA–VTAZ–SO3H). [ABSTRACT FROM AUTHOR]

The article discusses a study which synthesized magnetic beads for the removal of heavy-metal ions from synthetic solutions. It notes the suspension polymerization was used in this study to produce the magnetic beads. Particular focus is given to the specific surface area of the magnetic beads, as well as its swelling ratio. It cites the average magnetite content of the resulting beads, along with its maximum binding capacities.

The aim of this study is to prepare magnetic beads which can be used for the removal of heavy metal ions from synthetic solutions. Magnetic poly(ethylene glycol dimethacrylate-vinyl imidazole) [m-poly(EGDMA-VIM)] beads were produced by suspension polymerization in the presence of magnetite Fe3O4 nano-powder. The specific surface area of the m-poly(EGDMA-VIM) beads was found to be 63.1 m2/g with a size range of 150-200 µm in diameter and the swelling ratio was 85%. The average Fe3O4 content of the resulting m-poly(EGDMA-VIM) beads was 12.4%. The maximum binding capacities of the m-poly(EGDMA-VIM) beads were 32.4 mg/g for Cu2+, 45.8 mg/g for Zn2+, 84.2 mg/g for Cd2+and 134.5 mg/g for Pb2+. The affinity order on mass basis is Pb2+>Cd2+>Zn2+>Cu2+. Equilibrium data agreed well with the Langmuir model. pH significantly affected the binding capacity of the magnetic beads. Binding of heavy metal ions from synthetic wastewater was also studied. The binding capacities were 26.2 mg/g for Cu2+, 33.7 mg/g for Zn2+, 54.7 mg/g for Cd2+ and 108.4 mg/g for Pb2+. The magnetic beads could be regenerated up to about 97% by treating with 0.1 M HNO3. These features make m-poly(EGDMA-VIM) beads a potential candidate for support of heavy metal removal under magnetic field. [ABSTRACT FROM AUTHOR]

Abstract: The barium hexaferrite (BaFe12O19) containing magnetic poly(ethylene glycol dimethacrylate–vinyl pyridine), (mag-poly(EGDMA–VP)) beads (average diameter=53–212μm) were synthesized and characterized. Their use as an adsorbent in the removal of diethyl phthalate (DEP) from an aqueous solution was investigated. The mag-poly(EGDMA–VP) beads were prepared by copolymerizing of 4-vinyl pyridine (VP) with ethylene glycol dimethacrylate (EGDMA). The mag-poly(EGDMA–VP) beads were characterized by N2 adsorption/desorption isotherms (BET), vibrating sample magnetometer (VSM), X-ray powder diffraction (XRD), elemental analysis, scanning electron microscope (SEM) and swelling studies. At a fixed solid/solution ratio, the various factors affecting the adsorption of DEP from aqueous solutions such as pH, initial concentration, contact time and temperature were analyzed. The maximum DEP adsorption capacity of the mag-poly(EGDMA–VP) beads was determined as 98.9mg/g at pH 3.0, 25°C. All the isotherm data can be fitted with both the Langmuir and the Dubinin-Radushkevich isotherm models. The pseudo first-order, pseudo-second-order, Ritch-second-order and intraparticle diffusion models were used to describe the adsorption kinetics. The thermodynamic parameters obtained indicated the exothermic nature of the adsorption. The DEP adsorption capacity did not change after 10 batch successive reactions, demonstrating the usefulness of the magnetic beads in applications. [Copyright &y& Elsevier]

Abstract: The barium hexaferrite (BaFe12O19) containing magnetic poly (ethylene glycol dimethacrylate-vinyl pyridine; mag-poly [EGDMA–VP]) beads (average diameter=53–212μm) were synthesized and characterized. Their use as an adsorbent in the removal of dimethyl phthalate (DMP) from an aqueous solution was investigated. The mag-poly (EGDMA–VP) beads were prepared by copolymerizing of 4-vinyl pyridine (VP) with ethylene glycol dimethacrylate (EGDMA). The mag-poly (EGDMA–VP) beads were characterized by N2 adsorption/desorption isotherms (BET), vibrating sample magnetometer (VSM), X-ray powder diffraction (XRD), elemental analysis, scanning electron microscope (SEM), and swelling studies. At a fixed solid/solution ratio, the various factors affecting the adsorption of DMP from aqueous solutions such as pH, initial concentration, contact time, and temperature were analyzed. The maximum DMP adsorption capacity of the mag-poly (EGDMA–VP) beads was determined as 96.2mg/g at pH 3.0, 25°C. All the isotherm data can be fitted with both the Langmuir and the Dubinin–Radushkevich isotherm models. The pseudo-first-order, pseudo-second-order, Ritch-second-order, and intraparticle diffusion models were used to describe the adsorption kinetics. The thermodynamic parameters obtained indicated the exothermic nature of the adsorption. The DMP adsorption capacity did not change after 10 batch successive reactions, demonstrating the usefulness of the magnetic beads in applications. [Copyright &y& Elsevier]