Phase Behavior, Small-Angle Neutron Scattering and Rheology of Ternary Nonionic Surfactant–Oil–Water Systems: A Comparison of Oils

Abstract

The phase behavior of the nonionic surfactant Triton X-100 (polyethylene glycol p-(1,1,3,3-tetramethylbutyl)-phenyl ether) was studied in two three-component systems: Triton-water-p-xylene and Triton-water-trichloroethylene. It was found that the aromatic solvent was able to produce monophasic soft matter systems at a significantly greater range of compositions. The structural characteristics of the phases generated were analyzed by small-angle neutron scattering, showing evidence for microemulsion, lamellar, and reverse-microemulsion phases. In addition, for the Triton-water-p-xylene system, an L3 "sponge" phase was found in a water-rich region of the phase diagram and the properties of this were examined using rheological measurements. The differences in phase behavior are discussed in light of the solvation properties of the surfactant in the different solvents studied. Most notably, xylene appears to favor phases with low-curvature interfaces, suggesting preferential solvation of the central phenyl group of Triton.

Topical Delivery of Meloxicam using Liposome and Microemulsion Formulation Approaches

“…In general, all investigated systems revealed Newtonian behavior, which is considered as typical for microemulsions [51], except for bicontinuous systems containing intertwining polar and non-polar domains forming an internal structure that might contribute to slightly shear-thinning behavior [52]. On the other hand, high initial viscosity of the system and highly pseudoplastic properties indicate the presence of lamellar systems which are not classified as microemulsions.…”

Fluorinated lamellar phases: structural characterisation and use as templates for highly ordered silica materials

“…33 In the Nallet and Roux model used to t the lamellar scattering here, this region corresponds to uctuations in the extended bilayer surfaces. However, due to the other factors that may inuence scattering in this region, the feature has proven to offer rather poor ts to the low-q scattering from a range of lamellar phases, [34][35][36] although the reason for this is not entirely clear. It may suggest a departure from the ideal model of the bilayer due to perforation, inclusions, etc.…”

“…In comparison, typical lamellar phases stabilised by hydrocarbon surfactants show one or two peaks at comparable volume fractions. 36 Once again, this can be rationalised by the structure of the surfactant and alcohol. As both are relatively short and rigid, they tend to favour very planar interfaces that are comparatively rigid.…”

Self-assembly of quaternary ammonium gemini surfactants in cyclohexane upon reinforcement by simple counterions

“…4c shows the SAXS spectrum, where scattering in the low-q region showed characteristic q À4 dependency as marked by solid lines. This was indicative of sharp interfaces, [35][36][37] suggesting that a LC phase was present in the sample: however, the present Bragg reections were atypical and only two peaks can be distinguished. A position ratio of 1 : 1.738 was obtained, indicating that the LC phase here was a H 2 phase.…”