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CN-117030075-B - Multi-layer closed narrow opening conductive material and preparation method thereof

CN117030075BCN 117030075 BCN117030075 BCN 117030075BCN-117030075-B

Abstract

The invention relates to the technical field of conductive materials, in particular to a multi-layer closed narrow opening conductive material and a preparation method thereof. The method comprises the steps of forming circular through holes which are communicated with each other in a foam carrier, inserting a rectangular foam carrier into the circular through holes, forming the foam carrier with a special narrow opening structure, and loading a polydopamine coating and a polypyrrole nanofiber layer on the surface of the foam carrier through a certain process to obtain the multi-layer closed narrow opening conductive material. According to the invention, a narrow structure is designed through a bionic unique scorpion slit receptor structure, the rapid change of a conductive path under pressure is realized, polypyrrole nanofibers formed by self-polymerization are attached to a polyurethane foam skeleton through a simple coating process to form a continuous conductive network, and finally, the conductive composite foam with a multi-layer closed narrow structure is prepared, so that the piezoresistive performance response regulation and control of the high-performance conductive composite foam material are realized.

Inventors

  • MI HAOYANG
  • REN XIAOYUE
  • DONG BINBIN
  • LIU CHUNTAI

Assignees

  • 郑州大学

Dates

Publication Date
20260508
Application Date
20230808

Claims (10)

  1. 1. A multi-layer closed narrow opening conductive material is characterized by comprising a foam carrier (1), wherein circular through holes (2) are formed in the foam carrier (1), the number of the circular through holes (2) is at least two and are mutually communicated, a rectangular foam carrier (3) is inserted into the communicated circular through holes (2), a narrow opening structure (4) is formed between the communicated part of the circular through holes (2) and the rectangular foam carrier (3), and a bonding material coating (5) and a conductive layer (6) are loaded on the surface of the foam carrier (1).
  2. 2. The multi-layered closed slit conductive material of claim 1, wherein the foam carrier (1) is one or more of polyurethane foam, polyimide foam, melamine foam, polylactic acid foam, silicone rubber, thermoplastic polystyrene elastomer, thermoplastic polyolefin elastomer, thermoplastic copolyester elastomer, thermoplastic polyamide elastomer, and thermoplastic polyurethane elastomer, the bonding material coating (5) is a polydopamine coating, and the conductive layer (6) is a polypyrrole nanofiber layer.
  3. 3. A multi-level closed slit conductive material as claimed in claim 1, wherein said slit structure (4) is adapted to adjust the center-to-center distance, the number of holes, the aperture of the circular through-holes (2) and the thickness of the rectangular foam carrier (3) according to the desired sensing performance.
  4. 4. A method of preparing a multi-level closure slit conductive material as claimed in any one of claims 1 to 3, comprising the steps of: s1, preparing a foam carrier (1) with a narrow opening structure (4); S2, loading a bonding material coating (5) on the surface of the foam carrier (1) prepared in the S1 to form composite foam; And S3, attaching a conductive layer (6) on the surface of the composite foam prepared in the step S2, and thus obtaining the multi-layer closed narrow opening conductive material.
  5. 5. The method for preparing a multi-level closed slit conductive material according to claim 4, wherein in the step S1, a punching die is used for forming a round through hole (2) of the foam carrier (1), and a rectangular foam carrier (3) is inserted into the communicated round through hole (2), so that the foam carrier (1) with the slit structure (4) is obtained.
  6. 6. The method for preparing the multi-layer closed slit conductive material according to claim 5, wherein in the step S1, the obtained foam carrier (1) with the slit structure (4) is placed into absolute ethyl alcohol for ultrasonic cleaning for 10min, and then placed into an oven for drying at a drying temperature of 45 ℃ for 3h.
  7. 7. The method for preparing the multi-layer closed slit conductive material according to claim 4, wherein in the step S2, the foam carrier (1) is soaked in ethanol solution of tris (hydroxymethyl) aminomethane and dopamine hydrochloride, the pH is regulated, the mixture is stirred at room temperature, the mixture is washed with deionized water and dried at room temperature, and then the polydopamine coating is loaded on the surface of the foam carrier (1).
  8. 8. The method of claim 7, wherein in S2, V Ethanol :V Deionized water = 3:7 in ethanol solution, 0.08-0.1% of tris (hydroxymethyl) aminomethane, 0.18-0.2% of dopamine hydrochloride, pH value of 8.5, and stirring time of 12h at room temperature.
  9. 9. The method for preparing the multi-level closed slit conductive material according to claim 4, wherein in the step S3, pyrrole and methyl orange are dissolved in deionized water to obtain a first solution, ferric trichloride hexahydrate is dissolved in deionized water to obtain a second solution, the two solutions are precooled to 0-4 ℃ and mixed in an equal volume ratio, the composite foam is fully immersed in the mixed solution, polymerized at room temperature, then washed by hydrochloric acid until no colored byproducts are released, and then washed by ethanol, and dried in an oven to obtain the multi-level closed slit conductive material.
  10. 10. The method of claim 9, wherein in S3, the mass fraction of pyrrole in the first solution is 0.2-0.3%, the mass fraction of methyl orange is 0.04-0.05%, the mass fraction of ferric trichloride hexahydrate in the second solution is 2-3%, the room temperature polymerization time is 1h, the concentration of flushing hydrochloric acid is 0.1mol/L, the drying temperature is 50 ℃, and the drying time is 8h.

