Because of low cost, fast response time, and high light transmittance, thin-film-transistor （TFT） driven twisted nematic （TN） liquid-crystal displays （LCDs） have been widely used in calculators, computer screens...Because of low cost, fast response time, and high light transmittance, thin-film-transistor （TFT） driven twisted nematic （TN） liquid-crystal displays （LCDs） have been widely used in calculators, computer screens, and cell phones. The pretilt angle of the TN medium within the TFT-TN panel affects not only its response times and view- ing angles but also the light-leakage positions of fringed- field-induced disclination lines within pixels of theTFT-TN panel.展开更多
In this study,a novel series of chiral 1,2-propanediol derivatives with different electron-donating and electron-withdrawing groups were synthesized and characterized by FT-IR and ~1H NMR.The helical twisting properti...In this study,a novel series of chiral 1,2-propanediol derivatives with different electron-donating and electron-withdrawing groups were synthesized and characterized by FT-IR and ~1H NMR.The helical twisting properties of all the chiral dopants were investigated by doping the chiral dopants into a nematic liquid crystal host（SLC-1717）.The results indicate that the donor-acceptor electron effect have a prominent influence on helical twisting property of the chiral nematic phase induced by the chiral dopants. Introducing electron-withdrawing groups into the terminal ends of chiral 1,2-propanediol can decrease the absolute values of the helical twisting power.In addition,the helix inversion temperatures of the induced chiral nematic phase are variational with the change of terminal groups.展开更多
文摘Because of low cost, fast response time, and high light transmittance, thin-film-transistor （TFT） driven twisted nematic （TN） liquid-crystal displays （LCDs） have been widely used in calculators, computer screens, and cell phones. The pretilt angle of the TN medium within the TFT-TN panel affects not only its response times and view- ing angles but also the light-leakage positions of fringed- field-induced disclination lines within pixels of theTFT-TN panel.
基金supported in part by the National Natural Science Foundation of China(No.51173155)the Hebei Province Science Foundation of China(No.E2010001182)
文摘In this study,a novel series of chiral 1,2-propanediol derivatives with different electron-donating and electron-withdrawing groups were synthesized and characterized by FT-IR and ~1H NMR.The helical twisting properties of all the chiral dopants were investigated by doping the chiral dopants into a nematic liquid crystal host（SLC-1717）.The results indicate that the donor-acceptor electron effect have a prominent influence on helical twisting property of the chiral nematic phase induced by the chiral dopants. Introducing electron-withdrawing groups into the terminal ends of chiral 1,2-propanediol can decrease the absolute values of the helical twisting power.In addition,the helix inversion temperatures of the induced chiral nematic phase are variational with the change of terminal groups.
