Advanced Materials Research Vols. 807-809

Abstract: The absorptions of CO₂ on the 1-butyl-3-methylimidazolium acetate ([Bmi [Ac]) with different substituents are calculated systematically at GGA/PW91 level. Three hydrogen bonds are formed between [A and cations of 1-n-[Bmi [A ([NBmi⁺) and 1-tert-[Bmi [A ([TBmi⁺). The interaction between CO₂ and the [NBmi [A by a C-O bond is much weaker than that with the [TBmi [A by forming a O...O...C...C four member-ring. The chemisorption of CO₂ on the ion pairs of [NBmi [A is much weaker than that on the [TBmi [A, resulted from the absorption energies analysis. The frontier molecular orbitals shows the electronic density overlap between absorbed CO₂ and the [A in CO₂-[NBmi [A is much weaker than that in [TBmi [A. Therefore, the chemisorption of CO₂ on the ion pair of [NBmi [A is much weaker than that on the [TBmi [A. The ionic liquids based [NBmi⁺ can be used repetitively, and the adsorbed CO₂ would be easier desorbed.

Abstract: Dynamic and thermodynamic characteristics of gasoline vapor adsorption at 0.3 mol/mol on different activated carbons (ACs) were investigated. The adsorption capacities of AC1 and AC3 were 0.295 g/g and 0.189 g/g at 20 oC, and 0.284 g/g and 0.165 g/g at 30 °C, respectively. Bed temperature rise was up to 50°C to 60°C in the adsorption of gasoline vapor at 0.3 mol/mol.The heat effect formula for high concentration vapor adsorption was deduced to evaluate the relationship of the adsorption capacity of the activated carbons, the mole fraction of the inlet gasoline vapor, the recovery efficiency of the gasoline vapor with the temperature rise.

Abstract: Three-dimensional (3D) ordered SiO₂ macroporous materials doped with metal oxides (M = Co, Fe, Ni, and Sn) were synthesized respectively, using poly (methyl methacrylate) (PMMA) spheres as templates. The porous structure and morphology of samples has been characterized by TEM images. Further investigation of the photocatalytic degradation of methylene blue in the presence of H₂O₂, the observed photocatalytic performance of the samples was attributed to the effects of the metal oxides and porosity.

Abstract: AgCl-TiO₂ nanocomposites with a core-shell structure were successfully prepared by hydrothermal treatment. And the products were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), Brunauer Emmett teller (BET) Analysis, and UV-vis diffuse reflectance spectroscopy (DRS). It is found that the composites consist of anatase TiO₂ and cubic phase AgCl, which has higher surface area, stronger spectral response in visible region compared with pure TiO₂. The photocatalytic activity of these samples was evaluated by photocatalytic decoloration of methyl orange (MO) under simulated solar light. The results show AgCl-TiO₂ composite has much higher photocatalytic activity than that of pure TiO₂, and it also has very good stability. The kinetic study showed that this photocatalytic process coincided with the Langmuir-Hinshelwood (L-H) pseudo first order reaction model.

Abstract: Four kinds of Cu₂O microcrystals with different morphologies are synthesized via low temperature hydrothermal synthetic method. The photocatalytic degradation of methylene blue (MB) of the above different Cu₂O is preliminary explored based on this observation. 6-facet, 8-facet, 14-facet are prepared by PVP system and 26-facet is prepared by NaOH system. They are characterized by means of Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD) and Diffuse Reflectance Spectra (DRS). Under 150 W xenon lamp irradiation, 0.5 gL¹ catalyst and 0.1% (v/v) 30% H₂O₂ as co-catalyst are used to degrade 5% 100 mL MB solution. The reaction time is 80 min. 26-facet Cu₂O polyhedral discolor about 89.48% of MB while 6-facet Cu₂O microcrystal about discolor about 20.18% which is the lowest decolourization rate among all the samples. The photocatalytic performance of 8-facet Cu₂O microcrystal is slight better than that of 14-facet. The decolourization rate of 8-facet and 14-facet are 56.00% and 41.08%, respectively. The main reason is that the planes of Cu₂O microcrystal have a main influence on photocatalytic degradation of MB.

