Preparation method of supramolecular gel electrode patch for electrocardiogram monitoring
By preparing supramolecular gel electrode patches, the problem of poor skin contact between Ag/AgCl gel electrodes and the skin during ECG monitoring was solved. Stable skin adhesion and effective collection of ECG signals were achieved during exercise. The patches have excellent conductivity and good adhesion, making them suitable for health monitoring and medical applications.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SHAANXI UNIV OF SCI & TECH
- Filing Date
- 2023-10-10
- Publication Date
- 2026-07-17
AI Technical Summary
Existing Ag/AgCl gel electrodes have problems with poor skin contact in electrocardiogram monitoring, which affects electrical performance and physiological signal acquisition, and the use of additional conductive adhesive is inconvenient.
A supramolecular gel electrode patch was prepared by cross-linking gallic acid prepolymer, gelatin solution and thioctic acid monomer to form a conductive gel electrode patch with good adhesion and self-adaptation. The method utilizes polyphenol Michael addition and non-covalent bond interaction to avoid the use of organic solvents.
It achieves stable skin adhesion during exercise, effectively collects electrocardiogram signals, has excellent conductivity and good adhesion, and is suitable for health monitoring and medical care.
Smart Images
Figure CN117562545B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of supramolecular conductive gel preparation technology, specifically relating to a method for preparing supramolecular gel electrode patches for electrocardiogram monitoring. Background Technology
[0002] Currently, clinically standard Ag / AgCl gel electrodes are widely used to record epidermal potential signals. While they meet daily testing accuracy requirements, several major issues remain in detecting electrocardiogram (ECG) signals. For example, corrosive damage to human tissue and the inconvenience of using additional conductive adhesives to reduce electrode-skin impedance limit their further development. With the continuous development of supramolecular gels, biomass gel electrode patches with good conductivity and flexible wearable technology are gradually being applied. In ECG monitoring, supramolecular gel electrode patches can convert the ionic potential generated by chemical activities within the body into external electrical signals to measure and acquire physiological signal data. However, their contact with the skin presents problems; for example, a large gap can affect electrical performance and the acquisition of physiological signals. Therefore, developing a highly adhesive and easily peelable supramolecular gel electrode patch is of great significance for flexible electronic wearables, health monitoring, and medical applications. Summary of the Invention
[0003] The purpose of this invention is to provide a method for preparing a supramolecular gel electrode patch for electrocardiogram monitoring. This supramolecular gel electrode patch has excellent conductivity and good adhesion and self-adaptability to the skin.
[0004] The technical solution adopted in this invention is a method for preparing supramolecular gel electrode patches for electrocardiogram monitoring, which is implemented according to the following steps: Step 1: Prepare gallic acid prepolymer solution; Step 2, prepare the gelatin solution; Step 3: Dissolve thioctic acid monomer in gelatin solution, heat to cause ring-opening polymerization, and obtain yellow transparent liquid. Then add crosslinking agent polyethylene glycol diacrylate to carry out crosslinking reaction. After that, add crosslinking agent lithium bis(trifluoromethanesulfonylimide) to form a second crosslinking network until it is completely dissolved to obtain transparent liquid. Step 4: Add gallic acid prepolymer solution to the transparent liquid, mix well to obtain a transparent solution, pour the transparent solution into a mold, and cool to room temperature to obtain a supramolecular gel electrode patch for electrocardiogram monitoring.
[0005] The invention is further characterized in that, Step 1 specifically involves: Gallic acid was dissolved in water and heated until completely dissolved. The pH of the solution was adjusted to 8-9 with Tris base and then exposed to air for oxidative polymerization to obtain a gallic acid prepolymer solution.
[0006] The heating temperature is 30-45 ℃, the oxidation polymerization time is 5 min-24 h, and the oxidation polymerization temperature is 30-45 ℃; the mass ratio of gallic acid to water is 1-4:20-50.
[0007] Step 2 specifically involves: Gelatin was dissolved in water and heated until completely dissolved. The pH of the solution was adjusted to 8-10 with Tris base to obtain a gelatin solution. The mass fraction of gelatin in the gelatin solution was 15-25 wt%.
