Graphene fever cooling patch and preparation method thereof

Abstract

The invention belongs to the technical field of medical instruments, and particularly relates to a graphene fever cooling patch and a preparation method thereof. The graphene fever cooling patch comprises hydrogel and graphene foam which is distributed in the hydrogel and is of a three-dimensional structure. According to the present invention, the heat can be rapidly transferred, the heat transfer efficiency is improved, the cooling effect is significant, the preparation method is simple, and the prepared product has the better antipyretic effect compared with the existing similar products.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical devices, and in particular relates to a graphene cooling patch and a preparation method thereof. Background Art

[0002] Fever is one of the common symptoms. Traditional methods of reducing fever include drug cooling and physical cooling.

[0003] Physical cooling requires strict application conditions and is not suitable for mobile or long-term use, such as wiping the patient's back, face, abdomen, and armpits with alcohol or warm water. Cooling patches are widely used as a convenient and effective method because they can overcome these difficulties. However, the thermal conductivity of hydrogels currently available on the market is low, only around 0.5W / (mK), resulting in the need to improve the heat dissipation and heat transfer efficiency of existing cooling patches. Summary of the Invention

[0004] In view of the above-mentioned shortcomings of the prior art, the present invention provides a graphene cooling patch and a preparation method thereof, which can effectively solve the above-mentioned problems of the prior art.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0006] A graphene cooling patch comprises a hydrogel and graphene foam with a three-dimensional structure distributed in the hydrogel.

[0007] The mass proportion of graphene foam in graphene cooling patches is 0.3-10%.

[0008] The mass proportion of graphene foam in graphene cooling patches is 1-5%.

[0009] The thickness of the graphene foam in the graphene cooling patch is 2-15mm.

[0010] The hydrogel comprises water, glycerol, EDTA-2Na, edible gelatin, sodium polyacrylate, menthol, aluminum glycolate and tartaric acid.

[0011] The weight percentages of the components in the hydrogel are:

[0012] 500-700 parts water

[0013] 200-350 parts of glycerin

[0014] 30-80 parts EDTA-2Na

[0015] 1-50 servings of edible gelatin

[0016] 10-100 parts of sodium polyacrylate

[0017] 1-10 parts menthol

[0018] 1-5 parts of aluminum glycolate

[0019] 2-6 parts of tartaric acid.

[0020] A method for preparing a graphene cooling patch, wherein the method for preparing the three-dimensional graphene foam comprises the following steps:

[0021] S1: mixing graphene oxide aqueous solution and ammonia water;

[0022] S2: freeze drying;

[0023] S3: high temperature carbonization to obtain graphene foam;

[0024] Wherein, the content of graphene oxide in the graphene oxide aqueous solution is 1-10wt%;

[0025] The relative addition amount of ammonia water is 0.05 to 1% wt.

[0026] In step S2, the freezing temperature is -40°C to -70°C, and the freezing time is 24-72 hours;

[0027] In step S3, the carbonization method is (900-1200)°C / (1-3)h+(1500-2600)°C(1-4)h.

[0028] The hydrogel is further poured into the graphene foam, the gel is formed, and after cooling, a graphene cooling patch is obtained.

[0029] The gel forming temperature is 20-120° C.; the perfusion method is vacuum-assisted perfusion or high-pressure-assisted perfusion.

[0030] Beneficial effects

[0031] Compared with the known public technologies, the technical solution provided by the present invention has the following beneficial effects:

[0032] 1. Good heat dissipation effect: Utilizing the high thermal conductivity of graphene and the design of the three-dimensional network structure, heat is transferred quickly, thereby improving heat transfer efficiency.

[0033] 2. Fast heat transfer efficiency: three-dimensional structural design increases the water evaporation area and achieves effective cooling.

[0034] 3. Good biocompatibility: The materials used in the present invention are safe, suitable for human skin and non-irritating.

[0035] The three-dimensional network structure forms a long-range heat conduction path (like a "welding" effect) through covalent bonds or physical interlocking between graphene sheets, significantly reducing phonon scattering and interfacial thermal resistance. However, in an average dispersion structure, graphene sheets lack good mutual contact, resulting in high phonon heat dissipation and large interfacial thermal resistance, resulting in poor heat dissipation performance of the overall material.

[0036] Compared with the average dispersed structure, the three-dimensional interconnected graphene structure has significant advantages in thermal conductive materials, mainly reflected in the following two points:

[0037] Form a continuous heat conduction path to improve heat conduction efficiency

[0038] The three-dimensional network structure interconnects the graphene sheets, forming a continuous heat transfer path and reducing phonon scattering. In contrast, the fillers in the average dispersion structure are isolated from each other, and heat must be transferred through the matrix (high interfacial thermal resistance), which is less efficient.

