Application of hydrogel, hydrogel dressing, intelligent switch and heating lamp

Abstract

The invention provides application of hydrogel, a hydrogel dressing, an intelligent switch and a heating lamp. According to the application of the hydrogel, the hydrogel is applied to temperature detection products. According to the hydrogel disclosed by the invention, when the resistance is reduced to the minimum, the transparency is changed from transparency to opaqueness, meanwhile, the resistance change shows a special V-shaped pattern, and the hydrogel can be applied to hydrogel dressing or an intelligent switch, so that the temperature can be monitored more simply.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogel materials, and in particular to applications of hydrogels, hydrogel dressings, smart switches, and heating lamps. Background Art

[0002] With the rapid development of modern science and technology, various testing technologies play a vital role in numerous fields, including healthcare, industrial monitoring, and daily life. Accurate and efficient testing is crucial for protecting people's health, improving production efficiency, and maintaining quality of life. Among them, temperature and resistance testing, as fundamental and critical testing items, have always been the focus of scientific research and industry. Related testing technologies are constantly evolving, and new testing materials are constantly emerging.

[0003] Traditional temperature detection technologies such as thermocouples and thermistors, while meeting conventional temperature measurement needs to a certain extent, have many limitations. Thermocouples have relatively low sensitivity, making it difficult to accurately capture tiny temperature changes, and are susceptible to electromagnetic interference in complex environments, resulting in increased measurement errors. Although thermistors have high precision, their response speed is slow and they cannot meet the requirements for real-time monitoring of rapid temperature changes. In addition, these traditional temperature detection elements are often hard and have poor flexibility, making them extremely inconvenient to use in scenarios where temperature detection requires fitting to complex curved surfaces or human skin. For example, in the medical field, traditional temperature detection equipment makes it difficult to achieve comfortable and accurate measurements for long-term, continuous, and accurate monitoring of human surface temperature, which hinders early diagnosis of diseases and tracking of recovery processes.

[0004] As a new material with great potential, hydrogel has brought new opportunities for breakthroughs in temperature detection technology. The resistance of traditional conductive hydrogels generally changes with temperature, and the resistance gradually decreases as the temperature rises. Hongjie Chen et al. designed a PDRG organic hydrogel, using dimethyl sulfoxide (DMSO) / H2O binary solvent to dissolve polyvinyl alcohol (PVA) and evenly disperse GO / rGO conductive nanomaterials in the solution. It has high sensitivity (temperature coefficient of resistance TCR = 3.81% ℃ -1 However, the resistance changes with temperature in a single straight line, and macroscopically, the PDRG hydrogel remains transparent, limiting its application in various situations, such as detecting human motion and fever. Therefore, the existing technology needs further development. Summary of the Invention

[0005] In view of the various deficiencies of the existing technology and to solve the above problems, we now propose an application of hydrogel, hydrogel dressing, smart switch, and heating lamp. We also provide the following technical solutions: An application of hydrogel, applying hydrogel to temperature detection products.

[0006] Furthermore, the hydrogel is applied to a hydrogel dressing that senses temperature.

[0007] A hydrogel dressing formed using the above-mentioned hydrogel, the hydrogel dressing comprising N-isopropylacrylamide, 4-acryloylmorpholine, acrylic acid, a cross-linking agent, an initiator, magnesium chloride and deionized water, wherein the mass ratio of N-isopropylacrylamide, 4-acryloylmorpholine, acrylic acid and deionized water is (3-5): (2-4): (0.5-0.9): (9-11), and the hydrogel dressing has a minimum critical solution dissolution temperature. When the temperature is higher than the minimum critical solution dissolution temperature of the hydrogel dressing, the hydrogel dressing is opaque, and when the temperature is lower than the minimum critical solution dissolution temperature of the hydrogel dressing, the hydrogel dressing is transparent.

[0008] Furthermore, calculated by weight, the hydrogel dressing consists of 3-5 parts of N-isopropylacrylamide, 2-4 parts of 4-acryloylmorpholine, 0.5-0.9 parts of acrylic acid, 0.01-0.02 parts of a cross-linking agent, 0.02-0.03 parts of an initiator, 0.1-0.3 parts of magnesium chloride, and 9-11 parts of deionized water, and the minimum critical solution dissolution temperature is 37-38°C.

