Nanofiltration membrane and membrane performance regulation and control method based on nanocapsules

Abstract

The invention relates to a nanofiltration membrane and a membrane performance regulation and control method based on nanocapsules, and relates to the technical field of membrane separation materials.According to the invention, a functional group pre-protection strategy is introduced to obtain the nanofiltration membrane with accurately adjustable surface charge characteristics, and in the work, high separation efficiency can be realized for charged materials in a wide pH range. An introduced amino protective agent can prevent part of amino groups from participating in interfacial polymerization, and the protective agent can fall off in hydrochloric acid and release amino groups, so that a controllable charged film is obtained. Meanwhile, as the surface charges gradually change into positive charges, the rejection rate to divalent anions is reduced. Conversely, the retention of a divalent cationic solution is increased and always maintained at a high level. For charged organic materials with different characteristics in different pH ranges, the membrane with different isoelectric points can realize higher retention performance at any pH. According to the membrane, the surface electrical property of the membrane can be accurately adjusted, and high interception performance can be kept for charged organic small molecules with similar molecular weights.

Description

technical field [0001] The invention relates to a nanofiltration membrane and a nanocapsule-based membrane performance regulation method, and relates to the technical field of membrane separation materials. Background technique [0002] With the rapid development of society, the discharge of industrial wastewater has caused more and more serious pollution to the environment. Nanofiltration membrane technology plays an important role in water treatment due to its advantages of low energy consumption and environmental friendliness. Nanofiltration membrane is a water treatment technology between ultrafiltration and reverse osmosis. The average pore size is between 0.5-2nm. It is mainly used in the separation of divalent salts and other small molecular substances. At present, the main problems faced by nanofiltration membranes are low flux and limited scope of application. It is difficult to achieve high-efficiency interception of small molecular substances without sacrificing ...

AI Technical Summary

Problems solved by technology

[0005] The first technical problem to be solved by the present invention is: for the regulation and control of the chargeability of the surface of the nanofiltration membrane, the steps of the conventional grafting reaction are cumbersome, the reaction degree is difficult to control, and it is difficult to realize precise regulation in a large area, and the reaction The rate is not easy to control; the present invention proposes a means to precisely regulate the isoelectric point in a wide pH range

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