Department of Civil Engineering, Monash University, Building 60, Melbourne, Victoria 3800, Australia.
Department of Civil Engineering, Monash University, Building 60, Melbourne, Victoria 3800, Australia.
J Colloid Interface Sci. 2021 Mar;585:250-257. doi: 10.1016/j.jcis.2020.11.022. Epub 2020 Nov 9.
Structure and self-assembly of surfactants in the solution shows a fundamental influence on its viscosity. Through molecular simulations using Martini force field, synergistic effects in aggregation as well as the viscosity changes of a binary ionic surfactant system can be modelled. Simulations: Coarse-grained molecular dynamics simulations are performed to model the SDS/CAPB binary surfactant solution, and both equilibrium and non-equilibrium methods are used to calculate the viscosity of the equilibrated micellar systems.
Our simulation results indicate that the new version of the Martini force field can provide more reasonable self-assembly of surfactant, both single and binary system. Synergistic effects in micelle formation for SDS/CAPB have been successfully reproduced, that is, the formation of cylindrical micelles or even wormlike micelles at a lower concentration when compared with the pure system. Meanwhile, both equilibrium and non-equilibrium methods provide quantitatively comparable viscosity for each system. For pure micellar system, the viscosity linearly increases with the total concentration. Nevertheless, our simulation fails to capture the viscosity enhancement of the solution in corresponding with the formation of rodlike or wormlike micelles, and a full parameter optimization of force field is still necessary.
表面活性剂在溶液中的结构和自组装对其粘度有根本影响。通过使用马蒂尼力场的分子模拟，可以模拟出协同聚集效应以及二元离子表面活性剂体系的粘度变化。
通过粗粒化分子动力学模拟来模拟 SDS/CAPB 二元表面活性剂溶液，使用平衡和非平衡方法来计算平衡胶束体系的粘度。
我们的模拟结果表明，新版本的马蒂尼力场可以提供更合理的表面活性剂自组装，无论是单一体系还是二元体系。成功地再现了 SDS/CAPB 中胶束形成的协同效应，即在与纯体系相比更低的浓度下形成圆柱状胶束甚至蠕虫状胶束。同时，平衡和非平衡方法都为每个体系提供了定量可比的粘度。对于纯胶束体系，粘度随总浓度线性增加。然而，我们的模拟未能捕捉到溶液在形成棒状或蠕虫状胶束时的粘度增强，仍然需要对力场进行全面的参数优化。
