A separation membrane with pH-dependent flux under acidic conditions and preparation method thereof

Abstract

The invention relates to the technical field of polymer separating membrane surface modification, in particular to a method for polymer separating membrane surface modification. The invention provides a preparation method for a separating membrane with pH-dependent flux under an acidic condition; according to the method, hydroxyethyl acrylate is grafted on the surface and / or the membrane pore surface of a PVDF (polyvinylidene fluoride) membrane in a radiation field of Co60. According to the preparation method, the hydroxyethyl acrylate is grafted on the PVDF membrane through Co60 high-energy radiation; the sensitivity of the membrane to the solutions with different pH values is changed. The grafted membrane has pH dependence, so that the membrane flux is reduced along with the increment of the pH; moreover, the membrane flux is remarkably reduced when the pH is between 4 and 5, so that the membrane is very suitable for selective separation; by changing the pH value of the environment, a pollution behavior in a membrane control process and separating characteristics of the membrane are controlled.

Description

technical field [0001] The invention relates to the technical field of surface modification of polymer separation membranes, in particular to a method for surface modification of polymer separation membranes. Background technique [0002] Membrane separation technology, which emerged in the 1960s, has many advantages, such as high efficiency, high selectivity, small footprint, low cost, and low energy consumption. Due to its outstanding filtration and separation performance, it has played and is playing a huge role in the field of water treatment. [0003] However, membrane fouling is a bottleneck problem that limits the widespread application of membrane wastewater treatment technology (Rana and Matsuura 2010). Membrane fouling will lead to a serious decline in membrane filtration performance and affect filtration efficiency. Backwashing and chemical cleaning can remove membrane fouling to a certain extent, but it will undoubtedly increase the operating cost and the threat...

AI Technical Summary

Problems solved by technology

These methods of chemical grafting to modify the surface of the grafted polymer membrane have achieved positive experimental results in terms of hydrophilicity and anti-fouling properties. However, there are also various defects, such as harsh conditions for the grafting reaction. , the reaction is difficult to effectively control, the grafting efficiency is not ideal, a large amount of catalysts and initiators are used, etc.

This will undoubtedly increase the cost of separation membrane applications, and such complex experimental conditions are also an insurmountable challenge for large-scale industrial applications

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