A kind of novel liquid crystalline oxetane monomers containing biphenyl, flexible spacer and cinnamoyl group was synthesized. The monomer was initiated to polymerize by boron trifluoride etherate and resulted in photo...A kind of novel liquid crystalline oxetane monomers containing biphenyl, flexible spacer and cinnamoyl group was synthesized. The monomer was initiated to polymerize by boron trifluoride etherate and resulted in photoreactive polymer, which was highly sensitive to the LPL photochemically. The thermal properties and the mesophase structure of the polymer were investigated by DSC and thermal optical polarized microscope. Three exothermal peaks corresponding to an isotropic-nematic transition, nematic-smectic transition and smectic-crystal transition, respectively, were found on the DSC cooling curve of the polymer. Well-developed fan texture was observed by optical polarizing microscope. The polymer was spin-coated on a SiO-2 glass substrate from DMF solution, resulting in a thin film. Irradiation of a LP-UV light resulted in anisotropic cycloadditions of the cinnamon acyl groups, which caused the alignment of biphenyl groups in side chains at the same time. The differences of absorbance at different irradiation time were obtained which can be used to explain that the polymer can be applied in photoalignment layer.展开更多
Sr-doped nanostructured crystalline TiO2 microspheres were fabricated by modifying the bare microspheres with the method of soaking in strontium nitrate solution and heat treatment.The morphology,crystal structure and...Sr-doped nanostructured crystalline TiO2 microspheres were fabricated by modifying the bare microspheres with the method of soaking in strontium nitrate solution and heat treatment.The morphology,crystal structure and photoabsorption ability were characterized by scanning electron microscopy（SEM）,X-ray diffraction（XRD） and UV-Vis spectrophotometer.The observation of SEM showed that both the bare and Sr-doped microspheres presented the same honeycomb porous morphology.The XRD spectra affirmed that the incorporation of Sr was in the form of strontium titanate(SrTiO3) as eutectic structure with anatase TiO2.The photocatalytic efficiency of Sr-doped TiO2 microspheres was assessed by monitoring the photodecomposition of KN-R dye.The results reveal that Sr-doped microspheres provided a higher efficiency than the unmodified,which was consistent with the analysis results of UV-Vis absorption spectra.Obvious phenomenon of red-shift on UV-Vis spectrum was seen in comparison with the bare microspheres.Both the phenomena of red-shift and the photocatalytic activity improvement were attributed to the synergistic action between SrTiO3 and anatase TiO2.展开更多
文摘A kind of novel liquid crystalline oxetane monomers containing biphenyl, flexible spacer and cinnamoyl group was synthesized. The monomer was initiated to polymerize by boron trifluoride etherate and resulted in photoreactive polymer, which was highly sensitive to the LPL photochemically. The thermal properties and the mesophase structure of the polymer were investigated by DSC and thermal optical polarized microscope. Three exothermal peaks corresponding to an isotropic-nematic transition, nematic-smectic transition and smectic-crystal transition, respectively, were found on the DSC cooling curve of the polymer. Well-developed fan texture was observed by optical polarizing microscope. The polymer was spin-coated on a SiO-2 glass substrate from DMF solution, resulting in a thin film. Irradiation of a LP-UV light resulted in anisotropic cycloadditions of the cinnamon acyl groups, which caused the alignment of biphenyl groups in side chains at the same time. The differences of absorbance at different irradiation time were obtained which can be used to explain that the polymer can be applied in photoalignment layer.
文摘Sr-doped nanostructured crystalline TiO2 microspheres were fabricated by modifying the bare microspheres with the method of soaking in strontium nitrate solution and heat treatment.The morphology,crystal structure and photoabsorption ability were characterized by scanning electron microscopy（SEM）,X-ray diffraction（XRD） and UV-Vis spectrophotometer.The observation of SEM showed that both the bare and Sr-doped microspheres presented the same honeycomb porous morphology.The XRD spectra affirmed that the incorporation of Sr was in the form of strontium titanate(SrTiO3) as eutectic structure with anatase TiO2.The photocatalytic efficiency of Sr-doped TiO2 microspheres was assessed by monitoring the photodecomposition of KN-R dye.The results reveal that Sr-doped microspheres provided a higher efficiency than the unmodified,which was consistent with the analysis results of UV-Vis absorption spectra.Obvious phenomenon of red-shift on UV-Vis spectrum was seen in comparison with the bare microspheres.Both the phenomena of red-shift and the photocatalytic activity improvement were attributed to the synergistic action between SrTiO3 and anatase TiO2.
