摘要
通过实验和耗散粒子动力学模拟相结合的方法,研究了非离子型Gemini表面活性剂在水溶液中的聚集行为和表面活性剂分子在水-气界面的分布情况。结果表明:10个环氧乙烷(EO)的α,α′-[2,4,7,9-四甲基-5-癸炔-4,7-二醇]双[ω-羟基-聚(环氧乙烷)](S-10)的单体和团簇共存于低浓度溶液中。随着浓度的增加,表面活性剂分子聚集成球状胶束且尺寸增大;当球状胶束的尺寸增加到一定程度时,它们不能稳定存在并聚集成棒状胶束。在水-气界面处,表面活性剂分子或垂直或水平分布,但是随着浓度的增加,疏水基团垂直插进空气,而EO段在水中呈不规则的锯齿形分布。随着EO链段长度的增加,S-4、S-10和S-30的最小吸附分子截面积逐渐增大,这就是随着表面活性剂的EO段长度增加而润湿性降低的原因。实验与模拟相结合的方法为研究非离子Gemini表面活性剂的聚集行为提供了新的思路,通过模拟结果可以快速判断实验的准确性。
In this study,the aggregation behavior of nonionic Gemini surfactants in aqueous solution and the distribution of surfactant molecules at water-air interface were studied by combining experimental and dissipative particle dynamics simulative methods.The results show the monomer and polymer-cluster of theα,α′-[2,4,7,9-tetramethyl-5-decyne-4,7-diyl]bis[ω-hydroxyl-poly(ethylene oxide)]with 10 EO per molecule(S-10)coexist in solutions with low concentration.With the increase of concentration,the surfactant molecules agglomerate into spherical micelles and increase in size.When the size of spherical micelles increases to a certain extent,they cannot exist stably and agglomerate into rodlike micelles.At the water-air interface,the surfactant molecules either lie vertically or horizontally at the interface,but with the increase of concentration,hydrophobic groups are vertically arranged when being inserted into the air while the EO segment shows an irregular zigzag distribution in water.With the increase of EO chain segment in length,the minimum adsorption molecular cross-sectional area of S-4,S-10 and S-30 gradually increase.This is why the wettability of the EO segment decreases as its length grows.The method of combining experiment and simulation provides a new idea for studying the aggregation behavior of nonionic Gemini surfactants,and the accuracy of the experiment can be quickly judged by the simulation results.
作者
王辉
徐金杰
党乐平
卫宏远
WANG Hui;XU Jinjie;DANG Leping;WEI Hongyuan(School of Chemical Engineering and Technology,Tianjin University,Tianjin 300072,China;Tianjin Key Laboratory of Chemical Process Safety and Equipment Technology,Tianjin 300072,China)
出处
《化学工业与工程》
CAS
CSCD
北大核心
2022年第4期116-126,共11页
Chemical Industry and Engineering
作者简介
王辉(1996-),男,硕士研究生,现从事表面化学方面的研究;通信作者:党乐平,副教授,E-mail:dangleping@tju.edu.cn。
