Polymer-polyacid-ferric chloride hydrogel as well as preparation and application thereof
By preparing polymer-polyacid-ferric chloride hydrogels, the problems of environmental adaptability and stability in taste detection and reconstruction were solved, enabling the detection of tongue movement and astringent substances, and providing health monitoring data support.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-20
- Publication Date
- 2026-03-27
AI Technical Summary
Existing technologies for taste detection and reconstruction suffer from insufficient environmental adaptability, neural compatibility, and perceptual complexity, making it difficult to simulate the chemical taste experience in real food. Furthermore, the sensors lack stability and sensitivity in humid environments.
A polymer-polyacid-ferric chloride hydrogel was prepared by using polymer as the backbone material, polyacid as the crosslinking agent, and ferric chloride as the conductive agent. The hydrogel exhibits the property of responding to tongue movement and astringent substances, and can detect the content of astringent substances in tongue movement and food.
It enables effective detection of tongue movement and astringent substances, providing data support for health monitoring and medical quality. The hydrogel components are readily available, low in cost, and simple to prepare. It can detect the concentration of polyphenols and produce color changes.
Smart Images
Figure CN121736426A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of hydrogel preparation technology, and in particular to a polymer-polyacid-ferric chloride hydrogel and its preparation and application. Background Technology
[0002] In the current field of sensory rehabilitation technology, solutions for patients with taste loss mainly focus on two directions: taste detection and taste reconstruction. However, existing taste detection-based technologies still have significant limitations in terms of environmental adaptability, neural compatibility, and perceptual complexity. For example, electro-taste measurement uses a weak current to stimulate the tongue and measure taste sensitivity; however, it can only assess basic taste thresholds and cannot simulate the complex chemical taste experience of real food. Chemical taste measurement involves having patients directly taste different concentrations of taste solutions (such as salty sodium chloride and bitter magnesium sulfate), but the testing process is complex, unsuitable for routine or bedside screening, and it is difficult to exclude the influence of the patient's subjective psychological and physiological state. Liquid-phase environmental sensing uses materials such as graphene oxide films to detect taste molecules in an aqueous environment; however, the stability and sensitivity of the devices still face challenges in simulating the real moist environment of the oral cavity.
[0003] Overall, existing technologies are making progress in helping patients with taste loss regain a complete eating experience; however, many sensors have poor sensing performance when in operation.
[0004] Therefore, it is crucial to provide a technical solution that can solve the above-mentioned technical problems. Summary of the Invention
[0005] To address the aforementioned problems, the present invention aims to provide a polymer-polyacid-ferric chloride hydrogel and its preparation and application. In the hydrogel provided by the present invention, the polymer serves as the skeletal material, the polyacid as a crosslinking agent, and ferric chloride is uniformly dispersed within the polymer. The prepared hydrogel exhibits the property of generating different resistances in response to different movements, and also possesses the property of responding to astringent substances such as polyphenols. It can detect tongue movement and the content of astringent substances in food, providing a solution for patients to address tongue movement and astringency detection. Furthermore, the data obtained from the hydrogel provided by the present invention can further support health monitoring and medical quality.
[0006] The objective of this invention can be achieved through the following technical solutions: The first objective of this invention is to provide a polymer-polyacid-ferric chloride hydrogel, which is prepared from a polymer, a polyacid, and ferric chloride; wherein the polymer serves as the skeletal material of the hydrogel, the polyacid serves as a crosslinking agent, and ferric chloride is dispersed in the polymer as a conductive agent. The mass ratio of polymer, polybasic acid, and ferric chloride is 5~15%: 1~10%: 0.5~3%.
[0007] In one embodiment of the present invention, the polymer is selected from one or two of polyacrylic acid, polyacrylamide, or polyvinyl alcohol.
[0008] In one embodiment of the present invention, the polyacid is selected from one or more of citric acid, malic acid or tartaric acid.
[0009] The second objective of this invention is to provide a method for preparing a polymer-polyacid-ferric chloride hydrogel. When the polymer is polyvinyl alcohol, the preparation method is as follows: (S1) Mix the polymer solution, polybasic acid and ferric chloride to obtain a mixed solution; (S2) The mixture is subjected to freeze-thaw cycles to obtain a polymer-polyacid-ferric chloride hydrogel; When the polymer is polyacrylic acid or polyacrylamide, the preparation method is as follows: (A1) Mix the polymer monomer solution, polybasic acid and ferric chloride to obtain a mixed solution; (A2) After mixing the mixture with potassium persulfate, thermally initiated polymerization was performed to obtain polymer-polyacid-ferric chloride hydrogel.
