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

Larson， ronald表面活性剂用于许多家用，医疗和工业产品。表面活性剂分子在溶液中可以自发地组装成结构，这对液体的性质有很大的影响。本项目将发展一种理论来预测丝状胶束溶液的性质，丝状胶束是一种长柔性表面活性剂结构。本研究的重点是探讨胶束分支在这些有趣溶液中的作用。这项工作的结果将被纳入一个开放源码软件包，该软件包将免费提供，用于表面活性剂溶液的工业配方。参与研究的学生将有机会通过在合作公司实习获得与工业相关的研究经验。将发展一个详细的定量理论来预测分支线状胶束溶液的线性流变学，包括胶束通过纠缠网络的重复（或滑动）影响，以及胶束“原始路径”的波动，胶束断裂和重新连接，网络结的形成和破坏，以及其他松弛现象。这些现象将使用PI开发的“指针算法”来建模，该算法可以解释胶束松弛现象，但不能解释胶束分支。分支形成的结合将代表着对表面活性剂溶液动力学和流变学理解的重大进步。这种方法将提供胶束长度、断裂率、分支点的形成和断裂率以及每个胶束分支的数量的准确估计，这些数据是从流变学数据中提取的，通过将这些数据拟合到指针算法的预测中。

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.