Preparation method of hydrophilic polyvinylidene fluoride hollow fiber dry membrane filaments

Abstract

The invention discloses a preparation method of hydrophilic polyvinylidene fluoride hollow fiber dry membrane filaments, and the method comprises the following steps: soaking a polyvinylidene fluoridehollow fiber membrane in a surface hydrophilization treatment solution for membrane surface chemical reaction to form a hydrophilic polyvinylidene fluoride membrane, wherein the surface hydrophilization treatment solution is a strongly alkaline solution containing a strong oxidant or a strongly alkaline solution containing a phase transfer catalyst, removing fluorine groups on the surface of themembrane after hydrophilization reaction treatment on the surface of the membrane, substituting to form compact hydroxyl groups, and carrying out surface hydrophilicity improvement treatment on the polyvinylidene fluoride membrane, drying membrane filaments to obtain dry membrane filaments. The membrane filaments retain the original high strength and high alkali resistance, and has good organic and biological pollution resistance due to the excellent hydrophilic surface, and the membrane filaments or the assembly products thereof can be stored and transported without any humectant, do not needany membrane surface wetting agent treatment, and have the advantages of environmental protection, no toxicity and no harm to the human body. By soaking in water, the hydrophilic polyvinylidene fluoride hollow fiber dry membrane filaments directly recover the water flux for use.

Description

technical field [0001] The invention relates to a preparation method of a polyvinylidene fluoride hollow fiber membrane, in particular to a preparation method of a hydrophilic polyvinylidene fluoride hollow fiber dry membrane thread. Background technique [0002] Due to its hydrophobicity, heat resistance, chemical stability, radiation resistance and other excellent properties, polyvinylidene fluoride has been widely prepared into hollow fiber membranes and used in the field of water treatment in recent years, especially in river water and groundwater. In terms of turbidity and bacteria removal, purification of industrial water, treatment of municipal sewage and reuse of reclaimed water, etc. [0003] Polyvinylidene fluoride resin (PVDF) can be used to prepare hollow fiber membranes by non-solvent phase transfer process (NIPS), and the membrane strength is generally below 2MPa. In actual water treatment applications, in order to maintain good operation, strong or After long...

AI Technical Summary

Problems solved by technology

[0004] In order to solve the existing patent CN101590374B through the thermally induced phase separation (TIPS) process to prepare polyvinylidene fluoride (PVDF) film surface hydrophilic problem, to make the dry silk prepared by the thermally induced phase separation (TIPS) process, not Soak in water directly after other treatments to make the surface of the membrane silk wet and restore water flux. The surface of the membrane must have permanent strong hydrophilicity, and the critical wet surface tension of the membrane surface should be 70dyn / cm or above