[0008] In step 3, the heating temperature is 70-110 ℃ and the heating time is 5-30 min; the cross-linking reaction temperature is 70-110 ℃ and the cross-linking reaction time is 0.5-4 h.
[0009] In step 3, the mass ratio of thioctic acid monomer to gelatin solution is 1-6:10-24; the amount of polyethylene glycol diacrylate added is 10-40 wt% of the mass of thioctic acid monomer; and the amount of lithium bis(trifluoromethanesulfonyl)imide added is 5-15 wt% of the mass of thioctic acid monomer.
[0010] In step 4, the volume ratio of the transparent liquid to the gallic acid prepolymer solution is 15-40:1-5.
[0011] The beneficial effects of this invention are: (1) In the preparation method of the present invention, free radicals are generated by thermal initiation, and then controlled preparation is achieved by ring-opening polymerization-polyphenol Michael addition and the non-covalent bond in the thioctic acid polymer and gelatin polymer network. This process does not require organic solvents for multi-step synthesis, is simple to operate, has high safety, and the main materials such as thioctic acid and gelatin are inexpensive and readily available. (2) The supramolecular gel electrode patch of the present invention has excellent conductivity and good adhesion and self-adaptability to the skin. It can effectively adhere to the skin even in motion and can effectively collect electrocardiogram signals. It has good application prospects in health monitoring, medical care and other fields. Attached Figure Description
[0012] Figure 1 The polymerization reaction equation for thioctic acid of the present invention is as follows; Figure 2 This is a photograph of the supramolecular gel electrode patch of the present invention adhering to the skin. Figure 3 This is a transparency diagram of the supramolecular gel electrode patch of the present invention; Figure 4 This is a diagram showing the shear strength of the supramolecular gel electrode patch of the present invention against different substrates; Figure 5This is a diagram showing the continuous peel strength of the supramolecular gel electrode patch of the present invention on pigskin. Figure 6 This is a diagram illustrating the self-healing properties of the supramolecular gel electrode patch of the present invention. Figure 7 A local electrocardiogram collected using the supramolecular gel electrode patch of the present invention. Detailed Implementation
[0013] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.
[0014] The present invention discloses a method for preparing a supramolecular gel electrode patch for electrocardiogram monitoring, which is implemented according to the following steps: Step 1: Prepare gallic acid prepolymer solution; Gallic acid is dissolved in water and heated until it is completely dissolved at a temperature of 30-45 °C. The pH of the solution is adjusted to 8-9 with Tris base and then exposed to air for oxidative polymerization to obtain a gallic acid prepolymer solution. The oxidative polymerization time is 5 min-24 h, and the oxidative polymerization temperature is 30-45 ℃; The mass ratio of gallic acid to water is 1-4:20-50; Step 2: Prepare a gelatin aqueous solution; Dissolve gelatin in water, heat until completely dissolved, and adjust the pH of the solution to 8-10 with Tris base to obtain a gelatin solution; The gelatin has a freezing power of 180-250 bloom; the mass fraction of gelatin in the gelatin solution is 15-25 wt%. Step 3: Dissolve the thioctic acid monomer in the gelatin solution from Step 2, heat it to cause ring-opening polymerization, and then add the crosslinking agent polyethylene glycol diacrylate to carry out the crosslinking reaction. After that, add the crosslinking agent lithium bis(trifluoromethanesulfonyl)imide to form a second crosslinking network until it is completely dissolved to obtain a transparent liquid. The mass ratio of thioctic acid monomer to gelatin solution is 1-6:10-24; The heating temperature is 70-110 ℃, and the heating time is 5 min-30 min; The amount of polyethylene glycol diacrylate added is 10-40 wt% of the mass of thioctic acid monomer; The amount of lithium bis(trifluoromethanesulfonyl)imide added is 5-15 wt% of the mass of the lipoic acid monomer; The cross-linking reaction temperature is 70-110 ℃, and the cross-linking reaction time is 0.5-4 h; Step 4: Add gallic acid prepolymer solution to the transparent liquid obtained in step 3, mix well to obtain a transparent solution, pour the transparent solution into a mold, and cool to room temperature to obtain a supramolecular gel electrode patch for electrocardiogram monitoring. The volume ratio of the transparent liquid to the gallic acid prepolymer solution is 15-40:1-5; The supramolecular gel electrode patch obtained by the method of this invention is transparent yellow and has stable mechanical properties, conductivity, antibacterial properties, ultraviolet shielding properties, adhesion, and easy complete peeling.
