Liquid crystals （LCs） and polymers are extensively used in various electro-optical applications. In this paper, normal mode polymer stabilized cholesteric LC film is prepared and studied. The effects of chiral dopan...Liquid crystals （LCs） and polymers are extensively used in various electro-optical applications. In this paper, normal mode polymer stabilized cholesteric LC film is prepared and studied. The effects of chiral dopant and monomer concentrations on the electro-optical properties, such as contrast ratio, driving voltage, hysteresis width and response time, are investigated. The reasons of electro-optical properties influenced by the concentrations of the materials are discussed. Through the proper material recipe, the electro-optical properties of polymer stabilized cholesteric LC film can be optimized.展开更多
An epoxy-based precursor polymer was prepared from the diglycidyl ether of Bisphenol A and aniline.The precursor polymer was doped with a certain amount of cross-linking agent M20S to obtain a thermal-curable polymeri...An epoxy-based precursor polymer was prepared from the diglycidyl ether of Bisphenol A and aniline.The precursor polymer was doped with a certain amount of cross-linking agent M20S to obtain a thermal-curable polymeric system BPAN+M20S.The thermal curing behavior of BPAN+M20S was studied by means of in-situ infrared spectroscopy and it was found that BPAN+M20S showed significant thermal-curability and had the similar curing dynamics at both 120℃ and 180℃.The curing degree can reach 70 7% at 120℃ and 81 8% at 180℃ within 20 min,respectively.When a two-layer film was prepared with the cured polymer BPAN+M20S as the bottom cladding and an E.O.polymer BPAN-1A-NT as the upper layer,SEM studies showed a perfect interface between the bottom and the upper layers of the two-layer film and the surface of the upper layer was quite smooth.A polymeric planar prototype waveguide,which was fabricated based on the above two-layer film and covered by another layer of UV photoresist,showed good wave-guide performance.展开更多
A polymer dispersed liquid crystal (PDLC) film that has good electro-optical properties is produced by the method of polymerized-induced phase separation. Based on the application foreground, its capability parameters...A polymer dispersed liquid crystal (PDLC) film that has good electro-optical properties is produced by the method of polymerized-induced phase separation. Based on the application foreground, its capability parameters, such as contrast ratio, work voltage, and visual angle, are characterized for the first time by a white light but not a fixed wavelength light. The results show the PDLC film has a low work-voltage of 20 V, more than 150° visual angle, high stability, and long lifetime. The differences between plastic and glass ITO-coated substrates of PDLC films are also studied in this paper. The plastic substrate has better property and will have a wider perspective especially in the portable, tender and folded display devices. Due to adjustable properties of film by electric field, PDLC has the potential application for display device, sensor, switch, grating, and new generation analytical apparatus.展开更多
2-Hydroxyethyl methacrylate (HEMA) and styrene copolymers are prepared by photopolymerization. The electrooptical behavior and microstructure of the polymer dispersed liquid crystal films are investigated by using He-...2-Hydroxyethyl methacrylate (HEMA) and styrene copolymers are prepared by photopolymerization. The electrooptical behavior and microstructure of the polymer dispersed liquid crystal films are investigated by using He-Ne laser and scanning electron microscopy, respectively. With increasing E7 content in the copolymer, droplet size increased, threshold voltage decreased.展开更多
Binary polymer blends that can form hydrogen-bond networks were prepared and used to fabricate the guest-host organic electrooptic （EO） materials. The hydrogen-bonds network in the solid films of novel guest-host or...Binary polymer blends that can form hydrogen-bond networks were prepared and used to fabricate the guest-host organic electrooptic （EO） materials. The hydrogen-bonds network in the solid films of novel guest-host organic EO materials was verified by FT-IR spectra. After corona poling, two kinds of EO films revealed the maximum EO coefficient value （r 33 ） of 19.5 and 30 pm/V at the wavelength of 1310 nm. The EO activity and the order parameter of the chromophores in the poled films both indicated that the hydrogen-bond network has little impact on the motion of the chromophores while poling. These new EO films exhibited better temporal stability after 250 h at 55 and 85 °C compared with the conventional guest-host systems that have the similar or higher T g s. Moreover, the results also indicated that polymer blends as the host of EO materials can change the dielectric strength of the materials, which directly influence the poling efficiency.展开更多
基金Project partially supported by the National Natural Science Foundation of China （Grant Nos. 60736042, 60578035 and 50703039） and the Science Foundation of Jilin Province of China （Grant Nos. 20050520 and 20050321-2）.