[0010] In one embodiment of the present invention, in step (S1), the polyvinyl alcohol is dissolved in hot water to obtain a polyvinyl alcohol solution; The polyvinyl alcohol solution was mixed with the polybasic acid and ferric chloride at room temperature.
[0011] In one embodiment of the present invention, in step (S2), during the freeze-thaw process, the sample is first frozen at -25 to -20 °C for 4 to 12 h; then thawed at 15 to 30 °C for 8 to 16 h. Repeat the freeze-thaw cycle more than 3 times.
[0012] In one embodiment of the present invention, in step (A1), the polymer monomer solution, polybasic acid and ferric chloride are mixed at room temperature.
[0013] In one embodiment of the present invention, in step (A2), the mass ratio of the mixture to potassium persulfate is 19-22:1; The temperature during the thermally initiated polymerization process is 45~55 ℃.
[0014] A third objective of this invention is to provide an application of a polymer-polyacid-ferric chloride hydrogel in the preparation of a semi-quantitative monitoring sensor for astringent substances and / or a tongue movement monitoring sensor.
[0015] The fourth objective of this invention is to provide a semi-quantitative monitoring sensor for astringent substances, which is prepared by the above-mentioned polymer-polyacid-ferric chloride hydrogel.
[0016] The fifth objective of this invention is to provide a tongue movement monitoring sensor, which is prepared by the above-mentioned polymer-polyacid-ferric chloride hydrogel.
[0017] Compared with the prior art, the present invention has the following beneficial effects: (1) In the hydrogel provided by the present invention, the polymer is used as the skeleton material of the hydrogel, the polybasic acid is used as the crosslinking agent, and the ferric chloride is uniformly dispersed in the polymer and can be used as a conductive agent; the prepared hydrogel has the property of generating different resistances for different movements, and also has the property of responding to astringent substances such as polyphenols, which can detect the movement of the tongue and the content of astringent substances in food, providing a solution for patients to solve the problem of tongue movement and astringent detection; the data obtained by the hydrogel provided by the present invention can further provide data support for health monitoring and medical quality.
[0018] (2) The hydrogel components provided by the present invention are readily available, low in cost, and simple to prepare; the ferric iron in the hydrogel can complex with polyphenols to form a colored substance, and at the same time, the concentration of polyphenols can be detected. Attached Figure Description
[0019] Figure 1 Image showing the appearance of the polymer-polyacid-ferric chloride hydrogel; Figure 2 The graph shows the relative resistance change of the polymer-polyacid-ferric chloride hydrogel when the tongue performs different movements. Figure 3 Digital photographs showing the color gradient changes after the reaction of polymer-polyacid-ferric chloride hydrogel with tannic acid solutions of different concentrations; Figure 4 The graph shows the linear relationship between the RGB values of the polymer-polyacid-ferric chloride hydrogel and the concentration of tannic acid. Detailed Implementation
[0020] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.
[0021] Unless otherwise specified, all reagents used in the following embodiments are commercially available reagents, and all detection methods and techniques used are conventional detection methods and techniques in the art.
[0022] Example 1 This embodiment provides a method for preparing a polymer-polyacid-ferric chloride hydrogel, as detailed below: (S1) Dissolve 5 grams of polyvinyl alcohol powder in 93 grams of hot water (60 °C) and mix well to obtain a homogeneous polyvinyl alcohol aqueous solution; (S2) Add 1 gram of citric acid and 1 gram of FeCl3 to the polyvinyl alcohol aqueous solution obtained in step (S1), and stir until completely dissolved to obtain a mixture; (S3) Inject (S2) into the mold and perform freeze-thaw cycle treatment (first freeze at -23 ℃ for 6 h; then thaw at 20 ℃ for 12 h) to finally form a stable three-dimensional network structure hydrogel: polymer-polyacid-ferric chloride hydrogel.
[0023] Example 2 This embodiment provides a method for preparing a polymer-polyacid-ferric chloride hydrogel, as detailed below: (S1) Dissolve 10 g of polyvinyl alcohol powder in 88 g of hot water (60 °C) and mix well to obtain a homogeneous polyvinyl alcohol aqueous solution; (S2) Add 1 gram of citric acid and 1 gram of FeCl3 to the polyvinyl alcohol aqueous solution obtained in step (S1), and stir until completely dissolved to obtain a mixture; (S3) Inject (S2) into the mold and perform freeze-thaw cycle treatment (first freeze at -23 ℃ for 6 h; then thaw at 20 ℃ for 12 h) to finally form a stable three-dimensional network structure hydrogel: polymer-polyacid-ferric chloride hydrogel.
