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CN-121971609-A - Composite electret flexible biological electrostatic electret patch and preparation method thereof

CN121971609ACN 121971609 ACN121971609 ACN 121971609ACN-121971609-A

Abstract

The invention relates to the technical field of medical biological materials, and particularly discloses a composite electret flexible biological electrostatic electret patch and a preparation method thereof. The functional layer of the invention adopts at least one of polylactic acid, polyvinylidene fluoride and polylactic acid-glycolic acid copolymer as a polymer matrix, is compounded with graphene, adopts a specific process of combining ultrasonic dispersion and high-precision 3D printing, introduces a deep level charge trap, solves the difficult problems of aggregation of high conductive filler and surface charge leakage, ensures that the surface potential retention rate of the material after 900 days can reach more than 60 percent, ensures that the charge loss rate is not more than 20 percent after 8 hours of air exposure, and realizes the high-efficiency physical static electret auxiliary sleep treatment under the conditions of no medicament and no transdermal.

Inventors

  • WANG XIANGYAN

Assignees

  • 云南巨研医用生物科技股份有限公司

Dates

Publication Date
20260505
Application Date
20260409

Claims (10)

  1. 1. The composite electret flexible biological electrostatic electret patch is characterized by comprising a backing layer, a medical pressure-sensitive adhesive layer and a functional layer which are sequentially arranged from outside to inside; The functional layer is a composite electret film prepared by performing ultrasonic dispersion on a polymer matrix and graphene, and then performing 3D printing forming and corona charging; The polymer matrix is at least one of polylactic acid, polyvinylidene fluoride and polylactic acid-glycolic acid copolymer.
  2. 2. The composite electret flexible bio-electrostatic electret patch of claim 1, wherein the graphene is aryl functionalized graphene, and the amount of the aryl functionalized graphene is 1-6% of the mass of the polymer matrix.
  3. 3. The composite electret flexible bio-electrostatic electret patch of claim 2, wherein the aryl functionalized graphene is made by the following method: (1) Adding graphene into an organic solvent, and uniformly dispersing the graphene by ultrasonic waves to obtain graphene dispersion liquid with the mass concentration of 3-8%; (2) Under the protection of inert gas, adding a functional monomer into the graphene dispersion liquid, stirring and heating to 60-70 ℃, dropwise adding isoamyl nitrite into the system at the temperature of between 60 and 70 ℃, controlling the dropwise adding time to be 30 minutes, continuously stirring and reacting for 8-12 hours after the dropwise adding is finished, and naturally cooling to room temperature after the reaction is finished to obtain a reaction liquid; (3) And pouring the reaction solution into absolute ethyl alcohol for sedimentation, centrifugally separating and collecting the sediment, washing and drying in vacuum to obtain the aryl functionalized graphene.
  4. 4. The composite electret flexible biological electrostatic electret patch of claim 3, wherein the addition amount of the functional monomer in the step (2) is 25-35% of the mass of graphene, and the addition amount of isoamyl nitrite is 45-60% of the mass of graphene.
  5. 5. The composite electret flexible bio-electrostatic electret patch of claim 3, wherein the functional monomer in (2) is aniline and/or 4-trifluoromethyl aniline.
  6. 6. The composite electret flexible bio-electrostatic electret patch of claim 1, wherein the functional layer further comprises a functional additive 1-3% by mass of the polymer matrix, the functional additive being a charge trapping agent and/or a piezoelectric agent.
  7. 7. The composite electret flexible bio-electrostatic electret patch of claim 6, wherein the mass ratio of the charge-trapping agent to the piezoelectric agent is 1:1-3.
  8. 8. The composite electret flexible bio-electrostatic electret patch of claim 6, wherein the charge-trapping agent is nano-titania or nano-silica and the piezoelectric agent is lead zirconate titanate.
  9. 9. A method of making a composite electret flexible bio-electrostatic electret patch as defined in any one of claims 1-8, comprising the steps of: S1, adding a polymer matrix and graphene into a solvent together, and uniformly dispersing by ultrasonic to obtain composite slurry; s2, rotary evaporating the composite sizing agent to recover the solvent to obtain printing materials, adding the printing materials into a single screw extruder, and stretching and shaping after melt extrusion to prepare printing wires with the diameter of 1.2-1.5 mm; S3, carrying out polarization charging on the film material by adopting a corona charging method to obtain a composite electret film with an electrostatic field on the surface, namely a functional layer; s4, compounding the functional layer with the medical pressure-sensitive adhesive layer and the backing layer to prepare the electrostatic electret patch.
  10. 10. The method for preparing the composite electret flexible biological electrostatic electret patch according to claim 9, wherein the charging voltage of corona charging in the step S3 is 12-18kV, the distance between the electrostatic rod and the film material is 3-5cm, and the charging time is 3-8min.

