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CN-119661872-B - Supermolecular deep eutectic conductive gel with microphase separation structure, and preparation method and application thereof

CN119661872BCN 119661872 BCN119661872 BCN 119661872BCN-119661872-B

Abstract

The invention discloses a supermolecule deep eutectic conductive gel with a microphase separation structure, and a preparation method and application thereof. The method comprises the steps of dissolving N- (2-hydroxyethyl) acrylamide monomer and poly (3- (methacrylamido) propyl) dimethyl (3-thiopropyl) ammonium hydroxide serving as a poly (amphoteric) monomer in a deep eutectic solvent composed of choline chloride and ethylene glycol, performing photocrosslinking, and forming soft and hard two phases enriched and absent in the deep eutectic solvent by utilizing the difference of the adsorption capacity of the poly (amphoteric) monomer to the deep eutectic solvent to prepare the supermolecule deep eutectic conductive gel. The conductive gel has excellent comprehensive mechanical properties and self-restorability, has the characteristics of good conductivity, environmental stability, biocompatibility and environmental protection, can normally work under extreme environment and larger strain and stress conditions, and has wide application prospect in the field of flexible electronics.

Inventors

  • CONG ZHENHUA
  • ZHAO ZHI
  • FANG JIAQUAN
  • SHEN ZEHAO
  • CUI ZEYU

Assignees

  • 南京理工大学

Dates

Publication Date
20260512
Application Date
20230919

Claims (11)

  1. 1. The preparation method of the supermolecular deep eutectic conductive gel with the microphase separation structure is characterized by comprising the following specific steps: (1) Dissolving choline chloride in ethylene glycol according to the mol ratio of choline chloride to ethylene glycol of 1:2, heating and stirring until the mixture is clear and transparent, and taking the mixture as a deep eutectic solvent; (2) Adding an N- (2-hydroxyethyl) acrylamide monomer and a [3- (methacrylamido) propyl ] dimethyl (3-thiopropyl) ammonium hydroxide amphoteric monomer into a deep eutectic solvent, and uniformly stirring until the mixture is transparent and clear to be used as a precursor solution; (3) Adding a photoinitiator into the precursor solution, stirring uniformly until the solution is transparent and clear, injecting the solution into a mold, and carrying out polymerization reaction under the irradiation of ultraviolet light to form the supermolecule deep eutectic conductive gel.
  2. 2. The method according to claim 1, wherein in the step (1), the heating temperature is 90 to 100 ℃ and the stirring speed is 800 to 1000 rpm.
  3. 3. The method according to claim 1, wherein in the step (2), the molar ratio of N- (2-hydroxyethyl) acrylamide to [3- (methacrylamido) propyl ] dimethyl (3-thiopropyl) ammonium hydroxide is 8:1 to 10:1, and the ratio of the total molar amount of choline chloride and ethylene glycol to the molar amount of [3- (methacrylamido) propyl ] dimethyl (3-thiopropyl) ammonium hydroxide is 5:1 to 8:1.
  4. 4. The process according to claim 3, wherein the molar ratio of N- (2-hydroxyethyl) acrylamide to [3- (methacrylamido) propyl ] dimethyl (3-thiopropyl) ammonium hydroxide is 9:1, and the ratio of the total molar amount of choline chloride and ethylene glycol to the molar amount of [3- (methacrylamido) propyl ] dimethyl (3-thiopropyl) ammonium hydroxide is 6:1.
  5. 5. The preparation method of claim 1, wherein the photoinitiator is 2-hydroxy-4 '- (2-hydroxyethoxy) -2-methylbenzophenone, and the mass of the 2-hydroxy-4' - (2-hydroxyethoxy) -2-methylbenzophenone is 0.1% -0.2% of the mass of the precursor solution.
  6. 6. The method according to claim 1, wherein in the step (2) or (3), the stirring speed is 800 to 1000 rpm, in the step (3), the material of the mold is glass, the interval of the mold is 900 to 1100 μm, the wavelength of ultraviolet light is 254 nm, the irradiation intensity of ultraviolet light is 800. Mu.J/cm 2 , and the polymerization time is 30 minutes.
  7. 7. The supermolecular deep eutectic conductive gel prepared by the preparation method according to any one of claims 1 to 6.
  8. 8. Use of the supermolecular deep eutectic conductive gel of claim 7 in the preparation of flexible electronic devices.
  9. 9. The use of claim 8, wherein the flexible electronic device is a flexible sensor or a flexible wearable sensor.
  10. 10. The use according to claim 9, wherein the flexible sensor or the flexible wearable sensor is composed of supermolecule deep eutectic conductive gel and copper sheet electrodes and adhesive tapes attached to both sides of the electrolyte.
  11. 11. The use of claim 10, wherein the tape is VHB tape.