[0024] Example 3 This embodiment provides a method for preparing a polymer-polyacid-ferric chloride hydrogel, as detailed below: (S1) Dissolve 15 g of polyvinyl alcohol powder in 83 g of hot water (60 °C) and mix well to obtain a homogeneous polyvinyl alcohol aqueous solution. (S2) Add 1 gram of citric acid and 1 gram of FeCl3 to the polyvinyl alcohol aqueous solution obtained in step (S1), and stir until completely dissolved to obtain a mixture; (S3) Inject (S2) into the mold and perform freeze-thaw cycle treatment (first freeze at -23 ℃ for 6 h; then thaw at 20 ℃ for 12 h) to finally form a stable three-dimensional network structure hydrogel: polymer-polyacid-ferric chloride hydrogel.
[0025] Example 4 This embodiment provides a method for preparing a polymer-polyacid-ferric chloride hydrogel, as detailed below: (S1) Dissolve 5 grams of polyvinyl alcohol powder in 89 grams of hot water (60 °C) and mix well to obtain a homogeneous polyvinyl alcohol aqueous solution; (S2) Add 5 g of citric acid and 1 g of FeCl3 to the polyvinyl alcohol aqueous solution obtained in step (S1), and stir until completely dissolved to obtain a mixture; (S3) Inject (S2) into the mold and perform freeze-thaw cycle treatment (first freeze at -23 ℃ for 6 h; then thaw at 20 ℃ for 12 h) to finally form a stable three-dimensional network structure hydrogel: polymer-polyacid-ferric chloride hydrogel.
[0026] Example 5 This embodiment provides a method for preparing a polymer-polyacid-ferric chloride hydrogel, as detailed below: (S1) Dissolve 10 g of polyvinyl alcohol powder in 84 g of hot water (60 °C) and mix well to obtain a homogeneous polyvinyl alcohol aqueous solution; (S2) Add 5 g of citric acid and 1 g of FeCl3 to the polyvinyl alcohol aqueous solution obtained in step (S1), and stir until completely dissolved to obtain a mixture; (S3) Inject (S2) into the mold and perform freeze-thaw cycles (first freeze at -23 ℃ for 6 h; then thaw at 20 ℃ for 12 h), ultimately forming a stable three-dimensional network structure hydrogel: polymer-polyacid-ferric chloride hydrogel (e.g. Figure 1 (As shown).
[0027] Example 6 This embodiment provides a method for preparing a polymer-polyacid-ferric chloride hydrogel, as detailed below: (S1) Dissolve 15 g of polyvinyl alcohol powder in 79 g of hot water (60 °C) and mix well to obtain a homogeneous polyvinyl alcohol aqueous solution. (S2) Add 5 g of citric acid and 1 g of FeCl3 to the polyvinyl alcohol aqueous solution obtained in step (S1), and stir until completely dissolved to obtain a mixture; (S3) Inject (S2) into the mold and perform freeze-thaw cycle treatment (first freeze at -23 ℃ for 6 h; then thaw at 20 ℃ for 12 h) to finally form a stable three-dimensional network structure hydrogel: polymer-polyacid-ferric chloride hydrogel.
[0028] Example 7 This embodiment provides a method for preparing a polymer-polyacid-ferric chloride hydrogel, as detailed below: (S1) Dissolve 5 g of polyvinyl alcohol powder in 84 g of hot water (60 °C) and mix well to obtain a homogeneous polyvinyl alcohol aqueous solution. (S2) Add 10 g of citric acid and 1 g of FeCl3 to the polyvinyl alcohol aqueous solution obtained in step (S1), and stir until completely dissolved to obtain a mixture; (S3) Inject (S2) into the mold and perform freeze-thaw cycle treatment (first freeze at -23 ℃ for 6 h; then thaw at 20 ℃ for 12 h) to finally form a stable three-dimensional network structure hydrogel: polymer-polyacid-ferric chloride hydrogel.
[0029] Example 8 This embodiment provides a method for preparing a polymer-polyacid-ferric chloride hydrogel, as detailed below: (S1) Dissolve 10 g of polyvinyl alcohol powder in 79 g of hot water (60 °C) and mix well to obtain a homogeneous polyvinyl alcohol aqueous solution. (S2) Add 10 g of citric acid and 1 g of FeCl3 to the polyvinyl alcohol aqueous solution obtained in step (S1), and stir until completely dissolved to obtain a mixture; (S3) Inject (S2) into the mold and perform freeze-thaw cycle treatment (first freeze at -23 ℃ for 6 h; then thaw at 20 ℃ for 12 h) to finally form a stable three-dimensional network structure hydrogel: polymer-polyacid-ferric chloride hydrogel.
