表面活性素与三种长链烷基苯磺酸盐之间的相互作用

利用表面张力和荧光方法研究了表面活性素(surfactin)与3种长链烷基苯磺酸盐C16ABS、C17ABS和C18ABS之间的相互作用。计算了混合体系吸附单层和混合胶束中分子间的相互作用参数(βσ和βm)以及热力学性质。负的相互作用参数表明,尽管表面活性剂均为负离子型,存在静电排斥,但是混合后两者之间的排斥作用减弱,从而产生增效作用。这可能是由于烷基苯磺酸盐与surfactin在混合吸附单层和胶束中形成了一种既能减弱头基间静电排斥又能增强疏水链之间相互作用的空间结构所致。荧光结果显示,混合表面活性剂能形成更紧密、体积更大的聚集体,并且在高烷基苯磺酸盐含量时可能存在大型的棒、层状胶束或囊泡。

Interaction Between Surfactin and Three Alkylbenzene Sulfonates with Long Hydrophobic Chain

Interaction between surfactin and three alkyl benzene sulfonates, C16ABS, C17ABS, and C18ABS, at different molar ratios were studied by surface tension and fluorescence methods. Various parameters including interaction parameters (b_s and b_m) and thermodynamic properties have been determined. The interaction showing negative b_s and b_m values in the mixed interfacial monolayer and micelle is attractive despite that both components are permanently negatively charged. Such an unexpected attractive interaction might be attributed to the arrangement of alkyl benzene sulfonates and surfactin molecules into a configuration that reduces the electrostatic repulsion and promotes the hydrophobic interaction between the molecules. The results of fluorescence measurements indicate that more packed and larger aggregates are formed from mixed surfactants and the mixed system may be able to form rod-shaped and lamellar micelle or vesicle at high molar fraction of alkyl benzene sulfonates.