Preparation method of composite membrane

Abstract

The invention relates to a preparation method of a composite membrane, which comprises the following steps: respectively introducing an oil-phase reaction monomer and a water-phase reaction monomer participating in a polymerization reaction from two sides of a porous base membrane, and contacting at openings of membrane holes through the membrane holes to cause an interfacial polymerization reaction. The concentrations and the supply amounts of the two reaction monomers are convenient to control, the reaction speeds and the reaction degrees of the two reaction monomers can be respectively controlled, and the bottleneck of the prior art is broken through, so that the aggregation state structure of the cross-linking layer is easy to regulate and control, and the composite membrane with a higher removal rate is obtained.

Description

technical field [0001] The invention belongs to the field of separation membranes, and relates to reverse osmosis membranes and nanofiltration membrane preparation technologies, in particular to a preparation method of composite membranes. Background technique [0002] Most of the currently commercialized reverse osmosis membranes and nanofiltration membranes are composite membranes. A very thin composite layer is constructed on the surface of the porous base membrane, and the composite layer provides the selective separation function of the composite membrane. In the prior art, the interfacial polymerization reaction between the reactive monomers in the oil phase and the reactive monomers in the water phase is used to form a dense composite layer with a separation function that is not easy to fall off on the membrane surface. In order to increase the membrane flux, it is necessary to minimize the thickness of the composite layer. In order to improve the selective separatio...

AI Technical Summary

Problems solved by technology

When the porous base film 1 has large pores 8 or the water phase solution and the oil phase solution are unevenly distributed, defects 4 will occur, such as figure 2 , in order to avoid defects, it is necessary to increase the thickness of the composite layer, which makes it difficult to reduce the thickness of the composite layer, making it difficult to further increase the membrane flux

At the same time, as an important factor to control the interfacial polymerization reaction, the supply amount and supply speed of the amine compounds in the aqueous phase solution and the acid chloride compounds in the oil phase solution are not easy to control. Moreover, in industrial production, the aqueous phase solution The concentrations of the amine-containing compounds in the oil phase solution and the acid chloride-containing compounds in the oil phase solution are not easy to achieve stable control

In addition, due to the limitation of the current interfacial polymerization method, currently prepared reverse osmosis membranes and nanofiltration membranes are usually flat membranes that are easy to industrially produce, and it is difficult to obtain hollow fiber reverse osmosis membranes that are easy to industrially produce through interfacial polymerization. Hollow Fiber Nanofiltration Membrane

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