CAJ | 학술논문

采用全原子分子动力学方法研究了抗衡离子为第一主族离子(Li+、Na+、K+、Rb+和Cs+)的十二烷基硫酸盐表面活性剂的气/液界面性质。通过分析体系中各组分的密度分布曲线，考察表面活性剂单分子层在界面的聚集形态，并利用径向分布函数分析了表面活性剂极性头基与抗衡离子间的相互作用。研究结果表明：随着抗衡离子半径的增大，不同体系的界面水层厚度依次增加，表面活性剂极性头基与抗衡离子形成的Stern和扩散层厚度也相应增加。但表面活性剂吸附层的抗衡离子缔合度以及体系表面张力却随抗衡离子半径的增大而减小。研究表明抗衡离子的差异对十二烷基硫酸盐表面活性剂气/液界面性质有很大影响。
채용전원자분자동역학방법연구료항형리자위제일주족리자(Li+、Na+、K+、Rb+화Cs+)적십이완기류산염표면활성제적기/액계면성질。통과분석체계중각조분적밀도분포곡선，고찰표면활성제단분자층재계면적취집형태，병이용경향분포함수분석료표면활성제겁성두기여항형리자간적상호작용。연구결과표명：수착항형리자반경적증대，불동체계적계면수층후도의차증가，표면활성제겁성두기여항형리자형성적Stern화확산층후도야상응증가。단표면활성제흡부층적항형리자체합도이급체계표면장력각수항형리자반경적증대이감소。연구표명항형리자적차이대십이완기류산염표면활성제기/액계면성질유흔대영향。
Molecular dynamics (MD) simulations have been carried out to study the micro-interfaces between counterions (Li+, Na+, K+, Rb+, Cs+) and dodecyl sulfate surfactant at the air/liquid interface. The morphology of the monolayer was analyzed by the density profile of the surfactant components, and the interactions between the polar head groups of the surfactants and the counterions were analyzed using the radial distribution function (RDF). The results showed that the interfacial thickness and thicknesses of the Stern and diffusion layers increased as the radius of counterion increased, whereas the surface tension and the degree of counterion association at the adsorbed layer decreased as the radius increased. These results indicated that the different counterions had a significant effect on the adsorption behavior of the dodecyl sulfate surfactants at the interface.