Phase behavior and thermodynamics of a mixture of cationic gemini and anionic surfactant

• Tipo: Artigo em Revista Científica Internacional
• Data: 2006

Autores

Wang, YJ (Autor) FCUP; Bai, GY (Autor) FCUP; Marques, EF (Autor) FCUP; Yan, HK (Autor) Outra

Revista

Título: Journal of Physical Chemistry B

Vol. 110

Páginas: 5294-5300

ISSN: 1520-6106

Editora: American Chemical Society

Indexação

ISI Web of Knowledge - 41 Citações

Scopus - 42 Citações

Classificação Científica

FOS: Ciências exactas e naturais > Química

Outras Informações

ID Authenticus: P-004-MPS

DOI: 10.1021/jp054323z

Abstract (EN): We present the phase behavior and thermodynamics of the catanionic mixture of the gemini surfactant hexanediyl-alpha,omega-bis(dodecyidimethylammonium bromide), designated here as 12-6-12Bn(2), and sodium dodecyl sulfate (SIDS) over the full range of composition, at the water-rich corner. Visual and turbidity measurements of the mixtures provide some basic macroscopic information on phase behavior. The structure of the aggregates formed spontaneously in the mixtures has been observed with TEM. As the molar fraction of SDS, X(SDS), is increased, at constant total surfactant concentration, the aggregation morphologies change gradually from gemini-rich micelles, through multiphase regions containing a precipitate (catanionic surfactant) and a vesicle region, to SDS-rich micelles. From isothermal titration calorimetry measurements, the phase boundaries and corresponding enthalpy changes for phase transitions have been obtained. The formation of the different microstructures, in particular, the spontaneously formed vesicles in the SDS-rich side, is discussed on the basis of geometric and electrostatic effects occurring in the SDS-gemini mixture.

Idioma: Inglês

Tipo (Avaliação Docente): Científica