Computational Analysis of Small Angle Scattering Measurements on Polymer Membranes

Polymers are widely used as materials to engineer membranes for chemical separations and ion/charge transport-related applications. In such applications, the morphology within the polymer films dictates how well the material performs. As such, researchers working with such materials need to characterize the membrane structures at various length scales as a function of polymer design and processing conditions. To characterize polymer membrane structure at multiple length scales and provide insights into the structural evolution at various processing and operating conditions, one can conduct small angle scattering (SAS) measurements. Analysis of the results from such SAS measurements, especially for materials with network morphologies often desired for membranes, is not easy with conventional analytical models. To alleviate this challenge with analysis of SAS measurements of network morphologies, we have developed a computational method using random fields. Using this method we can interpret SAS measurements and output the 3-dimensional (3D) structures of the domains present within the network structure and understand connectivity and domain size distributions. We validate our approach by taking as input the SAS profiles from simulated structures and show that our method is capable of outputting 3D structures that match, visually and quantitatively, the simulated structures that provided the SAS profile.