Papers by Author: Chang Gang Xu

Abstract: Monoclinic crystal bismuth vanadate (BiVO4) was synthesized by the high temperature solid state reaction after ball milling the materials of Bi2O3 and V2O5. The influences of sintering times on the crystal phases and structures of BiVO4 powders were studied through the XRD、FTIR characterization. Fe-doped BiVO4 was prepared by doping ferric chloride to pure monoclinic crystal BiVO4 to improve the photo absorbance performance of BiVO4 and to promote the isolation of photo-induced carriers. Visible light activity of BiVO4 and Fe-doping BiVO4 were characterized using the UV-diffuse reflectance spectroscopy. The electrochemical behaviors of BiVO4 and Fe-doping BiVO4 were investigated under the condition of avoiding light or under light.

Abstract: The effects of dicumyl peroxide (DCP) at low concentrations on initiating cross-linking of polylactide (PLA) by melt blending were investigated. Processing characteristics, morphology, thermal behavior and rheology character of PLA gel were characterized by torque rheometer, XRD, DSC and rotary rheometer. The results showed that the crosslink rate of the blends increased with dicumyl peroxide content increasing. The PLA gel with 0.73 wt% of DCP appeared obvious crystallization behavior and a new crystalline structure maybe formed as DCP was 1.4 wt%. And it was also found that the exothermal peak temperature of PLA gel decreased with increasing dicumyl peroxide content except for the gel with 1.4 wt% of dicumyl peroxide. It also has been inferred by rheology analysis that the blend may be the structure of gel or 3D network, and the melt strength was improved.

Abstract: A lignin-quaternary adsorbent was made from lignin after phenolization and then amination. As-prepared adsorbent was characterized by SEM, IR and DMA. Effects of adsorbent dose, initial pH and concentration on 2, 4, 6-Trinitrotoluene (TNT) removals from aqueous solution by adsorption of this adsorbent were comprehensively investigated. IR spectra showed that the product comprises quaternary ammonium groups in the form of ether bond. The mechanical strength of the adsorbent is enhanced by combining of PVA. It was possible to remove 66% of TNT from aqueous solution with 0.1 g of the adsorbent under certain conditions (100 mg/L and 25 °C). The results indicated that the amount of TNT adsorbed onto the adsorbent increased with increasing initial concentration; however, it decreased with an increase in pH. The adsorption process was determined to be consistent with the Langmuir isotherm.

Abstract: TiO2 / KGM composite membranes were prepared by blend. Effects of the content of TiO2 and glycerol, ratio of PVA to KGM on tensile strength of membranes were investigated. Structure and Morphology of TiO2 / KGM films were characterized by SEM, XRD and IR. Furthermore, anti-bacteria properties of composite films were evaluated. The results showed that there were hydrogen bonding interactions between konjac glucomannan molecule, PVA and titania particle after irradiation. Composite membranes enable the antibacterial properties improved by adding an appropriate amount of TiO2, but mechanical properties decreased. The composite membrane tensile strength decreased with increasing glycerol content but increased with PVA glucomannuronate composite ratio increasing.