Description

Composite electret flexible biological electrostatic electret patch and preparation method thereof Technical Field The invention relates to the technical field of medical biological materials, in particular to a composite electret flexible biological electrostatic electret patch and a preparation method thereof. Background An electret is a dielectric material that is capable of storing space charge for a long period of time and generating a stable electrostatic field in the surrounding space. In the biomedical field, the electrostatic field generated by the electret can generate continuous physical stimulation to specific parts (such as acupoints) of a human body, and regulate local bioelectric activity, thereby playing a role in physical auxiliary treatment. Existing medical electret patches typically employ a single polymeric material such as polypropylene (PP). However, the molecular chain polarity of the PP material is weak, the depth of the formed charge trap is shallow, when the skin of a human body is contacted or exposed to an air environment, the charge is easy to carry out trap removal migration due to the thermal excitation effect and the neutralization effect of environmental ions, so that the charge half-life period is short, and the duration of the effective physical effect is limited. In order to improve the electret performance, the prior art attempts to introduce conductive fillers such as graphene into a polymer matrix to build interface traps. However, when the traditional melt blending process is adopted, because of the high specific surface area and van der Waals force of the graphene sheet, uncontrollable agglomeration is very easy to generate in a polymer matrix, which not only causes structural defects such as stress concentration points and the like in the composite material, but also is easy to form a continuous conductive path when the filler content exceeds a seepage threshold value, and instead, bulk leakage and surface migration of charges are accelerated. In addition, the traditional melt extrusion or compression molding process is difficult to precisely control the microstructure of the patch, the mechanical compliance of the obtained film is poor, the dynamic fit degree with the skin is poor in actual use, and the interface micro stripping or edge warping is easy to occur due to physical activity, so that the effective transmission of an electrostatic field to a target skin area is influenced. Based on the above statement, the invention provides a composite electret flexible biological electrostatic electret patch and a preparation method thereof. Disclosure of Invention The invention provides a composite electret flexible biological electrostatic electret patch and a preparation method thereof, and aims to solve the technical problems that in the prior art, single polymer electret is poor in charge storage stability, high-conductivity filler is easy to cause charge loss, and the traditional forming process cannot give consideration to microstructure and skin fit degree. According to the invention, through adopting aryl functionalized modified graphene, a pi-pi conjugated structure and a strong electron withdrawing group are introduced, a multistage deep level trap is constructed at the interface of the graphene and a polar polymer matrix, the interface compatibility is improved, a synergistic auxiliary agent system formed by a charge trapping agent and a piezoelectric agent is introduced, static trapping and dynamic compensation of charges are realized, and a specific preparation process combining ultrasonic dispersion, fused deposition 3D printing and corona charging is adopted, so that nano-scale dispersion and ordered orientation of a filler are ensured, and a microstructure favorable for stable charge storage is constructed. In a first aspect, the invention provides a composite electret flexible biological electrostatic electret patch, which adopts the following technical scheme: a composite electret flexible biological electrostatic electret patch comprises a backing layer, a medical pressure-sensitive adhesive layer and a functional layer which are sequentially arranged from outside to inside; The functional layer is a composite electret film prepared by performing ultrasonic dispersion on a polymer matrix and graphene, and then performing 3D printing forming and corona charging; the polymer matrix is at least one of polylactic acid (PLA), polyvinylidene fluoride (PVDF) and polylactic acid-glycolic acid copolymer (PLGA). Preferably, the graphene is aryl functionalized graphene, and the dosage of the aryl functionalized graphene accounts for 1-6% of the mass of the polymer matrix. Preferably, the aryl functionalized graphene is prepared by the following method: (1) Adding graphene into an organic solvent, and uniformly dispersing the graphene by ultrasonic waves to obtain graphene dispersion liquid with the mass concentration of 3-8%; (2) Under the protection of inert