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CN-122006670-A - Double-needle independent injection type composite fiber membrane electrostatic spinning preparation technology

CN122006670ACN 122006670 ACN122006670 ACN 122006670ACN-122006670-A

Abstract

The application relates to the field of material science, and particularly discloses a double-needle independent injection type composite fiber membrane electrostatic spinning preparation technology. The composition comprises ZIF-67 powder, polyacrylonitrile, polyvinylpyrrolidone, N-dimethylformamide and the like, and the preparation method comprises the steps of standing at room temperature to synthesize ZIF-67 powder, independently preparing a polymer matrix and functional component double-system spinning solution, synchronously carrying out electrostatic spinning by double needles to interweave and compound the jet, and drying at low temperature to obtain the composite fiber membrane. The product can be used for adsorbing pollutants, especially for radioactive iodine capture, industrial iodine resource recovery and the like, has the advantages of high iodine adsorption capacity, fully exposed active sites, stable structure and easiness in recovery, and the preparation method has the advantages of continuous and stable process, high ZIF-67 load, uniform dispersion, low energy consumption, environmental friendliness, strong scene adaptability of nuclear facility tail gas purification and the like, green and sustainable process, controllable cost and suitability for large-scale production requirements.

Inventors

  • LU HONG
  • Qiao Yusheng
  • ZHANG HAIXIN
  • Zang Haotong
  • Geng Chengbao
  • JIA HONGGE
  • YAN ERYUN
  • JI WENJIE

Assignees

  • 齐齐哈尔大学

Dates

Publication Date
20260512
Application Date
20260226

Claims (10)

  1. 1. The double-needle independent jet type composite fiber membrane electrostatic spinning preparation method is characterized by comprising the following steps of: S1, preparing a functional component ZIF-67 powder, namely synthesizing the ZIF-67 powder by adopting a room temperature standing method, wherein the preparation method comprises the steps of mixing cobalt salt and 2-methylimidazole in a methanol solvent for reaction, and then carrying out solid-liquid separation, washing and drying; S2, independently preparing a double-system spinning solution, namely independently preparing a polymer matrix spinning solution and a functional component spinning solution, wherein the polymer matrix spinning solution does not contain ZIF-67 powder, and the functional component spinning solution contains the ZIF-67 powder prepared in the step S1; S3, double-needle synchronous electrostatic spinning, namely respectively loading a polymer matrix spinning solution and a functional component spinning solution into two independent injection devices, and providing two parallel spinning needles, and synchronously carrying out electrostatic spinning on the same collecting device, so that jet flows from the two spinning solutions are interweaved and compounded on the collecting device to form a composite fiber film precursor; S4, post-treatment, namely drying the precursor of the composite fiber film to obtain the composite fiber film.
  2. 2. The method for preparing the double-needle independent jet type composite fiber membrane by electrostatic spinning is characterized in that in the step S3, the process parameters of electrostatic spinning are that the spinning voltage is 10-25kV, the receiving distance between a needle and a collecting device is 5-25cm, the rotating speed of the collecting device is 600-1000rpm, the advancing rate of spinning solution of a single needle is 0.5-2mL/h, the ambient temperature is 5-30 ℃, and the ambient humidity is 30-70%.
  3. 3. The preparation method of the double-needle independent jet type composite fiber membrane electrostatic spinning is characterized in that the room temperature standing method in the step S1 comprises the steps of dissolving cobalt salt in methanol to form solution A, dissolving 2-methylimidazole in methanol to form solution B, mixing the solution B and the solution A, stirring for 5-30min, standing at room temperature for 24-36h under a dark environment, carrying out suction filtration on a product after standing, washing the obtained solid for 3-5 times sequentially by using methanol and absolute ethyl alcohol, and finally drying and grinding the washed solid at 50-70 ℃ to obtain ZIF-67 powder.
  4. 4. The method for preparing the double-needle independent jet type composite fiber membrane by electrostatic spinning according to claim 1, wherein in the step S2, the polymer matrix spinning solution consists of polyacrylonitrile, polyvinylpyrrolidone and N, N-dimethylformamide solvent, wherein the mass of the polyacrylonitrile is 0.5-1.5g, the mass of the polyvinylpyrrolidone is 0.5-1.5g, and the mass of the N, N-dimethylformamide is 7-10g.
  5. 5. The method for preparing the double-needle independent jet type composite fiber membrane by electrostatic spinning according to claim 1, wherein in the step S2, the functional component spinning solution consists of ZIF-67 powder, polyvinylpyrrolidone and N, N-dimethylformamide solvent and is prepared independently of the polymer matrix spinning solution, wherein the ZIF-67 powder has a mass of 0.25-1.00g, the polyvinylpyrrolidone has a mass of 0.05-0.10g and the N, N-dimethylformamide has a mass of 7-10g.
  6. 6. The method for preparing the double-needle independent jet type composite fiber membrane by electrostatic spinning according to claim 1, wherein in the step S3, the spinning needles are arranged in a parallel mode, and the tip interval is 2-3cm, so that two jet flows are fully interweaved in space.
  7. 7. The method for preparing the double-needle independent jet type composite fiber membrane by electrostatic spinning according to claim 1, wherein in the step S3, the collecting device is a metal roller with a release material coated on the surface, and the release material is silicone paper.
  8. 8. The method for preparing the double-needle independent jet type composite fiber membrane by electrostatic spinning according to claim 1, wherein in the step S4, the drying temperature is 50-60 ℃, and the drying time is 2-3h.
  9. 9. The preparation method of the double-needle independent jet type composite fiber membrane electrostatic spinning is characterized in that in the step S2, magnetic stirring is adopted for 3-6 hours when the polymer matrix spinning solution and the functional component spinning solution are prepared, and ultrasonic dispersion treatment is further carried out after magnetic stirring when the functional component spinning solution is prepared, wherein the ultrasonic dispersion time is 1-3 hours.
  10. 10. A composite fibre membrane produced by the method of any one of claims 1 to 9, wherein the composite fibre membrane has a continuous network porous fibre structure based on polyacrylonitrile and polyvinylpyrrolidone, and ZIF-67 crystals are dispersed and anchored on the surface and inside of the fibre structure, with active adsorption sites of ZIF-67 being fully exposed.

