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CN-121972033-A - Solid solution membrane containing high-load porous organic cage CC3, preparation method and application thereof in gas separation

CN121972033ACN 121972033 ACN121972033 ACN 121972033ACN-121972033-A

Abstract

A solid solution membrane containing a high-load porous organic cage CC3, a preparation method and application thereof in gas separation belong to the technical field of membrane materials and separation thereof. The method comprises the steps of mixing porous organic cage CC3, polymer PI and N-methyl pyrrolidone to form a premix, performing ball milling treatment to form a ball milling mixed solution, uniformly and evenly spreading the ball milling mixed solution in a film forming device, and performing heating treatment to completely volatilize a solvent to form a solid solution film containing high-load porous organic cage CC 3. According to the invention, through the synergistic effect of mechanical shearing force of ball milling and a small amount of solvent, on one hand, non-covalent interaction among CC3 cage molecules is cut off, and on the other hand, molecular mobility is limited by utilizing a high-viscosity medium and dynamic quenching is realized by combining with quick solvent volatilization, so that the loading capacity of the porous organic cage CC3 is successfully increased to 10-30wt%, no agglomeration phenomenon and interface defect exist in the membrane, and the obtained solid solution membrane shows excellent CO 2 permeability coefficient and CO 2 /CH 4 selectivity.

Inventors

  • KANG ZIXI
  • YU LITING
  • WANG RONGMING
  • FAN LILI

Assignees

  • 中国石油大学(华东)

Dates

Publication Date
20260505
Application Date
20260407

Claims (9)

  1. 1. A preparation method of a solid solution film containing a high-load porous organic cage CC3 comprises the following steps: (1) Mixing porous organic cage CC3, polymer PI and N-methyl pyrrolidone to form a premix; (2) Ball milling is carried out on the premix obtained in the step (1) to form ball milling mixed solution; (3) And (3) uniformly and flatly paving the ball-milling mixed solution obtained in the step (2) in a film forming device, and then performing heating treatment to completely volatilize the solvent to form a solid solution film containing the high-load porous organic cage CC 3.
  2. 2. The method for preparing the solid solution film containing the high-load porous organic cage CC3, as claimed in claim 1, is characterized in that in the step (1), the doping amount is 10-30wt%, the doping amount is 100% (mass of the porous organic cage CC 3/(mass of the porous organic cage CC 3+mass of the polymer PI)), and the mass of the porous organic cage CC 3+mass of the polymer PI is 1:12.5-12.9.
  3. 3. The preparation method of the solid solution film containing the high-load porous organic cage CC3, which is disclosed in claim 1, is characterized in that in the step (2), the ball milling speed is 600-700 rpm, the ball milling time is 2-4 hours, and the ball mass ratio is 18-20:1.
  4. 4. The method for preparing a solid solution film containing a high-load porous organic cage CC3 according to claim 1, wherein in the step (3), the temperature of the heating treatment is 60-80 ℃.
  5. 5. The method for preparing a solid solution film containing a highly loaded porous organic cage CC3 as defined in claim 1, wherein in the step (1), the porous organic cage CC3 is prepared by the following steps, (A) Mixing trimesic aldehyde and methylene dichloride with the mass ratio of 1:40-45 to form a solution A; (b) Mixing 1, 2-cyclohexanediamine and methylene dichloride with the mass ratio of 1:40-45 to form a solution B; (c) Slowly mixing the solution A and the solution B, wherein the mass ratio of trimesic aldehyde to 1, 2-cyclohexanediamine is 1:1.0-1.5, then placing the mixture at 25-35 ℃ for reaction for 5-7 days, centrifugally collecting the product, washing the product to remove unreacted reactants, and drying the obtained product.
  6. 6. The method of claim 5, wherein in the step (c), the solution film is washed with dichloromethane 3 to 5 times and ethanol 3 to 5 times in order to remove unreacted reactants.
  7. 7. The method of claim 5, wherein in the step (C), the drying temperature is 70-80 ℃ and the drying time is 8-10 hours.
  8. 8. A solid solution film containing a high-load porous organic cage CC3 is characterized by being prepared by the preparation method of any one of claims 1-7.
  9. 9. The use of a solid solution membrane comprising highly loaded porous organic cage CC3 as claimed in claim 8 for separating CO 2 and CH 4 .

