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Macromolecular cholesteric order observed by electron microscopy
Authors:Y Huang  J Loos  Y Q Yang  J Petermann
Abstract:The macromolecular cholesteric structure in the ethyl-cyanoethyl cellulose (E-CE)C]/acrylic acid AA] cholesteric liquid crystalline solutions is studied by directly observing the morphology and structure of the ethyl-cyanoethyl cellulose (E-CE)C]/polyacrylic acid PAA] using electron microscopy. A periodical lamellar structure is observed in ultrathin slices of the composites with cholesteric order by both transmission electron microscopy (TEM) and low-voltage scanning electron microscopy (LVSEM). It is suggested that the periodical lamellar structure is induced by the twist of the molecular orientation in the cholesteric phase and reflects the structural features of the macromolecular cholesteric phase. The macromolecular cholesteric phase exhibits the twisted ring morphology in the initial stage of the formation of the liquid crystalline phase. The swelling of the ultrathin slices with cholesteric order in water is heterogeneous, which suggests the tight packing of the (E-CE)C chains in the direction of the helix axis in the macromolecular cholesteric phase. © 1998 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 36: 439–445, 1998
Keywords:cholesteric order  electron microscopy  periodical lamellar structure  macromolecules
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