| 초록 |
Liquid crystal alignment properties were investigated in liquid crystal (LC) cells fabricated with poly(3-thiopheneacetate)/dialkyldimethylammonium (PTA-Cns) complexes, where n is the number of carbon atoms in the alkyl groups in dialkyldimethylammonium bromide. Homeotropic LC alignment was observed in PTA-Cn LC cells containing long alkyl groups (n= 14, 16, 18) with high pretilt angles. LC cells fabricated from PTA-C10 and PTA-C12 showed random alignment behavior. The surface orientational order parameters of the alkyl groups of PTA-Cn films were estimated by near edge X-ray absorption fine structure (NEXAFS) spectroscopy, producing values of 0.040, 0.111, 0.153, 0.151 and 0.170 for PTA-C10, PTA-12 PTA-14, PTA-16 and PTA-18, respectively. Therefore, homeotropic LC alignment behavior correlated well with the order of alkyl groups on the complex surface. |
