Mesomorphic Properties of a Homologous Series of Liquid Crystals with Short Fluorocarbon Chain
摘要:
A homologous series of short fluorocarbon chain-containing liquid crystals has been synthesized. Several of them show the phase sequence N --> SmA --> SmC in the cooling process from the isotropic liquid. The mesomorphic properties have been studied by polarizing microscopy and DSC measurements. The thermostability of SmC phases was enhanced along with the lengthening of fluorocarbon chains.
Mesomorphic Properties of a Homologous Series of Liquid Crystals with Short Fluorocarbon Chain
摘要:
A homologous series of short fluorocarbon chain-containing liquid crystals has been synthesized. Several of them show the phase sequence N --> SmA --> SmC in the cooling process from the isotropic liquid. The mesomorphic properties have been studied by polarizing microscopy and DSC measurements. The thermostability of SmC phases was enhanced along with the lengthening of fluorocarbon chains.
Callimatic and T-shaped liquid crystalline compounds with fluorinated terminal groups
作者:V. V. Zuev
DOI:10.1134/s1070363208090119
日期:2008.9
A series of liquid crystalline polyesters with a rigid T-shaped or a stick-like mesogenic fragment and fluorinated terminal groups of various structures was synthesized and studied by means of polarization optical microscopy, differential scanning calorimetry, and IR and H-1 NMR spectroscopy. It was shown that the effect of the fluorinated group on the thermostability of the mesophase depends on the shape of the mesogenic fragment. The thermostability of the mesophase in callimatic liquid crystalline compounds with perfluorinated terminal groups is higher and in those with difluoromethyl terminal groups containing one hydrogen atom is lower compared with their alkyl analogs. This is connected with the possibility of weak hydrogen bonding that destroys the liquid crystalline order. The thermostability of the mesophase in compounds with a T-shaped mesogenic fragment and any fluorinated terminal groups is always higher compared with their alkyl analogs.
Mesomorphic Properties of a Homologous Series of Liquid Crystals with Short Fluorocarbon Chain
作者:Y. G. Yang、G. Tang、J. X. Wen
DOI:10.1080/10587250210547
日期:2002.1.1
A homologous series of short fluorocarbon chain-containing liquid crystals has been synthesized. Several of them show the phase sequence N --> SmA --> SmC in the cooling process from the isotropic liquid. The mesomorphic properties have been studied by polarizing microscopy and DSC measurements. The thermostability of SmC phases was enhanced along with the lengthening of fluorocarbon chains.