[0015] The formation mechanism of the supramolecular gel electrode patch for electrocardiogram monitoring of the present invention is as follows: Under heating conditions, thioctic acid monomer is added to an alkaline gelatin solution. The thioctic acid monomer dissolves and undergoes ring-opening polymerization and reacts with a crosslinking agent. Furthermore, inspired by the free radical scavenging phenomenon of polyphenols, a gallic acid prepolymer solution is added to further bind with the thiol free radicals in thioctic acid, thereby improving the adhesion of the supramolecular gel. Finally, the resulting transparent solution is poured into a mold and cooled to room temperature. During the cooling process, utilizing the cooling gel properties of gelatin (formation of a triple helix), the carboxyl groups on the side chains of the thioctic acid polymer synergistically form a multifunctional supramolecular gel electrode patch through hydrogen bonds and non-covalent interactions between gelatin and the thioctic acid polymer.
[0016] Example 1 The present invention discloses a method for preparing a supramolecular gel electrode patch for electrocardiogram monitoring, which is implemented according to the following steps: Step 1, Preparation of gallic acid prepolymer solution: Add 0.1 g gallic acid to 10 g water, heat to 35°C and stir until the gallic acid is completely dissolved; then adjust the pH of the solution to 8, expose it to air for oxidative polymerization for 20 min to obtain gallic acid prepolymer solution; Step 2, prepare gelatin aqueous solution: Dissolve 2 g of gelatin in 8 g of water, heat to 60 ℃ and stir until the gelatin is completely dissolved; then adjust the pH of the solution to 9 and set aside.
[0017] Step 3: Dissolve 4 g of thioctic acid monomer in gelatin solution and heat to 90 °C to obtain a yellow transparent liquid. Then add 1.5 g of polyethylene glycol diacrylate and react for 2 h. Next, add 0.4 g of lithium bis(trifluoromethanesulfonyl)imide and stir until completely dissolved. As a hydrogen bond donor, it can form hydrogen bond crosslinks with gelatin and thioctic acid polymers to obtain a yellow transparent liquid.
[0018] Step 4: Add 1 mL of gallic acid prepolymer solution to the transparent liquid, mix well to obtain a transparent solution, pour the transparent solution into a mold, and cool to room temperature to obtain a conductive gel electrode patch that can be used for electrocardiogram monitoring.
[0019] The chemical reaction equation in Example 1 is as follows: Figure 1 As shown, the reaction involves the polymerization of thioctic acid monomers, free radical polymerization, and Michael addition reaction between thiol-polyphenols.
[0020] The supramolecular gel electrode patch obtained in Example 1 for electrocardiogram monitoring was tested as follows: (1) Adhesion test of supramolecular gel electrode patch The adhesion properties of the supramolecular gel electrode patch prepared in Example 1 were characterized. Figure 2 The image shows the actual photos of the supramolecular gel electrode patch prepared in Example 1 adhering to the skin. It can be seen that it adheres firmly to the human skin and will not detach with movement. In addition, after it is peeled off from the skin, there is no residue on the skin and no allergic reaction occurs. Figure 3 The transparency of the supramolecular gel electrode patch prepared in Example 1 is such that text and patterns can be clearly seen through the patch; Figure 4 The supramolecular gel electrode patch prepared in Example 1 exhibits excellent substrate universality in terms of shear strength against different substrates, with an adhesion strength of up to 48 kPa to pigskin. Figure 5 The continuous peel strength of the supramolecular gel electrode patch prepared in Example 1 against pigskin shows that the peel strength remains stable after 15 repetitions, which proves the durability of the supramolecular gel electrode patch. (2) Self-healing performance test of supramolecular gel electrode patch The self-healing properties of the supramolecular gel electrode patch prepared in Example 1 were tested. Figure 6 To demonstrate the self-healing properties of the supramolecular gel electrode patch prepared in Example 1, the patch can achieve a healing effect simply by cutting it open and then re-contacting it.
