Ultrathin Membrane Fouling Mechanism Transitions in Dead-End Filtration of Protein

Ultrathin membranes will likely see great utility in future membrane-based separations, but key aspects of the performance of these membranes, especially when they are used to filter protein, remain poorly understood. In this work we perform protein filtrations using new nanoporous silicon nitride (NPN) membranes. Several concentrations of protein are filtered using dead end filtration in a benchtop centrifuge, and we track fouling based on the amount of filtrate passed over time. A modification of the classic fouling model that includes the effects of using a centrifuge and allow for the visualization of a transition between pore constriction and cake filtration demonstrate that for a range of protein concentrations, cake filtration supersedes pore constriction after ∼30 seconds at 690 g.