A photophysical study of the interactions in poly(styrene-4-sulphonate)-n-butylvinylether block and random copolymers

A photophysical study of the interactions in poly(styrene-4-sulphonate)-n-butylvinylether block and random copolymers

Autor Neumann, M. G. Google Scholar
Sena, G. L. de Google Scholar
Instituição Universidade Federal de São Paulo (UNIFESP)
Univ Fed Espirito Santo
Resumo Interactions between the moieties responsible for the conformations and hydrophobic microdomains in poly(styrene-4-sulphonate) (PSS) and its copolymers with n-butylvinylether (BVE) were studied by their emission spectra and the lifetimes of the phenyl groups and pyrene used as a photochemical probe. the emission spectra of PSS shows bands due to dimers and higher aggregates as well as the characteristic excimer band. At low concentrations, the random copolymers have spectra similar to that of the free monomer, whereas the block copolymers have spectra like that of PSS. At higher concentrations, the random copolymer also shows these excimer bands, due to inter-chain interactions. Results from the emission of pyrene prove that the behaviour of the copolymers with approximately 40% BVE seems to be relatively independent of having random or block configurations. Except at low concentrations (< 0.05 g/dl), where the block copolymer already has a conformation with stable hydrophobic microdomains, both types of copolymers behave similarly. There is an initial aggregate equilibrium between individual chains and aggregates, associated with a relocation of the probes. At higher concentrations, both copolymers suffer a severe change in conformation, due to the formation of stable hydrophobic microdomains, resulting from interchain interactions. in both cases the lifetimes of pyrene are of the order of 240 +/- 10 ns.
Palavra-chave polyelectrolytes
poly(styrene sulphonate)
hydrophobic microdomains
Idioma Inglês
Data de publicação 1999-05-01
Publicado em Colloid and Polymer Science. New York: Springer Verlag, v. 277, n. 5, p. 414-421, 1999.
ISSN 0303-402X (Sherpa/Romeo, fator de impacto)
Publicador Springer
Extensão 414-421
Fonte http://dx.doi.org/10.1007/s003960050403
Direito de acesso Acesso restrito
Tipo Artigo
Web of Science WOS:000080265400002
Endereço permanente http://repositorio.unifesp.br/handle/11600/26070

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