[0030] Example 9 This embodiment provides a method for preparing a polymer-polyacid-ferric chloride hydrogel, as detailed below: (S1) Dissolve 15 g of polyvinyl alcohol powder in 84 g of hot water (60 °C) and mix well to obtain a homogeneous polyvinyl alcohol aqueous solution. (S2) Add 10 g of citric acid and 1 g of FeCl3 to the polyvinyl alcohol aqueous solution obtained in step (S1), and stir until completely dissolved to obtain a mixture; (S3) Inject (S2) into the mold and perform freeze-thaw cycle treatment (first freeze at -23 ℃ for 6 h; then thaw at 20 ℃ for 12 h) to finally form a stable three-dimensional network structure hydrogel: polymer-polyacid-ferric chloride hydrogel.
[0031] Example 10 This embodiment provides a method for preparing a polymer-polyacid-ferric chloride hydrogel, as detailed below: (S1) Dissolve 5 g of polyvinyl alcohol powder in 93.5 g of hot water (60 °C) and mix well to obtain a homogeneous polyvinyl alcohol aqueous solution; (S2) Add 1 gram of citric acid and 0.5 grams of FeCl3 to the polyvinyl alcohol aqueous solution obtained in step (S1), and stir until completely dissolved to obtain a mixture; (S3) Inject (S2) into the mold and perform freeze-thaw cycle treatment (first freeze at -23 ℃ for 6 h; then thaw at 20 ℃ for 12 h) to finally form a stable three-dimensional network structure hydrogel: polymer-polyacid-ferric chloride hydrogel.
[0032] Example 11 This embodiment provides a method for preparing a polymer-polyacid-ferric chloride hydrogel, as detailed below: (S1) Dissolve 10 g of polyvinyl alcohol powder in 83 g of hot water (60 °C) and mix well to obtain a homogeneous polyvinyl alcohol aqueous solution; (S2) Add 5 g of citric acid and 2 g of FeCl3 to the polyvinyl alcohol aqueous solution obtained in step (S1), and stir until completely dissolved to obtain a mixture; (S3) Inject (S2) into the mold and perform freeze-thaw cycle treatment (first freeze at -23 ℃ for 6 h; then thaw at 20 ℃ for 12 h) to finally form a stable three-dimensional network structure hydrogel: polymer-polyacid-ferric chloride hydrogel.
[0033] Example 12 This embodiment provides a method for preparing a polymer-polyacid-ferric chloride hydrogel, as detailed below: (S1) Dissolve 15 g of polyvinyl alcohol powder in 72 g of hot water (60 °C) and mix well to obtain a homogeneous polyvinyl alcohol aqueous solution. (S2) Add 10 g of citric acid and 3 g of FeCl3 to the polyvinyl alcohol aqueous solution obtained in step (S1), and stir until completely dissolved to obtain a mixture; (S3) Inject (S2) into the mold and perform freeze-thaw cycle treatment (first freeze at -23 ℃ for 6 h; then thaw at 20 ℃ for 12 h) to finally form a stable three-dimensional network structure hydrogel: polymer-polyacid-ferric chloride hydrogel.
[0034] Example 13 This embodiment provides a method for preparing a polymer-polyacid-ferric chloride hydrogel, as detailed below: (S1) Dissolve 5 grams of polyvinyl alcohol powder in 93 grams of hot water (60 °C) and mix well to obtain a homogeneous polyvinyl alcohol aqueous solution; (S2) Add 1 gram of tartaric acid and 1 gram of FeCl3 to the polyvinyl alcohol aqueous solution obtained in step (S1), and stir until completely dissolved to obtain a mixture; (S3) Inject (S2) into the mold and perform freeze-thaw cycle treatment (first freeze at -23 ℃ for 6 h; then thaw at 20 ℃ for 12 h) to finally form a stable three-dimensional network structure hydrogel: polymer-polyacid-ferric chloride hydrogel.
[0035] Example 14 This embodiment provides a method for preparing a polymer-polyacid-ferric chloride hydrogel, as detailed below: (S1) Dissolve 10 g of polyvinyl alcohol powder in 84 g of hot water (60 °C) and mix well to obtain a homogeneous polyvinyl alcohol aqueous solution; (S2) Add 5 g of tartaric acid and 1 g of FeCl3 to the polyvinyl alcohol aqueous solution obtained in step (S1), and stir until completely dissolved to obtain a mixture; (S3) Inject (S2) into the mold and perform freeze-thaw cycle treatment (first freeze at -23 ℃ for 6 h; then thaw at 20 ℃ for 12 h) to finally form a stable three-dimensional network structure hydrogel: polymer-polyacid-ferric chloride hydrogel.