[0039] Reduce interfacial thermal resistance and optimize phonon transmission

[0040] The three-dimensional network reduces the contact thermal resistance between graphene sheets through covalent bonds or tight connections, and shortens the heat flow path through geometric design (such as honeycomb and vertical orientation structures), further reducing the overall interface thermal resistance.

[0041] Core principle: The three-dimensional continuous network significantly reduces the loss of heat energy during transmission by enhancing the connectivity and directionality of phonon transmission channels, thereby achieving high thermal conductivity at low filler content. DETAILED DESCRIPTION

[0042] The present invention mainly uses animal experiments to take 9 rabbits with qualified body temperature and randomly divide them into three groups, with 3 rabbits in each group. Bacterial endotoxin is injected into the ear vein to cause the rabbits to become infected and feverish, 60EU / ml

[0043] The first group of rabbits had the fever-reducing patch prepared in Example 1 applied to their backs;

[0044] The second group of rabbits had the fever-reducing patch prepared in Example 2 applied to their backs;

[0045] The third group of rabbits had the fever-reducing patch made in comparison applied to their backs.

[0046] The size of the cooling patch is 9cm*4cm.

[0047] The rabbit's body temperature and the temperature of the patch at five different locations (four corners and the center) were recorded every 30 minutes. The thermal conductivity of the hydrogel was tested using ASTM D5470. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 This is a morphology picture of the graphene cooling patch prepared by the preparation method described in Example 1.

[0049] As can be seen from the figure, the three-dimensional network reduces the contact thermal resistance between graphene sheets through covalent bonds or tight connections, and at the same time shortens the heat flow path through geometric design (such as honeycomb and vertical orientation structures), further reducing the overall interface thermal resistance.

[0050] Example 1

[0051] A graphene cooling patch comprises graphene foam and hydrogel distributed in the graphene foam.

[0052] Furthermore, the thickness of the graphene foam is 4 mm, and the hydrogel includes, by mass, 600 parts of water, 250 parts of glycerol, 50 parts of EDTA-2Na, 30 parts of edible gelatin, 40 parts of sodium polyacrylate, 5 parts of menthol, 3 parts of aluminum glycolate, and 4 parts of tartaric acid.

[0053] A method for preparing the above-mentioned cooling patch comprises the following steps:

[0054] S1: preparing a graphene oxide aqueous solution: mixing graphene oxide, pure water and ammonia water, wherein the graphene oxide content in the graphene oxide aqueous solution is 3 wt % and the ammonia water content is 0.25 wt %;

[0055] S2: Freeze drying: The graphene oxide aqueous solution obtained in step S1 is coated on a substrate and freeze dried at -50°C for 48 hours to obtain a three-dimensional graphene oxide foam;

[0056] S3: High-temperature carbonization: The graphene oxide foam obtained in step S2 is carbonized and graphitized to obtain graphene foam; the carbonization and graphitization method is 900°C / 2h+2000°C / 1h+2600°C / 1h.

[0057] S4: Auxiliary perfusion: The hydrogel composite liquid is perfused into the graphene foam, and the hydrogel composite liquid is gel-formed at 60° C. After cooling, the graphene cooling patch is obtained.

[0058] The perfusion method is vacuum-assisted perfusion.

[0059] The thermal conductivity of the obtained cooling patch was 1.5 W / (m·K).

[0060] The antipyretic patch had a significant antipyretic effect on endotoxin-induced fever in rabbits. The antipyretic effect was more pronounced 3 hours after use, and the rabbits' body temperatures returned to normal after 6 hours. The temperature difference at the five points of the antipyretic patch was 0.5 degrees. The five-point temperature refers to the temperature at five different parts of the patch (the four corners and the center).

[0061] Example 2

[0062] The method of Example 1 was followed, except that the hydrogel comprised 650 parts of water, 300 parts of glycerol, 60 parts of EDTA-2Na, 40 parts of edible gelatin, 50 parts of sodium polyacrylate, 8 parts of menthol, 4 parts of aluminum glycolate, and 5 parts of tartaric acid;

[0063] In step S1, the content of graphene oxide in the graphene oxide aqueous solution is 5 wt %, and the content of ammonia water is 0.4 wt %;

[0064] In step S2, the freezing temperature is -60°C and the freezing time is 72 hours;

[0065] In step S4, the gel forming temperature is 70° C., and the perfusion method is high-pressure assisted perfusion.

[0066] The thermal conductivity of the obtained cooling patch was 1.7 W / (m·K).

[0067] The antipyretic patch had an antipyretic effect on endotoxin-induced fever in rabbits. The antipyretic effect was more pronounced 2.5 hours after application, and the rabbits' body temperatures essentially returned to normal after 5 hours. The temperature difference at the five points of the antipyretic patch was 0.4 degrees Celsius.

