Interfacial tensions of aqueous two-phase systems formed by mixtures of cationic and anionic surfactants were measured by the spinning drop method. The effect of the molar ratio of cationic surfactants to anionic surf...Interfacial tensions of aqueous two-phase systems formed by mixtures of cationic and anionic surfactants were measured by the spinning drop method. The effect of the molar ratio of cationic surfactants to anionic surfactants (C +/C -) and the alkyl chain symmetry on the interfacial tensions were investigated. It was showed that values of the interfacial tensions of the aqueous two-phase systems were in the scale of ultralow interfacial tensions. Two types of γ～C +/C - curves were observed, in which DoTEAB/SDS and OTEAB/SDS systems were the typical representatives (DoTEAB, OTEAB and SDS are the abbreviations for dodecyltriethylammonium bromide, octyltriethylammonium bromide and sodium dodecylsulfate, respectively). The two types of curves were explained in terms of the change of the mixed micelles composition and symmetry of hydrophobic chains of cationic and anionic surfactants with molar ratio.展开更多
This study was about the effect of pH and small molecule organic compound on the phase behavior of SDS/CTAB/H 2O mixture.The ATPS regions and LC regions were mainly discussed.It was shown that when the pH of the syste...This study was about the effect of pH and small molecule organic compound on the phase behavior of SDS/CTAB/H 2O mixture.The ATPS regions and LC regions were mainly discussed.It was shown that when the pH of the system was not neutral LC regions enlarged but ATPS regions reduced.In the condition of strong acid,the ATPS a region in which anionic surfactant in excess would extend to the SDS-H 2O axis of the pseudo phase diagram of SDS/CTAB/H 2O system.Small molecule organic compound that was not ionized in aqueous solution combined with water in the form of hydrogen bond.For this reason,the hydration of surfactant decrease and cationic surfactant and anionic surfactant integrate to form precipitate.So the surfactant-rich phase of ATPS showed milky white and the polarizing appearance was not clear.展开更多
文摘Interfacial tensions of aqueous two-phase systems formed by mixtures of cationic and anionic surfactants were measured by the spinning drop method. The effect of the molar ratio of cationic surfactants to anionic surfactants (C +/C -) and the alkyl chain symmetry on the interfacial tensions were investigated. It was showed that values of the interfacial tensions of the aqueous two-phase systems were in the scale of ultralow interfacial tensions. Two types of γ～C +/C - curves were observed, in which DoTEAB/SDS and OTEAB/SDS systems were the typical representatives (DoTEAB, OTEAB and SDS are the abbreviations for dodecyltriethylammonium bromide, octyltriethylammonium bromide and sodium dodecylsulfate, respectively). The two types of curves were explained in terms of the change of the mixed micelles composition and symmetry of hydrophobic chains of cationic and anionic surfactants with molar ratio.
文摘This study was about the effect of pH and small molecule organic compound on the phase behavior of SDS/CTAB/H 2O mixture.The ATPS regions and LC regions were mainly discussed.It was shown that when the pH of the system was not neutral LC regions enlarged but ATPS regions reduced.In the condition of strong acid,the ATPS a region in which anionic surfactant in excess would extend to the SDS-H 2O axis of the pseudo phase diagram of SDS/CTAB/H 2O system.Small molecule organic compound that was not ionized in aqueous solution combined with water in the form of hydrogen bond.For this reason,the hydration of surfactant decrease and cationic surfactant and anionic surfactant integrate to form precipitate.So the surfactant-rich phase of ATPS showed milky white and the polarizing appearance was not clear.