[0036] Example 15 This embodiment provides a method for preparing a polymer-polyacid-ferric chloride hydrogel, as detailed below: (S1) Dissolve 15 g of polyvinyl alcohol powder in 72 g of hot water (60 °C) and mix well to obtain a homogeneous polyvinyl alcohol aqueous solution. (S2) Add 10 g of tartaric acid and 1 g of FeCl3 to the polyvinyl alcohol aqueous solution obtained in step (S1), and stir until completely dissolved to obtain a mixture; (S3) Inject (S2) into the mold and perform freeze-thaw cycle treatment (first freeze at -23 ℃ for 6 h; then thaw at 20 ℃ for 12 h) to finally form a stable three-dimensional network structure hydrogel: polymer-polyacid-ferric chloride hydrogel.
[0037] Example 16 This embodiment provides a method for preparing a polymer-polyacid-ferric chloride hydrogel, as detailed below: (S1) Dissolve 5 grams of polyvinyl alcohol powder in 97 grams of hot water (60 °C) and mix well to obtain a homogeneous polyvinyl alcohol aqueous solution. (S2) Add 1 gram of malic acid and 1 gram of FeCl3 to the polyvinyl alcohol aqueous solution obtained in step (S1), and stir until completely dissolved to obtain a mixture; (S3) Inject (S2) into the mold and perform freeze-thaw cycle treatment (first freeze at -23 ℃ for 6 h; then thaw at 20 ℃ for 12 h) to finally form a stable three-dimensional network structure hydrogel: polymer-polyacid-ferric chloride hydrogel.
[0038] Example 17 This embodiment provides a method for preparing a polymer-polyacid-ferric chloride hydrogel, as detailed below: (S1) Dissolve 10 g of polyvinyl alcohol powder in 84 g of hot water (60 °C) and mix well to obtain a homogeneous polyvinyl alcohol aqueous solution; (S2) Add 5 g of malic acid and 1 g of FeCl3 to the polyvinyl alcohol aqueous solution obtained in step (S1), and stir until completely dissolved to obtain a mixture; (S3) Inject (S2) into the mold and perform freeze-thaw cycle treatment (first freeze at -23 ℃ for 6 h; then thaw at 20 ℃ for 12 h) to finally form a stable three-dimensional network structure hydrogel: polymer-polyacid-ferric chloride hydrogel.
[0039] Example 18 This embodiment provides a method for preparing a polymer-polyacid-ferric chloride hydrogel, as detailed below: (S1) Dissolve 15 g of polyvinyl alcohol powder in 72 g of hot water (60 °C) and mix well to obtain a homogeneous polyvinyl alcohol aqueous solution. (S2) Add 10 g of malic acid and 1 g of FeCl3 to the polyvinyl alcohol aqueous solution obtained in step (S1), and stir until completely dissolved to obtain a mixture; (S3) Inject (S2) into the mold and perform freeze-thaw cycle treatment (first freeze at -23 ℃ for 6 h; then thaw at 20 ℃ for 12 h) to finally form a stable three-dimensional network structure hydrogel: polymer-polyacid-ferric chloride hydrogel.
[0040] Example 19 This embodiment provides a method for preparing a polymer-polyacid-ferric chloride hydrogel, as detailed below: (S1) Dissolve 5 g of acrylamide in 93 g of hot water (50 °C) and mix well to obtain a homogeneous acrylamide aqueous solution; (S2) Add 1 gram of citric acid and 0.5 grams of FeCl3 to the acrylamide aqueous solution obtained in step (S1), and stir until completely dissolved to obtain a mixture; (S3) Add 0.5 g of potassium persulfate to the mixture obtained in step (S2), stir at 50 °C for 20 minutes, pour into a mold and let stand for 6 hours to finally form a stable three-dimensional network structure hydrogel: polymer-polyacid-ferric chloride hydrogel.
[0041] Example 20 This embodiment provides a method for preparing a polymer-polyacid-ferric chloride hydrogel, as detailed below: (S1) Dissolve 10 g of acrylamide in 92.5 g of hot water (50 °C) and mix well to obtain a homogeneous aqueous solution of acrylamide; (S2) Add 5 g of citric acid and 2 g of FeCl3 to the acrylamide aqueous solution obtained in step (S1), and stir until completely dissolved to obtain a mixture; (S3) Add 0.5 g of potassium persulfate to the mixture obtained in step (S2), stir at 50 °C for 20 minutes, pour into a mold and let stand for 6 hours to finally form a stable three-dimensional network structure hydrogel: polymer-polyacid-ferric chloride hydrogel.