文摘Liquid crystals （LCs） and polymers are extensively used in various electro-optical applications. In this paper, normal mode polymer stabilized cholesteric LC film is prepared and studied. The effects of chiral dopant and monomer concentrations on the electro-optical properties, such as contrast ratio, driving voltage, hysteresis width and response time, are investigated. The reasons of electro-optical properties influenced by the concentrations of the materials are discussed. Through the proper material recipe, the electro-optical properties of polymer stabilized cholesteric LC film can be optimized.
文摘An epoxy-based precursor polymer was prepared from the diglycidyl ether of Bisphenol A and aniline.The precursor polymer was doped with a certain amount of cross-linking agent M20S to obtain a thermal-curable polymeric system BPAN+M20S.The thermal curing behavior of BPAN+M20S was studied by means of in-situ infrared spectroscopy and it was found that BPAN+M20S showed significant thermal-curability and had the similar curing dynamics at both 120℃ and 180℃.The curing degree can reach 70 7% at 120℃ and 81 8% at 180℃ within 20 min,respectively.When a two-layer film was prepared with the cured polymer BPAN+M20S as the bottom cladding and an E.O.polymer BPAN-1A-NT as the upper layer,SEM studies showed a perfect interface between the bottom and the upper layers of the two-layer film and the surface of the upper layer was quite smooth.A polymeric planar prototype waveguide,which was fabricated based on the above two-layer film and covered by another layer of UV photoresist,showed good wave-guide performance.
基金Supported by the National Natural Science Foundation of China (Grant No. 20575021)
文摘A polymer dispersed liquid crystal (PDLC) film that has good electro-optical properties is produced by the method of polymerized-induced phase separation. Based on the application foreground, its capability parameters, such as contrast ratio, work voltage, and visual angle, are characterized for the first time by a white light but not a fixed wavelength light. The results show the PDLC film has a low work-voltage of 20 V, more than 150° visual angle, high stability, and long lifetime. The differences between plastic and glass ITO-coated substrates of PDLC films are also studied in this paper. The plastic substrate has better property and will have a wider perspective especially in the portable, tender and folded display devices. Due to adjustable properties of film by electric field, PDLC has the potential application for display device, sensor, switch, grating, and new generation analytical apparatus.
文摘2-Hydroxyethyl methacrylate (HEMA) and styrene copolymers are prepared by photopolymerization. The electrooptical behavior and microstructure of the polymer dispersed liquid crystal films are investigated by using He-Ne laser and scanning electron microscopy, respectively. With increasing E7 content in the copolymer, droplet size increased, threshold voltage decreased.
文摘基于电光聚合物,提出了一种结构简单,尺寸小,效率高的表面等离激元(SPP)调制器.该调制器采用M-Z干涉仪结构的金属波导,金属周围是均匀极化后的电光聚合物,通过在金属波导两臂间加电压对聚合物折射率进行调制,折射率调制再通过M-Z干涉仪结构转化为对金属波导中SPP强度的调制.通过求解金属波导附近的电场分布,并结合SPP场分布的特点,在理论上说明了这种结构可以通过外加电压有效地调制金属波导输出端SPP的强度,调制所需的半波电压约为2.8 V.
基金the Directional Program of the Chinese Academy of Sciences(KJCX2.YW.H02)Innovation Fund of Chinese Academy of Sciences(CXJJ-11-M035)the National Natural Science Foundation of China(61101054)for financial support
文摘Binary polymer blends that can form hydrogen-bond networks were prepared and used to fabricate the guest-host organic electrooptic （EO） materials. The hydrogen-bonds network in the solid films of novel guest-host organic EO materials was verified by FT-IR spectra. After corona poling, two kinds of EO films revealed the maximum EO coefficient value （r 33 ） of 19.5 and 30 pm/V at the wavelength of 1310 nm. The EO activity and the order parameter of the chromophores in the poled films both indicated that the hydrogen-bond network has little impact on the motion of the chromophores while poling. These new EO films exhibited better temporal stability after 250 h at 55 and 85 °C compared with the conventional guest-host systems that have the similar or higher T g s. Moreover, the results also indicated that polymer blends as the host of EO materials can change the dielectric strength of the materials, which directly influence the poling efficiency.
