Fe2O3/SiO2 nano-composite films were prepared by sol-gel technique combining heat treatment in the range of 100-900 ℃. The particle size was observed by FE-SEM. Optical properties of the films were investigated by UV...Fe2O3/SiO2 nano-composite films were prepared by sol-gel technique combining heat treatment in the range of 100-900 ℃. The particle size was observed by FE-SEM. Optical properties of the films were investigated by UV-visible spectra. Structural and magnetic characteristics were investigated through FT-IR and VSM. The transparency of the Fe2O3/SiO2 nano-composite films decreased with the content of the Fe2O3. Water and organic solvent in the films were evaporated with heat treatment, so the transparency of the films was enhanced under high temperature. It is also found that the saturation magnetization （Ms） of the films increases with the temperature. As the content of the Fe2O3 increases, when the content of the Fe2O3 is around 30wt%, the Ms of the films has a maximum value.展开更多
The Fe3O4@SiO2 composite nanoparticles were obtained from as-synthesized magnetite (Fe3O4) nanoparticles through the modified St?ber method. Then, the Fe3O4 nanoparticles and Fe3O4@SiO2 composite nanoparticles were ch...The Fe3O4@SiO2 composite nanoparticles were obtained from as-synthesized magnetite (Fe3O4) nanoparticles through the modified St?ber method. Then, the Fe3O4 nanoparticles and Fe3O4@SiO2 composite nanoparticles were characterized by means of X-ray diffraction (XRD), Raman spectra, scanning electron microscope (SEM) and vibrating sample magnetometer (VSM). Recently, the studies focus on how to improve the dispersion of composite particle and achieve good magnetic performance. Hence effects of the volume ratio of tetraethyl orthosilicate (TEOS) and magnetite colloid on the structural, morphological and magnetic properties of the composite nanoparticles were systematically investi-gated. The results revealed that the Fe3O4@SiO2 had better thermal stability and dispersion than the magnetite nanoparticles. Furthermore, the particle size and magnetic property of the Fe3O4@SiO2 composite nanoparticles can be adjusted by changing the volume ratio of TEOS and magnetite colloid.展开更多
Using a liquid-solid phase inversion method, a hybrid matrix poly（vinylidene fluoride）（PVDF） membrane was prepared with alumina（Al2O3） nanoparticle addition. Pd/Fe nanoparticles（NPs） were successfully immobili...Using a liquid-solid phase inversion method, a hybrid matrix poly（vinylidene fluoride）（PVDF） membrane was prepared with alumina（Al2O3） nanoparticle addition. Pd/Fe nanoparticles（NPs） were successfully immobilized on the Al2O3/PVDF membrane, which was characterized by Scanning Electron Microscopy（SEM） and Transmission Electron Microscopy（TEM）. The micrographs showed that the Pd/Fe NPs were dispersed homogeneously. Several important experimental parameters were optimized, including the mechanical properties, contact angle and surface area of Al2O3/PVDF composite membranes with different Al2O3 contents. At the same time, the ferrous ion concentration and the effect of hydrophilization were studied. The results showed that the modified Al2O3/PVDF membrane functioned well as a support. The Al2O3/PVDF membrane with immobilized Pd/Fe NPs exhibited high efficiency in terms of dichloroacetic acid（DCAA） dechlorination. Additionally, a reaction pathway for DCAA dechlorination by Pd/Fe NPs immobilized on the Al2O3/PVDF membrane system was proposed.展开更多
