Tensiometry-based sensing of aggregation and of evaporation behavior of a volatile amphiphile in mixed solutions with ionic and nonionic surfactants

• Published in: Colloids and surfaces. A, Physicochemical and engineering aspects Vol. 676; p. 132119
• Main Authors: Soboleva, Oxana A., Gryzunova, Elina A., Tsarkova, Larisa A.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 05.11.2023
• Subjects: Dynamic surface tension; Evaporation; Geraniol; Headspace concentration; Mixed surfactant solutions; Sensing; Synergetic effect; Terpenes; Dynamic surface tension; Synergetic effect; Headspace concentration; Sensing; Mixed surfactant solutions; Evaporation; Terpenes; Geraniol
• ISSN: 0927-7757; 1873-4359
• DOI: 10.1016/j.colsurfa.2023.132119

Mixed surfactants solutions containing volatile amphiphiles, e.g. fragrances, are envisaged to exhibit correlations between aggregation behavior, molecular interactions, composition of the mixed adsorbed layers and the concentration of the volatile component in the vapors. These issues are addressed with tensiometric methods by considering dynamic and steady-state interfacial adsorption-evaporation behavior at both sides of air-liquid interface in mixed solutions of geraniol and micelle-forming ionic and non-ionic surfactants. Pendant drop tensiometry proved to be a sensitive method in assessing the concentration of geraniol in the vapors above mixed solutions. Differences in the release of the fragrance from the mixed interfacial layers are explained by competitive contributions of specific barrier mechanisms and concentration-dependent aggregation in bulk solutions. Synergetic effect in reducing surface tension was evident for mixtures of geraniol with anionic sodium dodecyl sulfate (SDS) and cationic dodecyltrimethylammonium bromide (DTAB) surfactants. Dynamic anti-synergetic effect in SDS-geraniol mixtures is attributed to strong aggregation behavior, which was found to hinder the evaporation of geraniol. Measurements of the headspace concentration indicated weak interactions between geraniol and micelles of non-ionic highly surface active Brij-35 surfactant. The presented results extend the traditional analytical toolbox for evaluating factors which affect the mass transfer of volatile organic amphiphiles between aqueous and gas phases. [Display omitted]