介观模拟研究水包油型微乳液的形成及稳定性

Mesoscopic Simulations on the Formation and Stability of the O/W Microemulsion Systems

采用耗散颗粒动力学模拟方法从介观尺度上研究了水包油(O/W)型微乳液的形成条件并对所形成的O/W型微乳液的耐环境(油水体积比、温度、盐度和剪切作用)稳定性进行分析。结果表明,油水体积比小于1:3时,油水界面张力最小,可以形成O/W型微乳液。此微乳液具有一定的耐低温稳定性,其耐温稳定性范围为0.8 kBT^1.0 kBT。在此温度范围内,1.0 kBT时的微乳液具有最好的耐盐性,αHH降低为22时微乳液才发生相转变。此外,剪切作用对不同条件下所形成的微乳液具有一定破坏作用,当温度为1.0 kBT、αHH为25时,剪切速率增加到0.009,微乳液才受到破坏,也就是说,此条件下的微乳液是稳定的。此模拟结果从介观尺度上提供了微乳液的结构变化,为微乳液的实际应用提供理论指导。

Dissipative particle dynamics（ DPD） simulations are performed to study the formation and stability of the O / W microemulsion systems affected by oil / water ratio,temperature,salinity and shear on the mesoscopic scales. The results showed that it can form O / W microemulsion systems when the oil / water ratio is less than 1 ∶ 3.These microemulsions had certain stability resistance to low temperature at the range of 0. 8 kBT to 1. 0 kBT. The microemulsion formed in 1. 0 kBT had the best resistance to salt because of a phase transition occurred when αHH reduced to 22. In addition,the shear had certain damage to the microemulsion,and the damage happened only when the shear rate increased to 0. 009,and the temperature and αHHwere 1. 0kBT and 25,that is,the microemulsion was stable under these conditions. The simulation results provide the structure changes of the microemulsion systems from the mesoscopic scale and supply theoretical guidance for the practical application of the microemulsion.