Alignment effects of the nematic liquid crystal on polythiophene Surfaces

Polythiophene막을 이용한 네마틱액정의 배향효과

The high pretilt angles in nematic liquid crystals (NLCs) have been generated on robbed polythiophene (PTP) surfaces with alkyl chain lengths. The pretilt angle of the NLC was observed on unidirectionally rubbed PTP surfaces with alkyl chains with more than 9 carbon atoms. We obtained the Pretilt angle of 15~40$^{\circ}$ on rubbed PTP surfaces with 10 carbon atoms in the a1ky1 chain. Also, the pretilt angles of 65~80$^{\circ}$ of NLC were obtained on rubbed PTP surfaces with 11 and 12 carbon atoms in the alkyl chain. We suggest that this high pretilt angle generation in NLC is due to the surface-excluded volume effect by the alkyl chain lengths between. the LCs and the PTP surfaces. Finally, we conclude the odd-even effect on rubbed PTP surfaces is clearly contributed to the pretilt angle generation.