Additives for salt rejection enhancement of a membrane

Provided is an interfacial polymerization process for preparation of a 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 acyl halide to the coated support membrane to interfacially polymerize the polyamine and the polyfunctional acyl halide to form a discrimination layer of a thin film composite membrane, where during formation of the membrane, the polyfunctional acyl halide is purified in situ by removal of hydrolyzed acyl halide through addition of a salt rejection-enhancing additive that includes a biguanide compound, dicarbonate compound, pentathiodicarbonate compound, or salt thereof. Also provided are the membranes prepared by the methods and reverse osmosis modules containing the membranes.

Chemical additives for enhancement of water flux of a membrane

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 at low energy conditions. The process includes contacting a porous support membrane with an aqueous phase containing a polyamine and a flux enhancing combination of additives that includes a metal chelate additive containing a bidentate ligand and a metal atom or metal ion and a phosphoramide 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 the thin film composite membrane. Also provided are the membranes prepared by the methods and reverse osmosis modules containing the membranes.

Combination of chemical additives for enhancement of water flux of a membrane

Provided is an interfacial polymerization process for preparation of a highly permeable thin film composite membrane, which can be used for nanofiltration, or forward or reverse osmosis, for use with tap water, seawater and brackish water, particularly for use with brackish water at low energy conditions. The process includes contacting a porous support membrane with an aqueous phase containing a polyamine and a flux enhancing combination, which includes a metal chelate additive containing a bidentate ligand and a metal atom or metal ion and a dialkyl sulfoxide, 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 the thin film composite membrane. Also provided are the membranes prepared by the methods and reverse osmosis modules containing the membranes.

ADDITIVES FOR SALT REJECTION ENHANCEMENT OF A MEMBRANE

Provided is an interfacial polymerization process for preparation of a 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 acyl halide to the coated support membrane to interfacially polymerize the polyamine and the polyfunctional acyl halide to form a discrimination layer of a thin film composite membrane, where during formation of the membrane, the polyfunctional acyl halide is purified in situ by removal of hydrolyzed acyl halide through addition of a salt rejection-enhancing additive that includes a biguanide compound, dicarbonate compound, pentathiodicarbonate compound, or salt thereof. Also provided are the membranes prepared by the methods and reverse osmosis modules containing the membranes. 1. A process for preparing a thin film composite membrane , comprising:providing an aqueous phase comprising a polyamine and an organic phase comprising a polyfunctional acyl halide;introducing a salt rejection-enhancing additive in the aqueous phase, the salt rejection-enhancing additive able to form a complex with hydrolyzed polyfunctional acyl halide;applying the aqueous phase to a surface of a porous support membrane to form a coated support membrane;applying the organic phase to the coated support membrane to allow interfacial polymerization between the aqueous phase and organic phase, wherein hydrolyzed and non-hydrolyzed polyfunctional acyl halide are present during interfacial polymerization;forming a complex between the salt rejection-enhancing additive and the hydrolyzed polyfunctional acyl halide and interfacially polymerizing the polyamine and the non-hydrolyzed acyl halide to produce a discrimination layer of a thin film composite membrane comprising the porous ...

CHEMICAL ADDITIVES FOR ENHANCEMENT OF WATER FLUX OF A MEMBRANE

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 at low energy conditions. The process includes contacting a porous support membrane with an aqueous phase containing a polyamine and a flux enhancing combination of additives that includes a metal chelate additive containing a bidentate ligand and a metal atom or metal ion and a phosphoramide 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 the thin film composite membrane. Also provided are the membranes prepared by the methods and reverse osmosis modules containing the membranes. 1. A process for preparing a thin film composite membrane , comprising: (i) a metal chelate additive containing a bidentate ligand and a metal atom or metal ion; and', '(ii) a phosphoramide;, '(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 further include a flux enhancing combination that comprises(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 water flux and that is greater than the water flux of a thin film composite membrane prepared in the absence of the flux enhancing combination.3. The process of claim 2 , wherein the bidentate ligand is an acetylacetonate (acac) or ...

COMBINATION OF CHEMICAL ADDITIVES FOR ENHANCEMENT OF WATER FLUX OF A MEMBRANE

Provided is an interfacial polymerization process for preparation of a highly permeable thin film composite membrane, which can be used for nanofiltration, or forward or reverse osmosis, for use with tap water, seawater and brackish water, particularly for use with brackish water at low energy conditions. The process includes contacting a porous support membrane with an aqueous phase containing a polyamine and a flux enhancing combination, which includes a metal chelate additive containing a bidentate ligand and a metal atom or metal ion and a dialkyl sulfoxide, 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 the thin film composite membrane. Also provided are the membranes prepared by the methods and reverse osmosis modules containing the membranes. 1. A process for preparing a thin film composite membrane , comprising: (i) a metal chelate additive containing a bidentate ligand and a metal atom or metal ion; and', '(ii) a dialkyl sulfoxide;, '(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 further include a flux enhancing combination that comprises(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 water flux that is greater than the water flux of a thin film composite membrane prepared in the absence of the water flux enhancing combination.3. The process of claim 1 , wherein the ...

Chemical additives for enhancement of water flux of a membrane