Description

Multi-layer closed narrow opening conductive material and preparation method thereof Technical Field The invention relates to the technical field of conductive materials, in particular to a multi-layer closed narrow opening conductive material and a preparation method thereof. Background In recent years, flexible pressure sensors have attracted extensive research attention in the fields of motion monitoring, speech recognition, robotic prostheses, intelligent robots, and the like. Piezoresistive pressure sensors have attracted considerable research interest due to their simple device assembly and excellent sensing sensitivity, as well as the ability to monitor mechanical changes by translating the mechanical load applied to a conductive material into a change in resistance signal. Commercial polyurethane foams with typical three-dimensional structures are considered to be ideal substrates for piezoresistive pressure sensors due to their low density, high porosity and good elasticity. The sensing mechanism of the piezoresistive pressure sensor based on polyurethane foam is that when the foam sensor is repeatedly pressed and restored, the conductive path is repeatedly generated and eliminated through the contact and separation of the conductive coating decorated on the foam skeleton, so that the conversion from a mechanical signal to an electrical signal is realized. Although the research of piezoresistive pressure sensors has been greatly advanced, how to prepare high-performance conductive composite foam materials through the selection of active layer materials and the design of sensing structures, realize rapid changes of conductive paths under pressure and response regulation and control on piezoresistive performance, and how to realize low-cost, high-sensitivity and large-scale preparation remain a great challenge. Disclosure of Invention The invention aims to provide a multi-layer closed narrow opening conductive material and a preparation method thereof, so as to achieve the aim of preparing a high-performance conductive composite foam material in a large scale at low cost. In order to achieve the purpose, the technical scheme is that the multi-layer closed narrow opening conductive material comprises a foam carrier, wherein round through holes are formed in the foam carrier, the number of the round through holes is at least two and are mutually communicated, a rectangular foam carrier is inserted into the communicated round through holes, a narrow opening structure is formed between the communicated part of the round through holes and the rectangular foam carrier, and a bonding material coating and a conductive layer are loaded on the surface of the foam carrier. Further, the foam carrier is one or more of polyurethane foam, polyimide foam, melamine foam, polylactic acid foam, silicon rubber, thermoplastic polystyrene elastomer, thermoplastic polyolefin elastomer, thermoplastic copolyester elastomer, thermoplastic polyamide elastomer and thermoplastic polyurethane elastomer, the bonding material coating is a polydopamine coating, and the conductive layer is a polypyrrole nanofiber layer. Further, the slit structure can adjust the center distance, the number of holes, the aperture and the thickness of the rectangular foam carrier according to the required sensing performance. The preparation method of the multi-layer closed narrow opening conductive material comprises the following steps: s1, preparing a foam carrier with a narrow opening structure; s2, loading a bonding material coating on the surface of the foam carrier prepared in the step S1 to form composite foam; And S3, attaching a conductive layer on the surface of the composite foam prepared in the step S2, so as to obtain the multi-layer closed slit conductive material. Further, in the step S1, a circular through hole of the foam carrier is formed by using a punching die, and a rectangular foam carrier is inserted into the communicated circular through hole, so that the foam carrier with a narrow structure can be obtained. Further, in the step S1, the obtained foam carrier with the narrow structure is put into absolute ethyl alcohol for ultrasonic cleaning for 10min, and then is put into an oven for drying at the temperature of 45 ℃ for 3h. Further, in the step S2, the foam carrier is soaked in ethanol solution of tris (hydroxymethyl) aminomethane and dopamine hydrochloride, the proper pH is regulated, and the mixture is stirred at room temperature, washed by deionized water and dried at room temperature, so that a polydopamine coating can be formed on the surface of the foam carrier. Further, in the step S2, V Ethanol :V Deionized water =3:7 in the ethanol solution, the mass fraction of tris (hydroxymethyl) aminomethane is 0.08-0.1%, the mass fraction of dopamine hydrochloride is 0.18-0.2%, the pH is adjusted to 8.5, and the stirring duration at room temperature is 12h. In the step S3, pyrrole and methyl orange are dissolved in deionized w