Surface tension properties of aqueous solutions of disulfur betaine derivatives

• Published in: Colloids and surfaces. A, Physicochemical and engineering aspects Physicochemical and engineering aspects, 1994-07, Vol.87 (2), p.117-123
• Main Authors: Pinazo, A., Infante, M.R., Chang, C.-H., Franses, E.I.
• Format: Article
• Language: English
• Subjects: Chemistry; Colloidal state and disperse state; Disulfur betaine derivatives; Dynamic adsorption; Dynamic surface tension; Exact sciences and technology; General and physical chemistry; Oscillating bubble surfactometry; Physical and chemical studies. Granulometry. Electrokinetic phenomena
• ISSN: 0927-7757; 1873-4359
• DOI: 10.1016/0927-7757(94)02772-2

The equilibrium and dynamic surface tensions of aqueous solutions of two newly synthesized surfactants relevant to wool dyeing were studied by means of the Wilhelmy plate and a bubble method. The surfactants ( N α, N α′-bis( N-dodecyl- N, N-dimethylglycine cystine dimethyl ester dihydrochloride) and ( N α, N α′-bis( N-dodecyl- N, N-dimethylglycine) cystamine dihydrochloride), are double-chain and bicationic in character. Their CMCs and Langmuir adsorption equilibrium parameters were determined at 25°C. Both molecules are very efficient surfactants. Their surface tensions equilibrate in time-scales ranging from seconds to hours (concentration c=1000—2 μM). Their dynamic surface tensions under constant and pulsating area conditions indicate that there is a strong barrier to adsorption at the air—water interface. The presence of the micelles accelerates the net rate of adsorption, suggesting fast micellar dissociation.