Effects of membrane morphology on separation efficiency

The Workshop was asked by Pall Corporation to consider ways in which membrane morphology may be characterized, and how such characterization can be used to assess filtration efficiency. The working group considered a variety of different (but related) approaches, which are outlined below but which will be described in more detail in the forthcoming report. 1 Darcy flow model In an effort to characterize the effect of membrane variations across the thickness, a simple Darcy flow model was considered first. Taking x to be the variable perpendicular to the membrane (in the direction of flow), and assuming no variation in the plane of the membrane, basic Darcy flow gives u(x, t) = − k(x, t) μ ∂p ∂x , ∂ ∂x (