Gas separation membrane, preparation method thereof, and membrane type gas separation device

Abstract

The invention discloses a gas separation membrane and a preparation method thereof and belongs to the technical field of membrane separation. The gas separation membrane comprises a porous substrate, wherein a composite membrane which is prepared by mixing oxidized graphene and polymeric branched polyethyleneimine is attached to at least one surface of the porous substrate. The preparation method of the gas separation membrane disclosed by the invention comprises the following steps: dispersing a flaky oxidized graphene material in an aqueous solution; and then preparing a single-layered or a multi-layered composite membrane on the porous substrate with a polymeric branched polyethyleneimine solution by a coating method of overlaying layer by layer. The invention further discloses a membrane assembly unit, namely a membrane type gas separation device which uses the gas separation membrane. By means of a special molecular transmission characteristic of a layered graphene material, a limiting relationship between the permeability and selectivity in the gas separation membrane is broken and an excellent gas separating performance is exhibited. The method disclosed by the invention is simple and economic in process, wide in application range and suitable for scaled preparation.

Description

technical field [0001] The invention relates to a gas separation membrane and a preparation method thereof, belonging to the technical field of membrane separation. Background technique [0002] Membrane gas separation is widely used in chemical industry, energy, environment, biomedicine and pharmaceutical industry. In energy science, high-purity H 2 and CH 4 It is regarded as the basic material for fuel cells and hydrogen power generation. In environmental science, CO suppression 2 Increase is the main direction to improve the greenhouse effect. The same direct, low-cost, and environmentally friendly extraction of usable gas and oil from waste gas and oil is a new requirement and challenge for the separation technology in the chemical industry. [0003] Compared with traditional refrigerated distillation and pressure swing adsorption separation technologies, membrane separation technology has many advantages such as energy saving, low price, easy installation, operatio...

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Problems solved by technology

Graphene oxide membranes in the Z direction are also considered unsuitable as membrane separation materials due to their dense stacking methods and lack of gas and liquid permeation channels.

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