Grafted polysulfone membranes

Patent metadata

Field	Value
Publication number	US-11273436-B2
Application number	US-201515738969-A
Country	US
Kind code	B2
Filing date	Nov 19, 2015
Priority date	Jun 26, 2015
Publication date	Mar 15, 2022
Grant date	Mar 15, 2022

Abstract

A polysulfone membrane is modified so that monomers are grafted onto the surface of the membrane. The polysulfone membranes can be grafted by contacting the membrane with a grafting solution and exposing the membrane to electromagnetic radiation, typically within the ultraviolet portion of the spectrum. The monomers that are grafted are typically anionic or cationic. The grafted membranes can be used for filtering impurities, such as positively and negatively charged particles, from a liquid. Anionic membranes provide improved filtration of negatively charged impurities, while cationic membranes provide improved filtration of positively charged impurities.

First claim

What is claimed is:

1. A grafted polysulfone membrane comprising:
one or more monomers grafted onto one or more surfaces of a polysulfone membrane and
benzophenone on the grafted polysulfone membrane, wherein the grafted polysulfone membrane has been dried and has a water flow rate that is at least 75% of the water flow rate of the polysulfone membrane, and wherein the grafted monomer is a cationic monomer is one or more of 2-(dimethylamino)ethyl hydrochloride acrylate, [2-(acryloyloxy)ethyl]trimethylammonium chloride, 2-aminoethyl methacrylate hydrochloride, N-(3-aminopropyl) methacrylate hydrochloride, 2-(dimethylamino)ethyl methacrylate hydrochloride, [2-(methacryloyloxy)ethyl]trimethylammonium chloride, 2-aminoethyl methacrylamide hydrochloride, N-(2-aminoethyl) methacrylamide hydrochloride, diallyldimethylammonium chloride, allylamine hydrochloride, vinyl imidazolium hydrochloride, vinyl pyridinium hydrochloride, and vinyl benzyl trimethyl ammonium chloride.

2. The grafted polysulfone membrane of claim 1 , wherein the cationic monomer diallyldimethylammonium chloride.

3. The grafted polysulfone membrane of claim 1 , wherein the grafted polysulfone membrane has a dye binding capacity between about 1 μg/cm 2 and about 5 μg/cm 2 .

4. The grafted polysulfone membrane of claim 1 , wherein the brittleness of the grafted polysulfone membrane in the machine direction does not exceed the brittleness of the polysulfone membrane in the machine direction, the crossweb direction or both by more than 30%.

5. The grafted polysulfone membrane of claim 1 , wherein the grafted polysulfone membrane has a bubble point between about 65 psi and about 75 psi when determined by an ethoxy-nonafluorobutane bubble point test.

6. A method of removing an impurity from a liquid, comprising contacting the liquid with the grafted polysulfone membrane according to claim 1 .

Assignees

• Entegris Inc

Inventors

• Jaber Jad Ali
• Gjoka Alketa
• Ly Saksatha

Classifications

• B01D67/00931

  by introduction of specific groups after membrane formation, e.g. by grafting · CPC title

• B01D2323/36

  Introduction of specific chemical groups · CPC title

• B01D2323/385

  involving radiation · CPC title

• B01D2325/16

  Membrane materials having positively charged functional groups · CPC title

• B01D71/78

  Graft polymers · CPC title