SHERP

Temperature Dependence of Molecular Orientation on the Surfaces of Semifluorinated Polymer Thin Films

Cited 0 time in webofscience Cited 81 time in scopus
Authors
Genzer, Jan; Sivaniah, Easan; Kramer, Edward J.; Wang, Jianguo; Körner, Hilmar; Char, Kookheon; Ober, Christopher K.; DeKoven, Benjamin M.; Bubeck, Robert A.; Fischer, Daniel A.; Sambasivan, Sharadha
Issue Date
1999-12-29
Publisher
American Chemical Society
Citation
Langmuir, 1999, 16, 1993-1997
Abstract
Near-edge X-ray absorption fine structure is used to investigate the temperature dependence of molecular orientation of semifluorinated liquid crystalline (SF-LC) mesogens, which are attached to the modified isoprene backbone of (i) a poly(1,2-isoprene) homopolymer and (ii) a diblock copolymer consisting of polystyrene and poly(1,2-isoprene) blocks. Our experiments reveal the existence of two temperature regions in which the surface orientation of the SF-LC mesogens changes abruptly, but even 30 K above the highest such temperature region the surface orientation does not become isotropic. The lower temperature surface transition for both homopolymer and block copolymer occurs close to the temperature of the bulk homopolymer smectic-B to smectic-A transition and well above the bulk smectic-B to smectic-A transition in the block copolymer. It seems to be controlled exclusively by the ordering phenomena originating from the surface. In contrast, the change in the surface organization of the SF-LC mesogens at higher temperatures can be associated with the bulk LC transition from the smectic-A to the isotropic phase.
ISSN
0743-7463 (print)
1520-5827 (online)
Language
English
URI
http://hdl.handle.net/10371/5764
DOI
https://doi.org/10.1021/la9910327
Files in This Item:
There are no files associated with this item.
Appears in Collections:
College of Engineering/Engineering Practice School (공과대학/대학원)Dept. of Chemical and Biological Engineering (화학생물공학부)Journal Papers (저널논문_화학생물공학부)
  • mendeley

Items in S-Space are protected by copyright, with all rights reserved, unless otherwise indicated.

Browse