[0042] Example 21 This embodiment provides a method for preparing a polymer-polyacid-ferric chloride hydrogel, as detailed below: (S1) Dissolve 15 g of acrylamide in 71.5 g of hot water (50 °C) and mix well to obtain a homogeneous acrylamide aqueous solution; (S2) Add 10 g of citric acid and 3 g of FeCl3 to the acrylamide aqueous solution obtained in step (S1), and stir until completely dissolved to obtain a mixture; (S3) Add 0.5 g of potassium persulfate to the mixture obtained in step (S2), stir at 50 °C for 20 minutes, pour into a mold and let stand for 6 hours to finally form a stable three-dimensional network structure hydrogel: polymer-polyacid-ferric chloride hydrogel.
[0043] Example 22 This embodiment provides a method for preparing a polymer-polyacid-ferric chloride hydrogel, as detailed below: (S1) Dissolve 5 g of acrylamide in 93.5 g of hot water (50 °C) and mix well to obtain a homogeneous acrylamide aqueous solution; (S2) Add 1 gram of tartaric acid and 0.5 grams of FeCl3 to the acrylamide aqueous solution obtained in step (S1), and stir until completely dissolved to obtain a mixture; (S3) Add 0.5 g of potassium persulfate to the mixture obtained in step (S2), stir at 50 °C for 20 minutes, pour into a mold and let stand for 6 hours to finally form a stable three-dimensional network structure hydrogel: polymer-polyacid-ferric chloride hydrogel.
[0044] Example 23 This embodiment provides a method for preparing a polymer-polyacid-ferric chloride hydrogel, as detailed below: (S1) Dissolve 15 g of acrylamide in 71.5 g of hot water (50 °C) and mix well to obtain a homogeneous acrylamide aqueous solution; (S2) Add 10 g of tartaric acid and 3 g of FeCl3 to the acrylamide aqueous solution obtained in step (S1), and stir until completely dissolved to obtain a mixture; (S3) Add 0.5 g of potassium persulfate to the mixture obtained in step (S2), stir at 50 °C for 20 minutes, pour into a mold and let stand for 6 hours to finally form a stable three-dimensional network structure hydrogel: polymer-polyacid-ferric chloride hydrogel.
[0045] Example 24 This embodiment provides a method for preparing a polymer-polyacid-ferric chloride hydrogel, as detailed below: (S1) Dissolve 5 g of acrylamide in 93 g of hot water (50 °C) and mix well to obtain a homogeneous acrylamide aqueous solution; (S2) Add 1 gram of malic acid and 0.5 grams of FeCl3 to the acrylamide aqueous solution obtained in step (S1), and stir until completely dissolved to obtain a mixture; (S3) Add 0.5 g of potassium persulfate to the mixture obtained in step (S2), stir at 50 °C for 20 minutes, pour into a mold and let stand for 6 hours to finally form a stable three-dimensional network structure hydrogel: polymer-polyacid-ferric chloride hydrogel.
[0046] Example 25 This embodiment provides a method for preparing a polymer-polyacid-ferric chloride hydrogel, as detailed below: (S1) Dissolve 15 g of acrylamide in 71.5 g of hot water (50 °C) and mix well to obtain a homogeneous acrylamide aqueous solution; (S2) Add 10 g of malic acid and 3 g of FeCl3 to the acrylamide aqueous solution obtained in step (S1), and stir until completely dissolved to obtain a mixture; (S3) Add 0.5 g of potassium persulfate to the mixture obtained in step (S2), stir at 50 °C for 20 minutes, pour into a mold and let stand for 6 hours to finally form a stable three-dimensional network structure hydrogel: polymer-polyacid-ferric chloride hydrogel.
[0047] Example 26 This embodiment provides a method for preparing a polymer-polyacid-ferric chloride hydrogel, as detailed below: (S1) Dissolve 5 grams of acrylic acid in 93 grams of hot water (60 °C) and mix well to obtain a homogeneous aqueous solution of acrylic acid; (S2) Add 1 gram of citric acid and 0.5 grams of FeCl3 to the acrylic acid aqueous solution obtained in step (S1), and stir until completely dissolved to obtain a mixture; (S3) Add 0.5 g of potassium persulfate to the mixture obtained in step (S2), stir at 50 °C for 20 minutes, pour into a mold and let stand for 12 hours to finally form a stable three-dimensional network structure hydrogel: polymer-polyacid-ferric chloride hydrogel.
