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CN-122006606-A - Preparation method of aluminum-based MOF nanofiber aerogel

CN122006606ACN 122006606 ACN122006606 ACN 122006606ACN-122006606-A

Abstract

The invention relates to the technical field of preparation of functionalized nano materials, in particular to a preparation method of aluminum-based MOF nanofiber aerogel. The preparation method comprises the following steps of S1, calcining prepared precursor nanofiber membranes with different diameters to obtain amorphous silicon aluminum oxygen precursor nanofiber membranes, putting the membranes into a reaction solution A for synthesis to obtain aluminum-based MOF nanofiber membranes X, Y, Z with different diameters, S2, respectively putting the crushed aluminum-based MOF nanofiber membranes with different diameters into a reaction solution B for reaction, carrying out ultrasonic homogenization and dispersion after the reaction is finished to obtain homogenized dispersion liquid X1, Y1 and Z1, S3, freezing and crushing the homogenized dispersion liquid X1, Y1 and Z1, filling the homogenized dispersion liquid X1, Y1 and Z1 into a template to obtain a solidified block, then drying the solidified block, and putting the solidified block into a reaction solution C for activation treatment to obtain the aluminum-based MOF nanofiber aerogel, thereby realizing specific utilization of the aluminum-based MOF nanofiber aerogel in the fields of chemical protection, toxic and harmful gas treatment and the like.

Inventors

  • DAI ZIJIAN
  • HE GUANGJUN
  • ZHANG ZIXIAN
  • SI YANG
  • YU JIANYONG

Assignees

  • 东华大学

Dates

Publication Date
20260512
Application Date
20260413

Claims (10)

  1. 1. A preparation method of an aluminum-based MOF nanofiber aerogel is characterized by comprising the following steps: S1, calcining the prepared precursor nanofiber membranes with different diameters to obtain an amorphous sialon precursor nanofiber membrane, and placing the amorphous sialon precursor nanofiber membrane into a reaction solution A to obtain an aluminum-based MOF nanofiber membrane X, Y, Z with different diameters, wherein the reaction solution A comprises an organic carboxylic acid ligand and a solvent; s2, crushing the aluminum-based MOF nanofiber membranes with different diameters prepared in the step S1, respectively putting the crushed aluminum-based MOF nanofiber membranes into a reaction solution B prepared by mixing a thickening agent, a cross-linking agent, a catalyst and a solvent for reaction, and performing ultrasonic homogenization and dispersion after the reaction is finished to obtain homogenized dispersion liquid X1, Y1 and Z1; S3, freezing and crushing the homogeneous dispersion liquid X1, Y1 and Z1, stacking the homogeneous dispersion liquid into a template according to the sequence from the large diameter to the small diameter and from the small diameter to the top, flattening, continuously freezing to obtain a solidified block, then performing low-pressure vacuum drying treatment to prepare aerogel with a space gradient cell structure, and placing the aerogel into a reaction solution C for activation treatment to obtain the aluminum-based MOF nanofiber aerogel with an adsorption-digestion function, wherein the reaction solution C is one or more of sodium hypochlorite solution, calcium hypochlorite solution, sodium hypobromite solution and potassium bromate solution.
  2. 2. The method of claim 1, wherein in step S1, precursor nanofiber membranes with different diameters are prepared by an electrostatic spinning technology, wherein the electrostatic spinning parameters are that the solution injection rate is 0.5-2mL/h, the voltage is 15-20kV, the spinning distance is 15-20cm, the ambient relative humidity is 30-40%, the ambient temperature is 20-25 ℃, and the average diameter ranges of the prepared nanofiber membranes X, Y, Z are 400nm-600nm, 600nm-1 μm and 1-1.5 μm respectively.
  3. 3. The method according to claim 1 or 2, wherein in step S1, the calcination temperature is 400-600 ℃, the temperature rise rate is 5-10 ℃ per minute, and the duration is 2-6 hours.
  4. 4. The preparation method of claim 1, wherein in the step S1, the organic carboxylic acid ligand is one or more of 2-amino terephthalic acid, 1H-pyrazole-3, 5-dicarboxylic acid and (E) -5- (2-carboxyvinyl) -1H-pyrazole-3-carboxylic acid, the solvent is one or more of N, N-dimethylformamide, dimethyl sulfoxide, methanol, ethanol and deionized water, the mass fraction of the organic carboxylic acid ligand in the solvent is 0.01% -0.2%, and the mass ratio of the amorphous silicon-aluminum-oxygen precursor nanofiber membrane to the organic carboxylic acid ligand is 1:5-1:12.
  5. 5. The preparation method of the nano fiber membrane according to claim 1 or 4, wherein in the step S1, the reaction temperature is 100-200 ℃ for 18-48 hours, the first suction filtration is carried out after the reaction is finished and cooled, the nano fiber membrane obtained by the first suction filtration is washed by one or more of N, N-dimethylformamide, dimethyl sulfoxide, methanol and ethanol for 12-24 hours on a shaking table, the second suction filtration is carried out, the membrane obtained by the second suction filtration is washed by deionized water on the shaking table for 12-24 hours, the third suction filtration is carried out, the membrane obtained by the third suction filtration is dried, and the drying temperature is 50-200 ℃ and the drying duration is 4-24 hours.
  6. 6. The preparation method of claim 1, wherein in the step S2, the thickening agent is one or more of polyacrylamide, polyvinyl alcohol, chitosan, methylcellulose and poly (N-isopropyl acrylamide), the cross-linking agent is one or more of methyltriethoxysilane, trimethylmethoxysilane and dimethyldimethoxysilane, the catalyst is one or more of hydrochloric acid, acetic acid, anhydrous oxalic acid and ammonium chloride, and the solvent is deionized water.
  7. 7. The method according to claim 1 or 6, wherein in step S2, the mass ratio of the thickener to the solvent is 1:100-1:500, the mass ratio of the aluminum-based MOF nanofiber membrane to the crosslinking agent is 1:1-1:4, the mass ratio of the crosslinking agent to the catalyst is 1:50-1:400, and the mass ratio of the crosslinking agent to the solvent is 1:100-1:300.
  8. 8. The preparation method of claim 1, wherein in the step S2, the reaction time of the aluminum-based MOF nanofiber membrane in the reaction solution B is 0.5-2h, the ultrasonic homogenization frequency range is 15-30KHz, and the power is 30-80%.
  9. 9. The method according to claim 1, wherein in the step S3, crushed ice obtained by freezing and crushing has a particle size of 10-500 μm, and crushed ice obtained by homogenizing the dispersions Z1, Y1 and X1 is stacked in the form in the order of the fiber diameters from large to small and from bottom to top to obtain a solidified block, wherein the volume ratio of the homogenized dispersions X1, Y1 and Z1 is 1:1:1-1:2:4; the low-pressure vacuum drying treatment time is 24-72h, the drying temperature is-45-25 ℃, the pH value of the reaction solution C is 3-7, the activation temperature is 15-40 ℃, and the activation time is 1-10h.
  10. 10. An aluminum-based MOF nanofiber aerogel prepared by the preparation method according to any one of claims 1 to 9, wherein the aluminum-based MOF nanofiber aerogel has a spatially gradient cell structure.

