Nanoporous Membrane with Ultrahigh Selectivity and Flux Suitable for Filtration of Viruses*

We introduce a new double layered nanoporous membrane suitable for virus filtration. One layer is an 80 nm thick film having cylindrical pores with diameters of 15 nm and a narrow pore size distribution. This layer is prepared by using a thin film of the mixture of a block copolymer and a homopolymer, and mainly acts to separate viruses. The support layer is a conventional micro-filtration membrane with a broad pore size distribution. This asymmetric membrane showed very high selectivity and flux for the separation of human rhinovirus type 14 which has a diameter of $\sim$ 30 nm and is a major pathogen of the common cold in humans.