High-temperature resistance double-layer forward osmosis composite film and preparation method thereof

Abstract

The invention discloses a high-temperature resistance double-layer forward osmosis composite film and a preparation method thereof. The forward osmosis composite film comprises a non-woven fabric layer; each of the two surfaces of the non-woven fabric layer is provided with a high-temperature resistance porous supporting film layer; each of the high-temperature resistance porous supporting film layers is provided with a polyamide separation layer; the high-temperature resistance porous supporting film layer is mainly formed by high-temperature resistance polymer. The preparation method comprises the following steps: carrying out blade coating of a casting solution prepared from the high-temperature resistance polymer, a solvent and an additive on both surfaces of the non-woven fabric layer and by phase inversion and heat treatment, and obtaining a supporting film material comprising the non-woven fabric layer and the high-temperature resistance porous supporting film layers; firstly soaking the supporting film material in a water-phase solution and then soaking the supporting film material into an organic-phase solution and forming the polyamide separation layers by reaction so as to obtain the high-temperature resistance double-layer forward osmosis composite film. The forward osmosis composite film disclosed by the invention has high salt rejection, large water flux and high processing efficiency; the preparation method is simple; the process is relatively mature; the forward osmosis composite film is easy for scale production.

Description

technical field [0001] The invention belongs to the technical field of forward osmosis composite membrane preparation, and in particular relates to a high-temperature-resistant double-skin forward osmosis composite membrane and a preparation method thereof. Background technique [0002] Forward osmosis (FO) is currently the most advanced desalination and water purification technology in the world. Compared with reverse osmosis technology, forward osmosis relies on the osmotic pressure of the feed liquid itself to realize the mass transfer process, and has the advantages of no external pressure drive, low energy consumption, high recovery rate, less concentrated water discharge, and low membrane pollution. Forward osmosis technology has shown good application prospects in seawater desalination, sewage treatment, industrial wastewater treatment, landfill leachate treatment, food processing, medical treatment and other fields. [0003] Forward osmosis technology relies on the ...

AI Technical Summary

Problems solved by technology

At present, there are mainly the following three technical solutions that have made some progress: (1) Modify the nanofiltration membrane to improve the membrane performance by controlling the pore size and distribution, but the rejection rate of monovalent salts is still low, which limits its treatment of raw materials (2) Optimizing the performance by optimizing the material and structure of the support layer and the selection layer through interfacial polymerization. Although the interception performance is good, the degree of internal concentration polarization is serious; (3) Through multi-layer co-extrusion, interphase The double selective layer membrane with dense upper and lower surface layers prepared by conversion and heat treatment can alleviate the internal concentration polarization, but the desalination performance is basically lost under high temperature conditions.

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