Association Characteristics of Copolymer Micelles in a Solvent Selective for the Middle Block

Autor:	Dennis G. Peiffer, Benjamin Chu, Zukang Zhou
Rok vydání:	1995
Předmět:	Copolymer composition Surfaces and Interfaces Condensed Matter Physics Micelle Krafft temperature Styrene Solvent chemistry.chemical_compound Chemical engineering chemistry Critical micelle concentration Polymer chemistry Electrochemistry Copolymer General Materials Science Long chain Spectroscopy
Zdroj:	Langmuir. 11:1956-1965
ISSN:	1520-5827 0743-7463
DOI:	10.1021/la00006a022
Popis:	A combination of static and dynamic light-scattering studies provides a clear picture concerning the temperature-dependent association behavior of a long chain triblock copolymer-(t-Bs) 385 S 770 (t-Bs) 385 (S and t-BS represent styrene and tert-butylstyrene, respectively) in N,N-dimethylacetamide, a selective solvent for the middle block. The so-called anomalous micellization has been consistently observed between the unimer and micelle regions, which can be ascribed to the copolymer composition heterogeneity. The self-assembly process is enthalpy-driven, yielding closed association structures in the form of flower-like micelles, but only at or below room temperatures. A much lower critical micelle temperature or a much higher critical micelle concentration as well as the reduced association number is characteristic of the triblock micelles as compared with the diblock copolymer micelles of the same composition. The entropy penalty associated with the loop formation largely reduces the micellization ability.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::63b434cf9a777694dd1a64b1f76ad9ea https://doi.org/10.1021/la00006a022 Zobrazit plný text záznamu