Impact of Adsorption Layer Properties on Drainage Behavior of Microscopic Foam Films: The Case of Cationic/Nonionic Surfactant Mixtures

Abstract

Aqueous mixtures of cationic hexadecyltrimethylammonium chloride (CTAC) and nonionic pentaethyleneglycol monododecyl ether (C12E5) are investigated. Adsorption layer properties are systematically studied within a wide concentration range for a 1:1 molar ratio of the surfactants. Surface tension and dilatational rheology measurements are conducted by profile analysis tensiometry. The interfacial data are juxtaposed to drainage kinetics and stability results for microscopic foam films, investigated by microinterferometric thin liquid film instrumentation. The obtained results give experimental evidence of synergistic interactions in the studied solutions, as compared to the corresponding single surfactant systems. Specific runs of dynamic and equilibrium surface tension curves are registered against the total surfactant quantity; the surface dilatational elasticities for the mixtures are systematically higher. A clear correlation is established between adsorption layer performance and foam film characteristics. The maxima of the film lifetimes are well outlined, and the respective values are shifted towards lower overall concentrations. The reported results substantiate the key role of the adsorption layers, and the surface dilatational properties in particular, for foam film drainage kinetics and stability. The well-expressed synergy observed in adsorption layer and foam film properties suggests the substantial benefits of using mixed surfactant systems in the design and fine-tuning of foam systems for innovative applications.

Synergistic effects between a non-ionic and an anionic surfactant on the micellization process and the adsorption at liquid/air surfaces

“…Similar behaviour was observed by Aaraadhya et al 34 for solutions containing 1 : 1 mixtures of cationic (hexadecyltrimethylammonium chloride, CTAC) and non-ionic (pentaethyleneglycol monododecyl ether, C 12 E 5 ) surfactants, where the CMC values of the surfactant mixtures decrease as the molar fraction of the non-ionic surfactant in the mixtures increases.…”

“…Similar behaviour was observed by Aaraadhya et al 34 for solutions containing 1 : 1 mixtures of cationic (hexadecyltrimethylammonium chloride, CTAC) and non-ionic (pentaethyleneglycol As shown in Fig. 3, for n EOT /n NaDDBS = 0.01, 0.1 and 1 the equilibrium surface tension values fall in between those of the individual single surfactants.…”

N-Alkylimidazolium carboxylates as a new type of catanionic surface active ionic liquid: synthesis, thermotropic behavior and micellization in water

“…Interestingly, [C 10 mim][C 13 COO] already shows a plateau below the cmc, indicating a premicellar aggregation of the longer-chain anion [C 13 COO] , while above the cmc the cation and anion are expected to form a mixed micelle. 63 In the second step, the cation chain length n was varied while the anion chain length was kept constant at m = 10 ( [C n mim][C 9 COO] ). As shown in Fig.…”

Surfactant mixtures: A short review

“…The viscoelastic nature of the air‐water interface can be changed significantly with the use of mixtures (Arabadzhieva et al, 2020; Danov et al, 2004; Marinova et al, 2017; Song et al, 2015). The dilatational (or dilatational) modulus increases with an increase in excess surface concentration, so mixtures with more favorable interactions lead to higher dilatational moduli.…”