With interfering illumination of Ar++ laser beams (488 nm),surface relief gratings (SRGs) were photo-inscribed on epoxy-based azo polymer (BP-AZ-CN) films.The modulation depth was about 160 nm and the spatial period w...With interfering illumination of Ar++ laser beams (488 nm),surface relief gratings (SRGs) were photo-inscribed on epoxy-based azo polymer (BP-AZ-CN) films.The modulation depth was about 160 nm and the spatial period was about 670 nm.The quartz slides covered with SRG films were assembled to liquid crystal (LC) cell to study the LC alignment behavior.Homogeneous liquid crystal alignment was observed in the surface relief gratings regions of the LC cell.Alignment of LC molecules was monitored by measuring the transmittance passing through the cell between crossed polarizers as a function of the angle of the cell rotating around the experiment optical axis.The transmittance changed periodically with a regular 90° separation of the rotational angle and the pretilt angle of the cell was found to be 3.2°.This alignment technique could have useful applications in the future LC displays.展开更多
A new kind of amorphous molecular materials containing azobenzene chromophors has been synthesized.The precursor molecule was prepared by esterification between 1,3,5-benzenetricarbonyl chloride and N-ethyl-N-hydroxye...A new kind of amorphous molecular materials containing azobenzene chromophors has been synthesized.The precursor molecule was prepared by esterification between 1,3,5-benzenetricarbonyl chloride and N-ethyl-N-hydroxyethyl-aniline.The precursor molecule was then reacted with the diazonium salts of 5-aminoisophthalic acid to introduce donor-acceptor azobenzene chromophores at the peripheral groups.The azobenzene amorphous molecular material was characterized by the spectroscopic methods and thermal analysis.The azo compound synthesized can form stable amorphous glass.The amorphous molecular material was used to fabricate surface relief gratings(SRG) by exposing spin-coated thin films of the azo compound to an interference pattern of Ar^+ laser beams at modest intensity(120 mW/cm^2).The surface modulation was about 390 nm and the first order of diffraction efficiency was up to 23%.展开更多
Multilayer films of a polyacrylate-based azo polyelectrolyte were fabricated by a spin self-assembly method.By spin-coating solutions of the azo polyelectrolyte in DMF/H2O mixed solvent and polydiallyldimethylammonium...Multilayer films of a polyacrylate-based azo polyelectrolyte were fabricated by a spin self-assembly method.By spin-coating solutions of the azo polyelectrolyte in DMF/H2O mixed solvent and polydiallyldimethylammonium chloride（PDAC） in water,high quality multilayer films were obtained.Dichroism was optically induced in the self-assembled films under the irradiation of a polarized Ar+ laser beam at 488 nm.The dichroism was easily detected from UV-Vis spectra and exhibited long term stability.The orientational order parameter obtained was about 0.06 for the film.With interfering illumination of Ar+ laser beams,significant surface relief gratings formed on the self-assembled multiplayer films were observed.展开更多
A novel polyelectrolyte PNANT functionalized with electron donor-acceptor type azobenzene chromophores has been synthesized through post-polymerization azo coupling reaction and characterized by 1H-NMR,FTIR and UV-Vis...A novel polyelectrolyte PNANT functionalized with electron donor-acceptor type azobenzene chromophores has been synthesized through post-polymerization azo coupling reaction and characterized by 1H-NMR,FTIR and UV-Vis spectroscopy.The degree of functionalization (DF) of PNANT was 20% measured by elemental analysis.The degree of polymerization and its distribution were determined by GPC to be X n=251 with a polydispersion index 1.53.A glass transition temperature of 119℃ was observed from DSC thermogram. H-aggregation of azo chromophores of PNANT in spin-coated film and self-assembled film were detected from UV-Vis spectra,and the degree of H-aggregation of PNANT in the self-assembled film was found to be higher than that in the spin-coated film.Dichroism was optically induced in the spin-coated film and self-assembled film upon the irradiation of a polarized Ar + laser beam at 488 nm.The orientational order parameter obtained was 0.15 for spin-coated film and 0.07 for the self-assembled film.The resulting dichroism detected by UV-Vis spectra exhibited long-term stability.展开更多
文摘With interfering illumination of Ar++ laser beams (488 nm),surface relief gratings (SRGs) were photo-inscribed on epoxy-based azo polymer (BP-AZ-CN) films.The modulation depth was about 160 nm and the spatial period was about 670 nm.The quartz slides covered with SRG films were assembled to liquid crystal (LC) cell to study the LC alignment behavior.Homogeneous liquid crystal alignment was observed in the surface relief gratings regions of the LC cell.Alignment of LC molecules was monitored by measuring the transmittance passing through the cell between crossed polarizers as a function of the angle of the cell rotating around the experiment optical axis.The transmittance changed periodically with a regular 90° separation of the rotational angle and the pretilt angle of the cell was found to be 3.2°.This alignment technique could have useful applications in the future LC displays.
文摘A new kind of amorphous molecular materials containing azobenzene chromophors has been synthesized.The precursor molecule was prepared by esterification between 1,3,5-benzenetricarbonyl chloride and N-ethyl-N-hydroxyethyl-aniline.The precursor molecule was then reacted with the diazonium salts of 5-aminoisophthalic acid to introduce donor-acceptor azobenzene chromophores at the peripheral groups.The azobenzene amorphous molecular material was characterized by the spectroscopic methods and thermal analysis.The azo compound synthesized can form stable amorphous glass.The amorphous molecular material was used to fabricate surface relief gratings(SRG) by exposing spin-coated thin films of the azo compound to an interference pattern of Ar^+ laser beams at modest intensity(120 mW/cm^2).The surface modulation was about 390 nm and the first order of diffraction efficiency was up to 23%.
文摘Multilayer films of a polyacrylate-based azo polyelectrolyte were fabricated by a spin self-assembly method.By spin-coating solutions of the azo polyelectrolyte in DMF/H2O mixed solvent and polydiallyldimethylammonium chloride（PDAC） in water,high quality multilayer films were obtained.Dichroism was optically induced in the self-assembled films under the irradiation of a polarized Ar+ laser beam at 488 nm.The dichroism was easily detected from UV-Vis spectra and exhibited long term stability.The orientational order parameter obtained was about 0.06 for the film.With interfering illumination of Ar+ laser beams,significant surface relief gratings formed on the self-assembled multiplayer films were observed.
文摘A novel polyelectrolyte PNANT functionalized with electron donor-acceptor type azobenzene chromophores has been synthesized through post-polymerization azo coupling reaction and characterized by 1H-NMR,FTIR and UV-Vis spectroscopy.The degree of functionalization (DF) of PNANT was 20% measured by elemental analysis.The degree of polymerization and its distribution were determined by GPC to be X n=251 with a polydispersion index 1.53.A glass transition temperature of 119℃ was observed from DSC thermogram. H-aggregation of azo chromophores of PNANT in spin-coated film and self-assembled film were detected from UV-Vis spectra,and the degree of H-aggregation of PNANT in the self-assembled film was found to be higher than that in the spin-coated film.Dichroism was optically induced in the spin-coated film and self-assembled film upon the irradiation of a polarized Ar + laser beam at 488 nm.The orientational order parameter obtained was 0.15 for spin-coated film and 0.07 for the self-assembled film.The resulting dichroism detected by UV-Vis spectra exhibited long-term stability.
