Additives for boron rejection enhancement of a membrane

Patent metadata

Field	Value
Publication number	US-9687792-B2
Application number	US-201514841546-A
Country	US
Kind code	B2
Filing date	Aug 31, 2015
Priority date	Aug 31, 2015
Publication date	Jun 27, 2017
Grant date	Jun 27, 2017

Abstract

Provided is an interfacial polymerization process for preparation of a highly permeable thin film composite membrane, which can be used for nanofiltration, forward osmosis, or reverse osmosis, particularly for use with brackish water or seawater. The process includes contacting a porous support membrane with an aqueous phase containing a polyamine to form a coated support membrane, and applying an organic phase containing a polyfunctional acid halide to the coated support membrane to interfacially polymerize the polyamine and the polyfunctional acid halide to form a discrimination layer of a thin film composite membrane, where the aqueous and/or organic phases include a flux-enhancing additive and a boron rejection-enhancing additive that includes a biguanide compound, dicarbonate compound, pentathiodicarbonate compound, or salts thereof. Also provided are the membranes prepared by the methods and reverse osmosis modules containing the membranes.

First claim

What is claimed is:

1. A process for preparing a thin film composite membrane, comprising:
(a) preparing an aqueous phase comprising a polyamine and an organic phase comprising a polyfunctional acid halide, wherein the aqueous phase or organic phase or both include an additive comprising:
a boron rejection-enhancing additive having the formula:

wherein:
the formula represents a recurring polymer unit;
n is a number between 1 and 60; and
X is an alkyl chain having between 1 and 30 carbons; and

(b) applying the aqueous phase to a surface of a porous support membrane to form a coated support membrane; and
(c) applying the organic phase to the coated support membrane and interfacially polymerizing the polyamine and the polyfunctional acid halide to form a discrimination layer of a thin film composite membrane comprising the porous support membrane and the discrimination layer, the thin film composite membrane having a boron rejection that is greater than the boron rejection of a thin film composite membrane prepared in the absence of the boron rejection-enhancing additive.

2. The process of claim 1 , wherein X is —(CH 2 ) 6 —.

3. The process of claim 1 , wherein the concentration of boron rejection-enhancing additive in the aqueous phase or organic phase is from about 0.01% to 5% based on the weight of the aqueous phase or organic phase.

4. The process of claim 1 , wherein the aqueous phase or organic phase or both further include a metal chelate additive containing a bidentate ligand and a metal atom or metal ion.

5. The process of claim 4 , wherein the bidentate ligand is selected from among:

wherein each of R 1 , R 2 , R 3 , R 4 and R 5 separately is selected from among a C 1 -C 10 alkyl, a halogenated C 1 -C 10 alkyl, a 5-membered aromatic ring, a 6-membered aromatic ring, an aromatic bicyclic ring, system containing two fused 6-membered rings, and an aromatic bicyclic ring system containing a 5-membered ring fused to a 6-membered aromatic ring.

6. The process of claim 4 , wherein the bidentate ligand is an acetylacetonate (acac) or fluorinated acetylacetonate.

7. The process of claim 4 , wherein the metal chelate additive containing a bidentate ligand and a metal atom or metal ion is selected from among Al(acac) 3 , Al(F 6 acac) 3 , Ba(acac) 2 , Ba(F 6 acac) 2 , Be(acac) 2 , Be(F 6 acac) 2 , Ca(acac) 2 , Ca(F 6 acac) 2 , Cd(acac) 2 , Cd(F 6 acac) 2 , Ce(acac) 3 , Ce(F 6 acac) 3 , Cr(acac) 3 , Co(acac) 2 , Cu(acac) 2 , Cu(F 6 acac) 2 , Dy(acac) 3 , Er(acac) 3 , Fe(acac) 2 , Fe(acac) 3 , Ga(acac) 3 , Hf(acac) 4 , In(acac) 3 , K(acac), Li(acac), Mg(acac) 2 , Mg(F 6 acac) 2 , Mn(acac) 2 , Mn(acac) 3 , MoO(acac) 2 , MoO(F 6 acac) 2 , Na(acac), Nd(acac) 3 , Nd(F 6 acac) 3 , Ni(acac) 2 , Ni(F 6 acac) 2 , Pd(acac) 2 , Pr(acac) 3 , Pr(F 6 acac) 3 , Ru(acac) 3 , Ru(F 6 acac) 3 , Sc(acac) 2 , Sc(F 6 acac) 2 , Sm(acac) 3 , Sn(acac) 2 , Sn(acac) 2 Cl 2 , t-butyl-Sn(acac) 2 , t-butyl-Sn(acac) 2 Cl 2 , Sn(F 6 acac) 2 , Sr(acac) 2 , Sr(F 6 acac) 2 , Tb(acac) 3 , V(acac) 3 , Y(acac) 3 , Y(F 6 acac) 3 , Zn(acac) 2 , Zn(F 6 acac) 2 , and Zr(acac) 4 , wherein F 6 acac refers to 1,1,1,5,5,5-hexafluoroacetylacetonate.

8. The process of claim 4 , wherein the bidentate ligand is a beta-diketonate or a fluorinated beta-diketonate.

9. The process of claim 4 , wherein the amount of bidentate ligand in the metal chelate additive yields a concentration of bidentate ligand in the aqueous phase of step (a) of from about 0.001 wt % to about 1 wt %, based on the weight of the aqueous phase.

10. The process of claim 4 , wherein the metal atom or metal ion is an alkaline earth metal.

11. A thin film composite membrane prepared according to the process of claim 1 .

Assignees

• Lg Chemical Ltd
• Lg Nanoh2O Inc

Inventors

• Goenaga Alberto
• Anderson Holmberg Brett
• Ford Andrew
• Sankhe Amit
• Kurth Christopher
• Burk Robert
• Lee Jin Kuk
• Koehler Jeff
• Choi Sung Yeol
• Eom Youngsik
• Choi Hyungsam

Classifications

• B01D63/10

  Spiral-wound membrane modules · CPC title

• B01D69/125 Primary

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

• B01D71/60

  Polyamines · CPC title

• B01D71/601

  Polyethylenimine · CPC title

• B01D63/107

  Specific properties of the central tube or the permeate channel · CPC title