[0021] (3) Supramolecular gel electrode patches for electrocardiogram monitoring The supramolecular gel electrode patch prepared in Example 1 was used for electrocardiogram monitoring. Figure 7 The image shows a partial electrocardiogram (ECG) collected from the supramolecular gel electrode patch prepared in Example 1. As can be seen from the waveform, the supramolecular gel electrode patch can be used for human ECG monitoring.
[0022] Example 2 The present invention discloses a method for preparing a supramolecular gel electrode patch for electrocardiogram monitoring, which is implemented according to the following steps: Step 1, preparation of gallic acid prepolymer solution: Add 0.1 g gallic acid to 10 g water, heat to 35°C and stir until the gallic acid is completely dissolved; then adjust the pH of the solution to 8, expose it to air for oxidative polymerization for 1 h to obtain gallic acid prepolymer solution; Step 2, prepare gelatin aqueous solution: Dissolve 1.5g of gelatin in 8g of water, heat to 60℃ and stir until the gelatin is completely dissolved; then adjust the pH of the solution to 9 and set aside.
[0023] Step 3: Dissolve 4 g of thioctic acid monomer in the gelatin solution from Step 2, heat to 90°C to obtain a yellow transparent liquid, then add 1.2 g of polyethylene glycol diacrylate and react for 3 h; then add 0.5 g of lithium bis(trifluoromethanesulfonyl)imide and stir until completely dissolved. As a hydrogen bond donor, it can form hydrogen bond crosslinks with gelatin and thioctic acid polymers to obtain a yellow transparent liquid.
[0024] Step 4: Add 1.5 mL of gallic acid prepolymer solution to the transparent liquid, mix well to obtain a transparent solution, pour the transparent solution into a mold, and cool to room temperature to obtain a conductive gel electrode patch that can be used for electrocardiogram monitoring.
[0025] Example 3 The present invention discloses a method for preparing a supramolecular gel electrode patch for electrocardiogram monitoring, which is implemented according to the following steps: Step 1, preparation of gallic acid prepolymer solution: 0.1 g gallic acid was added to 10 g water, heated to 35°C and stirred until the gallic acid was completely dissolved; then the pH of the solution was adjusted to 8, and the solution was exposed to air for oxidative polymerization for 12 h to obtain gallic acid prepolymer solution; Step 2, prepare gelatin aqueous solution: Dissolve 2.5g of gelatin in 8g of water, heat to 60℃ and stir until the gelatin is completely dissolved; then adjust the pH of the solution to 10 and set aside.
[0026] Step 3: Dissolve 4g of thioctic acid monomer in the gelatin solution from Step 2, heat to 110°C to obtain a yellow transparent liquid, then add 1g of polyethylene glycol diacrylate and react for 5h; then add 0.4g of lithium bis(trifluoromethanesulfonyl)imide and stir until completely dissolved. As a hydrogen bond donor, it can form hydrogen bond crosslinks with gelatin and thioctic acid polymers to obtain a yellow transparent liquid.
[0027] Step 4: Add 1 mL of gallic acid prepolymer solution to the transparent liquid, mix well to obtain a transparent solution, pour the transparent solution into a mold, and cool to room temperature to obtain a conductive gel electrode patch that can be used for electrocardiogram monitoring.
