Membranes for use in methods and apparatuses for
hemodialysis and
hemofiltration are composed of at least one polyarylethernitrile block
copolymer having structural units of formula IwhereinZ is a direct bond, O, S, CH2, SO, SO2, CO, RPO, CH2, alkenyl, alkynyl, a C1-C12aliphatic radical, a C3-C12cycloaliphatic radical, a C3-C12aromatic radical or a combination thereof;R is a C6-12 aromatic radical or a C1-12aliphatic radical;R1 and R2 are independently H, halo, nitro, a C1-C12aliphatic radical, a C3-C12cycloaliphatic radical, a C3-C12aromatic radical, or a combination thereof;a is 0, 1, 2 or 3;b is 0, 1, 2, 3 or 4; andm and n are independently 0 or 1.