High flux, chlorine resistant coating for sulfate removal membranes

Patent metadata

Field	Value
Publication number	US-11794149-B2
Application number	US-202016849856-A
Country	US
Kind code	B2
Filing date	Apr 15, 2020
Priority date	Jun 22, 2017
Publication date	Oct 24, 2023
Grant date	Oct 24, 2023

Abstract

A filtration membrane coating comprising a hydrophilic polymer, a surfactant, and one or more charged compounds, each containing one or more sulfonate functionalities and one or more linkable functionalities selected from the group consisting of amine, monochlorotriazine, and dichlorotriazine. The hydrophilic polymer and surfactant form a thin primer layer which is also superhydrophilic. The primer layer improves flux, and enables improved adhesion of the one or more charged compounds, which form a charged dye layer on top of the primer layer when enhances rejection of charged divalent ions. The coating can be applied while the membrane is packaged in its final form, such as in a spiral wound or other configuration.

First claim

We claim:

1. A conformal chlorine-resistant, fouling resistant, and permeate flux-enhancing coating for a filtration membrane, comprising:
a hydrophilic polymer;
a surfactant; and
one or more charged compounds, each containing one or more sulfonate functionalities and one or more linkable functionalities selected from the group consisting of amine, monochlorotriazine, and dichlorotriazine;
wherein the hydrophilic polymer comprises at least one material selected from the group consisting of polydopamine and its copolymers, poly (dopamine-acrylamide) and its copolymers, polyethylene, polyvinyl alcohol, hydroethyl cellulose, hydroxyl propyl cellulose, methyl cellulose poly (hydroxyethyl methacrylate) and its copolymers, styrene-maleic anhydride copolymer, methyl vinyl ether-maleic anhydride copolymer, polyethylenimine, carboxy methyl cellulose, locust bean gum, bean gum, carrageenan, agar, polyvinylpyrrolidone, sulfonate polysulfone, polyethylene oxide and copolymers, polyethylene glycol, polyacrylamide, and polysaccharide; and
wherein the surfactant comprises at least one hydrocarbon chain having at least 16 carbon atoms.

2. The coating of claim 1 , wherein the coating comprises greater than 10 wt % of said surfactant.

3. The coating of claim 1 , wherein a thickness of the coating is less than or equal to 20 nm.

4. The coating of claim 3 , wherein the thickness of the coating is less than or equal to 5 nm.

5. The coating of claim 1 , wherein the surfactant comprises at least one hydrocarbon chain having 16 to 24 carbon atoms.

6. The coating of claim 1 , wherein the surfactant comprises N-erucyl-N,N-bis(2-hydroxyethyl)-N-methyl ammonium chloride.

7. The coating of claim 1 , wherein the surfactant comprises of one or more of sodium lauryl sulfate, sodium laureth sulfate, sodium lactate, tetrazolides, phospholipids capable of assuming a zwitterionic state, cocamidopropyl betaine, sulfobetaines, and polyethylene glycol.

8. The coating of claim 1 , wherein said coating comprises:
a primer layer comprising said hydrophilic polymer and said surfactant; and
a first dye layer comprising one of said charged compounds.

9. The coating of claim 8 , further comprising a second dye layer comprising a second charged compound containing one or more sulfonate functionalities and one or more linkable functionalities selected from the group consisting of amine, monochlorotriazine, and dichlorotriazine.

10. A coated filtration membrane, comprising:
a filtration membrane,
a coating on said membrane, said coating comprising:
a hydrophilic polymer;
a surfactant; and
one or more charged compounds, each containing one or more sulfonate functionalities and one or more linkable functionalities selected from the group consisting of amine, monochlorotriazine, and dichlorotriazine;
wherein the hydrophilic polymer comprises at least one material selected from the group consisting of polydopamine and its copolymers, poly (dopamine-acrylamide) and its copolymers, polyethylene, polyvinyl alcohol, hydroethyl cellulose, hydroxyl propyl cellulose, methyl cellulose poly (hydroxyethyl methacrylate) and its copolymers, styrene-maleic anhydride copolymer, methyl vinyl ether-maleic anhydride copolymer, polyethylenimine, carboxy methyl cellulose, locust bean gum, bean gum, carrageenan, agar, polyvinylpyrrolidone, sulfonate polysulfone, polyethylene oxide and copolymers, polyethylene glycol, polyacrylamide, and polysaccharide; and
wherein the surfactant comprises at least one hydrocarbon chain having at least 16 carbon atoms.

11. The coated filtration membrane of claim 10 , wherein said membrane is selected from the group consisting of a nanofiltration membrane, a tight ultrafiltration membrane, and a reverse osmosis membrane.

12. The coated filtration membrane of claim 10 , wherein said membrane comprises a polyamide-based nanofiltration membrane.

13. A conformal chlorine-resistant, fouling resistant, and permeate flux-enhancing coating for a membrane, comprising:
dopamine HCl;
a surfactant;
a first charged compound; and
a second charged compound containing one or more sulfonate functionalities and one or more linkable functionalities from the group consisting of amine, monochlorotriazine, and dichlorotriazine;
wherein said surfactant is 40% sodium lauryl ether sulfate in water, said first charged compound is a solution of 0.1% benzopurpurine 4B, and said second charged compound is a solution of 0.4% 4-amino-5-hydroxynaphthalene-2,7-disulfonic acid Na salt hydrate.

Assignees

• Teledyne Scient & Imaging Llc

Inventors

• Strauss Dennis R
• Ganguli Rahul
• Liao Ten-Luen T
• Mehrotra Vivek
• Verbeek Paulus Henricus Johannes
• Krebs Thomas

Classifications

• B01D67/00931

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

• B01D69/1216

  Three or more layers · CPC title

• B01D2321/167

  Use of scale inhibitors · CPC title

• B01D69/02 Primary

  characterised by their properties · CPC title

• B01D65/08

  Prevention of membrane fouling or of concentration polarisation · CPC title