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Accession Number:
ADA281205
Title:
Isomorphism Within the Hexagonal Columnar Mesophase of Molecular and Macromolecular Self- and Co-Assembled Columns Containing Tapered Groups
Descriptive Note:
Corporate Author:
CASE WESTERN RESERVE UNIV CLEVELAND OH DEPT OF MACROMOLECULAR SCIENCE
Report Date:
1994-06-30
Pagination or Media Count:
47.0
Abstract:
The phase behaviour of binary mixtures of self assembled tapering molecules based on monoesters of oligooxyethylene glycol and 3,4,5-tris4-n- dodecan-1-yloxybenzyloxybenzoic acid, their corresponding polymethacrylates, and of 4-methyl benzo-15-crown-3,4,5-tris4-n-dodecan-1-yloxybenzyloxy benzoate within their hexagonal columnar mesophase Phi sub h is described. The binary blends between molecular tapers co-assemble into a single supramolecular column resulting in isomorphism within their Phi sub h mesophase over the entire range of composition. The binary blends between polymetharylates containing tapered side groups co-assemble into a single phi sub h phase only when the columns of the parent polymers are of similar diameters. This results in binary mixtures which are isomorphic within the Phi sub h mesophase over the entire composition range. When the diameters of the columns formed by the parent polymers are dissimilar, isomorphic mixtures are obtained only over a narrow range of composition. Binary mixtures between molecular tapers and macromolecular systems containing tapered side groups co-assemble into a single column to the extent that intercalation of the molecular taper, within the column formed by the macromolecular system containing tapered side groups, is permissible. In all systems increased intra-columnar interactions can be induced by complexation of LiCF3SO3 by the oligooxyethylenic receptors and specific crown ether receptors and NaCF3SO3 as the third component are non-isomorphic within their Phi sub h phase due to preferential complexation of the alkali metal cation by the column of the crown ether containing the molecular taper. This results in two columns of dissimilar diameters, which are isomorphic in the Phi sub h phase only within a limited range of composition.
Distribution Statement:
APPROVED FOR PUBLIC RELEASE
