Abstract: A liquid filtering structure having high filtering efficiency, excellent transparency, and excellent durability can be provided. The liquid filtering structure includes a filtering layer, wherein the filtering layer includes a nanopore structure unit including a plurality of nanopores and a functional group-containing compound including functional groups at one end, and has selectivity with respect to liquid molecules to be filtered, for example, water molecules, and effectively filter liquid, particularly water by preventing ions or compounds from being passed.

Abstract: 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.

Abstract: 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.

Abstract: 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° C. for about 3.5 minutes and then rinsed in a 0.2% Na2CO3 aqueous solution at room temperature. The resultant membrane exhibits a flux of 47.9 gfd and a salt rejection of 97.

Abstract: 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.