Description

Preparation method of aluminum-based MOF nanofiber aerogel Technical Field The invention relates to the technical field of preparation of functionalized nano materials, in particular to an aluminum-based MOF nanofiber aerogel and a preparation method thereof, and especially relates to an aluminum-based MOF nanofiber aerogel with a space gradient cell structure and a preparation method thereof. Background The Metal Organic Framework (MOF) material has high specific surface area, adjustable pore channel structure and rich active sites, and has wide prospect in the fields of adsorption, catalysis, separation and the like. The aluminum-based MOF material has the characteristics of low toxicity and good stability, and becomes a research hot spot in the fields of chemical protection and gas treatment. Compared with a two-dimensional porous fiber material, the fiber aerogel is an ideal carrier for carrying the MOF material due to the characteristics of high porosity, abundant pore structure, adjustable radial size and the like, however, the preparation and application of the aluminum-based MOF nanofiber aerogel in the prior art still have a plurality of defects. The existing aluminum-based MOF nanofiber aerogel is prepared by adopting a mode of mixing or post-loading MOF powder and a fiber base material, wherein the MOF powder and the nanofiber are combined only by means of weak molecular acting force, interface combination is not tight and easy to fall off, meanwhile, the aerogel obtained by the existing preparation process is single in cell structure, no gradient exists in pore size distribution, gas mass transfer efficiency is low, the synergistic performance of adsorption and digestion is poor, and the requirements of quick adsorption and efficient digestion of toxic and harmful gases in chemical protection are difficult to be met. Therefore, the invention provides the aluminum-based MOF nanofiber aerogel which does not need to be additionally added with a metal source, has a gradient pore channel structure and has excellent adsorption-digestion performance, so that the special effect utilization of the aerogel in the fields of chemical protection, toxic and harmful gas treatment and the like is realized. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a preparation method of aluminum-based MOF nanofiber aerogel with a space gradient cell structure, and the obtained product can efficiently adsorb and degrade toxic substances such as small molecules of toxic agents and the like so as to realize specific utilization of the product in the fields of chemical protection, toxic and harmful gas treatment and the like. In order to achieve the above purpose, the invention is realized by the following technical scheme: the invention discloses a preparation method of an aluminum-based MOF nanofiber aerogel, which comprises the following steps: S1, calcining the prepared precursor nanofiber membranes with different diameters to obtain an amorphous sialon precursor nanofiber membrane, and placing the amorphous sialon precursor nanofiber membrane into a reaction solution A to obtain an aluminum-based MOF nanofiber membrane X, Y, Z with different diameters, wherein the reaction solution A comprises an organic carboxylic acid ligand and a solvent; s2, crushing the aluminum-based MOF nanofiber membranes with different diameters prepared in the step S1, respectively putting the crushed aluminum-based MOF nanofiber membranes into a reaction solution B prepared by mixing a thickening agent, a cross-linking agent, a catalyst and a solvent for reaction, and performing ultrasonic homogenization and dispersion after the reaction is finished to obtain homogenized dispersion liquid X1, Y1 and Z1; S3, freezing and crushing the homogeneous dispersion liquid X1, Y1 and Z1, stacking the homogeneous dispersion liquid on a template according to the sequence of the fiber diameter from large to small and from bottom to top, flattening, continuously freezing to obtain a solidified block, then performing low-pressure vacuum drying treatment to prepare aerogel with a space gradient cell structure, and placing the aerogel into a reaction solution C for activation treatment to obtain the aluminum-based MOF nanofiber aerogel with the adsorption-digestion function, wherein the reaction solution C is one or more of sodium hypochlorite solution, calcium hypochlorite solution, sodium hypobromite solution and potassium bromate solution. Preferably, in the step S1, precursor nanofiber membranes with different diameters are prepared by an electrostatic spinning technology, wherein the electrostatic spinning parameters are that the solution injection rate is 0.5-2mL/h, the voltage is 15-20kV, the spinning distance is 15-20cm, the ambient relative humidity is 30-40%, the ambient temperature is 20-25 ℃, and the average diameter ranges of the prepared nanofiber membranes X, Y, Z are 400nm-600nm, 600nm-1 mu m and 1-1.5 mu