Preparation method of in-situ hollow fiber composite nanofiltration membrane

Abstract

The invention discloses a preparation method of an in-situ hollow fiber composite nanofiltration membrane, which is characterized in that in the fiber spinning process, the hollow fiber composite nanofiltration membrane with an outer selective layer is prepared through in-situ interfacial polymerization; the preparation method comprises the following steps: preparing a membrane casting solution; preparing core liquid and double baths; spinning a hollow fiber composite nanofiltration membrane; the external selective hollow fiber composite nanofiltration membrane is prepared on a dry-wet spinning line through in-situ interfacial polymerization, has the advantages of being easy to clean, large in specific surface area, low in energy consumption and cost and the like, and is stable in performance and structure in the separation process, a functional layer is not prone to falling off, and the preparation method is simple, continuous and controllable; wide market application prospects are realized.

Description

Technical field [0001] The present invention relates to the preparation of nanofiltration membranes, and more particularly to a method of preparation of an inner hollow fiber composite nanofiltration membrane. Background technique [0002] Nonofiltration is a pressure-driven film having separation characteristics between reverse osmosis and ultrafiltration. The nation filter has a huge potential in the field of water purification and wastewater treatment in the field of water purification and wastewater treatment in the field of water purification and wastewater treatment. [0003] So far, the commercially available nanofiltration membrane is mainly a thin film composite plate membrane. Compared with the flat film, the hollow fiber module exhibits a greater fill density, a higher specific surface area, and self-support characteristics. Therefore, it is increasingly interest in developing hollow fiber composite northern films. [0004] The composite method is currently the most ef...

AI Technical Summary

Problems solved by technology

The above research and development is to form a selective layer on the inner surface of the hollow fiber. In actual application, there must be cleaning difficulties, which will shorten the service life of the membrane, and the specific surface area of ​​the internal selective layer is small, and the effective functional layer area is limited.

In addition, although the preparation of flat nanofiltration membranes by interfacial polymerization on the surface of ultrafiltration membranes is relatively mature, compared with flat surfaces, the hollow fiber membranes have a small radius of curvature, making this technology perform on the outer surface of hollow fiber ultrafiltration membranes. much more difficult than flat membranes

At the same time, in the actual separation process, since the selection layer is on the outer surface of the hollow fiber, it will easily fall off on the base membrane, so there are few reports on the preparation of the outer surface hollow fiber composite nanofiltration membrane by interfacial polymerization.

In addition, in the dry-wet spinning process, compared with the existing technology of in-situ generation of composite membranes on the inner surface of fibers, the technology of in-situ generation of composite membranes on the outer surface has technical difficulties such as discontinuity, defects, and difficulty in controlling the outer surface.

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