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CN-121975155-A - Polyacid composite polymer single-chain nano particle and preparation method thereof

CN121975155ACN 121975155 ACN121975155 ACN 121975155ACN-121975155-A

Abstract

The invention belongs to the field of single-chain polymer nano-particles and preparation thereof, and relates to a method for preparing single-chain polyacid composite polymer nano-particles in a low-cost and large-scale manner. The method takes polyacid as a physical crosslinking agent, utilizes electrostatic/hydrogen bond interaction between pyridine polymer and polyacid to carry out intramolecular crosslinking, and prepares the polyacid composite polymer single-chain nano particles under high concentration. The single-chain nano particle has physical and chemical properties of inorganic polyacid and organic polymer, and has wide application prospect in catalysis, medicine, magnetism, electricity and other aspects.

Inventors

  • SHI SHAOWEI
  • LIU XUEQING
  • WANG MENG

Assignees

  • 北京化工大学

Dates

Publication Date
20260505
Application Date
20250620

Claims (10)

  1. 1. The preparation method of the polyacid composite polymer single-chain nano particle is characterized by comprising the following steps of: S1) fully dissolving a pyridine polymer in a polar organic solvent to prepare a pyridine polymer solution, and fully dissolving polyacid in the polar organic solvent to prepare a polyacid solution, wherein the polar organic solvent is one or more of N, N-dimethylformamide, N-dimethylacetamide, dimethyl sulfoxide, tetrahydrofuran, acetone and acetonitrile; S2) adding the polyacid solution into the pyridine polymer solution, fully stirring, and carrying out intramolecular crosslinking by utilizing electrostatic/hydrogen bond interaction between the pyridine polymer and the polyacid to obtain physically crosslinked polyacid composite polymer single-chain nanoparticle dispersion liquid, wherein the addition amount of the polyacid is 1% -15% of the mole number of pyridine units; s3) adding a covalent cross-linking agent into the polyacid composite polymer single-chain nanoparticle dispersion liquid prepared in the step S2) to carry out intramolecular cross-linking, and heating and stirring for a period of time to obtain the covalent cross-linked polyacid composite polymer single-chain nanoparticle dispersion liquid, wherein the addition amount of the covalent cross-linking agent is 0.05% -10% of the mole number of pyridine units; S4) adding the polyacid composite polymer single-chain nano particle dispersion liquid prepared in the step S2) or the step S3) into ultrapure water or an organic solvent for precipitation, repeatedly washing, centrifuging and freeze-drying to obtain the physically cross-linked or covalent cross-linked polyacid composite polymer single-chain nano particles, wherein the organic solvent is an alcohol reagent or an ether reagent, the alcohol reagent is one or more of methanol, ethanol, isopropanol, ethylene glycol and glycerin, and the ether reagent is diethyl ether and/or isopropyl ether.
  2. 2. The method for preparing single-chain nano particles of polyacid composite polymer according to claim 1, wherein the pyridine polymer is one or more of a homopolymer, a random copolymer and a block copolymer, and the homopolymer, the random copolymer and the block copolymer each contain 4-vinyl pyridine monomer or 2-vinyl pyridine monomer.
  3. 3. The method for preparing single-chain nano particles of polyacid composite polymer according to claim 1, wherein the pyridine polymer topology structure is one or more of linear, star-shaped, brush-shaped, ring-shaped and branched.
  4. 4. The method for preparing polyacid composite polymer single-chain nano-particles according to claim 1, wherein the molecular weight of the polymer is 1-1000 kda, preferably 20-400 kda.
  5. 5. The method for preparing single-chain nano particles of polyacid composite polymer according to claim 1, wherein the polyacid is one or more of Keggin type polyacid, dawson type polyacid, anderson type polyacid, waugh type polyacid, silverton type polyacid, LINDQVIST type polyacid and Weakly type polyacid.
  6. 6. The method for preparing the polyacid composite polymer single-chain nano-particles according to claim 1, wherein the concentration of the pyridine polymer solution is 0.1-5000 mg/mL, preferably 50-1000 mg/mL, and the concentration of the polyacid solution is 0.1-5000 mg/mL, preferably 20-2000 mg/mL.
  7. 7. The method for preparing the polyacid composite polymer single-chain nano-particles according to claim 1, wherein the addition amount of the polyacid is 5% -10% of the mole number of pyridine units.
  8. 8. The method for preparing the polyacid composite polymer single-chain nanoparticle according to claim 1, wherein the covalent cross-linking agent is one or more of a polyfunctional haloalkane cross-linking agent, a polyfunctional sulfonate cross-linking agent, a polyfunctional epoxy cross-linking agent, a polyfunctional acyl chloride or anhydride cross-linking agent, a polyfunctional isocyanate cross-linking agent, a polyhalotriazine cross-linking agent and a polyhalosilane or siloxane cross-linking agent, and the addition amount of the covalent cross-linking agent is 0.05% -10% of the mole number of pyridine units, preferably 0.1% -5%.
  9. 9. The method for preparing the polyacid composite polymer single-chain nano particles according to claim 1, wherein the stirring speed is 200-2000 r/min, preferably 600-1000 r/min, the stirring time is 4-72 h, preferably 12-36 h, the covalent crosslinking temperature is 50-120 ℃, preferably 60-80 ℃, and the centrifugation rate is 5000-12000 r/min, preferably 7500-10000 r/min.
  10. 10. A single-chain nanoparticle of a polyacid composite polymer, characterized in that the single-chain nanoparticle of a polyacid composite polymer is a nanoparticle produced by the method for producing a single-chain nanoparticle of a polyacid composite polymer according to claim 1.

