The phase diagram of the binary water/Brij58 system has been studied at constant temperature T = 20• C first by simple optical observation and then by small angle X-ray scattering. The small angle X-ray scattering patterns in the isotropic diluted phase are analyzed in a quantitative way by refining the experimental measurements with a model assuming hard spherical micelles in interaction. The micelles are described by a poly dispersed core-shell model and the interaction by the Perkus-Yevick hard-sphere model. The fitted parameters are analyzed in detail to determine the way polyoxyethylene blocks are hydrated with respect to the volumic fraction of water. In the more concentrated regime, the crystalline phases that are identified are the F m3m cubic, the 2D hexagonal and the lamellar phases. The structural parameters that describe each phases are analyzed and commented. The small angle X-ray scattering study is complemented by the determination of the temperature dependent liquid-solid transition by rheology.PACS: 81.30.−t, 61.05.C−, 64.70.dg IntroductionThe full understanding of the properties of surfactants when added to oil and water is of considerable interest given their tremendous applications in many scientific fields such as the design of hybrid mesoporous materials, drug delivery, or more prosaically industrial applications of detergents. Among widely used surfactants one finds the non-ionic surfactant of the Brij family characterized by a hydrophilic head made of polyoxyethylene (PEO) and a hydrophobic tail made of an alkyl chain. Quite surprisingly very little information is found in the literature about the phase diagram of the Brij58 (polyoxyethylene(20) cetyl ether). Apart from a neutron study of Brij58 micelles made by Sheffer et al. [1] by small angle neutron scattering and the study done by Mitchell on the phase behavior of polyoxyethylene surfactants with water, no real analysis of the phase diagram is available to the best of our knowledge [1][2][3].Our objective in this paper is to present the small angle X-ray scattering (SAXS) determination of the structures developed by the Brij58 when mixed with water from 5% to 95% in weight at a constant temperature of 20
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.