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CN-122006513-A - Ordered ion channel polyamide nano composite membrane, preparation method and application

CN122006513ACN 122006513 ACN122006513 ACN 122006513ACN-122006513-A

Abstract

The invention discloses an ordered ion channel polyamide nano composite membrane, a preparation method and application thereof, relates to the field of lithium-magnesium membrane separation, and aims to solve the problems in the prior art The method comprises the steps of grafting aminobenzo crown ether onto an ultrafiltration base film in situ through diazotization-coupling reaction, preparing a polyamide compact layer on an in-situ self-assembled crown ether nano layer through interfacial polymerization, and constructing the ordered ion transmission channel polyamide nano composite film together. Because the amino group remained on the surface of the in-situ covalent grafted crown ether nano-layer can also participate in the interfacial polymerization reaction, the crown ether macromolecular layer of the ordered ion channel and the polyamide compact layer are connected through chemical bonds to jointly form the polyamide nano-composite membrane of the ordered ion transmission channel. Can obviously promote Selectivity and The permeability is suitable for extracting lithium from salt lake brine.

Inventors

  • ZHANG XIAOZHUAN
  • HAN SONGWEI
  • HU PING

Assignees

  • 河南师范大学

Dates

Publication Date
20260512
Application Date
20260227

Claims (9)

  1. 1. The ordered ion channel polyamide nano composite membrane is characterized by comprising a polysulfone ultrafiltration base membrane, wherein an ordered ion channel crown ether macromolecule layer is covalently grafted on the polysulfone ultrafiltration base membrane in situ, and the ordered ion channel crown ether macromolecule layer is connected with a polyamide compact layer through a chemical bond; the retention rate of magnesium ions of the polyamide nano composite membrane is not lower than 95%, and the retention rate of lithium ions is not higher than 35%.
  2. 2. The ordered ion channel polyamide nanocomposite membrane of claim 1 wherein said aminobenzocrown ether comprises a macrocyclic polyether having at least 2 terminal anilines attached thereto.
  3. 3. The ordered ion channel polyamide nanocomposite membrane of claim 2 wherein said aminobenzo crown ether is one of an aminobenzo-18-crown ether-6 having a terminal anilino group of 2 or 4 and an aminobenzo-15-crown ether-5 supramolecular macrocyclic compound having a terminal anilino group of 2 or 4.
  4. 4. A method of preparing the ordered ion channel polyamide nanocomposite membrane of claim 1, comprising the steps of: Step 1, in-situ covalent grafting of aminobenzo crown ether on a polysulfone ultrafiltration base membrane through diazotization-coupling reaction, wherein the aminobenzo crown ether forms an ordered ion channel crown ether macromolecule layer; Step 2, applying a polyamine aqueous solution on the ordered ion channel crown ether macromolecular layer, and removing a water phase after the reaction; step 3, applying an acyl chloride organic solvent, and removing redundant oil phase after the reaction; step 4, further inducing a crosslinking reaction to obtain the ordered ion channel polyamide nanocomposite film according to claim 1.
  5. 5. The method according to claim 4, wherein the specific steps in the step 1 are that the polysulfone ultrafiltration base membrane is immersed in an aminobenzo crown ether acid solution of 5-30 min, excess solution is removed, immersed in a sodium nitrite solution of 1-5 min, diazotization-coupling reaction is carried out, excess solution is removed, and the membrane is stored in deionized water.
  6. 6. The method according to claim 4, wherein in the step 2, the monomer of the polyamine is one of piperazine, tri (2-aminoethyl) amine, triethylenetetramine, tetraethylenepentamine, tetraethylenediamine, polymer bond and ethylenediamine, 1, 2-diaminocyclohexane, polyethyleneimine, cyclohexane-1, 4-diamine.
  7. 7. The method according to claim 4, wherein in the step 3, the monomer of the acyl chloride is one of trimesoyl chloride, 1, 2, 3, 4-cyclobutanetetra-formyl chloride, 1, 2, 3, 4-cyclopentanetetraformyl chloride, and the organic solvent is one of cyclohexane, n-hexane, n-heptane, n-octane and ISOPAR-G.
  8. 8. The method of claim 4, wherein the step 4 is performed by placing the mixture in a vacuum drying oven at 50-70deg.C to induce crosslinking, and crosslinking is performed by 2-10 min.
  9. 9. An application of the ordered ion channel polyamide nano composite membrane is characterized in that the ordered ion channel polyamide nano composite membrane as claimed in any one of claims 1-3 is applied to salt lake brine to extract lithium ions.