[0009] Furthermore, calculated by weight, the hydrogel dressing consists of 4 parts of N-isopropylacrylamide, 3 parts of 4-acryloylmorpholine, 0.9 parts of acrylic acid, 0.018 parts of a cross-linking agent, 0.023 parts of an initiator, 0.2 parts of magnesium chloride, and 10 parts of deionized water.

[0010] A smart switch formed from the above-mentioned hydrogel, wherein the smart switch is provided with a hydrogel, wherein the hydrogel is composed of N-isopropylacrylamide, 4-acryloylmorpholine, acrylic acid, a crosslinker, an initiator, magnesium chloride, and deionized water, wherein the mass ratio of N-isopropylacrylamide, 4-acryloylmorpholine, acrylic acid, and deionized water is (3-5):(2-4):(1.5-2.1):(9-11), the hydrogel has a minimum critical solution dissolution temperature, and the hydrogel has a minimum electrical resistance at its minimum critical solution dissolution temperature. When the temperature is between 5°C and 15°C, the smart switch is turned on, and when the temperature is not between 5°C and 15°C, the smart switch is turned off.

[0011] Furthermore, calculated by mass, the hydrogel on the smart switch consists of 4 parts of N-isopropylacrylamide, 3 parts of 4-acryloylmorpholine, 2.1 parts of acrylic acid, 0.018 parts of a cross-linking agent, 0.023 parts of an initiator, 0.2 parts of magnesium chloride, and 10 parts of deionized water.

[0012] A heating lamp has the above-mentioned intelligent switch. When the temperature is between 5-15°C, the heating lamp works; when the temperature is not between 5-15°C, the heating lamp turns off.

[0013] Beneficial effects: 1. The hydrogel dressing of the present invention utilizes the fact that the electrical resistance of the hydrogel is lowest at the lowest critical solution dissolution temperature. At the same time, the transparency of the hydrogel appearance changes accordingly. The hydrogel is applied to temperature detection products, thereby realizing macroscopic visualization of the change of resistance with temperature. When the resistance of the hydrogel drops to the lowest, the transparency changes from transparent to opaque.

[0014] 2. The present invention utilizes the resistance change of the hydrogel to present a special “√” pattern, which can be applied to hydrogel dressings or smart switches to more easily monitor temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Schematic diagram showing the change in relative resistance of the hydrogel according to Example 2 of the present invention as a function of temperature. DETAILED DESCRIPTION

[0016] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention is clearly and completely described below in conjunction with the embodiments of the present invention. Based on the embodiments in this application, other similar embodiments obtained by ordinary technicians in this field without making any creative work should fall within the scope of protection of this application.

[0017] According to an embodiment of the present invention, a hydrogel dressing is provided. The hydrogel dressing is composed of N-isopropylacrylamide, 4-acryloylmorpholine, acrylic acid, a crosslinker, an initiator, magnesium chloride, and deionized water. The mass ratio of N-isopropylacrylamide, 4-acryloylmorpholine, acrylic acid, and deionized water is (3-5): (2-4): (0.5-0.9): (9-11). When the hydrogel dressing comes into contact with the human body and the body temperature is above the minimum critical solution temperature of the hydrogel dressing, the hydrogel dressing becomes opaque. When the body temperature is below the minimum critical solution temperature of the hydrogel dressing, the hydrogel dressing becomes transparent. By adjusting the mass ratio of N-isopropylacrylamide, 4-acryloylmorpholine, acrylic acid, and deionized water, the hydrogel's electrical resistance is minimized at the minimum critical solution temperature, and the hydrogel's apparent transparency changes accordingly. If too much acrylic acid is added, it will combine with water, preventing the aforementioned phenomenon. When the mass ratio of N-isopropylacrylamide, 4-acryloylmorpholine, acrylic acid, and deionized water is (3-5): (2-4): (0.5-0.9): (9-11), the hydrogel appears transparent below the lower critical solution temperature (LCST). At this point, hydrogen bonds form between the polymer chains and water molecules. However, above the LCST, the interactions between the polymer chains and water molecules weaken, while interactions between the polymer molecules strengthen, leading to the collapse of the polymer molecules and, macroscopically, an opaque state. The corresponding resistance change is that below the LCST, like traditional hydrogels, increasing temperature accelerates ion movement and decreases resistance. Above the LCST, as temperature increases, the resistance is dominated by pore size. Higher temperature reduces the pore size within the hydrogel's cross-linked network, severely restricting ion movement and increasing resistance. Overall, this results in a "check mark" phenomenon, where resistance first decreases and then increases with increasing temperature.

