Stochastic microstructure delineation and flow simulation in asymmetric block copolymer ultrafiltration membranes

Asymmetric block copolymer ultrafiltration membranes have a wide range of applications from water purification and virus filtration all the way to drug delivery. Although optimizing flow is critical to the performance of such ultrafiltration membranes, their numerical flow characterization has remained challenging. The main problems include hierarchical pore structure delineation and lack of an efficient, image-based pore-scale modeling approach. In this study, we use 2D scanning electron microscopy (SEM) images with a variety of resolutions to delineate the hierarchical asymmetric pore structure. To simulate flow, a novel stochastic pore network model is proposed. The absolute permeabilities of two asymmetric block copolymer ultrafiltration membranes are computed and compared with experimental results showing good agreement.

Automated summary

Asymmetric block copolymer ultrafiltration membranes find wide applications in water purification, virus filtration, and drug delivery. However, numerical flow characterization of these membranes has been challenging due to difficulties in hierarchical pore structure delineation and lack of efficient image-based modeling approach. In this study, we used 2D scanning electron microscopy (SEM) images with different resolutions to delineate the hierarchical asymmetric pore structure. We proposed a novel stochastic pore network model to simulate flow, and computed the absolute permeabilities of two asymmetric block copolymer ultrafiltration membranes, which showed good agreement with experimental results.