Preparation method and application of zif-8 modified cellulose membrane with switchable surface wettability

Abstract

The invention belongs to the technical field of preparation of environmental functional materials, and specifically relates to a preparation method and application of a switchable surface wettability ZIF-8 modified cellulose film; the steps are: immerse the RC film in a tris-HCl solution, and then add dopamine after soaking , ultrasonically cleaned after shaking, and dried naturally to obtain RC@PDA film; the Zn(NO 3 ) 2 ·6H 2 O was mixed with methanol solution to obtain mixed solution A; then dimethylimidazole and methanol solution were mixed to obtain mixed solution B; RC@PDA membrane was immersed in mixed solution A, after soaking, then added mixed solution B, after standing , rinsed and dried to obtain RC@PDA / ZIF‑8 film. The method of the invention is simple, economical and practical, and the prepared membrane material can be switched between underwater superoleophobicity and underwater hydrophobicity without external stimulation, has an oil-water emulsion separation efficiency as high as 99%, and has good recyclability.

Description

technical field [0001] The invention belongs to the technical field of preparation of environmental functional materials, and in particular relates to a preparation method and application of a ZIF-8 modified cellulose film with switchable surface wettability. Background technique [0002] As society progresses, water pollution is becoming a growing problem. A large amount of oily wastewater is produced in industrial production process and daily life, and oily wastewater is one of the most common environmental problems. Oily wastewater is not only harmful to the environment, but also affects human health. Therefore, it is of great significance to develop materials that can effectively solve this problem. To solve the problem of oil pollution, scholars at home and abroad have done a lot of work, such as gravity separation, centrifugal separation, air flotation, electrocoagulation, precipitation, coagulation and membrane separation for oil-water separation. Among them, the m...

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Problems solved by technology

[0003] Superwetting materials have attracted much attention in the field of emulsion separation, usually these materials show higher separation efficiency, but the monotonic wettability of membranes severely limits their application in treating different types of oily wastewater

Researchers have achieved on-demand controllable oil / water separation with switchable wetting materials, such as the cellulose-PVA membrane developed by XiXu et al., which has good durability but can only separate oil-in-water emulsions, however, The use of these materials usually requires some external stimuli, such as temperature, electricity, light, etc., which are inconvenient to use, and there are also high energy consumption (such as heat energy, electric energy and light energy) and secondary pollution (acidic and alkaline solutions, toxic solvents and ions, etc.) still need to be solved; another example is the reversible wettable biocellulose material developed by MeixiaoCheng et al., which can change hydrophilicity to hydrophobicity, lipophilicity to oleophobicity, but it needs to be PH controlled, and the separation efficiency is not good. high

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