Oppositely charged polyelectrolyte/surfactant and the coacervate polyanion/polycation mixtures are known to display complex properties at water/air interface which are not fully elucidated. The change in surface tension of the anionic polyelectrolyte sodium poly(styrene sulfonate) (NaPSS) with either benzyldimethylhexadecylammonium chloride (BAC) as the cationic surfactant or the cationic polyelectrolyte polyallylamine hydrochloride (PAACl) as a function of temperature and added salts was investigated. Neither of the pure polyelectrolytes showed significant surface activity; however, addition of oppositely charged surfactant or polyelectrolyte to varying concentrations of NaPSS solutions had changed the surface activity drastically. The surface tension of the NaPSS/BAC complex is lower than that of pure BAC surfactant. The surface tension of these complexes showed significant decrease with increasing temperatures and the surface excess entropy was deduced from these measurements. Addition of ionic salts enhanced the association of the polyelectrolyte/surfactant mixture but had little effect on the polyelectrolytes coacervate. The surface tension of low concentrations of NaPSS/PAACl coacervate displayed a peak which can be attributed to charge inversion. Graphical abstract

中文翻译：

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带相反电荷的聚（苯乙烯磺酸钠）/苄基二甲基十六烷基氯化铵和聚（苯乙烯磺酸钠）/聚烯丙胺盐酸盐混合物的表面张力

已知带相反电荷的聚电解质/表面活性剂和凝聚层聚阴离子/聚阳离子混合物在水/空气界面显示复杂的特性，但尚未完全阐明。研究了以苄基二甲基十六烷基氯化铵 (BAC) 作为阳离子表面活性剂或阳离子聚电解质聚烯丙胺盐酸盐 (PAACl) 的阴离子聚电解质聚苯乙烯磺酸钠 (NaPSS) 的表面张力随温度和添加盐的变化。纯聚电解质都没有显示出显着的表面活性；然而，将带相反电荷的表面活性剂或聚电解质添加到不同浓度的 NaPSS 溶液中会极大地改变表面活性。NaPSS/BAC 复合物的表面张力低于纯 BAC 表面活性剂。这些配合物的表面张力随着温度的升高而显着降低，并且从这些测量中推断出表面过量熵。离子盐的加入增强了聚电解质/表面活性剂混合物的结合，但对聚电解质凝聚层几乎没有影响。低浓度 NaPSS/PAACl 凝聚层的表面张力显示出一个峰值，这可归因于电荷反转。图形概要 低浓度 NaPSS/PAACl 凝聚层的表面张力显示出一个峰值，这可归因于电荷反转。图形概要 低浓度 NaPSS/PAACl 凝聚层的表面张力显示出一个峰值，这可归因于电荷反转。图形概要