The association and properties of multi-block like copolymers(TP)of acrylamide(AM)and acrylic acid(AA)prepared by template copolymerization in aqueous solution were studied.The results showed that the copolymers of th...The association and properties of multi-block like copolymers(TP)of acrylamide(AM)and acrylic acid(AA)prepared by template copolymerization in aqueous solution were studied.The results showed that the copolymers of this type exhibited a significant structure effect compared with that of similar random copolymers(CP)obtained by copoly-merization in the absence of template.Decreasing the value of pH or adding Ca2+ion to the copolymer solution will make phase separation occur.The TEM images demonstrated that the phase separation caused by Ca2+ion was due to the forma-tion of extensively intermolecular cross-linking.With the increase of the pH value of copolymer solution,the changes of the solution viscosity was similar with that of homopoly-acrylic acid,which originally increased and then decreased.But the increase range of template copolymer was higher than that of homopolyacrylic acid.TEM images indicated that at the maximal viscosity the copolymer obtained in the presence of template formed coiled aggregates.展开更多
Bismuth oxychloride(Bi OCl) with morphology of squared-like nanosheet is synthesized by solvothermal method using ethylene glycol aqueous reaction solution. The product is characterized by X-ray powder diffraction(XRD...Bismuth oxychloride(Bi OCl) with morphology of squared-like nanosheet is synthesized by solvothermal method using ethylene glycol aqueous reaction solution. The product is characterized by X-ray powder diffraction(XRD), scanning electron microscopy(SEM), energy dispersive spectroscopy(EDS), transmission electron microscopy(TEM) and ultraviolet-visible(UV-Vis) diffuse reflection spectroscopy, respectively. The layered structure, the hydrogen bonding between hydroxyl groups and their selective adsorption cause the formation of the squared-like nanosheets. The photocatalytic degradation activity of the as-prepared Bi OCl is tested by the degradation of methyl orange under UV light irradiation. Repeating the degradation process four times under the same condition, the results show that the squared-like Bi OCl nanosheets present high photocatalytic activity and stability.展开更多
In this paper, for improving the photocatalytic efficiency of titania(TiO2) nanoparticles(NPs), Ag Au alloy-TiO2 core-shell NPs are fabricated via a sol-gel(SG) process in the presence of Ag Au alloy NPs with block co...In this paper, for improving the photocatalytic efficiency of titania(TiO2) nanoparticles(NPs), Ag Au alloy-TiO2 core-shell NPs are fabricated via a sol-gel(SG) process in the presence of Ag Au alloy NPs with block copolymer shells as templates. The photocatalytic activities of the Ag Au-TiO2 NPs on the photodecomposition of methylene blue(MB) are investigated. The Ag Au-TiO2 composite NPs coated with 5.0% titania related to block copolymers show higher photocatalytic activity than the other samples in which the titania contents are larger than 5.0%. The results indicate that the increase of the thickness of the TiO2 shell leads to the decrease of the photocatalytic activity.展开更多
文摘The association and properties of multi-block like copolymers(TP)of acrylamide(AM)and acrylic acid(AA)prepared by template copolymerization in aqueous solution were studied.The results showed that the copolymers of this type exhibited a significant structure effect compared with that of similar random copolymers(CP)obtained by copoly-merization in the absence of template.Decreasing the value of pH or adding Ca2+ion to the copolymer solution will make phase separation occur.The TEM images demonstrated that the phase separation caused by Ca2+ion was due to the forma-tion of extensively intermolecular cross-linking.With the increase of the pH value of copolymer solution,the changes of the solution viscosity was similar with that of homopoly-acrylic acid,which originally increased and then decreased.But the increase range of template copolymer was higher than that of homopolyacrylic acid.TEM images indicated that at the maximal viscosity the copolymer obtained in the presence of template formed coiled aggregates.
基金supported by the National Natural Science Foundation of China(Nos.51272063 and 51172059)the Natural Science Foundation of Anhui Province(No.1408085QE85)
文摘Bismuth oxychloride(Bi OCl) with morphology of squared-like nanosheet is synthesized by solvothermal method using ethylene glycol aqueous reaction solution. The product is characterized by X-ray powder diffraction(XRD), scanning electron microscopy(SEM), energy dispersive spectroscopy(EDS), transmission electron microscopy(TEM) and ultraviolet-visible(UV-Vis) diffuse reflection spectroscopy, respectively. The layered structure, the hydrogen bonding between hydroxyl groups and their selective adsorption cause the formation of the squared-like nanosheets. The photocatalytic degradation activity of the as-prepared Bi OCl is tested by the degradation of methyl orange under UV light irradiation. Repeating the degradation process four times under the same condition, the results show that the squared-like Bi OCl nanosheets present high photocatalytic activity and stability.
基金supported by the National Natural Science Foundation of China(Nos.51173069 and 51473068)
文摘In this paper, for improving the photocatalytic efficiency of titania(TiO2) nanoparticles(NPs), Ag Au alloy-TiO2 core-shell NPs are fabricated via a sol-gel(SG) process in the presence of Ag Au alloy NPs with block copolymer shells as templates. The photocatalytic activities of the Ag Au-TiO2 NPs on the photodecomposition of methylene blue(MB) are investigated. The Ag Au-TiO2 composite NPs coated with 5.0% titania related to block copolymers show higher photocatalytic activity than the other samples in which the titania contents are larger than 5.0%. The results indicate that the increase of the thickness of the TiO2 shell leads to the decrease of the photocatalytic activity.
