Chemical and ionic cross-linked alginate hydrogel flat membrane for filtration and preparation method thereof

Abstract

The invention discloses a chemical and ionic cross-linked alginate hydrogel flat membrane for filtration, which is designed and prepared aiming at the problems of poor stability, low mechanical strength, overlarge pores and the like of a pure ionic cross-linked hydrogel filtering membrane. According to the flat membrane, sodium alginate is used as a membrane forming substrate, a water-soluble compound is used as a pore-forming agent, and a chemical cross-linking agent and an ionic cross-linking agent are added, so that the sodium alginate is subjected to covalent bonding and ionic cross-linking to improve the stability of the membrane. The mechanical strength and the pore size of the membrane and the stability in an electrolyte solution are adjusted by changing the types and the proportions of the chemical cross-linking agent and the ionic cross-linking agent. The hydrogel flat membrane is prepared through a simple preparation process and is low in cost; no organic waste liquid is produced; the obtained hydrogel membrane can resist the pressure of 0.2-1 MPa and has a good application prospect in the separation field in which membrane pollution is easy to produce, such as oil-water separation, protein separation and biological sample filtration. The hydrogel flat membrane is directly discarded and can be fully degraded by microorganisms after being used, so that no environmental harm is caused.

Description

technical field [0001] The invention relates to a chemically and ionically cross-linked alginate hydrogel flat membrane for filtration and a preparation method thereof, belonging to the field of environmental functional materials and membranes. Background technique [0002] Due to its own hydrophobicity, membrane filtration materials can easily cause irreversible deposition of macromolecules, colloids, electrolytes and particles on the membrane surface or in the membrane, and the resulting membrane fouling will cause the flux of the membrane to decrease continuously, so that the membrane separation process cannot be normal. conduct. At present, many methods are used, such as pretreatment of feed water, development of anti-fouling membranes, novel design of membrane modules, optimization of operating conditions and combination of membrane processes with other technologies. Due to its own hydrophobicity, traditional membrane filtration materials can easily cause irreversible ...

AI Technical Summary

Problems solved by technology

[0010] In view of the deficiencies in the prior art, the technical problem to be solved by the present invention is that the pure ion cross-linked hydrogel filtration membrane has poor stability, low mechanical strength, too large membrane pores, and the gel membrane porogen prepared by free radical polymerization is difficult to elute , Ordinary polymer membranes are difficult to biodegrade, etc.

[0011] The invention solves the problems of poor stability, low mechanical strength and too large membrane pores of the pure ionic cross-linked hydrogel filtration membrane, difficult elution of gel membrane porogens prepared by free radical polymerization, and difficulty in biodegradation of common polymer membranes. The technical solution is to design a chemically and ionically cross-linked alginate hydrogel flat sheet membrane for filtration