Description

Double-needle independent injection type composite fiber membrane electrostatic spinning preparation technology Technical Field The application relates to the field of material science, in particular to a double-needle independent jet type composite fiber membrane electrostatic spinning preparation technology. Background With the rapid development of the nuclear energy industry, efficient capture and safe treatment of radioactive iodine is an important requirement in the field of environmental remediation. The metal organic framework material (such as ZIF-67) has a very high specific surface area, rich active adsorption sites and specific affinity to various pollutants (especially iodine), and has wide application potential in the field of pollutant adsorption. The electrostatic spinning technology is often used as an effective means for preparing nanofiber composite membranes to composite MOFs materials with a polymer matrix so as to integrate the structural advantages of the matrix and the functional characteristics of the MOFs and improve the adsorption performance and practical application value of the materials. However, the preparation of traditional MOFs-based electrostatic spinning composite films adopts an blending spinning strategy, namely, MOFs powder is directly mixed into polymer matrix spinning solution for spinning. The mode often leads to the obvious increase of the viscosity of the spinning solution, is easy to cause the technological problems of spinning cutoff, nozzle blockage and the like, meanwhile, the loading capacity of MOFs is obviously limited, MOFs particles are easy to agglomerate under high concentration, and the MOFs particles can be excessively coated by a polymer matrix, so that the active adsorption sites of the MOFs particles are difficult to fully expose, the adsorption efficiency of a composite membrane is further influenced, and the high-performance adsorption material in practical application is difficult to meet, especially the high-efficiency adsorption requirement on target pollutants (such as iodine) under high loading. Disclosure of Invention In order to solve the problems that in the prior art, when a MOFs-based composite fiber membrane is prepared by adopting blending electrostatic spinning, the viscosity of spinning solution is easy to increase rapidly due to the mixing of functional components and matrix components, further technological faults such as spinning flow break, nozzle blockage and the like are caused, and active adsorption sites of the MOFs are shielded and cannot fully exert adsorption efficiency due to poor dispersion uniformity, the application provides a double-needle independent injection type composite fiber membrane electrostatic spinning preparation technology. Subsequently, two performance-optimized jets are stretched only in the electric field and finally three-dimensional interlacing and compounding is achieved on the collector by means of a double-needle simultaneous jet. The path of the 'first separation optimization and then accurate compounding' successfully converts the 'high MOFs loading', 'excellent spinning stability' and 'high active site exposure', which are difficult to be compatible in the traditional process, into the targets which can be cooperatively realized. In a first aspect, the application provides a double-needle independent injection type composite fiber membrane electrostatic spinning preparation method, which adopts the following technical scheme: the double-needle independent jet type composite fiber membrane electrostatic spinning preparation method comprises the following steps: S1, preparing a functional component ZIF-67 powder, namely synthesizing the ZIF-67 powder by adopting a room temperature standing method, wherein the preparation method comprises the steps of mixing cobalt salt and 2-methylimidazole in a methanol solvent for reaction, and then carrying out solid-liquid separation, washing and drying; S2, independently preparing a double-system spinning solution, namely independently preparing a polymer matrix spinning solution and a functional component spinning solution, wherein the polymer matrix spinning solution does not contain ZIF-67 powder, and the functional component spinning solution contains the ZIF-67 powder prepared in the step S1; S3, double-needle synchronous electrostatic spinning, namely respectively loading a polymer matrix spinning solution and a functional component spinning solution into two independent injection devices, and providing two parallel spinning needles, and synchronously carrying out electrostatic spinning on the same collecting device, so that jet flows from the two spinning solutions are interweaved and compounded on the collecting device to form a composite fiber film precursor; S4, post-treatment, namely drying the precursor of the composite fiber film to obtain the composite fiber film. By adopting the technical scheme, the viscosity, dispersion stability and compon