Effect of Composition on The Morphology and Electro-Optical Properties of Physically Crosslinked Liquid Crystals

Addition of an ABA triblock copolymer to a midblock-selective solvent can, depending on copolymer/blend composition and the magnitude of block-block and block-solvent interactions, result in the formation of a physical network that is stabilized by aggregates of the incompatible A-block. In this work, an ABA copolymer with a nematic side-chain liquid crystal midblock is added to a low-molar-mass nematic liquid crystal (LC) in an effort to produce a comparable copolymer network and bind the LC matrix. This nanostructured system, designated a physically crosslinked liquid crystal (PCLC), may not suffer as much from the constraint-induced LC anchoring problems associated with conventional polymer-dispersed liquid crystals (PDLCs). Results presented here demonstrate that hierarchical phase behavior must be carefully considered in the design of PCLCs.