Description

Supermolecular deep eutectic conductive gel with microphase separation structure, and preparation method and application thereof Technical Field The invention belongs to the technical field of conductive gel, and relates to supermolecule deep eutectic conductive gel with a microphase separation structure, and a preparation method and application thereof. Background With the rapid development of network communication and intelligent terminals, the technology of artificial intelligence and virtual reality is updated and iterated, and the demands of people for flexible electronic products with intelligence, portability and individuation are increasing, so that the flexible electronic field shows wide application prospect. Compared with the traditional electronic technology, the flexible electronic device has excellent stretchable and bendable characteristics, overcomes the basic defect of a hard device, and is widely applied to the aspects of wearable electronics, medical health, man-machine interaction and the like. Conductive gels are widely used in flexible electronic devices due to their flexibility and conductivity. The hydrogel contains 70% -80% of water, so that the hydrogel has excellent flexibility, but the water is not stable and is easy to evaporate or crystallize, so that the hydrogel taking water as a dispersion solvent loses flexibility and fails, and the application space of the hydrogel is greatly limited. In order to solve the problems, ionic liquid conductive gel is introduced, and chemically stable and non-volatile ionic liquid is used as a dispersion solvent, so that the risk of failure of similar hydrogels is avoided because the interior of the ionic liquid conductive gel is free of water, the environmental stability of the flexible electronic device is improved, but the ionic liquid is toxic, easy to cause environmental pollution, and the preparation process is complex and high in price, so that the market popularization and the application of biocompatibility of the ionic liquid conductive gel are limited. In contrast, the deep eutectic solvent is used as an emerging green solvent, has physical properties similar to those of ionic liquids, such as low melting point, low vapor pressure, high conductivity and the like, and the raw materials are green and nontoxic, and have a low price of (Hansen BB,Spittle S,Chen B,et al.Deep Eutectic Solvents:A Review of Fundamentals and Applications.Chem Rev.2021;121(3):1232-1285.)., however, the conductive gel prepared based on the deep eutectic solvent still cannot meet the requirements of the flexible electronic field at the present stage. For example, shu Hong et al polymerized acrylamide in a deep eutectic solvent composed of choline chloride-urea-glycerol and improved the mechanical properties of the gel by adding cellulose pulp to the dispersion, however, even if a double network structure composed of polyacrylamide and cellulose is constructed, the mechanical properties thereof are not significantly improved (fracture strain of only 250% -450% and tensile strength of 10kPa～60kPa)(S.Hong,Y.Yuan,C.Liu,et al.,A stretchable and compressible ion gel based on a deep eutectic solvent applied as a strain sensor and electrolyte for supercapacitors.J.Mater.Chem.C,8(2020),pp.550-560).Ren'ai Li) due to the lack of covalent/noncovalent interactions in the internal network, and the like, a deep eutectic gel is produced by copolymerizing a hard segment (poly (acrylamide/choline chloride)) and a soft segment (poly (acrylic acid/choline chloride)) due to unstable liquid system, irregular phase separation is caused by the increase of soft segment, soft domain is trapped in the hard segment, and soft domain shrinkage is caused by the increase of hard segment, and even if attempts are made to regulate the proportion of soft and hard segments, the gel as a whole exhibits hardness, The tensile strength is high (65.74-108.13 MPa), but the tensile property is only 5-10%. Meanwhile, the densely wound polymer chains limit ion migration, so that the gel has low conductivity (0.37～1.25*10-3S/m).(Ren'ai Li,Kaili Zhang,Guangxue Chen,et al.Stiff,Self-Healable,Transparent Polymers with Synergetic Hydrogen Bonding Interactions.Chem.Mater.2021,33,13,5189-5196).Ji Lan and the like, choline chloride/ethylene glycol is adopted as a deep eutectic solvent, and the double-network deep eutectic gel consisting of physical crosslinking zwitterionic poly (3-dimethyl (methacryloyloxyethyl) propane ammonium sulfonate (PDMAPS) and chemical crosslinking poly (2-hydroxyethyl methacrylate) (PHEMA) is prepared, so that the toughness (500% -1050%) of the gel is improved to a certain extent, but the internal polymer network crosslinking mode is mainly weak physical crosslinking, so that the breaking strength is lower (100kPa～210kPa)(Lan,J.,Zhou,B.,Yin,C.,Weng,L.,Ni,W.,&Shi,L.(2021).Zwitterionic dual-network strategy for highly stretchable and transparent ionic conductor.Polymer,231,124111.)