title: π-conjugation and conformation in a semiconducting polymer: small angle x-ray scattering study.
abstract: Small angle x-ray scattering (SAXS) in a poly[2-methoxy-5-(2'-ethyl-hexyloxy)-1,4-phenylene vinylene] (MEH-PPV) solution has shown the important role of π-electron conjugation in controlling the chain conformation and assembly. By increasing the extent of conjugation from 30 to 100%, the persistence length (l(p)) increases from 20 to 66 Å. Moreover, a pronounced second peak in the pair distribution function has been observed in a fully conjugated chain, at larger length scales. This feature indicates that the chain segments tend to self-assemble as the conjugation along the chain increases. Xylene enhances the rigidity of the PPV backbone to yield extended structures, while tetrahydrofuran solvates the side groups to form compact coils in which the l(p) is much shorter.
authors.affiliation: Department of Physics, Indian Institute of Science, Bangalore 560012, India.
authors.forename: Paramita Kar
authors.initials: PK
authors.lastname: Choudhury
authors.forename: Debjani
authors.initials: D
authors.lastname: Bagchi
authors.forename: Reghu
authors.initials: R
authors.lastname: Menon