Computer-Aided Design of a Perfluorinated Sulfonic Acid Proton Exchange Membrane Using Stochastic Optimization and Molecular Dynamic Method

In this paper, a computer-aided polymer design ( CAPD) framework with a stochastic optimization model is proposed for the design of perfluorinated sulfonic acid proton exchange membrane (PFSA-PEM) with desired properties. First, the requirements and target characteristics are identified and converted to property constraints. Then, the polymer design model is formulated as a stochastic optimization problem in which the operation temperature is treated as a random variable. Subsequently, the formulated stochastic mixed integer nonlinear programming problem is solved by a two-stage strategy. In stage I, molecular dynamics is utilized to simulate the target properties for different structures and quantities of side chains, thus establishing the quantitative structure-property relationship. In stage II, the operation temperature is considered subject to a specified probability distribution. The optimization model is solved to obtain the optimal polymer structure over the operating temperature range. Finally, a case study of PFSA-PEM design is given to illustrate the application of the CAPD framework.