Reverse osmosis membrane and its production method

Claims

1. A reverse osmosis membrane comprising a non-woven support layer, a porous polymer support layer and a polyamide desalting layer sequentially applied one on top of the other; characterized in that the polyamide desalting layer has an asymmetric structure comprising a loose layer and a dense layer; the loose layer is located on the side adjacent to the porous polymer support layer, and the dense layer is located on the side far from the porous polymer support layer; wherein the loose layer includes structures with artificial water channels.

2. A reverse osmosis membrane according to claim 1, characterized in that the structures with artificial water channels are a peptide-modified columnar aromatic amine structure.

3. A reverse osmosis membrane according to claim 1 or 2, characterized in that the loose layer has a degree of desalination from 40% to 95% and a water flow rate from 2 m³ / (m²⋅day) to 20 m³ / (m²⋅day) under conditions of 2000 ppm NaCl, temperature of 25°C, pH of 7 to 8 and pressure of 1.55 MPa.

4. A reverse osmosis membrane according to any one of paragraphs 1-3, characterized in that the material of the non-woven support layer is at least polyethylene, polypropylene and / or polyethylene terephthalate; additionally, the material of the polymer porous support layer is at least polysulfone, polyethersulfone, polyacrylonitrile or polyvinyl chloride; and additionally, the polyamide desalting layer is formed using an interfacial polymerization reaction between a polyamine and a polyacyl chloride.

5. A reverse osmosis membrane according to claim 4, characterized in that at least m-phenylenediamine, p-phenylenediamine and / or ethylenediamine is used as the polyamine; additionally, trimesoyl chloride and / or its partially hydrolyzed product can be used as the polyacyl chloride.

6. The reverse osmosis membrane according to claim 1 or 2, characterized in that the reverse osmosis membrane has a desalination rate of 99.7% to 99.9% and a water flow rate of 1.0 m³ / (m²⋅day) to 2.6 m³ / (m²⋅day) under conditions of 32,000 ppm NaCl, a temperature of 25°C, a pH of 7 to 8, and a pressure of 5.5 MPa.

7. A method for producing a reverse osmosis membrane according to any one of paragraphs 1-6, including the following steps: A. Obtaining a porous polymer support layer on a non-woven support layer by a deposition method by immersion with the application of an aqueous solution and a dispersed structure with artificial water channels onto the porous polymer support layer and subsequent first drying to obtain a semi-finished reverse osmosis membrane; B. Applying the first oil solution to the semi-finished reverse osmosis membrane to carry out the first reaction; then applying the second oil layer to the surface to carry out the second reaction; and finally obtaining the reverse osmosis membrane after drying and washing.

8. The production method according to claim 7, characterized in that the aqueous solution is a polyamine solution; additionally, the mass fraction of the polyamine solution can be from 1 to 5% by weight; additionally, the first oil solution contains polyacyl chloride and a non-polar organic solvent; additionally, the mass fraction of polyacyl chloride in the composition of the first oil solution is from 0.01 to 0.1% by weight; additionally, the second oil solution contains polyacyl chloride and a non-polar organic solvent; and additionally, the mass fraction of polyacyl chloride in the composition of the second oil solution is from 0.1 to 1% by weight.

9. The method of production according to paragraph 7 or 8, characterized in that the dispersed structure with artificial water channels contains a peptide-modified columnar aromatic amine and a non-polar organic solvent; in addition, the mass fraction of the dispersed structure with artificial water channels of the peptide-modified columnar aromatic amine is from 0.01 to 0.1% by mass.

10. The production method according to any one of paragraphs. 7-9, characterized in that the first reaction time is shorter than the second reaction time; additionally, the first reaction time is from 5 to 15 s; additionally, the second reaction time is from 10 to 30 s; additionally, the drying temperature is from 60 to 100°C; and additionally, cleaning is performed using a sodium carbonate solution.

11. The production method according to any of paragraphs 7-10, characterized in that the first reaction is carried out with the possibility of obtaining a loose layer, and the second reaction is carried out with the possibility of obtaining a dense layer.