表面活性剂与油-水界面的介观模拟研究

Mesoscopic Simulation of Surfactant on Oil-Water Interface

用介观模拟方法对2种类型的表面活性剂分子在油-水界面的分布形态进行了模拟。结果表明:与单链型表面活性剂相比,低聚型表面活性剂分子由于其空间结构上的分散性,导致与其通过化学键相连的部分极性基团进入油分子内部,在油-水界面处相对更靠近油相,使得低聚型表面活性剂分子在油-水界面处极性基团的排列没有单链型表面活性剂那样有序;低聚型表面活性剂存在时,油-水界面的接触面积相对较大,而表面活性剂在油-水中的分布相对比较均匀;相比单链型表面活性剂分子,低聚型表面活性剂分子可以更好地降低油-水界面的界面张力。

The mesoscopic simulation was used to simulate the distribution of surfactant molecules at the oil-water interface.Compared with single-chain surfactants, due to the dispersibility of its spatial structure, partial polar groups of oligomeric surfactant can enter the internal structures of the oil molecules.This causes that oligomeric surfactants are relatively closer to the oil phase at the oil-water interface, and the arrangement of the polar groups for the oligomeric surfactant molecules at the oil-water interface is not as ordered as that of the single-chain surfactants.In the presence of oligomeric surfactants, the contact area between the oil-water interface is relatively large, and the distribution of the surfactant molecules between oil and water is relatively uniform.Compared with single-chain surfactant molecules, oligomeric surfactant molecules can reduce the interfacial tension of the oil-water interface more efficiently.