Method for preparing compound nanofiltration membrane

Abstract

The invention discloses a method for preparing a compound nanofiltration membrane, which comprises the following steps: firstly adopting an electron beam irradiation basement membrane under nitrogen protection, wherein the irradiation dose is 10 to 300kGy, and the irradiation time is 1 to 3 minutes; then soaking the basement membrane into a monomer aqueous solution or hanging the basement membrane in monomer steam in a sealed container, processing for 2 to 12 hours, enabling a free radical on the surface of the basement membrane to initiate a liquid monomer or a gaseous monomer to generate cross linking and graft reactions, and forming a polyacrylic functional layer on the surface of the basement membrane to prepare the compound nanofiltration membrane, wherein the basement membrane is a polysulphone membrane, a polyvinylidene fluoride membrane, a polyether sulfone membrane, a polypropylene membrane or a cellulose acetate membrane; the form of the basement membrane is a flat sheet membrane, a tubular membrane or a hollow-fiber membrane; and the monomer is crylic acid, and the mass concentration of the monomer aqueous solution is 0.1 to 10g / L.

Description

technical field [0001] The invention relates to a separation membrane preparation technology, in particular to a method for preparing a composite nanofiltration membrane by using a pre-irradiation technology. Background technique [0002] Membrane separation is a new separation technology with high efficiency and energy saving. It is a cross combination of material science and medium separation technology. It has the advantages of high-efficiency separation, simple equipment, energy saving, normal temperature operation, and no pollution. , the environment and other major issues of effective means. Nanofiltration (NF) membrane is a special and promising type of separation membrane. The main feature of nanofiltration membrane is the charge selectivity and size selectivity to solutes, that is, it has the ability to select solutes or high-valent ions with a molecular weight greater than 200. Good retention performance, but low retention rate for low molecular weight solutes and...

AI Technical Summary

Problems solved by technology

The disadvantages of this method are: (1) the reaction conditions of chemical crosslinking have a great influence on the product performance, so the production conditions are harsh; High requirements; (3) A large amount of organic waste liquid is produced during the production process, which is costly and difficult to handle, and is harmful to the ecological environment and human health; (4) The production cycle is long

Although the process is simple and pollution-free, for some membranes with poor hydrophilicity (hydrophobic base membrane), the aqueous solution cannot form a uniform coating on the surface, so the performance of the prepared membrane is often not ideal and cannot be used directly.