UNS: Multi-scale Simulations of Branched Thread-like Micelles

CBET -1500377 PI：Larson，RonaldSurfactants用于许多家用、医疗和工业产品。 溶液中的表面活性剂分子可以自发地组装成结构，这可以强烈地影响液体的性质。 本计画将发展一种理论来预测线状胶束溶液的性质，线状胶束是一种长而有弹性的表面活性剂结构。 建议的工作的特别重点是探索胶束支化在这些有趣的解决方案的行为中的作用。 这项工作的结果将被纳入一个开源软件包，该软件包将免费提供给表面活性剂溶液的工业配方使用。 参与研究的学生将有机会通过在合作公司实习获得工业相关研究的经验。 一个详细的，定量的理论将被开发来预测的线性流变学的解决方案的分支threadlike胶束，包括爬行（或滑动）的胶束通过缠结网络的影响，以及波动的“原始路径”的胶束，胶束断裂和重新加入，网络连接的形成和断裂，和其他松弛现象。将使用PI开发的“指针算法”对这些现象进行建模，该算法考虑胶束松弛现象，但不考虑胶束分支。分支形成的纳入将代表理解表面活性剂溶液的动力学和流变学的重大进展。该方法将提供胶束长度、断裂速率和分支点的形成和断裂速率以及每个胶束的分支数的准确估计，通过将该数据拟合到指针算法的预测，从流变学数据中提取。

CBET - 1500377PI: Larson, RonaldSurfactants are used in many household, medical, and industrial products. Surfactant molecules in solution can spontaneously assemble into structures, which can strongly influence the properties of the liquid. This project will develop a theory to predict the properties of solutions of thread-like micelles, which are long flexible surfactant structures. The particular focus of the proposed work is to explore the role of micelle branching in the behavior of these interesting solutions. The results of the work will be incorporated into an open source software package that will be made freely available for use in the industrial formulation of surfactant solutions. Students involved in the research will have the opportunity to gain experience in industrially-related research through internships at collaborating companies. A detailed, quantitative theory will be developed to predict the linear rheology of solutions of branched threadlike micelles, including effects of reptation (or sliding) of the micelles through the entanglement network, as well as fluctuations in the "primitive path" of the micelles, micelle breakage and rejoining, formation and breakage of network junctions, and other relaxation phenomena. These phenomena will be modeled using a "Pointer Algorithm" developed by the PI that accounts for micelle relaxation phenomena, but not for micellar branching. The incorporation of branch formation will represent a major advance in understanding the dynamics and rheology of surfactant solutions. This methodology will provide accurate estimates of micelle lengths, breakage rates, and rates of formation and breakage of branch points, and the number of branches per micelle, extracted from rheology data by fits of this data to predictions of the Pointer Algorithm.