title: Self-assembling of guanidine-type surfactant.
abstract: Self-assembling characteristics of dodecylguanidine hydrochloride (C 12G), a cationic surfactant with a guanidine group in its molecule, were investigated and compared with those of dodecyltrimethylammonium chloride (DTAC) and sodium dodecylsulfate (SDS). Introduction of a guanidine group into the surfactant molecule was found to increase its assembly formability more than that of the trimethylammonium group on the basis of the experimental results on the phase diagram, Kraft point, area occupied per molecule at the air-water interface, and micellar aggregation number of C 12G. Thermodynamic parameters for micelle formation suggested that an attractive force acts between guanidine groups of C 12G molecules to facilitate their assembly formation. The presence of this force was evidenced by changes in the (1)H NMR and IR spectra before and after micelle formation of the guanidine-type (G-type) surfactant, indicating that the increased assembly formability is caused by an increase in hydrogen bonding between guanidine groups of the surfactant via water molecules.
authors.affiliation: Analytical Technology Research Center, Lion Corporation, 13-12 Hirai 7-Chome, Edogawa-ku, Tokyo, Japan. miyamiyu@lion.co.jp
authors.forename: Miyuki
authors.initials: M
authors.lastname: Miyake
authors.forename: Kaoru
authors.initials: K
authors.lastname: Yamada
authors.forename: Nobuo
authors.initials: N
authors.lastname: Oyama
mesh_terms: D000327:Adsorption; D019791:Guanidine / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008823:Micelles; D015394:Molecular Structure; D012995:Solubility; D012996:Solutions; D013055:Spectrophotometry, Infrared; D013499:Surface Properties; D013501:Surface-Active Agents / Q000737:chemistry*; D013816:Thermodynamics
chemical_list: D008823:Micelles; D012996:Solutions; D013501:Surface-Active Agents; D019791:Guanidine