[0048] Example 27 This embodiment provides a method for preparing a polymer-polyacid-ferric chloride hydrogel, as detailed below: (S1) Dissolve 10 g of acrylic acid in 82.5 g of hot water (60 °C) and mix well to obtain a homogeneous aqueous solution of acrylic acid; (S2) Add 5 g of citric acid and 2 g of FeCl3 to the acrylic acid aqueous solution obtained in step (S1), and stir until completely dissolved to obtain a mixture; (S3) Add 0.5 g of potassium persulfate to the mixture obtained in step (S2), stir at 50 °C for 20 minutes, pour into a mold and let stand for 12 hours to finally form a stable three-dimensional network structure hydrogel: polymer-polyacid-ferric chloride hydrogel.
[0049] Example 28 This embodiment provides a method for preparing a polymer-polyacid-ferric chloride hydrogel, as detailed below: (S1) Dissolve 15 g of acrylic acid in 71.5 g of hot water (60 °C) and mix well to obtain a homogeneous aqueous solution of acrylic acid; (S2) Add 10 g of citric acid and 3 g of FeCl3 to the acrylic acid aqueous solution obtained in step (S1), and stir until completely dissolved to obtain a mixture; (S3) Add 0.5 g of potassium persulfate to the mixture obtained in step (S2), stir at 50 °C for 20 minutes, pour into a mold and let stand for 12 hours to finally form a stable three-dimensional network structure hydrogel: polymer-polyacid-ferric chloride hydrogel.
[0050] Example 29 This embodiment provides a method for preparing a polymer-polyacid-ferric chloride hydrogel, as detailed below: (S1) Dissolve 5 grams of acrylic acid in 93 grams of hot water (60 °C) and mix well to obtain a homogeneous aqueous solution of acrylic acid; (S2) Add 10 g of tartaric acid and 0.5 g of FeCl3 to the acrylic acid aqueous solution obtained in step (S1), and stir until completely dissolved to obtain a mixture; (S3) Add 0.5 g of potassium persulfate to the mixture obtained in step (S2), stir at 50 °C for 20 minutes, pour into a mold and let stand for 12 hours to finally form a stable three-dimensional network structure hydrogel: polymer-polyacid-ferric chloride hydrogel.
[0051] Example 30 This embodiment provides a method for preparing a polymer-polyacid-ferric chloride hydrogel, as detailed below: (S1) Dissolve 15 g of acrylic acid in 71.5 g of hot water (60 °C) and mix well to obtain a homogeneous aqueous solution of acrylic acid; (S2) Add 10 g of tartaric acid and 3 g of FeCl3 to the acrylic acid aqueous solution obtained in step (S1), and stir until completely dissolved to obtain a mixture; (S3) Add 0.5 g of potassium persulfate to the mixture obtained in step (S2), stir at 50 °C for 20 minutes, pour into a mold and let stand for 12 hours to finally form a stable three-dimensional network structure hydrogel: polymer-polyacid-ferric chloride hydrogel.
[0052] Example 31 This embodiment provides a method for preparing a polymer-polyacid-ferric chloride hydrogel, as detailed below: (S1) Dissolve 5 grams of acrylic acid in 93 grams of hot water (60 °C) and mix well to obtain a homogeneous aqueous solution of acrylic acid; (S2) Add 1 gram of malic acid and 0.5 grams of FeCl3 to the acrylic acid aqueous solution obtained in step (S1), and stir until completely dissolved to obtain a mixture; (S3) Add 0.5 g of potassium persulfate to the mixture obtained in step (S2), stir at 50 °C for 20 minutes, pour into a mold and let stand for 12 hours to finally form a stable three-dimensional network structure hydrogel: polymer-polyacid-ferric chloride hydrogel.
[0053] Example 32 This embodiment provides a method for preparing a polymer-polyacid-ferric chloride hydrogel, as detailed below: (S1) Dissolve 15 g of acrylic acid in 71.5 g of hot water (60 °C) and mix well to obtain a homogeneous aqueous solution of acrylic acid; (S2) Add 10 g of malic acid and 3 g of FeCl3 to the acrylic acid aqueous solution obtained in step (S1), and stir until completely dissolved to obtain a mixture; (S3) Add 0.5 g of potassium persulfate to the mixture obtained in step (S2), stir at 50 °C for 20 minutes, pour into a mold and let stand for 12 hours to finally form a stable three-dimensional network structure hydrogel: polymer-polyacid-ferric chloride hydrogel.
[0054] Example 33 This embodiment provides the application of the polymer-polyacid-ferric chloride hydrogel prepared in Example 5 in tongue movement monitoring.
