Functionalization of nanofibrous microfiltration membranes for water purification
A high flux and low pressure drop microfiltration (MF) membrane and a method for making the MF membrane. The microfiltration membranes are formed by a method that includes: preparing a nanofibrous structure; and modifying the surface of the nanofibrous structure with a surface modifier. The nanofibrous structure includes an electrospun nanofibrous scaffold or a polysaccharide nanofiber infused nanoscaffold or mixtures thereof. The electrospun nanofibrous scaffold can include polyacrylonitrile (PAN) or polyethersulfone (PES))/polyethylene terephthalate (PET) or mixtures thereof. The surface modifier includes polyethylenimine (PEI) and polyvinyl amine (Lupamin) cross-linked by ethylene glycol diglycidyl ether (EGdGE)/glycidyltrimethylammonium chloride (GTMACl) or poly(1-(1-vinylimidazolium)ethyl-3-vinylimdazolium dibromide (VEVIMIBr).
1. A method of forming high flux and low pressure drop microfiltration membranes comprising:
preparing a nanofibrous structure, wherein the nanofibrous structure comprises an electrospun nanofibrous scaffold comprising polyacrylonitrile (PAN), polyethersulfone (PES))/polyethylene terephthalate (PET) or mixtures thereof; and
modifying the surface of the nanofibrous structure with a surface modifier, wherein the surface modifier comprises:
polyethylenimine (PEI)/glycidyltrimethyl-ammonium chloride (GTMACl) cross-linked by glutaraldehyde (GA);
PEI cross-linked by ethylene glycol diglycidyl ether (EGdGE)/glycidyltrimethyl-ammonium chloride (GTMACl);
polyvinyl amine cross-linked by GA;
polyvinyl amine cross-linked by EGdGE/GTMACl; or
poly(1-(1-vinylimidazolium)ethyl-3-vinylimdazolium dibromide (poly(VEVIMIBr)).
2. The method of claim 1 , wherein the nanofibrous structure comprises fibers having diameters of from about 50 nm to about 5 microns.
3. The method of claim 1 , wherein the nanofibrous structure comprises fibers having diameters of from about 50 to about 500 nm.
4. The method of claim 1 , wherein the surface modifier is produced by in-situ polymerization.
5. The method of claim 1 , wherein the surface modifier forms a coating on the surface of the nanofibrous structure, wherein the coating has a thickness of from about 5 to 30 nm.
6. The method of claim 1 , wherein the surface modifier forms a coating on the surface of the nanofibrous structure, wherein the coating has a thickness of from about 10 to 20 nm.
7. A method of forming high flux and low pressure drop microfiltration membranes comprising:
preparing a nanofibrous structure comprising an electrospun nanofibrous scaffold or a glass fiber scaffold or mixtures thereof, wherein the electrospun nanofibrous scaffold comprises polyacrylonitrile (PAN), polyethersulfone (PES))/polyethylene terephthalate (PET) or mixtures thereof; and
modifying the surface of the nanofibrous structure with a surface modifier, wherein the surface modifier comprises:
polyethylenimine (PEI)/glycidyltrimethyl-ammonium chloride (GTMACl) cross-linked by glutaraldehyde (GA);
PEI cross-linked by ethylene glycol diglycidyl ether (EGdGE)/glycidyltrimethyl-ammonium chloride (GTMACl);
polyvinyl amine cross-linked by GA;
polyvinyl amine cross-linked by EGdGE/GTMACl; or
poly(1-(1-vinylimidazolium)ethyl-3-vinylimdazolium dibromide (poly(VEVIMIBr)), wherein the surface modifier is produced by in-situ polymerization.
8. The method of claim 7 , wherein the nanofibrous structure comprises nanofibers having diameters of from about 50 nm to about 5 microns.
9. The method of claim 7 , wherein the surface modifier forms a coating on the surface of the nanofibrous structure, wherein the coating has a thickness of from about 50 to 500 nm.
10. A microfiltration membrane for water purification, the microfiltration membrane comprising:
a nanofibrous structure comprising an electrospun nanofibrous scaffold or a glass fiber scaffold or mixtures thereof, wherein the electrospun nanofibrous scaffold comprises polyacrylonitrile (PAN), polyethersulfone (PES))/polyethylene terephthalate (PET) or mixtures thereof; and
a coating applied to the nanofibrous structure comprising a surface modifier, wherein the surface modifier comprises:
polyethylenimine (PEI)/glycidyltrimethyl-ammonium chloride (GTMACl) cross-linked by glutaraldehyde (GA);
PEI cross-linked by ethylene glycol diglycidyl ether (EGdGE)/glycidyltrimethyl-ammonium chloride (GTMACl);
polyvinyl amine cross-linked by GA;
polyvinyl amine cross-linked by EGdGE/GTMACl; or
poly(1-(1-vinylimidazolium)ethyl-3-vinylimdazolium dibromide (poly(VEVIMIBr)), wherein the surface modifier is produced by in-situ polymerization.
11. The microfiltration membrane according to claim 10 , wherein the nanofibrous structure comprises nanofibers having diameters of from about 50 to about 5,000 nm.
12. The microfiltration membrane according to claim 10 , wherein the surface modifier forms a coating on the surface of the nanofibrous structure, wherein the coating has a thickness of from about 5 to 30 nm.