[0018] Example 1 A hydrogel dressing A system of N-isopropylacrylamide (NIPAAm) + 4-acryloylmorpholine (ACMO) + acrylic acid (AAC) + polyethylene glycol diacrylate (PEGDA) + ultraviolet photoinitiator (LAP) + magnesium chloride + deionized water (H2O) is used, with a mass ratio of 4:3:0.9:0.018:0.023:0.2:10. After blending, the ingredients are thoroughly stirred to completely dissolve in deionized water. Ultrasonic treatment is then performed for 5 minutes to fully disperse the molecules, resulting in a hydrogel precursor solution that should be stored away from light. To prepare the hydrogel, a small amount of the precursor solution is directly placed on a PTFE template and cured in a light-curing chamber for 30 seconds. Under UV light, the double bonds of NIPAAm, ACMO, PEGDA, and AAc in the solution open and copolymerize to form a NAPA hydrogel, which then solidifies into a hydrogel dressing in the corresponding mold shape. Alternatively, the solution can be directly poured into the trough of a light-curing 3D printer for 3D printing into various shapes. The base layer cures for 20 seconds, the curing time for 15 seconds, and the layer height is 0.05 mm. The transparency of NAPA was tested using a UV spectrophotometer at different temperatures. The temperature was initially raised to 45°C, and the transmittance of the hydrogel was measured at wavelengths of 580-620 nm at each degree Celsius increase. The results showed that the transmittance of the NAPA hydrogel was essentially 0% at temperatures between 39 and 45°C. From a temperature range of 37 to 39°C, the transmittance gradually increased, but remained visually opaque. Subsequently, within the temperature range of 35 to 37°C, the transmittance further increased, gradually approaching 90%. Based on transparency, we demonstrated that its LCST is 37°C. Subsequent variable temperature (25-45°C) rheological testing further confirmed that its LCST is approximately 37°C. The LCST of this hydrogel dressing is 37°C. When this hydrogel dressing is in contact with the human body, it becomes opaque when the body temperature is above 37°C and transparent when the body temperature is below 37°C. 37℃ is exactly the temperature at which human body generates fever, so it can be used to judge the fever condition of human body.

[0019] Specifically, the hydrogel dressing can be attached to the back of a person's hand, and the hydrogel dressing can stretch or retract with the local movement of the hand.

[0020] The hydrogel dressing was subjected to mechanical property testing. First, tensile and cyclic tensile tests revealed that the hydrogel exhibited a breaking strength exceeding 80 kPa and an elongation at break exceeding 1300%, while also being capable of cyclic tensile testing up to a strain of 100%. Furthermore, cyclic compression tests were performed on the hydrogel dressing, revealing that even when compressed to 80%, the hydrogel maintained a strength close to 0.5 MPa. Similarly, cyclic compression up to a compressive strain of 60% was also stable, demonstrating the stability of the hydrogel dressing's mechanical properties.

[0021] Example 2 A heating lamp A system of N-isopropylacrylamide (NIPAAm) + 4-acryloylmorpholine (ACMO) + acrylic acid (AAC) + polyethylene glycol diacrylate (PEGDA) + UV photoinitiator (LAP) + magnesium chloride + deionized water (H2O) is used in a mass ratio of 4:3:2.1:0.018:0.023:0.2:10. The raw materials are blended and thoroughly stirred to completely dissolve in deionized water. Ultrasonication is then applied for 5 minutes to fully disperse the molecules, resulting in a hydrogel precursor solution that should be stored away from light. To prepare the hydrogel, a small amount of the precursor solution is placed directly onto a PTFE template and cured in a light-curing oven for 30 seconds. Under UV light, the double bonds of NIPAAm, ACMO, PEGDA, and AAc in the solution open and copolymerize to form a NAPA hydrogel, which then solidifies into the corresponding smart switch patch. Alternatively, the solution can be directly poured into the trough of a light-curing 3D printer for 3D printing into various shapes. The bottom layer solidification time is 20 seconds, the curing time is 15 seconds, and the layer height is 0.05 mm. The intelligent switch has a minimum critical solution dissolution temperature of 15°C and a minimum resistance at its minimum critical solution dissolution temperature. A heating lamp equipped with this intelligent switch operates when the temperature is between 5°C and 15°C, and turns off when the temperature is outside the range.