Description

Polyacid composite polymer single-chain nano particle and preparation method thereof Technical Field The invention belongs to the field of polymer single-chain nano particles and preparation thereof, and relates to a method for preparing polyacid composite polymer single-chain nano particles in a large scale. Background The polymer single-chain nano-particles are novel nano-materials with specific size and structure, which are formed by crosslinking the polymer single chains in molecules by a physical or chemical method. The nano-size and specific surface area of the nano-material are adjustable, and the nano-material has unique physical and chemical properties and the like, so that the nano-material has wide application prospects in the fields of biological medicine, material science, nanotechnology and the like. However, the intramolecular crosslinking of polymers is usually carried out in extremely dilute solutions, intermolecular crosslinking is easy to occur at high concentrations and the system is gelled, which limits the large-scale preparation and application of single-chain nanoparticles of polymers. Recently, researchers have proposed that intramolecular cross-linking based on electrostatic regulation can be achieved in concentrated solutions for the preparation of single-stranded nanoparticles of polymers (CCS chem.2019,1, 407-430). However, the method requires electrostatic modification of the molecular chain, which increases the complexity of the preparation process. In addition, in order to realize the functionalized application of the polymer single-chain nano-particles, the single-chain nano-particles are required to be taken as a micro-reactor to further compound organic or inorganic materials, so that the preparation efficiency is low and the cost is high. The polyoxometallate is also called polyacid (polyoxometalates, POMs) and is a nano-scale molecular cluster formed by connecting pre-transition metal ions through oxygen, has the characteristics of rich chemical composition, multiple structures, high proton conductivity, good electrochemical stability and the like, and is widely applied to the fields of photoelectric materials, medicines, catalysis and the like. The polyacid is loaded on the polymer single-chain nano particles, so that the nano particles are expected to be endowed with wider functionality, and meanwhile, the compatibility of the polyacid and organic matters is enhanced, and therefore, the method for preparing the polyacid composite polymer single-chain nano particles in a large scale at low cost is developed, and the method has wide application prospect. Disclosure of Invention Therefore, the technical problem to be solved by the invention is to provide a method for preparing polyacid composite polymer single-chain nano particles in a large scale at low cost. The method directly takes polyacid as a physical crosslinking agent, utilizes the electrostatic/hydrogen bond interaction between pyridine polymer and polyacid to carry out intramolecular crosslinking on the polymer, and prepares the polyacid composite polymer single-chain nano particles by a one-step method; the electrostatic repulsion is introduced in the internal crosslinking process of the polyacid, so that the intramolecular crosslinking concentration can be effectively improved, the intramolecular crosslinking can be realized under the condition that the molar ratio of pyridine units to the polyacid is regulated and controlled to be far higher than the polymer overlapping concentration, the covalent crosslinking agent can be further introduced to carry out covalent crosslinking on the basis of physical crosslinking, and the polyacid composite polymer single-chain nano particles are taken as microreactors, so that the nano particles with different types/functions can be further prepared. In order to solve the technical problems, the invention provides the following technical scheme: a preparation method of polyacid composite polymer single-chain nano particles comprises the following steps: s1) fully dissolving pyridine polymers in a polar organic solvent to prepare a polymer solution, and fully dissolving polyacids in the polar organic solvent to prepare a polyacid solution, wherein the polar organic solvent comprises but is not limited to N, N-dimethylformamide, N-dimethylacetamide, dimethyl sulfoxide, tetrahydrofuran, acetone, acetonitrile and the like; s2) adding the polyacid solution into the pyridine polymer solution according to a certain proportion and fully stirring, and carrying out intramolecular crosslinking by utilizing electrostatic/hydrogen bond interaction between the pyridine polymer and the polyacid to obtain physically crosslinked polyacid composite polymer single-chain nanoparticle dispersion; S3) adding a covalent cross-linking agent into the polyacid composite polymer single-chain nanoparticle dispersion liquid prepared in the step S2) according to a certain proportion to carry out intramo