Preparation method of crosslinking nanofiltration membrane

Abstract

The invention discloses a preparation method of a crosslinking nanofiltration membrane. The method comprises the steps of completely dissolving phenolic resin and tetraethenyl triamine in a certain mass ratio through a medium, wherein the mass ratio of phenolic resin to tetraethenyl triamine is (2-3):(5-6), and the mass ratio of phenolic resin to the medium is (8-10):(2-3); uniformly agitating to obtain a settled solution, wherein the medium is prepared from polyethylene glycol and a surface active agent OP-10 in the mass ratio of (4-8):(2-3); removing bubbles; adding a crosslinking agent, namely, a formaldehyde solution; continuously agitating; preserving heat for 1 to 24 hours at the temperature of 60 to 80 DEG C in a drying tank; agitating for 2 to 4 minutes at the rotating speed of 1,000 to 3,000r / min to obtain a casting membrane solution; coating a glass sheet with the generated casting membrane solution by a film casting method; drying under a vacuum condition at the temperature of 60 to 80 DEG C; soaking for 2 to 4 hours through a diethyl ether solution to remove the medium, namely, polyethylene glycol and the surface active agent OP-10; washing with alcohol and distilled water for a plurality of times; and then drying to obtain the crosslinking nanofiltration membrane. The method is performed under mild preparation conditions, does not have strict requirements, is convenient to operate, enables simple forming, and meets the demand on mass production; the prepared nanofiltration membrane is of a symmetric structure, and is uniform in pore size distribution, adjustable in pore size, and outstanding in repeatability.

Description

Technical field [0001] The invention relates to a preparation method of a cross-linked nanofiltration membrane. Background technique [0002] Nanofiltration membranes have two characteristics: 1) the separation performance of different organic components, the molecular weight cut-off (MWCO) range is about 200-2000; 2) the surface charge of the membrane is different from the Donnan of the same charge and different valence ions. The potential is not the same. The unique performance of nanofiltration membrane determines its scope of application, and it is suitable for the separation of substances in the following situations: 1) The rejection rate of monovalent ions is not high or not required; 2) The separation of ions with different valence states is required. 3) The rejection rate of low molecular weight organics is not high or not required; 4) High molecular weight organics and low molecular weight organics need to be separated. 5) Specific substances such as dyes, etc., and sp...

AI Technical Summary

Problems solved by technology

The mixed solvent is difficult to recycle after the polymer film is formed, and it is difficult to handle

In addition to the deficiencies in the film-making process, these polymer materials often cannot meet the requirements of physical and chemical properties such as hydrophilicity, chemical solvent resistance, and temperature resistance at the same time.