[0022] When testing the resistance of the smart switch, the resistance changes with temperature in a special “check sign” shape, such as Figure 1 As shown, below the LCST, NAPA hydrogels, like traditional hydrogels, experience increased ion movement and decreased resistance as temperature rises. However, above the LCST, as temperature gradually increases, resistance is dominated by pore size. As temperature rises, the pore size within the NAPA hydrogel cross-linked network decreases, severely restricting ion movement and increasing resistance. Overall, this creates a "check mark" phenomenon where resistance first decreases and then increases with temperature.

[0023] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. An application of a hydrogel, characterized in that: Apply hydrogel to temperature detection products.

2. The use of the hydrogel according to claim 1, characterized in that: The hydrogel is applied to a hydrogel dressing that senses temperature detection.

3. A hydrogel dressing formed using the hydrogel according to claim 1 or 2, characterized in that: The hydrogel dressing is composed of N-isopropylacrylamide, 4-acryloylmorpholine, acrylic acid, a cross-linking agent, an initiator, magnesium chloride and deionized water, wherein the mass ratio of N-isopropylacrylamide, 4-acryloylmorpholine, acrylic acid and deionized water is (3-5): (2-4): (0.5-0.9): (9-11). The hydrogel dressing has a minimum critical solution dissolution temperature. When the temperature is higher than the minimum critical solution dissolution temperature of the hydrogel dressing, the hydrogel dressing is opaque. When the temperature is lower than the minimum critical solution dissolution temperature of the hydrogel dressing, the hydrogel dressing is transparent.

4. The hydrogel dressing according to claim 3, characterized in that Calculated by weight, the hydrogel dressing consists of 3-5 parts of N-isopropylacrylamide, 2-4 parts of 4-acryloylmorpholine, 0.5-0.9 parts of acrylic acid, 0.01-0.02 parts of a cross-linking agent, 0.02-0.03 parts of an initiator, 0.1-0.3 parts of magnesium chloride and 9-11 parts of deionized water. The minimum critical solution dissolution temperature is 37-38°C.

5. The hydrogel dressing according to claim 4, characterized in that Calculated by weight, the hydrogel dressing consists of 4 parts of N-isopropylacrylamide, 3 parts of 4-acryloylmorpholine, 0.9 parts of acrylic acid, 0.018 parts of a cross-linking agent, 0.023 parts of an initiator, 0.2 parts of magnesium chloride, and 10 parts of deionized water.

6. A smart switch formed using the hydrogel according to claim 1, characterized in that: The smart switch is provided with a hydrogel, which is composed of N-isopropylacrylamide, 4-acryloylmorpholine, acrylic acid, a cross-linking agent, an initiator, magnesium chloride, and deionized water. The mass ratio of N-isopropylacrylamide, 4-acryloylmorpholine, acrylic acid, and deionized water is (3-5): (2-4): (1.5-2.1): (9-11). The hydrogel has a minimum critical solution dissolution temperature and a minimum electrical resistance at its minimum critical solution dissolution temperature. When the temperature is between 5°C and 15°C, the smart switch is turned on, and when the temperature is not between 5°C and 15°C, the smart switch is turned off.

7. The intelligent switch according to claim 6, characterized in that: Calculated by mass, the hydrogel on the smart switch consists of 4 parts of N-isopropylacrylamide, 3 parts of 4-acryloylmorpholine, 2.1 parts of acrylic acid, 0.018 parts of cross-linking agent, 0.023 parts of initiator, 0.2 parts of magnesium chloride and 10 parts of deionized water.

8. A heating lamp, characterized in that: The intelligent switch according to claim 6 or 7 is provided, wherein the heating lamp works when the temperature is between 5 and 15°C, and the heating lamp is turned off when the temperature is not between 5 and 15°C.

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