Patent ID: 7959808

Claim:
A method for water filtration, said method comprising: contacting a protein containing water stream with a hydrophilic membrane comprising a polysulfone having structural units of Formula I wherein X is NR 1 R 2 ; R 1 and R 2 are independently at each occurrence hydrogen, a C 1 -C 5000 aliphatic radical, a C 3 -C 12 cycloaliphatic radical, a C 3 -C 12 aromatic radical, a polypeptide, a combination thereof, or R 1 and R 2 taken together form a 5- or 6-membered aliphatic ring or a 5-membered aromatic ring; B′ and C′ are independently at each occurrence a nitro group, C 1 -C 20 aliphatic radical, C 3 -C 12 cycloaliphatic radical, C 3 -C 12 aromatic radical, or a combination thereof; q and r are independently at each occurrence 0 to 4; and wherein said hydrophilic membrane has a contact angle of water less than 40°; and producing a retentate and water as permeate.