Adsorption and micellization behavior of novel gluconamide-type gemini surfactants

• Published in: Journal of colloid and interface science 2008-02, Vol.318 (2), p.440-448
• Main Authors: Sakai, Kenichi, Umezawa, Shin, Tamura, Mamoru, Takamatsu, Yuichiro, Tsuchiya, Koji, Torigoe, Kanjiro, Ohkubo, Takahiro, Yoshimura, Tomokazu, Esumi, Kunio, Sakai, Hideki, Abe, Masahiko
• Format: Article
• Language: English
• Subjects: Adsorption; Air; Calcitriol - analogs & derivatives; Calcitriol - chemistry; Chemistry; Colloidal state and disperse state; Cryoelectron Microscopy; Exact sciences and technology; Fluorescence; General and physical chemistry; Gluconates - chemistry; Micelles; Micelles. Thin films; Molecular Structure; Particle Size; Scattering, Radiation; Solutions - chemistry; Sugar-based gemini surfactants; Surface physical chemistry; Surface Tension; Surface-Active Agents - chemistry; Water - chemistry; Worm-like micelles
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2007.10.039

The adsorption and micellization behavior of novel sugar-based gemini surfactants ( N , N ′ -dialkyl- N , N ′ -digluconamide ethylenediamine, Glu( n)-2-Glu( n), where n is the hydrocarbon chain length of 8, 10 and 12) has been studied on the basis of static/dynamic surface tension, fluorescence, dynamic light scattering (DLS) and cryogenic transmission electron microscope (cryo-TEM) data. The static surface tension of the aqueous Glu( n)-2-Glu( n) solutions measured at the critical micelle concentration (cmc) is observed to be significantly lower than that of the corresponding monomeric surfactants. This suggests that the gemini surfactants, newly synthesized in the current study, are able to form a closely packed monolayer film at the air/aqueous solution interface. The greater ability in the molecular association is supported by the remarkably (approximately 100–200 times) lower cmc of the gemini surfactants compared with the corresponding monomeric ones. With a combination of the fluorescence and DLS data, a structural transformation of the Glu( n)-2-Glu( n) micelles is suggested to occur with an increase in the concentration. The cryo-TEM measurements clearly confirm the formation of worm-like micelles of Glu(12)-2-Glu(12) at the concentration well above the cmc. The adsorption and micellization behavior of novel sugar-based gemini surfactants has been studied on the basis of static/dynamic surface tension, fluorescence, DLS and cryo-TEM data.