[0068] Comparative Example 1

[0069] Graphene powder sold by Suzhou Tanfeng Technology Co., Ltd. was added to a hydrogel composite solution at a concentration of 2.1 wt%. This powder, with a carbon content similar to that of the graphene oxide in Example 1 (the oxygen content in graphene oxide is approximately 70 wt%), was stirred in a blender for 30 minutes. The hydrogel composite solution was then gelled at 60°C and cooled to produce a graphene cooling patch.

[0070] The thermal conductivity of the obtained cooling patch was 0.8 W / (m·K).

[0071] The antipyretic patch had a moderate antipyretic effect on endotoxin-induced fever in rabbits. The initial antipyretic effect was evident 5 hours after application, but the rabbits' body temperatures had not returned to normal after 6 hours. The temperature difference at the five points of the patch was 1.5 degrees Celsius.

[0072] Comparative Example 2

[0073] Graphene powder sold by Suzhou Tanfeng Technology Co., Ltd. was added to a hydrogel composite solution at a concentration of 3.5 wt%. The carbon content of the graphene oxide was similar to that of the graphene oxide in Example 2 (the oxygen content in graphene oxide was approximately 70 wt%). The mixture was stirred in a blender for 30 minutes. The hydrogel composite solution was then gelled at 60°C and cooled to produce a graphene cooling patch.

[0074] The thermal conductivity of the obtained cooling patch was 1.1 W / (m·K).

[0075] The patch had a moderate antipyretic effect on endotoxin-induced fever in rabbits. The initial antipyretic effect was evident 4.5 hours after application, but the rabbits' temperatures had not returned to normal after 6 hours. The temperature difference at the five points of the patch was 1.2 degrees Celsius.

[0076] Comparative Example 3

[0077] Without adding graphene, a common cooling patch without graphene was prepared according to the proportion and process of Example 1.

[0078] The thermal conductivity of the obtained cooling patch was 0.4 W / (m·K).

[0079] The antipyretic patch had a moderate antipyretic effect on endotoxin-induced fever in rabbits. The initial antipyretic effect was evident 5.5 hours after application, but the rabbits' temperatures had not returned to normal after 6 hours. The temperature difference at the five points of the patch was 2 degrees Celsius.

[0080] The relevant density and thermal conductivity are shown in Table 1:

[0081]

[0082] Table 1

Claims

1. A graphene cooling patch, characterized in that: The graphene cooling patch comprises a hydrogel and a three-dimensional graphene foam distributed in the hydrogel.

2. The graphene cooling patch according to claim 1, characterized in that: The hydrogel and the three-dimensional graphene foam distributed in the hydrogel have the morphology shown in FIG1 .

3. The graphene cooling patch according to claim 1, characterized in that: The mass proportion of graphene foam in graphene cooling patches is 0.3-10%.

4. The graphene cooling patch according to claim 1, characterized in that: The mass proportion of graphene foam in graphene cooling patches is 1-5%.

5. The graphene cooling patch according to claim 1, characterized in that: The thickness of the graphene foam in the graphene cooling patch is 2-15mm.

6. The graphene cooling patch according to claim 1, characterized in that: The hydrogel comprises water, glycerol, EDTA-2Na, edible gelatin, sodium polyacrylate, menthol, aluminum glycolate and tartaric acid.

7. The graphene cooling patch according to any one of claims 1 to 6, characterized in that: The weight percentages of the components in the hydrogel are: 500-700 parts water 200-350 parts of glycerin 30-80 parts EDTA-2Na 1-50 servings of edible gelatin 10-100 parts of sodium polyacrylate 1-10 parts menthol 1-5 parts of aluminum glycolate 2-6 parts of tartaric acid.

8. A method for preparing a graphene cooling patch, characterized in that: The preparation method of the three-dimensional graphene foam comprises the following steps: S1: mixing graphene oxide aqueous solution and ammonia water; S2: freeze drying; S3: high temperature carbonization to obtain graphene foam; Wherein, the content of graphene oxide in the graphene oxide aqueous solution is 1-10wt%; The relative addition amount of ammonia water is 0.05 to 1% wt.

9. The method for preparing the graphene cooling patch according to claim 8, wherein: In step S2, the freezing temperature is -40°C to -70°C, and the freezing time is 24-72 hours; In step S3, the carbonization method is (900-1200)°C / (1-3)h+(1500-2600)°C(1-4)h.

10. The method for preparing the graphene cooling patch according to claim 8 or 9, characterized in that: The hydrogel is further poured into the graphene foam to form the gel, and the graphene cooling patch is obtained after cooling; the temperature of the gel forming is 20-120° C.; the pouring method is vacuum-assisted pouring or high-pressure-assisted pouring.

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