四氟乙烯五聚体氧基苯磺酸钠与辛基三乙基溴化铵的相互作用

Interactions between Sodium Tetrafluoroethylene Pentamer-oxylbenzenesulfonate and Octyltriethylammonium Bromide

研究不同摩尔比的正负离子碳氢-碳氟表面活性剂——辛基三乙基溴化铵[C8H17N（CH2CH3）3Br,C8NE]与四氟乙烯五聚体氧基苯磺酸钠（C10F19OC6H4SO3Na,6201）混合溶液的表面张力,得到其临界胶束浓度（CMC）、最低表面张力（γCMC）、总饱和吸附量、不同表面张力时表面吸附层的组成;利用Gibbs-Duhem方程求得CMC处的胶团组成。采用规则溶液理论计算胶团中分子间相互作用参数（β^m）以及CMC后的胶团组成。C8NE-6201复配体系的CMC明显小于单体系,这与β^m负值很大相符（胶团内分子相互作用强）。但复配体系γCMC较6201单体系变化很小,这可能由于6201疏水链过长导致和C8NE复配后溶解性较差。6201自身的强疏水性使其成为表面吸附层和胶团在初始形成时的主导组分,而反电性C8NE参与提供协同作用。但是CMC后的胶团组成中6201的摩尔分数x6201^m基本维持在0.60.7附近,说明对于CMC后胶团的形成正负电性作用占主导。

The surface tension of the mixtures of cationic-anionic hydrogenated-fluorinated surfactants composed of octyltriethylammonium bromide（C8H17N（CH2CH3）3Br,C8NE） and sodium tetrafluoroethylene pentamer-oxylbenzenesulfonate（C10F19OC6H4SO3Na,6201） with different molar ratios was measured.The critical micelle concentration（CMC）,the minimum surface tension（γCMC）,total amount adsorbed,the composition of surface adsorbed layer at different surface tension values and the micelle composition at the CMC calculated by the Gibbs-Duhem equation were obtained.The molecular interaction parameter β^m and the micelle composition after the CMC were estimated by the regular solution theory.It showed that the CMC of C8NE-6201 mixtures was significantly smaller than that of the individual component,which was also consistent with the large negative value of β^m and thus the strong molecular interactions in micelles.However,the γCMC of C8NE-6201 mixtures changed very small compared with the single 6201,which might be attributed to the long hydrophobic chain of 6201 and the solubility was decreased when C8NE coexisted.Because of its strong hydrophobicity,6201 primarily comprised the surface adsorbed layer and the micelle that were initially formed,while the oppositely-charged C8NE offered the effect of synergism.The micelle composition after the CMC,x6201^m（the molar fraction of 6201 in micelle）,however,maintaining approximately in the range 0.6～0.7,indicating that the cationic-anionic electrostatic interaction was the major role in the micelle formation after the CMC.