介观模拟研究表面活性剂链长对油包水型微乳液的影响

The effect of surfactant chain length on the formation of the W/O microemulsion system by Mesoscopic Simulation

采用耗散颗粒动力学模拟方法从介观水平上研究了表面活性剂分子链长对油包水型微乳液形成的影响。结果表明:对于疏水链长不同的表面活性剂/油/水体系在一定的油水比和表面活性剂分子浓度下可以形成油包水型微乳液,此时体系的平均界面张力值最低,表面活性剂分子的平均末端距最小,即分子链最弯曲。而表面活性剂分子浓度相同时,其疏水链越长,形成油包水型微乳液所需的油水比越大;在油水比相同的情况下,疏水链越长,表面活性剂分子浓度对微乳液的影响越小。此模拟结果从介观水平上提供了表面活性剂分子链长对微乳液的形成的影响,为微乳液的实际应用提供理论指导。

Dissipative particle dynamics （DPD） simulation is performed to study the effect of the surfactant chain length on the formation of the W/O microemulsion system on mesoscopic level. The results show that the surfactant/oil/water systems can form water-in-oil mieroemulsion in a certain oil/water ratio and concentration of surfactant molecules, also have the lowest inteffacial tension and the smallest end-to-end distance of the surfactants. Comparing three surfactants system we know that the required water-oil ratio is larger when the hydrophobic chain is longer at the same surfactant concentration. However, under the condition of the same oil/water ratio, the effect of surfactant molecules on the formation The simulation results provide the effect of the surfactant chain length on the mieroemulsion systems from the mesoscopic scale, and supply theoretical guidance for the practical application of the microemulsion.