In order to modify inorganic particles as chromatic electrophoretic particles, an approach was designed and used to prepare Fe203 red electrophoretic particles. These Fe203-cationic hybrid nanoparticles （Fe203-CHNPs...In order to modify inorganic particles as chromatic electrophoretic particles, an approach was designed and used to prepare Fe203 red electrophoretic particles. These Fe203-cationic hybrid nanoparticles （Fe203-CHNPs）were prepared through Fe203 core covered with polymer shell which was composed of SiO2 and P （DMAEMA-co-HMA） by using atom transfer radical polymerization （ATRP）technique. The SiO：-coating could introduce the functional group on the surfaceof inorganic particles, through which the polymer shell could be formed by using ATRP tech- nique. The results of Fourier transform infrared spectra （FT-IR）, X-ray photoelectron spectroscopy （XPS） and thermal gravimetric analysis （TGA）confirmed the chemical compositions of Fe2O3-CHNPs; the images of transmission elec- tron microscopy （TEM） indicated the core-shell structure of Fe2O3-CHNPs; the measurements of dynamic light scatter- ing （DLS） showed a 253.7 nm average particle size with narrow size distribution; and the zeta potential measurements identified the high chargeability of Fe2O3-CHNPs. Furthermore, the resulting nanoparticles were successfully applied in the electrophoretic display cell, which demonstrated that it was an effective approach to preparing chromatic elec- trophoretic particles.展开更多
用溶胶-凝胶法制得Cu/Fe2O3-TiO2光催化材料。用XRD、Ram an、TPR、IR、TEM、UV-V is DRS测试技术和光催化反应等对固体材料的结构和性能进行了表征。结果表明,Fe2O3的质量分数为10%时,在TiO2表面以单分子层分散,Fe2O3的引入使TiO2吸光...用溶胶-凝胶法制得Cu/Fe2O3-TiO2光催化材料。用XRD、Ram an、TPR、IR、TEM、UV-V is DRS测试技术和光催化反应等对固体材料的结构和性能进行了表征。结果表明,Fe2O3的质量分数为10%时,在TiO2表面以单分子层分散,Fe2O3的引入使TiO2吸光限蓝移。Fe2O3含量超过单分子层分散时,有晶相Fe2O3生成,光吸收性能下降。Fe—O—Ti键的形成加强了半导体之间的相互作用,有利于光生载流子在半导体间的输送。少量Cu的引入,使复合材料的吸光域向可见光范围扩展。光催化反应性能与材料的光响应能力密切相关。在光催化CO2和CH3NH2直接合成NH2CH2COOH的反应中,负载质量分数为10%Fe2O3的光催化反应性能最优。在120℃、常压、空速200 h-1、CO2与CH3NH2摩尔比为1∶1和6.5×10-4W/cm2的紫外灯照射下,CH3NH2转化率为1.35%,NH2CH2COOH选择性达92.0%。展开更多
基金Funded by the Innovative Program of Shanghai Municipal Education Commission (No.08YZ97)the National Natural Science Foundation of China (No.10704048)
文摘Fe2O3/SiO2 nano-composite films were prepared by sol-gel technique combining heat treatment in the range of 100-900 ℃. The particle size was observed by FE-SEM. Optical properties of the films were investigated by UV-visible spectra. Structural and magnetic characteristics were investigated through FT-IR and VSM. The transparency of the Fe2O3/SiO2 nano-composite films decreased with the content of the Fe2O3. Water and organic solvent in the films were evaporated with heat treatment, so the transparency of the films was enhanced under high temperature. It is also found that the saturation magnetization （Ms） of the films increases with the temperature. As the content of the Fe2O3 increases, when the content of the Fe2O3 is around 30wt%, the Ms of the films has a maximum value.
文摘The Fe3O4@SiO2 composite nanoparticles were obtained from as-synthesized magnetite (Fe3O4) nanoparticles through the modified St?ber method. Then, the Fe3O4 nanoparticles and Fe3O4@SiO2 composite nanoparticles were characterized by means of X-ray diffraction (XRD), Raman spectra, scanning electron microscope (SEM) and vibrating sample magnetometer (VSM). Recently, the studies focus on how to improve the dispersion of composite particle and achieve good magnetic performance. Hence effects of the volume ratio of tetraethyl orthosilicate (TEOS) and magnetite colloid on the structural, morphological and magnetic properties of the composite nanoparticles were systematically investi-gated. The results revealed that the Fe3O4@SiO2 had better thermal stability and dispersion than the magnetite nanoparticles. Furthermore, the particle size and magnetic property of the Fe3O4@SiO2 composite nanoparticles can be adjusted by changing the volume ratio of TEOS and magnetite colloid.
