Functionalized copolymers and use thereof

1. An article comprising:

a) a porous substrate; and

b) a copolymer covalently attached to the porous substrate, the copolymer comprising a hydrocarbon backbone and a plurality of pendant groups attached to the hydrocarbon backbone, wherein:

1) each of a first plurality of pendant groups comprises:

(a) at least one acidic group or salt thereof; and

(b) a spacer group that directly links the at least one acidic group or salt thereof to the hydrocarbon backbone by a chain of at least 6 catenated atoms; and

2) each of a second plurality of pendant groups comprises:

(a) at least one acidic group or salt thereof; and

(b) a spacer group that directly links the at least one acidic group or salt thereof to the hydrocarbon backbone by a chain of at least 6 catenated atoms; and

wherein the first plurality of pendant groups are different than the second plurality of pendant groups; and

wherein a mole ratio of the first plurality of pendant groups to the second plurality of pendant groups is in a range of 95:5 to 5:95.

2. The article of claim 1 wherein the copolymer covalently attached to the porous substrate comprises a reaction product of a monomer composition comprising:

1) A first monomer comprising:

(a) at least one ethylenically unsaturated group;

(b) at least one acidic group or salt thereof; and

(c) a spacer group that directly links the at least one ethylenically unsaturated group and the at least one acidic group or salt thereof by a chain of at least 6 catenated atoms; and

2) a second monomer comprising:

(a) at least one ethylenically unsaturated group;

(b) at least one acidic group or salt thereof; and

(c) a spacer group that directly links the at least one ethylenically unsaturated group and the at least one acidic group by a chain of at least 6 catenated atoms;

wherein the second monomer is different than the first monomer; and

wherein a mole ratio of the first monomer to the second monomer is in a range of 95:5 to 5:95.

3. The article of claim 1 wherein the at least one acidic group or salt thereof of the copolymer covalently bonded to the porous substrate is present at a density of at least 0.01 mmole/gram of filter media.

4. The article of claim 1 wherein the at least one acidic group or salt thereof of the copolymer covalently bonded to the porous substrate is present at a density of up to 0.6 mmole/gram of filter media.

5. The article of claim 2 wherein the at least one ethylenically unsaturated group of the first monomer and/or second monomer is selected from an ethenyl group, a 1-alkylethenyl group, and a combination thereof.

6. The article of claim 1 wherein the spacer group is a catenated heteroatom-containing hydrocarbon group.

7. The article of claim 2 wherein the first monomer is one of a class represented by the following general formula:

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

wherein:

R 1 is selected from hydrogen, an alkyl group, a cycloalkyl group, an aryl group, and a combination thereof;

each R 2 is independently selected from a hydrocarbylene group, a heterohydrocarbylene group, and a combination thereof;

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

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

n is an integer of 0 or 1; and

L is a functional group comprising at least one acidic group or salt thereof.

8. The article of claim 2 wherein the second monomer is one of a class represented by the following general formula:

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

wherein:

R 1 is selected from hydrogen, an alkyl group, a cycloalkyl group, an aryl group, and a combination thereof;

each R 2 is independently selected from a hydrocarbylene group, a heterohydrocarbylene group, and a combination thereof;

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

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

n is an integer of 0 or 1; and

L is a functional group comprising at least one acidic group or salt thereof.

9. The article of claim 1 which is a filter element having a contacting surface.

10. The article of claim 1 which is an array of sample containers, wherein each container includes the filter element having a contacting surface.

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

providing a filter element of claim 9 ; and

allowing a biological solution comprising a target biomaterial to contact the contacting surface of the filter element under conditions effective for binding of the target biomaterial.

12. A process for separating aggregated proteins from monomeric proteins in a biological solution, the process comprising:

providing at least one filter element having a contacting surface, wherein the filter element comprises filter media comprising:

a) a porous substrate; and

b) a copolymer covalently attached to the porous substrate, the copolymer comprising a hydrocarbon backbone and a plurality of pendant groups attached to the hydrocarbon backbone, wherein:

1) Each of a first plurality of pendant groups comprises:

(a) at least one acidic group or salt thereof; and

(b) a spacer group that directly links the at least one acidic group or salt thereof to the hydrocarbon backbone by a chain of at least 6 catenated atoms; and

2) each of a second plurality of pendant groups comprises:

(a) at least one acidic group or salt thereof; and

(b) a spacer group that directly links the at least one acidic group or salt thereof to the hydrocarbon backbone by a chain of at least 6 catenated atoms; and

wherein the first plurality of pendant groups are different than the second plurality of pendant groups; and

wherein a mole ratio of the first plurality of pendant groups to the second plurality of pendant groups is in a range of 95:5 to 5:95; and

allowing an initial biological solution to contact the contacting surface of the filter element under conditions effective to separate the aggregated proteins from the monomeric proteins such that a final biological solution includes purified monomeric proteins.

13. The process of claim 12 wherein the copolymer covalently attached to the porous substrate comprises a reaction product of a monomer composition comprising

1) A first monomer comprising:

(a) at least one ethylenically unsaturated group;

(b) at least one acidic group or salt thereof; and

(c) a spacer group that directly links the at least one ethylenically unsaturated group and the at least one acidic group or salt thereof by a chain of at least 6 catenated atoms; and

2) a second monomer comprising:

(a) at least one ethylenically unsaturated group;

(b) at least one acidic group or salt thereof; and

(c) a spacer group that directly links the at least one ethylenically unsaturated group and the at least one acidic group or salt thereof by a chain of at least 6 catenated atoms;

wherein the second monomer is different than the first monomer; and

wherein a mole ratio of the first monomer to the second monomer is in a range of 95:5 to 5:95.

14. The process of claim 12 the conditions are effective to recover, in a final solution, at least 70% of the monomeric proteins present in the initial biological solution.

15. The process of claim 12 wherein the conditions are effective to remove at least 10% of the aggregated proteins from the initial biological solution.