Medicinski vjesnik, Vol. 42 No. (3-4), 2010.
Izvorni znanstveni članak
Self-similarity of molecular association in double layers
Suzana Šegota
Nenad Jalšenjak
Đurđica Težak
Sažetak
Surfactant molecules association, growth and aggregation of selt associates into lamellar bilayers (flexible and closed), micelles, vesicles and liquid crystals, is considered to present important fundamental research with application to trans-membrane properties in the drug delivery and encapsulation. Among many practical applications, the amphiphilic aggregates present the possibility of using well defined bilayers and multilayers in the cosmetic and pharmaceutical industry. Associates of catanionic surfactants show a wide variety of particle shapes, sizes and structures, and due to that, the new materials of different properties could be prepared. Vesicles can be formed spontaneously as a result of self-association of flexible monolayers into unilamellar and multilamellar soft particles with closed bilayers. In this paper investigations have been performed in catanionic mixtures of Sodium n-dodecylbenzensulfonate (SDBS) and Didodecyldimetyl ammonium bromide (DDAB) in water, and in the water solutions of nonionic double-chain surfactant, 4-( 1 pentylheptyl)benzenesulfonate (6SDBS). Phase diagram, regions of micelles and vesicles formation, phase transitions, outer and inner structures of particles, were investigated by light scattering, small angle X-ray scattering, and other related methods, e.g., rheological measurements within pseudoisotropic regions that indicated the formation of micelles and vesicles as characterised by the critical micellisation and vesiculation concentrations. In addition, mesophases have been confirmed by polarisation and electron microscopy.
Ključne riječi
Aggregation; Association; Katanionic surface active agents; Light scattering; Micelles; Self-similarity; X-ray scattering, Vesicles
Hrčak ID:
191919
URI
Datum izdavanja:
1.12.2010.
Posjeta: 1.041 *