Description

Solid solution membrane containing high-load porous organic cage CC3, preparation method and application thereof in gas separation Technical Field The invention belongs to the technical field of membrane materials and separation thereof, and particularly relates to a solid solution membrane containing a high-load porous organic cage CC3, a preparation method and application thereof in gas separation. Background The membrane separation technology has the advantages of low energy consumption, simple operation, environmental friendliness and the like, and has wide application prospect in the field of gas separation. Polymer membranes are dominant in the market due to their ease of processing and their high scalability, but their performance is limited by the trade-off relationship between gas permeability and selectivity, the upper Robeson limit. To overcome this limitation, researchers have incorporated porous fillers into polymer matrices to prepare mixed matrix membranes. Although the traditional fillers such as zeolite, metal organic framework, covalent organic framework and the like have excellent pore channel structures, the characteristic of being insoluble in organic solvents leads to poor interfacial compatibility with polymer matrixes, non-selectivity defects are easy to form, and the gas separation efficiency is reduced. The porous organic cage (Porous molecular cage, POC) is taken as a novel molecular porous material, is assembled by discrete molecules through weak interaction, can be dissolved in a specific solvent, and essentially avoids the problem of interfacial incompatibility of the traditional rigid filler. Cooper et al (ANGEWANDTE CHEMIE International Edition, 2013, 52, 1253-1256) co-dissolved POC and PIM-1 macromolecules in chloroform, and the POC nucleated and grew in situ in the casting solution during solvent evaporation to achieve effective binding with the macromolecules. However, in this work, the porous molecular cages are only present in molecular form in the casting solution, and are still present in particulate form in the mixed matrix membrane, and the discrete nature of the porous molecular cages is not fully utilized. The porous organic cage is used as a solid solution membrane formed by dispersing the molecular level of the solute in the polymer solvent, so that the molecular level mixing can be realized, and the interface defect is eliminated. Lively et al (ANGEWANDTE CHEMIE International Edition, 2019, 58, 2638-2643) compounded the vertex-functionalized CC3 cage molecules with matrix macromolecules to uniformly disperse the same in the macromolecular "solvent" in the form of a molecular "solute" to construct a single-phase solid solution film, thereby avoiding the dispersion problem of particles in a polymer matrix and the interfacial compatibility problem between the particles and the polymer, and realizing the substantial improvement of the permeability coefficient of CO 2. However, POC is limited in the polymer, and when the loading exceeds a critical value (usually 5 wt%), strong non-covalent interactions between cage molecules (e.g. hydrogen bonds, pi-pi stacking) can cause molecular cages to agglomerate to form crystals, causing non-selective interface defects to form between the filler and the polymer, severely restricting further improvement of solid solution film properties. Therefore, how to effectively inhibit the agglomeration of POC and realize the high-loading and uniform dispersion of POC in a polymer matrix is a core difficult problem for preparing high-performance solid solution films. Disclosure of Invention In order to solve the problems, the invention aims to provide a solid solution membrane containing a high-load porous organic cage CC3, which can realize high load capacity, no defects and high separation performance, a preparation method and application thereof in gas separation, in particular to separation of CO 2 and CH 4. The invention relates to a preparation method of a solid solution film containing a high-load porous organic cage CC3, which comprises the following steps: (1) Mixing porous organic cage CC3, polymer PI and N-methyl pyrrolidone to form a premix; (2) Ball milling is carried out on the premix obtained in the step (1) to form ball milling mixed solution; (3) And (3) uniformly and flatly paving the ball-milling mixed solution obtained in the step (2) in a film forming device, and then performing heating treatment to completely volatilize the solvent to form a solid solution film containing the high-load porous organic cage CC 3. In the step (1), the doping amount is 10-30wt%, preferably 10-20wt%, and the doping amount is = [ porous organic cage CC3 mass/(porous organic cage CC3 mass+polymer PI mass) ]; in the step (2), the ball milling rotating speed is 600-700 rpm, the ball milling time is 2-4 hours, and the ball material mass ratio is 18-20:1; In the step (3), the temperature of the heating treatment is 60-80 ℃; in the step (3), the