A kind of loose nanofiltration membrane based on branched polyethyleneimine, its preparation and application

Abstract

The invention belongs to the field of membrane separation, and particularly relates to a loose nanofiltration membrane based on branched polyethyleneimine as well as preparation and application thereof. The composite membrane comprises a polymer supporting layer and a polyelectrolyte active layer on the surface of the polymer supporting layer, wherein the polyelectrolyte active layer is obtained by assembling branched polyethyleneimine and branched polyethyleneimine derivatives layer by layer and then performing chemical crosslinking. A polyelectrolyte selection layer is loose and large in free volume, micromolecular water and inorganic salts can rapidly permeate, moderate crosslinking ensures that dye with large molecules can be intercepted, and therefore, the loose nanofiltration membrane with high water flux and high dye / inorganic salt selectivity is obtained. The branched polyethyleneimine derivative has a chemical structure represented by a formula (I), wherein R1 is or R2 is an Hatom or R1, and n is an integer not less than 1.

Description

technical field [0001] The invention belongs to the field of membrane separation, and more specifically relates to a branched polyethyleneimine-based loose nanofiltration membrane, its preparation and application. Background technique [0002] A large amount of wastewater generated by the textile industry contains toxic and refractory organic dyes, posing a huge threat to the environment. Traditional methods for removing organic dyes, such as chemical oxidation, microbial oxidation, and adsorption, generally face limitations of high cost, low efficiency, and / or secondary pollution. Membrane separation technology is more environmentally friendly and efficient than the above-mentioned traditional separation methods. Among them, nanofiltration membrane technology with a molecular weight cut-off in the range of 200-1000Da is especially suitable for textile industry wastewater treatment. However, textile industry wastewater also contains a large amount of inorganic salts at the ...

AI Technical Summary

Problems solved by technology

However, the commonly used multi-layer layer-by-layer assembly method usually forms a relatively dense selective layer, which has a low separation selectivity for dyes and inorganic salts; there are also a few literatures that obtain a looser selective layer through one-time assembly, but the membrane produced in this way has a long-term poor stability

[0006] Therefore, there is still a lack of loose nanofiltration membranes with large permeability, high selectivity, strong chemical stability and easy preparation process and preparation methods thereof.

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