Patent ID: 8007823

Claim:
A microporous polymeric article having a target pore diameter d v , comprising an essentially continuous porosity with a controlled void volume from 10 to 90%, wherein pore diameters show a unimodal distribution set at a predefined unimodal peak location corresponding to said target pore diameter d v , and wherein a majority of pores have a diameter d of at least d v −50% and at most d v +50%, prepared according to a method comprising the steps of: a) determining a target pore diameter d v ; b) selecting at least one polymer A and at least one polymer B at least partially immiscible with A, according to the target pore diameter d v determined in step a); c) melt blending the selected polymers from step b), thereby preparing a polymer blend, wherein said polymers A and B have an essentially continuous morphology; d) cooling said polymer blend to room temperature, thereby retaining its morphology; and e) extracting said polymer B, at least partially, from the polymer blend by dissolving said polymer B in a solvent that is a non-solvent of polymer A.