A preparation method of monoamine graft modified cross-linked polyimide solvent-resistant nanofiltration membrane

Abstract

The invention provides a preparation method for a monoamine-grafted-and-modified crosslinked polyimide solvent-resistant nanofiltration membrane. The preparation method comprises the following steps: a, preparing a mixed solution from a solvent and a cosolvent according to a mass ratio of 1: 0.1-5; b, adding 15 to 28% of a polyimide solution into the mixed solution so as to prepare a membrane casting liquid; c, adding 2.5 to 20% of monoamine into the membrane casting liquid and carrying out mixing at 25 to 80 DEG C for 3 to 24 h under stirring so as to guarantee complete grafting; d, preparing a membrane by using a immersion-precipitation phases inversion process, washing the prepared membrane with deionized water a plurality of times and standing the washed membrane for subsequent usage; e, preparing an alcoholic solution of diamine with a concentration of 0.5 to 20%; f, putting the prepared membrane in the alcoholic solution of diamine prepared in the previous step for crosslinking modification for 0.25 to 48 h; and g, after completion of the reaction, soaking and cleaning the membrane in an alcohol solvent so as to obtain the polyamide nanofiltration membrane with excellent performance. The polyimide solvent-resistant nanofiltration membrane prepared in the invention has the advantages of simple preparation, adjustable hydrophilicity, outstanding solvent resistance, great permeation flux, a high retention rate, etc. and is applicable to separation of substances in all the organic solvents and to the fields of pharmaceutical manufacturing, biology, catalyst recovery, etc.

Description

technical field [0001] The invention relates to a method for preparing a membrane, in particular to a method for preparing a polyimide solvent-resistant nanofiltration membrane. Background technique [0002] The nanofiltration membrane separation process has been widely used in various industrial fields and scientific research. At present, it is mainly concentrated in the aqueous solution system, while a large part of the actual industrial process involves the organic solvent system. The many advantages of the nanofiltration process, such as no phase transition in the separation process, no need for additives, and little influence of temperature, make it have great potential application value in non-aqueous solutions in the fields of petrochemical, pharmaceutical, and food. It is difficult to expand the use of filter membranes in non-aqueous systems. For this reason, further research and development of solvent-resistant nanofiltration membranes is extremely important for bro...

AI Technical Summary

Problems solved by technology

The many advantages of the nanofiltration process, such as no phase transition in the separation process, no need for additives, and small temperature influence, make it have great potential application value in non-aqueous solutions in the fields of petrochemical, pharmaceutical, and food. It is difficult to expand the use of filter membranes in non-aqueous systems. For this reason, further research and development of solvent-resistant nanofiltration membranes is extremely important for broadening the application of nanofiltration processes.

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