Morphology of Polymer/Liquid-Crystal Nanotubes: Influence of Confinement

Authors


  • The authors thank Silko Grimm for the preparation of the templates. This work was supported by the German Science Foundation (WE496/19-2, WE 496/26-1, STE 1127/2-1), and in the framework of the “Nanotechnology Support Project” of the Japanese Ministry of Education, Culture, Sports, Science and Technology (MEXT). A. K. S. is grateful for a fellowship funding by JSPS/DAAD, and S. M. acknowledges financial support by the Studienstiftung des Deutschen Volkes.

Abstract

Polymer/liquid-crystal (LC) tubes consisting of an approximately 30 nm thick poly(methyl methacrylate) (PMMA) layer on the outside and a 5 to 10 nm thick discotic liquid-crystalline layer on the inside of the tube walls have been prepared by wetting ordered porous alumina templates with a pore diameter of 400 nm. Decreasing the pore diameter to 60 nm results in a confinement-induced transition from a wetting state to a non-wetting state, and solid rods with a sequential morphology are obtained. The texture of the mesophase depends on the morphology type and the thermal history. Under certain conditions the LC mesophase exhibits a dominant, well-ordered planar texture where the discotic columns are aligned with the long axes of the tubes. The controlled generation of one-dimensional nano-objects possessing mesoscopic fine structures and intrinsic anisotropy should be the first step towards a rational design of miniaturized building blocks.

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