[0028] Example 4 The present invention discloses a method for preparing a supramolecular gel electrode patch for electrocardiogram monitoring, which is implemented according to the following steps: Step 1, preparation of gallic acid prepolymer solution: 0.1 g gallic acid was added to 10 g water, heated to 35°C and stirred until the gallic acid was completely dissolved; then the pH of the solution was adjusted to 8, and the solution was exposed to air for oxidative polymerization for 24 h to obtain gallic acid prepolymer solution; Step 2, prepare gelatin aqueous solution: dissolve 1.5g of gelatin in 8g of water, heat to 60℃ and stir until the gelatin is completely dissolved; then adjust the pH of the solution to 8 and set aside.
[0029] Step 3: Dissolve 4 g of thioctic acid monomer in the gelatin solution from Step 2, heat to 110°C to obtain a yellow transparent liquid, then add 1.1 g of polyethylene glycol diacrylate and react for 3 h; then add 0.6 g of lithium bis(trifluoromethanesulfonyl)imide and stir until completely dissolved. As a hydrogen bond donor, it can form hydrogen bond crosslinks with gelatin and thioctic acid polymers to obtain a yellow transparent liquid.
[0030] Step 4: Add 1.2 mL of gallic acid prepolymer solution to the transparent liquid obtained in step 3, mix well to obtain a transparent solution, pour the transparent solution into a mold, and cool to room temperature to obtain a conductive gel electrode patch that can be used for electrocardiogram monitoring.
Claims
1. A method for preparing supramolecular gel electrode patches for electrocardiogram monitoring, characterized in that, The specific steps are as follows: Step 1: Prepare gallic acid prepolymer solution; Step 2, prepare the gelatin solution; Step 3: Dissolve thioctic acid monomer in gelatin solution, heat to cause ring-opening polymerization, and obtain yellow transparent liquid. Then add crosslinking agent polyethylene glycol diacrylate to carry out crosslinking reaction. After that, add crosslinking agent lithium bis(trifluoromethanesulfonylimide) to form a second crosslinking network until it is completely dissolved to obtain transparent liquid. Step 4: Add gallic acid prepolymer solution to the transparent liquid, mix well to obtain a transparent solution, pour the transparent solution into a mold, and cool to room temperature to obtain a supramolecular gel electrode patch for electrocardiogram monitoring.
2. The method for preparing the supramolecular gel electrode patch for electrocardiogram monitoring according to claim 1, characterized in that, In step 1, specifically: Gallic acid was dissolved in water and heated until completely dissolved. The pH of the solution was adjusted to 8-9 with Tris base and then exposed to air for oxidative polymerization to obtain a gallic acid prepolymer solution.
3. The method for preparing the supramolecular gel electrode patch for electrocardiogram monitoring according to claim 2, characterized in that, In step 1, the heating temperature is 30-45 ℃, the oxidation polymerization time is 5 min-24 h, and the oxidation polymerization temperature is 30-45 ℃; the mass ratio of gallic acid to water is 1-4:20-50.
4. The method for preparing the supramolecular gel electrode patch for electrocardiogram monitoring according to claim 1, characterized in that, Step 2 specifically involves: Gelatin was dissolved in water and heated until completely dissolved. The pH of the solution was adjusted to 8-10 with Tris base to obtain a gelatin solution. The mass fraction of gelatin in the gelatin solution was 15-25 wt%.
5. The method for preparing the supramolecular gel electrode patch for electrocardiogram monitoring according to claim 1, characterized in that, In step 3, the heating temperature is 70-110 ℃ and the heating time is 5-30 min; the cross-linking reaction temperature is 70-110 ℃ and the cross-linking reaction time is 0.5-4 h.
6. The method for preparing the supramolecular gel electrode patch for electrocardiogram monitoring according to claim 1, characterized in that, In step 3, the mass ratio of thioctic acid monomer to gelatin solution is 1-6:10-24; the amount of polyethylene glycol diacrylate added is 10-40 wt% of the mass of thioctic acid monomer; and the amount of lithium bis(trifluoromethanesulfonyl)imide added is 5-15 wt% of the mass of thioctic acid monomer.
7. The method for preparing the supramolecular gel electrode patch for electrocardiogram monitoring according to claim 1, characterized in that, In step 4, the volume ratio of the transparent liquid to the gallic acid prepolymer solution is 15-40:1-5.