Method for preparing polylactic acid super-hydrophobic membranes by aid of phase separation process

Abstract

The invention discloses a method for preparing polylactic acid super-hydrophobic membranes by the aid of a phase separation process, and belongs to the field of high-polymer materials. The method includes steps of (1), preparing pre-coating liquid, to be more specific, uniformly mixing poor solvents and good solvents with one another to prepare mixed solvents, and dissolving polylactic acid in the mixed solvents to obtain the pre-coating liquid; (2), preparing coating liquid, to be more specific, adding poor solvents in the pre-coating liquid, and uniformly stirring the poor solvents and the pre-coating liquid to obtain the coating liquid; (3), carrying smearing and drying, to be more specific, smearing the coating liquid on carriers, and drying the carriers to obtain the polylactic acid super-hydrophobic membranes. The method has the advantages that super-hydrophobic surfaces with micrometer-nanometer two-level structures are prepared by the aid of the non-solvent auxiliary process at one step, the method is easy to operate, conditions are mild, curing and steam inducing can be omitted in membrane forming procedures, gel procedures can be omitted, accordingly, the reaction time can be shortened, and the method is high in work efficiency; inorganic nanometer particles or substances with low surface energy can be omitted in super-hydrophobic membrane preparing procedures, and accordingly the polylactic acid super-hydrophobic membranes are low in manufacturing cost.

Description

technical field [0001] The invention belongs to the field of polymer materials, and in particular relates to a method for preparing a polylactic acid superhydrophobic film by using a phase separation method. Background technique [0002] People have found through research that controlling the surface morphology of objects can improve the wetting properties of the object surface, and super-hydrophobic surfaces have gradually entered people's field of vision. A superhydrophobic surface refers to a surface with a static contact angle greater than or equal to 150°, and the surface of a lotus leaf and a rose are common superhydrophobic surfaces in nature. The surface of the lotus leaf has a micro-nano hierarchical structure, specifically: the surface of the lotus leaf is distributed with surface protrusions with a diameter of several to ten microns, and the protrusions are covered with tiny particles with a diameter of about 200 nanometers. The lotus leaf effect is a classic sup...

AI Technical Summary

Problems solved by technology

However, the first preparation method requires low surface energy substances or nanoparticle modification, which is expensive and not suitable for large-scale preparation of superhydrophobic surfaces. The first preparation method is complex and harsh, requiring a lot of manpower, material resources and time

In addition, the materials used to prepare superhydrophobic surfaces are mostly non-biodegradable petroleum-based polymers, which will bring huge pressure to the environment.

At the same time, the superhydrophobic materials that have been put into the market also have shortcomings such as low surface microstructure strength, easy aging, easy wear, easy pollution, and short service life.

[0004] Chinese patent CN102179188A discloses a superhydrophobic modification method for polyvinylidene fluoride hydrophobic membranes. While using non-solvent assistance, it is also necessary to conduct steam induction in air with a certain humidity to form a gel-like primary membrane state, and The preparation process has gone through membrane liquid curing, scraping, steam-induced gel film formation, hydrogel defilming, and drying. The preparation conditions are strict and the process is complicated.

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