Functionalization of a porous membrane with an adsorbed polyacid
AssigneeBoard of Trustees of Michigan State University
InventorsMerlin L. Bruening, Gregory L. Baker, Somnath Bhattacharjee, Yiding Ma
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Abstract
The disclosure relates to a process and related article for functionalizing a porous membrane by contacting the membrane with a polyacid polymer at low pH to stably adsorb a polyacid layer on the membrane pore surface. The resulting functionalized membrane is characterized by a high density of free acid groups, resulting in a higher specific capacity for its intended application. The process allows functionalization of porous membranes in a very simple, one-step process. Such functional membranes may find multiple uses, including rapid, selective binding of proteins for their purification or immobilization.
Claims34
A polyacid-coated porous membrane comprising:
- (a) a porous membrane substrate comprising a plurality of membrane pores;
- and
- (b) a polyacid layer adsorbed on surfaces of the membrane pores, the polyacid layer comprising a polyacid polymer comprising one or more of free acid carboxylic acid groups, free acid carboxylate groups, and protein affinity tag-binding ligands;
- wherein:
- the polyacid polymer comprises at least the protein affinity tag-binding ligands;
- the polyacid layer was deposited from a fluid mixture having a pH value lower than 4;
- and
- the polyacid-coated porous membrane has a free acid group content higher than that of an analogous polyacid-coated porous membrane in which the polyacid layer was deposited from a fluid mixture having a pH value of 4, but which has been otherwise prepared equivalently to the polyacid-coated porous membrane.
A polyacid-coated porous membrane comprising:
- (a) a porous membrane substrate comprising a plurality of membrane pores;
- and
- (b) a plurality of polyacid layers adsorbed on surfaces of the membrane pores, each polyacid layer comprising a polyacid polymer comprising free acid groups selected from the group consisting of carboxylic acid groups, carboxylate groups, and combinations thereof;
- wherein:
- the first polyacid layer in the plurality of polyacid layers is adsorbed directly on the surfaces of the membrane pores and is substantially free of covalent attachments to the surfaces of the membrane pores;
- one or more further polyacid layers in the plurality of polyacid layers are adhered to adjacent polyacid layers via one or more intervening polycation layers;
- the polyacid layers were deposited from a fluid mixture having a pH value lower than 4;
- and
- the polyacid-coated porous membrane has a free acid group content higher than that of an analogous polyacid-coated porous membrane in which the polyacid layers were deposited from a fluid mixture having a pH value of 4, but which has been otherwise prepared equivalently to the polyacid-coated porous membrane.
A polyacid-coated porous membrane comprising:
- (a) a porous membrane substrate comprising a plurality of membrane pores;
- and
- (b) a polyacid layer adsorbed on surfaces of the membrane pores, the polyacid layer comprising a polyacid polymer comprising free acid groups selected from the group consisting of carboxylic acid groups, carboxylate groups, and combinations thereof;
- wherein:
- the polyacid layer is adsorbed on the surfaces of the membrane pores via one or more adhesion layers and is substantially free of covalent attachments to the surfaces of the membrane pores, wherein at least one of the adhesion layers is adsorbed directly on the porous membrane substrate;
- the polyacid layer was deposited from a fluid mixture having a pH value lower than 4;
- and
- the polyacid-coated porous membrane has a free acid group content higher than that of an analogous polyacid-coated porous membrane in which the polyacid layer was deposited from a fluid mixture having a pH value of 4, but which has been otherwise prepared equivalently to the polyacid-coated porous membrane.
Dependencies are inferred from the claim text.