High-performance anion exchange membranes and methods of making same

Patent metadata

Field	Value
Publication number	US-2018057370-A1
Application number	US-201715805746-A
Country	US
Kind code	A1
Filing date	Nov 7, 2017
Priority date	Oct 4, 2012
Publication date	Mar 1, 2018
Grant date	—

Abstract

Anion exchange membranes may include a polymeric microporous substrate and a cross-linked anion exchange polymeric layer on the substrate. Anion exchange membranes may have a resistivity of less than about 1.5 Ohm-cm 2 and an apparent permselectivity of at least about 95%. The anion exchange membranes may be produced by a unique, two step process.

First claim

1 . A method of making an anion exchange membrane, comprising:
mixing a tertiary amine monomer with a quaternization agent to produce a functional monomer; mixing a cross-linking agent and a solvent with the functional monomer to form a monomeric solution; and casting the monomeric solution on a polymeric microporous substrate to form the anion exchange membrane.

2 . The method of claim 1 , wherein the tertiary amine monomer is selected from the group consisting of 1-vinylimidazole, 2-methyl-1-vinylimidazole, 9-vinylcarbazole, N-ethyl-2-vinylcarbazole, 2-vinylpyridine, 3-vinylpyridine, 4-vinylpyridine, and mixtures thereof.

3 . The method of claim 2 , wherein the quaternization agent is selected from the group consisting of benzyl chloride, benzyl bromide, benzyl iodide, p-dichlorobenzene, m-dichlorobenzene, 1,4-dichloro-2-nitrobenzene, 3-(Benzyloxy)benzyl chloride, 4-(Benzyloxy)benzyl chloride 2-(Trifluoromethyl)- benzyl chloride, 3-(Trifluoromethyl)benzyl chloride, 4-(Trifluoromethyl)benzyl chloride, 1-chlorohexane, 1-chloropentane, 1-chlorobutane, 1-chloropropane, 1,6 dichlorohexane, 1,5-dichloropentane, 1,4-dichlorobutane, 1,3-dichloropropane, 1-bromohexane, 1-bromopentane, 1-bromobutane, 1-bromopropane, 1,6-dibromohexane, 1,5-dibromopentane, 1,4-dibromobutane, 1,3-dibromopropane, 1-iodohexane, 1-iodopentane, 1-iodobutane, 1-iodoopropane, 1-iodideethane, 1-iodidemethane,1,6-diiodohexane, 1,5-diiodorpentane, 1,4-diiodobutane,1,3-diiodopropane, and mixtures thereof.

4 . The method of claim 3 , wherein the cross-linking agent is selected from the group consisting of vinylbenzyl chloride, m-divinylbenzene, ethyleneglycol-dimethacrylate, p-dichlorobenzene, m-dichlorobenzene, 1,4-dichloro-2-nitrobenzene, 1,6 dichlorohexane, 1,5-dichloropentane, 1,4-dichlorobutane, 1,3-dichloropropane, 1,6-dibromohexane, 1,5-dibromopentane, 1,4-dibromobutane, 1,3-dibromopropane, 1,6-dibromohexane, 1,5-dibromopentane, 1,4-dibromobutane, 1,3-dibromopropane, 1,4-butanediol dimethacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, Pentaerythritol triacrylate, divinyl benzene, (m- and p-mixture), trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, ethoxylated (n) bisphenol A di(meth)acrylate (n=1.5, 2, 4, 6, 10, 30), ethoxylated (n) trimethylolpropanetri(meth)Acrylate (n=3,6,9,10,15,20), propoxylated(n) trimethylolpropane triacrylate (n =3,6), and mixtures thereof.

5 . The method of claim 4 , wherein the solvent comprises dipropyleneglycol, n-propanol, 2-propanol, 1-methyl-2-pyrrolidinone, 1-butanol, and mixtures thereof.

6 . The method of claim 5 , further comprising mixing a polymerization initiator with the monomer solution.

7 . The method of claim 6 , wherein the polymerization initiator is selected from the group consisting of organic peroxides, 2,2′ azobis[2,[2-imdazolin-2-yl]-propane] dihydrochloride, α,α′-azoisobutyronitrile, 2,2′-azobis[2-methylpropioaminidine] dihydrochloride, 2,2′-azobis [2, [2 -imdazolin-2-yl]-propane], dimethyl2,2′azobis[2-methylpropionate] and benzoyl peroxide.

8 . The method of claim 7 , further comprising controlling polymerization with an inhibitor.

9 . The method of claim 8 , wherein the polymerization inhibitor is selected from the group consisting of 4-methoxyphenol and 4-tert-butyl catechol.

10 . The method of claim 9 , wherein the polymeric microporous substrate comprises at least one of polypropylene, high molecular weight polyethylene, ultrahigh molecular weight polyethylene, polyvinyl chloride, polyvinylidene difluoride, and polytetrafluoroethylene.

11 . The method of claim 10 , wherein casting comprises applying heat at a temperature of about 0° C. to about 100° C., ultraviolet light at a wavelength of about 100 nm to about 400 nm, or ionizing radiation.

Assignees

• Evoqua Water Tech Llc

Inventors

• Lin Juchi Ray

Classifications

• C08J2323/12

  Polypropene · CPC title

• C08J5/2287

  After-treatment · CPC title

• C02F2101/106

  Selenium compounds · CPC title

• C02F2103/08

  Seawater, e.g. for desalination · CPC title

• B05D3/068

  using ionising radiations (gamma, X, electrons) · CPC title