Method for preparing metal-organic framework gas separation membranes by pinning metal-organic nanorod arrays on macroporous substrates

Abstract

The invention discloses a method for preparing a metal organic frame gas separating film by utilizing the pinning effect of a metal organic nano rod array on a macro-pore substrate. The method comprises the following steps: 1) under magnetic stirring, adding an ethanol amine solution into a solution of cupric nitrate, zinc nitrate or cadmium nitrate of the same volume, slowing down the stirring speed to obtain a copper hydroxide, zinc hydroxide or cadmium hydroxide nano-wire solution, and directly filtering out the nano-wire solution onto a porous aluminum oxide film to form a nano-wire layer; 2) adding the nano-wire layer into a solution with trimesic acid so as to obtain the metal organic nano rod array; and 3) adding the nano rod array as a seed crystal layer into an organic ligand mixture solution with cupric nitrate, zinc nitrate or cadmium nitrate, so as to obtain the metal organic frame composite film. According to the method, the metal organic frame composite film directly grows on the metal organic nano rod array in a secondary growth manner, the adhesion of the film to the substrate is high, and the obtained composite metal organic frame film is applied to gas separation.

Description

technical field [0001] The invention relates to a preparation method of a metal organic framework nano-array, in particular to a method for preparing a metal organic framework gas separation membrane by utilizing the pinning action of the metal organic nanorod array on a macroporous substrate. technical background [0002] Due to their high porosity and good chemical stability, metal-organic framework films have good application prospects in many fields such as adsorption and separation, catalytic reactions, drug carriers and optical materials. At present, there are many methods for the preparation of metal-organic framework thin films, including traditional solvothermal method, layer-by-layer growth method, sol-gel method, colloid deposition method, and relatively novel microwave synthesis method and electrochemical synthesis method. However, these methods still have many disadvantages: although the preparation of the solvothermal method is relatively simple, the synthetic ...

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Problems solved by technology

However, these methods still have many disadvantages: although the preparation of the solvothermal method is relatively simple, the synthetic material is mainly powder, and it is difficult to produce a dense film; the thickness of the film prepared by the sol-gel method and the colloid deposition method is difficult to be unified. , the uniformity is not good; the steps of the layer-by-layer growth method are cumbersome, and the film growth cycle is relatively long; the development of microwave synthesis and electrochemical synthesis is immature, and the production cost is high

In addition, there is another big disadvantage that the adhesion between the film and the substrate is not strong enough, and it is easy to separate from each other in some applications such as gas separation.

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