Method for preparing superamphiphobic polysulfone membrane for membrane distillation

Abstract

The invention discloses a simple efficient method for preparing a superamphiphobic polysulfone membrane, and relates to the field of membrane separation. Firstly, a polysulfone membrane having an interpenetrating network pore structure is prepared by a conventional solvent-induced phase inversion manner, and interpenetrating network pores form a 'concave angle structure' on the surface of the membrane; then a stepwise sol-gel process is used to generate, in an in-situ manner, uniformly distributed silica nanoparticles on walls of the interpenetrating network pores to provide a certain nano-scale roughened structure for the polysulfone membrane; and finally, the roughened polysulfone membrane surface is coated with a fluorosilane compound film having low surface energy to obtain the superamphiphobic polysulfone membrane. Dual infiltration resistant functions for water droplets and organic liquid droplets are achieved, the contact angle of a water droplet can be 150 degrees or above, andthe contact angle of n-hexane can reach 65 degrees or above. The prepared superamphiphobic polysulfone membrane when applied in a membrane distillation process has a salt interception rate of 99.5% or above and has high anti-wetting stability.

Description

technical field [0001] The invention relates to a method for preparing a separation membrane used in a membrane distillation process, in particular to a method for preparing a super-amphiphobic membrane. Background technique [0002] At present, my country's water resources are relatively poor, and the per capita per mu is relatively small, especially in the northern coastal areas and islands. The problem of water resource shortage is becoming increasingly prominent. In order to alleviate the crisis of water resources, my country actively develops and utilizes unconventional water resources such as seawater while vigorously saving water. As a stable water resource increment technology, seawater desalination has gradually become an important supplement and strategic reserve of water resources. Actively developing the seawater desalination industry is of great significance to alleviate the shortage of water resources in my country's coastal water-scarce areas and islands, rat...

AI Technical Summary

Problems solved by technology

The Chinese invention patent with the application number 201710958054.2 discloses a method of preparing a superhydrophobic and oleophobic composite membrane by electrospinning the membrane and secondly spraying and modifying the surface of the membrane. However, the preparation process includes the preparation of nano-silica sol solution, the preparation of cellulose acetate solution, the preparation of electrospinning precursor solution, the hydrophobic modification of nano-silica sol solution, modification and modification. Spraying solution after curing, electrospinning method to prepare composite film, and surface modification two-step spraying method. The process of this method is too complicated, the steps are too cumbersome, and it takes a long time

Moreover, the electrospinning method is not a conventional method for preparing separation membranes, and it is not suitable for large-scale preparation of separation membranes.

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