DYNAMICS OF DISCLINATIONS IN NEMATIC LIQUID-CRYSTAL MAIN-CHAIN POLYMER-FILMS

With observation of the time evolution of the disclination density in nematic films consisting of thermotropic liquid-crystal main-chain polymers, a subsequent decrease of disclination density after sudden heating to the nematic phase has been found.3,4 Shiwaku et al. and Hashimoto et al. reported that the measured time dependence of the average distance, d, between two adjacent disclinations is fairly well fitted by assuming the scaling relation d ~ t035, i.e. the disclination density, p, should decay as ρ ~ t0,7. We propose a simple mean-field theory, which is based on results for diffusion reaction systems of the type A + B ->· 0 where A and B correspond to the two different types of end points of a disclination line, respectively. With our results the measured time dependence of ρ is described slightly better than by the simple algebraic relation since the measured tendency of In p(t) versus In t toward a convex function is reproduced. © 1990, American Chemical Society. All rights reserved.