Polyacid-functionalized porous membranes, related methods, and related polyacid polymers

A method for functionalizinq a porous membrane, the method comprising:

• (a) providing a porous membrane substrate comprising a plurality of membrane pores;
• and
• (b) contacting the membrane pores with an aqueous fluid mixture (i) having a pH value less than 3.8 and (ii) comprising a polyacid polymer comprising repeating units comprising a pendent metal-bindinq liqand comprising one or more free acid groups selected from the group consisting of carboxylic acid groups, carboxylate groups, and combinations thereof for a time sufficient to adsorb a polyacid layer on surfaces of the membrane pores, thereby forming a polyacid-coated porous membrane comprising the metal-bindinq liqand and the one or more free acid groups;
• wherein:
• (i) the repeating units comprise a nitrogen atom and have the general formula —[—CH2—CH2—NR—]—;
• and
• (ii) R comprises the pendent metal-binding ligand.

A method for functionalizinq a porous membrane, the method comprising:

• (a) providing a porous membrane substrate comprising a plurality of membrane pores;
• and
• (b) contacting the membrane pores with an aqueous fluid mixture (i) having a pH value less than 3.8 and (ii) comprising a polyacid polymer comprising repeating units comprising a pendent metal-binding ligand comprising one or more free acid groups selected from the group consisting of carboxylic acid groups, carboxylate groups, and combinations thereof for a time sufficient to adsorb a polyacid layer on surfaces of the membrane pores, thereby forming a polyacid-coated porous membrane comprising the metal-binding ligand and the one or more free acid groups;
• wherein:
• (i) the repeating units comprise an amide linking group and have the general formula —[—CH2—CR1(C(═O)NR2 R)—]—;
• (ii) R comprises the metal-binding ligand;
• (iii) R1 is H or a C1-C4 alkyl or heteroalkyl group;
• and
• (iv) R2 is H or a C1-C4 alkyl or heteroalkyl group.

A method for functionalizing a porous membrane, the method comprising:

• (a) providing a porous membrane substrate comprising a plurality of membrane pores;
• and
• (b) contacting the membrane pores with an aqueous fluid mixture (i) having a pH value less than 3.8 and (ii) comprising a polyacid polymer comprising repeating units comprising a pendent metal-binding ligand comprising one or more free acid groups selected from the group consisting of carboxylic acid groups, carboxylate groups, and combinations thereof for a time sufficient to adsorb a polyacid layer on surfaces of the membrane pores, thereby forming a polyacid-coated porous membrane comprising the metal-binding ligand and the one or more free acid groups;
• wherein:
• (i) the repeating units comprise an oxygen atom and have the general formula —[—O—CH2—CH(CH2 NR)—]—;
• and
• (ii) R comprises the metal-binding ligand.