[0055] The hydrogel prepared in Example 5 was cut into strips (20 mm × 5 mm × 2 mm), and conductive silver paste was used to connect the wires at both ends. The hydrogel strips were then attached laterally to the artificial tongue model, and the tongue was moved in and out, upward, left and right. The resistance changes were recorded in real time using an electrochemical workstation.
[0056] The results are as follows Figure 2 As shown, through Figure 2 It can be observed that different movements trigger characteristic resistance changes, proving that the hydrogel can effectively distinguish different tongue movement patterns.
[0057] Example 34 This embodiment provides the application of the polymer-polyacid-ferric chloride hydrogel prepared in Example 5 in the semi-quantitative detection of astringent substances.
[0058] The hydrogel prepared in Example 5 was cut into small round slices (10 mm in diameter and 2 mm in thickness). A series of tannic acid aqueous solutions (simulating astringent substances) with concentrations of 0 μmol / L, 50 μmol / L, 100 μmol / L, 150 μmol / L, 200 μmol / L, 250 μmol / L, and 300 μmol / L were prepared. The hydrogels were then placed in tannic acid aqueous solutions of different concentrations, allowed to stand for 2 minutes, and then photographed with a smartphone.
[0059] The results are as follows Figure 3 As shown, through Figure 3 It can be observed that as the concentration of tannic acid increases, the color of the hydrogel gradually changes from the initial yellowish-brown to grayish-green and then to dark blue-black. Using ImageJ software to extract the RGB values of the images, a good linear relationship was found between the RGB% values and the tannic acid concentration in the range of 0–300 μmol / L (e.g., ...). Figure 4 As shown in the figure, it can achieve semi-quantitative detection of astringency intensity.
[0060] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the interpretation of the present invention, without departing from the scope of the invention, should be within the protection scope of the present invention.
Claims
1. A polymer-polyacid-ferric chloride hydrogel, characterized in that, It is prepared from a polymer, a polybasic acid, and ferric chloride; the polymer serves as the framework material of the hydrogel, the polybasic acid serves as a crosslinking agent, and ferric chloride is dispersed in the polymer as a conductive agent. The mass ratio of polymer, polybasic acid, and ferric chloride is 5~15%: 1~10%: 0.5~3%.
2. The polymer-polyacid-ferric chloride hydrogel according to claim 1, characterized in that, The polymer is selected from one or two of polyacrylic acid, polyacrylamide, or polyvinyl alcohol.
3. The polymer-polyacid-ferric chloride hydrogel according to claim 1, characterized in that, The polyacids are selected from one or more of citric acid, malic acid, or tartaric acid.
4. A method for preparing a polymer-polyacid-ferric chloride hydrogel as described in any one of claims 1 to 3, characterized in that, When the polymer is polyvinyl alcohol, the preparation method is as follows: (S1) Mix the polymer solution, polybasic acid and ferric chloride to obtain a mixed solution; (S2) The mixture is subjected to freeze-thaw cycles to obtain a polymer-polyacid-ferric chloride hydrogel; When the polymer is polyacrylic acid or polyacrylamide, the preparation method is as follows: (A1) Mix the polymer monomer solution, polybasic acid and ferric chloride to obtain a mixed solution; (A2) After mixing the mixture with potassium persulfate, thermally initiated polymerization was performed to obtain polymer-polyacid-ferric chloride hydrogel.
5. The method for preparing a polymer-polyacid-ferric chloride hydrogel according to claim 4, characterized in that, In step (S2), during the freeze-thaw process, the sample is first frozen at -25 to -20 °C for 4 to 12 hours; then thawed at 15 to 30 °C for 8 to 16 hours. Repeat the freeze-thaw cycle more than 3 times.
6. The method for preparing a polymer-polyacid-ferric chloride hydrogel according to claim 4, characterized in that, In step (A2), the mass ratio of the mixture to potassium persulfate is 19~22:
1.
7. The method for preparing a polymer-polyacid-ferric chloride hydrogel according to claim 4, characterized in that, In step (A2), the temperature during the thermally initiated polymerization process is 45~55 ℃.
8. The application of a polymer-polyacid-ferric chloride hydrogel as described in any one of claims 1 to 3 in the preparation of a semi-quantitative monitoring sensor for astringent substances and / or a tongue movement monitoring sensor.
9. A semi-quantitative monitoring sensor for astringent substances, characterized in that, It was prepared by the polymer-polyacid-ferric chloride hydrogel according to any one of claims 1 to 3.
10. A tongue movement monitoring sensor, characterized in that, It was prepared by the polymer-polyacid-ferric chloride hydrogel according to any one of claims 1 to 3.