Nanoscale Fibrils and Grids: Aggregated Structures from Rigid-Rod Conjugated Polymers.

TitleNanoscale Fibrils and Grids: Aggregated Structures from Rigid-Rod Conjugated Polymers.
Publication TypeJournal Article
Year of Publication1999
AuthorsKim, J, McHugh, SK, Swager, TM
Keywordsfibril structure polyphenylene polyacetylene aggregation phase transition, polyphenylene ethynylene Langmuir Blodgett processing aligned film, supramol structure rigid rod polyphenylene ethynylene reorganization

Langmuir-Blodgett (LB) mol. processing of conjugated polymers [poly(phenylene ethynylenes)] into highly aligned films has revealed conditions for the formation of liq. cryst. monolayer films that structurally evolve into fibril aggregates. The structural requirements for poly(phenylene ethynylene)s to display liq. cryst. phases capable or alignment by LB methods were detd. The reconstruction of monolayers into fibril structures requires a low glass-transition temp. (Tg), weak surface anchoring, and a monolayer with a high energy that can be stabilized by reorganization. This assembly of polymers into aggregated structures produces rigid structural units analogous to naturally occurring fibrous proteins such as collagen and elastin. These oriented, shape-persistent nanoscale structures create new possibilities for the construction of complex supramol. structures, and this capability was demonstrated by the formation of a nanoscale grid. [on SciFinder(R)]