Woongjin Chemical Co., Ltd.

Saehan Industries Incorporation

Saehan Industries Incorporated

Saekan Industries Incorporation

Ja-Young Koo

Sung Pyo Hong

Jong Hwa Lee

Nowon Kim

Young Seo Yoon

Kwan Young Ryu

Jong-Eun Kim

Jun Suk Kim

Sung-Pyo Hong

Wan-Ju Kim

Ki Suop Park

Jin Woo Kang

Sungpyo Hong

Doowon Lee

Yeo-Jin Kim

Yong-Doo Jung

A selective membrane having a high fouling resistance. In one embodiment, the selective membrane is a composite polyamide reverse osmosis membrane having a hydrophilic coating made by covalently bonding a hydrophilic compound to the polyamide membrane, the hydrophilic compound including (i) a reactive group that is adapted to covalently bond directly to the polyamide membrane, the reactive group being at least one of a primary amine and a secondary amine; (ii) a non-terminal hydroxyl group; and (iii) an amide group. In another embodiment, the hydrophilic compound includes (i) a reactive group adapted to covalently bond directly to the polyamide membrane, the reactive group being at least one of a primary amine and a secondary amine; (ii) a hydroxyl group; and (iii) an amide group, the amide group being linked directly to the hydroxyl group by one of an alkyl group and an alkenyl group.

Selective membrane having a high fouling resistance

Method for preparing a filtration membrane and a filtration membrane prepared by the method. According to one embodiment, the method involves casting a polymer solution onto a porous support to form a coated support. The coated support is then quenched to form a membrane/support composite, and the membrane/support composite is then dried. Next, a first end of a first piece of adhesive tape is applied to the membrane side of the composite, and the second end of the first piece of adhesive tape is applied to a first rotatable winder. In addition, a first end of a second piece of adhesive tape is applied to the support side of the composite, and the second end of the second piece of adhesive tape is applied to a second rotatable winder. The two winders are then rotated so as to pull apart the membrane from the support.

Method for preparing a filtration membrane and filtration membrane prepared by said method

A selective membrane having a high fouling resistance. In one embodiment, the selective membrane is a composite polyamide reverse osmosis membrane in which a hydrophilic coating is applied to the polyamide layer of the membrane, the hydrophilic coating being made by covalently bonding a hydrophilic compound to residual acid chlorides of the polyamide membrane, the hydrophilic compound including (i) at least one reactive group that is adapted to covalently bond directly to the polyamide membrane, the at least one reactive group being at least one of a primary amine and a secondary amine; and (ii) at least one non-terminal hydroxyl group.

A selective membrane having a high fouling resistance. In one embodiment, the selective membrane is a composite polyamide reverse osmosis membrane in which a hydrophilic coating is applied to the polyamide layer of the membrane, the hydrophilic coating being made by covalently bonding a hydrophilic compound to residual acid chlorides of the polyamide membrane, the hydrophilic compound including (i) at least one reactive group that is adapted to covalently bond directly to the polyamide membrane, the at least one reactive group being at least one of a primary amine and a secondary amine; and (ii) at least one hydrophilic group, the at least one hydrophilic group being selected from the group consisting of a hydroxyl group, a carbonyl group, a trialkoxysilane group, an anionic group and a tertiary amino group; (iii) wherein the hydrophilic compound is devoid of a polyalkylene oxide group.

A composite polyamide reverse osmosis membrane and method of producing same. In a preferred embodiment, the membrane is made by coating a porous polysulfone support with an aqueous solution containing 2 wt % m-phenylenediamine (MPD), and 0.1 wt % di(ethylene glycol) hexyl methyl ether. Next, the excess solution is removed, and the coated support is dipped in 0.1 wt % organic solvent solution of trimesoyl chloride (TMC) in a mixture of alkanes having from 8 to 12 carbon atoms. After draining the TMC solution off, the resulting composite membrane is air dried and then rinsed in a basic aqueous solution. The resultant membrane exhibits a flux of 21.3 gfd and a salt rejection of 98.9% when used at 225 psi for an aqueous solution containing 2000 ppm of NaCl.

Composite polyamide reverse osmosis membrane and method of producing the same

A selective membrane having a high fouling resistance. In one embodiment, the selective membrane is a composite polyamide reverse osmosis membrane in which a hydrophilic coating has been applied to the polyamide layer of the membrane, the hydrophilic coating being made by (i) applying to the membrane a quantity of a polyfunctional epoxy compound, the polyfunctional epoxy compound comprising at least two epoxy groups, and (ii) then, cross-linking the polyfunctional epoxy compound in such a manner as to yield a water-insoluble polymer.

