Ligand-functionalized substrates with enhanced binding capacity

1. An article for biomaterial capture comprising

(a) a porous polymeric membrane; and

(b) grafted to said porous polymeric membrane, a polymer comprising interpolymerized units of at least one monomer of the formula:

CH 2 ═CR 1 —C(═O)—X—R 2 —[Z—R 2 ] n -L

wherein

R 1 is selected from hydrogen, alkyl, cycloalkyl, aryl, and combinations thereof;

each R 2 is independently selected from hydrocarbylene, heterohydrocarbylene, and combinations thereof;

X is —O— or —NR 3 —, where R 3 is selected from hydrogen, hydrocarbyl, heterohydrocarbyl, and combinations thereof;

Z is heterohydrocarbylene comprising at least one hydrogen bond donor, at least one hydrogen bond acceptor, or a combination thereof;

n is 1; and

L is a heteroatom-containing group comprising at least one monovalent ligand functional group selected from acidic groups, basic groups other than guanidino, and salts thereof.

2. The article of claim 1 wherein said article comprises at least one filter element.

3. A process for capture or removal of a target biomaterial comprising

(a) providing at least one article of claim 1 ; and

(b) allowing a moving biological solution containing a target biomaterial to impinge upon the upstream surface of said filter element for a time sufficient to effect binding of said target biomaterial.

4. The process of claim 3 , wherein said target biological species is a protein.