Aqueous Solution Properties of Disulfide Linked Gemini and Cleaved Monomeric Thiol Surfactants

Tsuyoshi Asakawa, Yasuhiro Shimizu, Tadahiro Ozawa, Akio Ohta, Shigeyoshi Miyagishi
2008 Journal of Oleo Science  
Monomeric thiol surfactants, [C n H 2n+1 N(CH 3 ) 2 CH 2 CH 2 SH]Br, were produced by the cleavage of gemini surfactant containing a disulfide bond in the spacer chain, [C n H 2n+1 N(CH 3 ) 2 CH 2 CH 2 SSCH 2 CH 2 N(CH 3 ) 2 C n H 2n+1 ]2Br. The disulfide bond was completely reduced by the addition of four times moles of dithiothreitol in water at room temperature. The critical micelle concentrations of monomeric surfactants were significantly increased in comparison with original gemini
more » ... ants. The monomeric thiol surfactants were stable in the presence of dithiothreitol, whereas they returned gradually to their original gemini surfactants within several days due to air oxidation in water without dithiothreitol. The micelle formation induced by the disulfide linkage formation was suggested by the fluorescence intensity ratio of pyrene. The time course of decrease in thiol concentration associated with the recovery of gemini surfactants was confirmed by the absorption spectra utilizing the reactions with 4,4'-dithiopyridine.
doi:10.5650/jos.57.243 pmid:18332588 fatcat:gppjmdtdkfhrjpxu7lgcsevj7i