Composite nanofiltration membrane, and preparation method and applications thereof

Abstract

The invention belongs to the field of separation membranes, and discloses a composite nanofiltration membrane, and a preparation method and an applications thereof. The composite nanofiltration membrane comprises a support layer and a polyamide separation layer; the polyamide separation layer contains phytic acid and multivalent metal cations chelated with phytic acid. According to the composite nanofiltration membrane disclosed by the invention, phytic acid is introduced in an interfacial polymerization process, so that the phytic acid and amino form hydrogen bonds to be fixed in a polyamidelayer, the phytic acid in the polyamide layer is chelated through multivalent metal cations, and surface crosslinking is realized so as to improve the salt rejection rate; meanwhile, phosphate groupsin phytic acid molecules improve the hydrophilicity of the polyamide surface, and the water flux of the nanofiltration membrane is improved. Meanwhile, the preparation method of the composite nanofiltration membrane is simple and has a great industrial application prospect.

Description

technical field

[0001] The invention belongs to the field of separation membranes, and more specifically relates to a composite nanofiltration membrane and its preparation method and application. Background technique

[0002] Membrane separation technology is a new separation technology that appeared in the early 20th century and rose rapidly after the 1960s. Because membrane separation technology not only has the functions of separation, concentration, purification and refining, but also has the characteristics of high efficiency, energy saving, environmental protection, molecular level filtration, simple filtration process and easy control, it is widely used in food, medicine, biology, environmental protection, chemical industry , metallurgy, energy, petroleum, water treatment, electronics, bionics and other fields, and has produced huge economic and social benefits, and has become one of the most important means in today's separation science.

[0003] The core of membran...