The paper describes an enhancement of the electroclinic characteristics of low molar mass dimeric organosiloxane liquid crystals. The degree of polymerisation of the siloxane core unit was varied in order to study the effect on phase transitions and electro-optic properties. It was found that the SmA*-SmC* phase transition temperature could be moved to any position in the range from 50°C to 10°C if we varied the number of SiMe₂ groups in the flexible linkage of the dimeric molecule. More importantly, because the organosiloxane liquid crystal material had some distribution of the number of SiMe₂ groups, it showed a rather broad SmA*-SmC* phase transition in contrast to the sharp phase transition of conventional electroclinic materials. The electroclinic coefficient reached the maximum value of 8 degrees/V/μm and was at least 1 degree/V/μm over a temperature range as broad as 10°C. The induced electroclinic tilt angle was as high as 22-23 degrees with good linearity and moderate applied electric fields.

Date Published: 28 May 2004
PDF: 9 pages
Proc. SPIE 5289, Liquid Crystal Materials, Devices, and Applications X and Projection Displays X, (28 May 2004); doi: 10.1117/12.532171

Published in SPIE Proceedings Vol. 5289:
Liquid Crystal Materials, Devices, and Applications X and Projection Displays X
Ming Hsien Wu; Liang-Chy Chien, Editor(s)