Atomic force microscopy on ethyl-cyanoethyl cellulose polyacrylic acid composites with cholesteric order

Ultra-thin slices of ethyl-cyanoethyl cellulose [(E-CE)C]/polyacrylic acid [PAA] composites with cholesteric order were prepared by ultra-microtoming and observed by atomic force microscopy (AFM). The morphology of a periodic lamellar structure in the composites with cholesteric order was revealed, which was induced by the twist of the molecular orientation in the cholesteric phase, and it reflected the structural features of the cholesteric phase in the systems. It was found that microphase separation appears even when the composites are prepared by photopolymerization, and the dimensions of the microphases are generally smaller than 200 nm. The structural features of the cholesteric phase were not influenced by the microphase separation. (C) 1998 Elsevier Science Ltd. All rights reserved.