基金supported by the Nature Science Foundation of Heilongjiang Province (No. B201410)the Postdoctoral Foundation Project of Heilongjiang Province (No. LBH-Z13128)+3 种基金the Science and Technology Research Program of Education Bureau of Heilongjiang Province (No. 12531206)the Special Scientific Research Projects of Harbin Normal University (12XQXG02)the National Nature Science Foundation of China (No. 41030743)the National Nature Science Foundation of China (No. 42171217)
文摘Using a liquid-solid phase inversion method, a hybrid matrix poly（vinylidene fluoride）（PVDF） membrane was prepared with alumina（Al2O3） nanoparticle addition. Pd/Fe nanoparticles（NPs） were successfully immobilized on the Al2O3/PVDF membrane, which was characterized by Scanning Electron Microscopy（SEM） and Transmission Electron Microscopy（TEM）. The micrographs showed that the Pd/Fe NPs were dispersed homogeneously. Several important experimental parameters were optimized, including the mechanical properties, contact angle and surface area of Al2O3/PVDF composite membranes with different Al2O3 contents. At the same time, the ferrous ion concentration and the effect of hydrophilization were studied. The results showed that the modified Al2O3/PVDF membrane functioned well as a support. The Al2O3/PVDF membrane with immobilized Pd/Fe NPs exhibited high efficiency in terms of dichloroacetic acid（DCAA） dechlorination. Additionally, a reaction pathway for DCAA dechlorination by Pd/Fe NPs immobilized on the Al2O3/PVDF membrane system was proposed.
文摘In order to modify inorganic particles as chromatic electrophoretic particles, an approach was designed and used to prepare Fe203 red electrophoretic particles. These Fe203-cationic hybrid nanoparticles （Fe203-CHNPs）were prepared through Fe203 core covered with polymer shell which was composed of SiO2 and P （DMAEMA-co-HMA） by using atom transfer radical polymerization （ATRP）technique. The SiO：-coating could introduce the functional group on the surfaceof inorganic particles, through which the polymer shell could be formed by using ATRP tech- nique. The results of Fourier transform infrared spectra （FT-IR）, X-ray photoelectron spectroscopy （XPS） and thermal gravimetric analysis （TGA）confirmed the chemical compositions of Fe2O3-CHNPs; the images of transmission elec- tron microscopy （TEM） indicated the core-shell structure of Fe2O3-CHNPs; the measurements of dynamic light scatter- ing （DLS） showed a 253.7 nm average particle size with narrow size distribution; and the zeta potential measurements identified the high chargeability of Fe2O3-CHNPs. Furthermore, the resulting nanoparticles were successfully applied in the electrophoretic display cell, which demonstrated that it was an effective approach to preparing chromatic elec- trophoretic particles.
文摘用溶胶-凝胶法制得Cu/Fe2O3-TiO2光催化材料。用XRD、Ram an、TPR、IR、TEM、UV-V is DRS测试技术和光催化反应等对固体材料的结构和性能进行了表征。结果表明,Fe2O3的质量分数为10%时,在TiO2表面以单分子层分散,Fe2O3的引入使TiO2吸光限蓝移。Fe2O3含量超过单分子层分散时,有晶相Fe2O3生成,光吸收性能下降。Fe—O—Ti键的形成加强了半导体之间的相互作用,有利于光生载流子在半导体间的输送。少量Cu的引入,使复合材料的吸光域向可见光范围扩展。光催化反应性能与材料的光响应能力密切相关。在光催化CO2和CH3NH2直接合成NH2CH2COOH的反应中,负载质量分数为10%Fe2O3的光催化反应性能最优。在120℃、常压、空速200 h-1、CO2与CH3NH2摩尔比为1∶1和6.5×10-4W/cm2的紫外灯照射下,CH3NH2转化率为1.35%,NH2CH2COOH选择性达92.0%。
