Preparation method for porous superhydrophobic membrane with structural gradient changes

Abstract

The invention belongs to the technical field of membrane science and provides a preparation method for a porous superhydrophobic membrane with structural gradient changes. The preparation method includes the following steps: utilizing a plasma technology to modify a basement membrane so that the porosity of the membrane can be increased; respectively adopting a coating method and an in-situ sol-gel method to prepare composite membranes with gradient changes of micron and nanoscale structures; and utilizing the surface chemical reaction of a low surface energy substance to obtain a superhydrophobic membrane through modification. The method utilizes plasma treatment to increase the surface porosity of the basement membrane; the basement membrane is coated with micron-sized particles; nanoscale particles can be generated on the surface of the basement membrane and the micron-sized particles in-situ; and the prepared superhydrophobic membrane can have characteristics of porousness and structural gradient changes by regulating the sizes and load capacity of the microparticles and nanoparticles on the surface of the basement membrane. The preparation method solves the problem of membranehole blockage caused by the direct coating method; new ideas of constructing multi-level rough structures can also be provided; and the preparation method is simple and low in cost, so that the preparation method has wide application prospects in the field of membrane separation.

Description

technical field [0001] The invention relates to a method for preparing a porous super-hydrophobic membrane with a gradient structure, and belongs to the field of membrane science and technology. Background technique [0002] Superhydrophobic membrane refers to the membrane material with surface static contact angle greater than 150°, which has excellent anti-wetting and anti-fouling properties. Superhydrophobic membranes are playing an increasingly important role in the fields of self-cleaning and membrane separation, and their preparation methods have become a research hotspot in the field of membrane science. Lotus leaves and butterfly wings in nature all exhibit excellent super-hydrophobic properties. Studies have found that the key to constructing super-hydrophobic films is to increase surface roughness while reducing surface energy. At present, the common preparation methods of superhydrophobic membranes mainly construct rough structures by coating inorganic nanopartic...

AI Technical Summary

Problems solved by technology

However, this method has high requirements for the selection of materials and properties of the bonding layer, and the uniformity of the bonded micron and nanostructures is difficult to control, which can easily lead to agglomeration of surface particles, which will increase the mass transfer resistance when used in the separation process, making it difficult to achieve efficient separation.