Molecular Design of Side-Group Liquid Crystalline Polymers: Understanding Their Interactions with Small Molecule Liquid Crystal Solvent

Citation

Kurji, Zuleikha (2013) Molecular Design of Side-Group Liquid Crystalline Polymers: Understanding Their Interactions with Small Molecule Liquid Crystal Solvent. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/Z9WH2N6R. https://resolver.caltech.edu/CaltechTHESIS:06102013-114658448

Abstract

Liquid crystal (LC) gels – the combination of macromolecules with small molecule LCs – couple the elasticity and mechanical strength of polymers to the order inherent to LCs and are attractive to many researchers hoping to marry liquid crystals' optical and electro-optical responsiveness with polymers' mechanical strength and ease of processing. In particular, side-group liquid crystal polymers (SGLCPs) are flexible-chain polymers that are functionalized with LC side-groups. Here we introduce the concept of polymer dopants: homogenously dissolved LC-containing SGLCP homopolymers that are molecularly designed for solubility in and coupling to small molecule LC solvents. Using polymer analogous chemistry (changing the molecular makeup of the side groups and their linkers, while keeping backbone molecular weight, polydispersity index, and degree of polymerization constant), we’ve targeted the effect of side-group orientation, dipole position and strength, spacer length and linking-group type on polymer solubility and bulk material properties. We've shown that, at low concentration, these dopants can have significant effects on the bulk material properties of two types of LCs: ferroelectric and vertically aligned nematic LCs.

Thesis Files