Composite polyamide membrane made via interfacial polymerization using a blend of non-polar solvents

Patent metadata

Field	Value
Publication number	US-10137418-B2
Application number	US-201414650127-A
Country	US
Kind code	B2
Filing date	Jan 3, 2014
Priority date	Jan 14, 2013
Publication date	Nov 27, 2018
Grant date	Nov 27, 2018

Abstract

A method for making a composite polyamide membrane comprising a porous support and a thin film polyamide layer, wherein the method includes: i) applying a polar solution comprising a polyfunctional amine monomer, and a non-polar solution comprising a polyfunctional acyl halide monomer to a surface of a porous support and interfacially polymerizing the monomers to form a thin film polyamide layer, wherein the non-polar solution further comprises at least 50 vol % of a C 5 to C 20 aliphatic hydrocarbon and from 2 to 25 vol % of benzene or benzene substituted with one or more C 1 to C 6 alkyl groups; and ii) applying an aqueous solution of nitrous acid to the thin film polyamide layer.

First claim

The invention claimed is:

1. A method for making a composite polyamide membrane comprising a porous support and a thin film polyamide layer, wherein the method comprises:
i) applying a polar solution comprising 2.5 to 6 wt % m-phenylene amine and a non-polar solution comprising 0.05 to 0.3 wt % trimesoyl chloride to a surface of a porous support and interfacially polymerizing the monomers to form a thin film polyamide layer,
wherein the non-polar solution comprises:
a) 50 to 90 vol % of C5 to C20 aliphatic hydrocarbon selected from a paraffin or isoparaffin, or combination thereof,
b) 3 to 15 vol % mesitylene, and
c) 0.02 to 0.08 wt % 1-carboxy-3,5-dichloroformyl benzene (mhTMC); and
ii) applying an aqueous solution of nitrous acid to the thin film polyamide layer.

2. The method of claim 1 wherein the thin film polyamide layer has a dissociated carboxylic acid content of at least 0.18 moles/kg at pH 9.5 as measured by RBS prior to the step of applying the aqueous solution of nitrous acid.

3. The method of claim 1 wherein the thin film polyamide layer has a dissociated carboxylic acid content of at least 0.45 moles/kg at pH 9.5 prior to the step of applying the aqueous solution of nitrous acid.

4. The method of claim 1 wherein the thin film polyamide layer has an isoelectric point (IEP) of less than or equal to 4.3 prior to the step of applying the aqueous solution of nitrous acid.

Assignees

• Dow Global Technologies Llc

Inventors

• Roy Abhishek
• Maeda Yasushi
• Paul Mou
• Rosenberg Steven
• Tomlinson Ian A

Classifications

• B01D71/82

  characterised by the presence of specified groups, e.g. introduced by chemical after-treatment · CPC title

• B01D67/0002

  Organic membrane manufacture · CPC title

• B01D2323/40

  in-situ membrane formation · CPC title

• B01D2323/36

  Introduction of specific chemical groups · CPC title

• B01D69/125

  In situ manufacturing by polymerisation, polycondensation, cross-linking or chemical reaction · CPC title