Time-resolved SANS for surfactant phase transitions

Citation
Su. Egelhaaf et al., Time-resolved SANS for surfactant phase transitions, PHYSICA B, 276, 2000, pp. 326-329
Citations number
19
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
PHYSICA B
ISSN journal
0921-4526 → ACNP
Volume
276
Year of publication
2000
Pages
326 - 329
Database
ISI
SICI code
0921-4526(200003)276:<326:TSFSPT>2.0.ZU;2-S
Abstract
Surfactants spontaneously self-assemble in solution to form a variety of mi crostructures. Our understanding of the equilibrium properties of these agg regates, such as their shape and size, has made significant progress. Howev er, only limited information is available on the kinetics and pathways of p hase transitions and an the existence of nonequilibrium or metastable state s. Fortunately, this unsatisfactory situation can now be overcome owing to recent developments in small-angle neutron scattering (SANS) instrumentatio n which significantly improve the temporal and spatial resolution. These ne w, fascinating possibilities are illustrated by two examples. Firstly, time -resolved SANS reveals the structure of the intermediate in a spontaneous t ransition from micelles to vesicles in aqueous mixtures of lecithin and bil e salt. Secondly, a microemulsion containing spherical oil droplets is temp erature quenched into a two-phase situation where excess oil separates out. The nucleation and growth of the separating oil droplets is, again, follow ed by time-resolved SANS. (C) 2000 Elsevier Science B.V. All rights reserve d.