Preparation method of high-selective-separation composite membrane

Abstract

The invention belongs to the technical field of membranes, and relates to a preparation method of a high-selective-separation composite membrane. The preparation method of the composite membrane with the high selective separation property has the beneficial effects that the polymerization reaction is more stable and uniform and the hydrophilicity of the membrane is improved by adopting a brand-new water-phase buffer system for interfacial polymerization, and the interfacial polymerization process is completed under the influence of monovalent salt by taking a neutral monovalent inorganic salt compound as an additive, so that the separation efficiency of the membrane is improved. A pore channel suitable for monovalent salt to pass through is formed in the polymerization process, the composite membrane with ultrahigh selective separation performance on inorganic high-valence ions and low-valence ions is prepared, acyl chloride monomers react with water-phase monomers more easily due to addition of organic-phase ketones, the polymerization depth is increased, and the polymerization network structure is enhanced; therefore, the rejection rate of high-valence salt is maintained. According to the preparation method provided by the invention, through simple and convenient operation steps, a high-performance preparation process is realized under the condition that raw materials and parameter variables are greatly simplified, and the application range of the composite membrane is greatly widened.

Description

technical field [0001] The invention belongs to the technical field of membrane separation, and relates to a preparation method of a composite membrane with high selectivity and separation. Background technique [0002] As a very common composite membrane preparation process, the interfacial polymerization method can not only prepare a polymer layer with good performance by virtue of its relatively simple process steps and excellent polymerization degree, but also can add or change the water phase and the water phase in the interfacial polymerization process. The monomer of the oil phase can improve one or more performance parameters of the original composite membrane. The existing preparation of nanocomposite membranes by interfacial polymerization not only requires a complex aqueous phase solution system, but even requires pretreatment of the aqueous phase or base membrane, and the performance of the prepared membranes still cannot avoid the difference between the rejectio...

AI Technical Summary

Problems solved by technology

The existing preparation of nanocomposite membranes by interfacial polymerization not only requires a complex aqueous solution system, but even requires pretreatment of the aqueous phase or base membrane, and the performance of the prepared membrane still cannot avoid the gap between the rejection rate and the membrane flux. trade-off relationship

[0003] In recent years, with the continuous development of membrane preparation technology, the application potential of interfacial polymerization to control the selective separation and permeation of monovalent and multivalent salts makes this method the core of further improving nanofiltration technology. Traditional methods want to improve the interception of divalent compounds. The rate is bound to be accompanied by the increase of the rejection rate of monovalent compounds, and no significant results can be obtained by controlling the rate and structure of the interfacial polymerization, and the addition of an intermediate layer or coating layer will complicate the film-making process and greatly increase the continuous process. production difficulty

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