Patent ID: 7462283

Claim:
A device comprising: a filter having a nominal pore diameter in between the ultraporous and microporous range, said filter treated with a surface treatment solution comprising 192.12 Kg deionized water, 0.26 Kg initiator, 6 Kg acrylic acid, and 1.62 Kg N,N′-methylenebisacrylamide that is subject to a UV treatment to cross link and bond the surface treatment to a filter surface; said filter surface has a zeta potential of between −5 millivolts and 5 millivolts in a liquid with a pH of from 1.5 to 2.3; said filter treated with said surface treatment solution and subject to UV treatment retains positive and negatively charged particles smaller than the nominal pore diameter of the filter from the liquid with and LRV of 3 or more.