The Effects of the Organic Groups Attached at the Silicone Atoms of the Organosilane-Based Gemini Nonionic Surfactants on Their Surface Activities

摘要

A novel trisiloxane gemini nonionic surfactant was synthesized by the reaction of 3-(diethoxy(methyl)silyl)pro-pan-1-amine with hexamethyldisiloxane to get 3-(trisilox-ane)propan-l-amine, which was further reacted with glutamyl dichloride to form the surfactant melecule, N~1,N~5-bis(3-(trisi-loxane)propyl)glutaramide (3). Some related compounds were also prepared, including N~1N~5-bis (3-(trimethoxysilyl)propyl) glularamide (1), and N~1,N~5-bis(3-(diemoxy(methyl)sily)pro-pyl)glutaramide (2). All prepared compounds were analyzed by J.R, ~1H-NMR and ~(13)C-NMR to confirm their structures. Their interfacial activities, including surface tension and wetting ability, were measured. These surface activities were compared each other and a discussion was carried out on how the organic groups attached on the silicone atoms affect then-surface tension and wetting ability. To explain the superior surface activities of the molecules 3, a hypothesis was proposed about a cyclic hydrophobic core area that could be formed by the two hydrophobic chains and the linker of the gemini mol-ecu le due to the dispersion force (Van der Waals force) between the two trisiloxane moieties, which close the hydrophobic cycle inside the molecule.