Sulfanilamide micromolecule surface modified polyamide composite membrane and preparation method thereof

Abstract

The invention provides a sulfanilamide micromolecule surface modified polyamide composite membrane and a preparation method thereof. The polyamide composite membrane comprises an ultra-filtration bottom membrane and a micromolecule modified polyamide layer, the polyamide layer covers the surface of the ultra-filtration bottom membrane, and functional groups of the small molecules are amino and sulfamido. According to the sulfanilamide micromolecule surface modified polyamide composite membrane, easily available functional micromolecule monomers with amino and sulfanilamide functional groups are grafted to the surface of the polyamide composite membrane through a secondary interface polymerization method to obtain a modified membrane, the hydrophilicity of the surface of the membrane is improved by utilizing the hydrophilicity of sulfanilamide groups, so that the mass transfer of water molecules is accelerated, the purposes of high flux and pollution resistance are achieved, and the water flux of the modified membrane can be increased by 38-65% compared with that of an unmodified polyamide membrane on the premise of keeping high rejection rate; and in addition, the existence of thesulfonamide groups provides more active N-chloro groups, so that the active chlorine resistance of the polyamide composite membrane is also improved.

Description

technical field [0001] The invention belongs to the field of separation membrane preparation, in particular to a polyamide composite membrane modified on the surface of sulfonamide small molecules and a preparation method thereof. Background technique [0002] As an efficient and energy-saving green separation technology, reverse osmosis technology has been widely used in seawater and brackish water desalination, wastewater treatment, separation of biological products, environmental engineering, food and medicine and other fields. Reverse osmosis polyamide composite membranes usually consist of a porous support layer and a dense separation skin, wherein the dense separation skin is prepared by interfacial polymerization of polyamines and polyacyl chlorides. Compared with other types of reverse osmosis membranes, it has the advantages of high permeation flux and good selective separation performance. [0003] Although the reverse osmosis polyamide composite membrane has many...

AI Technical Summary

Problems solved by technology

[0003] Although the reverse osmosis polyamide composite membrane has many advantages, there are still problems to be solved. Compared with other membrane separation technologies, its permeate flux is still low and cannot fully meet the use of large areas; the inevitable There are pollutants such as organic matter and colloidal particles. These pollutants are bound to the surface of the membrane due to electrostatic interaction and hydrophobicity. With the prolongation of the operation time, the water flux and salt rejection rate of the membrane will drop sharply, which will increase the operating cost; In order to reduce membrane fouling, active chlorine is usually added to the feed solution, but the increase in active chlorine will degrade the polyamide layer and destroy the membrane structure, resulting in a decrease in the rejection rate of the membrane, and the ideal aquatic product cannot be obtained

Images