Advanced Materials Research Vols. 1073-1076

Abstract: Catalyst precursor was prepared with the Fe-Al hydrotalcite as the support, Ce-doped TiO₂ as the active component. Then SO₄^2-/CeO₂-TiO₂/HTLC photocatalyst was obtained by SO₄^2- -modification with soak method. Catalysts were characterized by means of XRD, SEM-EDS and UV-Vis DRS. With methyl orange as model pollutant, the photocatalytic performance of the catalysts was determined. Experimental results showed that the absorption intensity for visible light of the CeO₂-TiO₂ particle was stronger than that of TiO₂ particle; moreover there was a synergistic effect between SO₄^2- and CeO₂-TiO₂/HTLC, thus the absorption intensity for visible light of SO₄^2-/CeO₂-TiO₂/HTLC photocatalyst was enhanced further. The decolorization rate for methyl orange of modified SO₄^2-/15%(CeO₂-TiO₂)/HTLC photocatalyst reached 93% after irradiation under simulated sunlight for 2 hours.

Abstract: Nano-titanium dioxide was prepared in a microemulsion system by solvothermal method. The microemulsion system is composed of ammonium hexafluorotitanate((NH₄)₂TiF₆) used as titanium source, water, cetyl trimethyl ammonium bromide (CTAB), n-butanol, and cyclohexane. The influences of reaction time, amount of urea added and the mole ratio of water to CTAB (ω) on particle size, and photocatalytic activity were investigated by photocatalytic degrading methyl orange and X-ray diffraction (XRD) characterization. The results show that the optimum preparation conditions are that reaction time 12 h, the amount of urea added 1.5 g, and the ratio of water to CTAB ratio (ω) 18:1.

Abstract: The natural rubber/polyvinyl alcohol (NR/PVA) blends containing epoxid natural rubber as the compatilizer were prepared using latex compounding techniques. The mechanical and thermal oxidation aging properties were studied. Mechanical test showed that the tear strength and hardness of the NR were significantly improved due to adding of the PVA. The tensile strength decreased significantly along with the PVA increasing. Thermal oxidation aging test had obviously impact on the mechanical properties of the material. The performance retention of the material properties was taken effect significantly on the aging test.

Abstract: This study reports on the modification of natural bentonite by a cationic polyelectrolyte, which is a lignin-based aldehyde-ketone resin, and the application of this modified clay as adsorbent in the removal of reactive dyes from aqueous solution. Modified bentonite was characterized by IR and zeta-potential test, its dye removal performance was evaluated. Results show that intermolecular interaction and electrostatic attraction between dyes and adsorbent are responsible for the adsorption behavior. The removal of reactive dyes increased with increasing temperature and the optimum pH range was 4.0-6.5. The negative values of ΔG reflected the spontaneous adsorption and the values of ΔH showed that it was a combination of chemical and physical adsorption. Equilibrium adsorption data fitted well to Langmuir isotherm and the adsorption capacity for reactive red and reactive blue was 125.0 and 159.2 mg/g, respectively.

Abstract: Different cooling process, annealing temperature and addition of B₂O₃ were experimented on the CaO-MgO-SiO₂-Al₂O₃-Cr₂O₃-Fe₂O₃ slag system with an aim to investigate the chromium precipitation behaviour. The solidified slags were characterized by XRD, SEM, EDX and EPMA. It was shown that, under melt-quenching process, chromium was immobilized in amorphous structure in the slag with basicity lower than 1.0 and Cr₂O₃ content less than 4.0 wt%. It was also found that addition of B₂O₃ and higher annealing temperature would be helpful for the precipitation of chromium into spinel solid solution in slag with basicity of 1.5.

Abstract: Nowadays, serious environmental pollution demands enterprises to dispose waste water, especially for the printing, dyeing and nonferrous metal ones. Wastewater treatment technology is needed to improve urgently. Hydroxyapatite with large specific surface area and more microporous structure becomes a hot research topic in recent years for its strong adsorption ability. In this paper, the pollution situation, adsorption properties, adsorption mechanism, influencing factors and adsorption kinetic of hydroxyapatite are introduced.

Abstract: As a kind of ideal porous absorbents with tunable porosity, large surface areas, and hydrophobicity, conjugated microporous polymers (CMPs) have recently received extensive attention in oil/organic solvent-water separation. However, reports on the application of CMPs in adsorption of erythromycin (ERY) from water are very few. In this work, the adsorption of ERY by three kinds of CMPs was firstly studied. It was observed that all the CMPs extracted ERY quickly from water. The adsorption kinetics of ERY on the three CMPs was well expressed by the pseudo-second-order model, and the adsorption process was found to be mainly controlled by film diffusion. Increasing surface area of the CMPs resulted in greater extent of adsorption. This work may provide fundamental guidance for removal of antibiotics by CMPs.

Abstract: Possible catalytic activity of different metals in hydrothermal reduction of CO₂ into formic acid with Zn was investigated under low temperatures. Among the several catalysts (Cu, Fe and Sn) were used, Cu shows the best catalytic activity for the formic acid production. The formic acid yield is as high as 61% under hydrothermal condition. XRD analysis was also carried out to investigate the possible role of reactants.

Abstract: In this study, the tensile strength of phenolic resin adhesive was reinforced by the use of surface-modified nanocrystalline cellulose (NCC). The original NCC was modified by 3-methacryloxy-propyltrimethoxysilane (MPS) to improve the wetting property with the phenolic resin adhesive. The phenolic resin adhesive with surface-modified NCC was analyzed by Fourier transform infrared (FT-IR). Tensile strength of the modified phenolic resin adhesive was tested according to Chinese National Standard GB/T 2567-2008. The results showed that the wetting property between NCC modified by MPS and phenolic resin adhesive was increased by 21.7% and the tensile strength of phenolic resin adhesive with modified NCC was enhanced from 6.25 MPa to 15.97 MPa.