US 9,808,769 B2
Composite polyamide membrane post treated with nitrious acid
Mou Paul, Edina, MN (US); Abhishek Roy, Edina, MN (US); and Ian A. Tomlinson, Midland, MI (US)
Assigned to Dow Global Technologies LLC, Midland, MI (US)
Appl. No. 15/30,919
Filed by Dow Global Technologies LLC, Midland, MI (US)
PCT Filed Oct. 29, 2014, PCT No. PCT/US2014/062830
§ 371(c)(1), (2) Date Apr. 21, 2016,
PCT Pub. No. WO2015/084511, PCT Pub. Date Jun. 11, 2015.
Claims priority of provisional application 61/910,559, filed on Dec. 2, 2013.
Prior Publication US 2016/0271567 A1, Sep. 22, 2016
Int. Cl. B01D 67/00 (2006.01); B01D 69/12 (2006.01); B01D 71/56 (2006.01); B05D 3/10 (2006.01)
CPC B01D 67/0093 (2013.01) [B01D 67/0006 (2013.01); B01D 69/125 (2013.01); B01D 71/56 (2013.01); B05D 3/108 (2013.01); B01D 2323/40 (2013.01); B01D 2325/20 (2013.01)] 9 Claims
 
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 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;
ii) treating the thin film polyamide layer with a polyfunctional arene compound comprising 1 or 2 benzene rings collectively substituted with the follow four functional groups:
(a) a first functional group (w) selected from the group consisting of: —NR4R5 and —OH,
(b) a second functional group (x) selected from the group consisting of: —NR4R5, —OH, —COOH, and-SO3H,
(c) a third functional group (y) is selected from the group consisting of: —H, —NR4R5, —OH, —COOH, and —SO3H,
(d) a fourth functional group (z) selected from the group consisting of: —H, —CH3, —NR4R5, —OH, —COOH and —SO3H,
wherein: (R4) and (R5) are independently selected from the group consisting of: —H and hydrocarbyl groups comprising from 1 to 10 carbon atoms; and
iii) exposing the thin film polyamide layer to nitrous acid;
wherein step ii) may occur before, during or after step iii) and, wherein the method is characterized by:
(A) at least one of the polar and non-polar solutions further comprises a tri-hydrocarbyl phosphate compound represented by Formula I:

OG Complex Work Unit Drawing
wherein R1, R2 and R3 are independently selected from the group consisting of: hydrogen and hydrocarbyl groups comprising from 1 to 10 carbon atoms, with the proviso that no more than one of R1, R2 and R3 are hydrogen; and
(B) the non-polar solution further comprises an acid-containing monomer comprising a C2-C20 hydrocarbon moiety substituted with at least one carboxylic acid functional group or salt thereof and at least one amine-reactive functional group selected from the group consisting of: acyl halide, sulfonyl halide and anhydride, wherein the acid-containing monomer is distinct from the polyfunctional acyl halide monomer.