High performance liquid crystalline physical gels prepared by side chain liquid crystalline polymers

Abstract

Liquid crystalline physical gels (LCPGs) with stable mechanical properties and fast electro-optical response properties were prepared through the self-assembly of side chain liquid crystalline polymers (SCLCPs) with different spacer length poly [ω-4′-cyano-(1, 1′-biphenyl)] acrylate (PmACB, m is the spacer length of SCLCP, m = 0, 2, 4) as gelators in a nematic liquid crystal, 4-pentyl-4′-cyanobiphenyl (5CB). The gel-sol phase transition temperature (TGS), micro morphology, mechanical properties and electro-optical properties of LCPGs (SCLCPs/5CB) were systematically studied. The results show that only P0ACB can form stable liquid crystalline physical gels in 5CB and show excellent thermal stability, good self-supporting ability and fast electro-optical response properties. The TGS of 6 wt% P0ACB/5CB gel is 192 °C, and it also showed stable mechanical properties, its storage modulus is about 1.0 × 104 Pa. The threshold voltage (Vth) and saturation voltage (Vsat) of P0ACB/5CB gel with 3 wt% concentration are 0.29 V μm−1and 3.906 V μm−1 respectively, and the off state response time is only 6.748 ms. Moreover, the addition of the polymer does not affect the electro-optical response of the LCPGs.