Self-organization of double-chained and pseudodouble-chained surfactants: counterion and geometry effects

• Tipo: Artigo em Revista Científica Internacional
• Data: 2003

Autores

Marques, EF (Autor) FCUP; Regev, O (Autor) Outra; Khan, A (Autor) Outra; Lindman, B (Autor) Outra

Revista

Título: Advances in Colloid and Interface Science

Vol. 100

Páginas: 83-104

ISSN: 0001-8686

Editora: Elsevier

Indexação

ISI Web of Knowledge - 165 Citações

Scopus - 169 Citações

Classificação Científica

FOS: Ciências exactas e naturais > Química

Outras Informações

ID Authenticus: P-000-HQ8

DOI: 10.1016/s0001-8686(02)00068-4

Abstract (EN): Self-organization in aqueous systems based on ionic surfactants, and their mixtures, can be broadly understood by a balance between the packing properties of the surfactants and double-layer electrostatic interactions. While the equilibrium properties of micellar systems have been extensively studied and are understood, those of bilayer systems are less well characterized. Double-chained and pseudodouble-chained (or catanionic) surfactants are among the amphiphiles which typically form bilayer structures, such as lamellar liquid-crystalline phases and vesicles. In the past 10-15 years, an experimental effort has been made to get deeper insight into their aggregation patterns. With the double-chained amphiphiles, by changing counterion, adding salt or adding anionic surfactant, there are possibilities to depart from the bilayer aggregate in a controlled manner. This is demonstrated by several studies on the didodecyldimethylammonium bromide surfactant. Mixtures of cationic and anionic surfactants yield the catanionics, surfactants of the swelling type, and also show a rich phase behavior per se. A variety of liquid-crystalline phases and, in dilute regimes, equilibrium vesicles and different micellar shapes are often encountered. Phase diagrams and detailed structural studies, based on several techniques (NMR, microscopy and scattering methods), have been reported, as well as theoretical studies. The main features and conclusions emerging from such investigations are presented.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 22