Description

Ordered ion channel polyamide nano composite membrane, preparation method and application Technical Field The invention relates to the technical field of lithium-magnesium membrane separation, in particular to an ordered ion channel polyamide nano composite membrane, a preparation method and application. Background At present, two main ways of introducing crown ether into polyamide nanofiltration membranes to construct ion channels exist. Crown ether and derivatives thereof are used as water phase additives and are introduced into polyamide polymer chain segments through interfacial polymerization (for example, chinese patent CN118831451A and Chinese patent CN 120838200A), in the scheme, the crown ether and the derivatives thereof are introduced between polymer chain segments through hydrogen bonding, so that the introduced crown ether has limited addition amount, the crown ether is wrapped by polymer chains, the continuity of an ion transmission channel is poor, the ion recognition effect of a crown ether cavity structure cannot be exerted, and the lithium-magnesium separation effect is poor. Another approach is to introduce crown ethers and their derivatives into the polyamide separation layer surface (e.g. CN 120827815A) by a secondary interfacial polymerization or surface grafting process, but limited by the reaction sites or grafting density, and the introduced crown ether functionalized modified layer not only increases the water molecule transport resistance, but also reduces the membrane surface hydrophilicity, resulting in a sacrifice of water permeability. Therefore, how to introduce crown ether structure into polyamide nanometer film to construct ordered ion transmission channel, develop high levelSelective polyamide nanofiltration composite membranes are extremely challenging. Disclosure of Invention The invention aims to overcome the existing defects, and provides an ordered ion channel polyamide nano composite membrane, a preparation method and application thereof, which can effectively solve the problems in the background technology. In order to achieve the aim, the invention discloses an ordered ion channel polyamide nano composite membrane, which adopts the technical scheme that the ordered ion channel polyamide nano composite membrane comprises a polysulfone ultrafiltration base membrane, wherein an ordered ion channel crown ether macromolecular layer is covalently grafted on the polysulfone ultrafiltration base membrane in situ (namely, the ordered ion channel crown ether macromolecular layer is connected with the polysulfone ultrafiltration base membrane through covalent bonds), and the ordered ion channel crown ether macromolecular layer is connected with a polyamide compact layer through chemical bonds; the retention rate of magnesium ions of the polyamide nano composite membrane is not lower than 95%, and the retention rate of lithium ions is not higher than 35%. As a preferred embodiment of the present invention, the aminobenzocrown ether comprises a macrocyclic polyether to which at least 2 terminal anilines are attached. As a preferable technical scheme of the invention, the aminobenzo crown ether is one of aminobenzo-18-crown ether-6 with an anilino group of 2 or 4 and aminobenzo-15-crown ether-5 supermolecular macrocyclic compound with an anilino group of 2 or 4; wherein, the aminobenzo-15-crown ether-5 supermolecular macrocyclic compound with the terminal anilino group of 2 is 3, 5-diamino-N-aminobenzo-15-crown ether-5, and the molecular structural formula is as follows: The aminobenzo-15-crown-5 supermolecular macrocyclic compound having a terminal anilino group of 4 is 3, 5-diamino-N- (3- { [ (3, 5-diaminophenyl) carbonyl ] -amino } -15-crown-5 having the molecular structural formula: aminobenzo-18-crown-6 having a terminal anilino group of 2 is 3, 5-diamino-N-aminobenzo-18-crown-6 having the following molecular structural formula: aminobenzo-18-crown-6 having a terminal anilino group of 4 is 3, 5-diamino-N- (3- { [ (3, 5-diaminophenyl) carbonyl ] -amino } -18-crown-6 having the following molecular formula: 。 The invention further discloses a preparation method of the ordered ion channel polyamide nano composite membrane, which adopts the technical scheme that the preparation method comprises the following steps: Step 1, in-situ covalent grafting of aminobenzo crown ether on a polysulfone ultrafiltration base membrane through diazotization-coupling reaction, wherein the aminobenzo crown ether forms an ordered ion channel crown ether macromolecule layer; Step 2, applying a polyamine aqueous solution on the ordered ion channel crown ether macromolecular layer, and removing a water phase after the reaction; step 3, applying an acyl chloride organic solvent, and removing redundant oil phase after the reaction; And step 4, further inducing a crosslinking reaction to obtain the ordered ion channel polyamide nano composite membrane. The in-situ covalent grafted aminobenzo crown ether