Abstract: A series of biodegradable segmented poly (ester-urethane) s were prepared by solution polymerization of poly (butylene succinate) (PBS), mesogenic diol (MD), and hexamethylene diisocyanate (HDI). The MD content was varied from 0 to 40 mol% so that the effects of the mesogen content on the thermal and physical properties, and enzymatic degradation were examined respectively. It was found that introducing mesogen segments could increase the thermal stability and the elastic properties, while reduced the phase transition temperatures, the degree of relative crystallinity (Xc) and the enzymatic degradation rate.

Abstract: In the part of the paper, use bentonite as a basic material synthesis with phenolic aldehyde foam plastic. The experiment mainly researched into the capacity of the synthesis to purify and store rain water. The results show that, water absorption polymerphenolic aldehyde foams addition to environmental mineral material can promote the capacity of purifying rain water greatly, with 10 percent of bentonite, the removal of BOD5 in the rain water can be promoted to 90 percent, CODs to 80 percent, during which the removal turbidity can be 83 percent. While use bentonite only, the removal rate of BOD5 can only be 62 percent, the removal rate of COD can be 20 percent, and the removal rate of turbidity can be 68 percent. So it depends on the locals pollution conditions to choose environment mineral material to purify the rain water effectively. When choosing bentonite as basic material to synthesis with phenolic aldehyde foam plastic, the polymers water absorption rate and rate of water loss to rain water change with different proportion of bentonite. Through the purify rain water test with plants cultivated in environmental mineral material, purify layer and storage layer can meet all the requirements including the function of purifying and storing rain water, exhibit benefit of the synthesis polymer.

Abstract: A series of PLA blends were prepared by solution co-precipitation of polylactide (PLA), polyethylene glycol (PEG) and different crystallization nucleating agents. The crystallization behavior of blends was investigated by differential scanning calorimeter (DSC) and X-ray diffraction (XRD). The results showed that the crystallization ability of PLA blends was accelerated by plasticizer PEG, but the crystal structure of the obtained PLA blends was imperfect; the crystal structure and crystallization rate of the PLA blends were improved with the addition of nucleating agent, moreover, the crystallinity was 34.1% and 36.5%, respectively.

Abstract: The adsorption characteristics of Cr(VI) on activated carbon prepared from several agriculture by-products via sulphuric acid-treatment were compared and the best concentration of sulphuric acid for carbonization were evaluated. It is confirmed that peanut shell is best material for the absorption of Cr(VI) ion from aqueous solution among hybrid giant napier straw, rice husk and commercial activated carbon in this study. The effects of agitation time, solution pH, temperature and Cr(VI) initial concentration on Cr(VI) adsorption were investigated. The 3:1 volume ratio of sulphuric acid : deionized water is the optimal concentration for Cr(VI) biosorption for peanut shell carbonization. Cr(VI) adsorption is highly dependent on solution pH. Initial solution pH =1.5 was the most favorable pH for Cr(VI) removal. Cr(VI) biosorption increases with increasing initial concentration, agitation time and solution temperature. The adsorption kinetics is found well fitted to the pseudo-second-order kinetic model. The adsorption equilibrium data are best represented by Langmuir model.The maximum adsorption capacity of carbonized peanut shell for Cr(VI) reached 26.22 mg/g.

Abstract: High performance silicalite-1 membranes were successfully synthesized on silica tubes by seeding method after filling the tubes with water and glycerol mixtures. After seeding the silica tubes with 200 nm seeds, all the silicalite-1 membranes show acceptable separation performance towards ethanol/water mixture after 4-12 h hydrothermal synthesis, and the highest flux of membrane with 8 h hydrothermal synthesis reaches about 0.98 kg/m².h and the separation factor reaches about 60 towards 3 wt.% ethanol/water mixture. This result shows that the as-synthesized silicalite-1 membrane can concentrate the ethanol from 3% to about 65%, and the ethanol can be obtained over 600 g/m².h by using the silicalite-1 membrane, which shows that seeding method and suitable control of synthesis conditions is possible for preparing high-performance silicalite-1 membranes.