A composite polyamide reverse osmosis membrane and method of producing same. In one embodiment, the membrane is made by coating a porous polysulfone support for about 40 seconds with an aqueous solution containing (i) a polyfunctional amine in the form of 2 wt % of meta-phenylenediamine (MPD), (ii) a polar solvent in the form of 0.3 wt % 2-ethyl-1,3-hexanediol (EHD), and (iii) an amine salt-forming combination of 2.3 wt % camphorsulfonic acid (CSA) and 1.1 wt % triethylamine (TEA). Next, the excess aqueous solution is removed, and the coated support is dipped for about 1 minute in a 0.1 wt % organic solvent solution of trimesoyl chloride (TMC) in a mixture of alkanes having from 8 to 12 carbon atoms. After draining the organic solvent solution off, the resulting composite membrane is heated at 90&deg; C. for about 3.5 minutes and then rinsed in a 0.2% Na CO aqueous solution at room temperature. The resultant membrane exhibits a flux of 47.9 gfd and a salt rejection of 97.6% when used at 225 psi for an aqueous solution containing 2000 ppm of NaCl. In another embodiment, the aqueous solution contains (i) a polyfunctional amine in the form of 2 wt % of MPD, (ii) a combination of polar solvents in the form of 0.3 wt % of EHD and 2 wt % of dimethyl sulfoxide, and (iii) an amine salt-forming combination of 1 wt % of 1,1,3,3-tetramethylguanidine and 1.6 wt % toluene sulfonic acid. The resultant membrane exhibits a flux of 63.7 gfd and a salt rejection of 90.8% when used at 225 psi for an aqueous solution containing 2000 ppm of NaCl.

A composite polyamide reverse osmosis membrane and method of producing same. In one embodiment, the membrane is made by coating a porous polysulfone support for about 40 seconds with an aqueous solution containing (i) a polyfunctional primary or secondary amine in the form of 1.6 wt. % of meta-phenylenediamine (MPD), (ii) a polyfunctional tertiary amine in the form of 0.4 wt. % N,N,N&prime;,N&prime;-tetramethyl-1,6-hexanediamine (TMHD), and (iii) a polar solvent in the form of 0.2 wt. % 2-ethyl-1,3-hexanediol (EHD). Next, the excess aqueous solution is removed, and the coated support is dipped for about 1 minute in a 0.1 wt. % organic solvent solution of trimesoyl chloride (TMC) in a mixture of alkanes having from 8 to 12 carbon atoms. After draining the organic solvent solution off, the resulting composite membrane is air dried at room temperature for about 1 minute and then rinsed in a 0.2% Na,CO,aqueous solution for 30 minutes at room temperature. The resultant membrane exhibits a flux of 46.5 gfd and a salt rejection of 97.1% when used at 225 psi for an aqueous solution containing 2000 ppm of NaCl. In another embodiment, instead of including a polyfunctional tertiary amine in the aqueous solution, there is included the reaction product of a polyfunctional tertiary amine and a strong acid, preferably in a ratio ranging from greater than 1:0, respectively, to less than or equal to 1:(0.95)n, respectively, where n is the number of tertiary functional groups in the polyfunctional tertiary amine.

A composite polyamide reverse osmosis membrane and method of producing same. In one embodiment, the membrane is made by coating a porous polysulfone support for about 40 seconds with an aqueous solution containing 2 wt % of meta-phenylenediamine (MPD), 1 wt % 1,4-diazabicyclo[2,2,2]octane (DABCO) and 0.85 wt % methanesulfonic acid (MSA). Next, the excess MPD solution is removed, and the coated support is dipped for about 1 minute in 0.1 wt % organic solvent solution of trimesoyl chloride (TMC) in a mixture of alkanes having from 8 to 12 carbon atoms. After draining the TMC solution off, the resulting composite membrane is heated at 90.degree. C. for about 3.5 minutes and then rinsed in a basic aqueous solution at 40-60.degree. C. for 30 minutes. The resultant membrane exhibits a flux of 32.3 gfd and a salt rejection of 97.0% when used at 225 psi for an aqueous solution containing 2000 ppm of NaCl.

Composite polyamide reverse osmosis membrane and method of producing the

A composite polyamide reverse osmosis membrane and method of producing same. In a preferred embodiment, the membrane is made by coating a porous polysulfone support for about 1 minute with an aqueous solution containing 2 wt % m-phenylenediamine (MPD), 2 wt % 2-butoxyethanol and 2 wt % propylene glycol. Next, the excess MPD solution is removed, and the coated support is dipped for about 1 minute in 0.1 wt % organic solvent solution of trimesoyl chloride (TMC) in a mixture of alkanes having from 8 to 12 carbon atoms. After draining the TMC solution off, the resulting composite membrane is air dried at room temperature to 40.degree. C. for about 1 minute and then rinsed in a basic aqueous solution at 40-60.degree. C. for 1 to 30 minutes. The resultant membrane exhibits a flux of 27.5 gfd and a salt rejection of 98.2% when used at 225 psi for an aqueous solution containing 2000 ppm of NaCl.

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Billerica, MA, United States of America

Ja-Young Koo