A preparation method of flexible polymer material for monitoring sensing and corresponding materials and applications

Abstract

The present invention relates to the technical field of flexible polymer material preparation, and specifically to a method for preparing a flexible polymer material for monitoring and sensing, as well as corresponding materials and applications. The material is prepared by the following method: (1) Delignification: Take wood and soak it in an acidic solution for delignification, soak the delignified material in an alkaline solution, and wash to obtain delignified wood A; the wood is natural balsa wood; (2) Filling wood: Soak the delignified wood A in a sodium alginate solution to obtain heavy-filled wood B; (3) Cross-linking and curing: Soak the heavy-filled wood B in a zinc salt solution and cure to obtain a flexible polymer material for monitoring and sensing. The material has the advantages of extremely high mechanical strength, low temperature resistance, easy degradation, high material durability, good biocompatibility, etc., and can be used to prepare wearable sensors.

Description

Technical Field

[0001] The present invention relates to the technical field of flexible polymer material preparation, and in particular to a method for preparing a flexible polymer material for monitoring and sensing, and corresponding materials and applications. Background Art

[0002] In people's daily life, physical labor and daily exercise always inevitably cause joint injuries, including but not limited to common elbow, knee and finger joint activities. Therefore, how to monitor joint movement and accurately judge the movement state and joint mobility during injury recovery has become one of the current research hotspots. At present, flexible wearable monitoring sensor devices show great development prospects in solving such problems. The most widely used is flexible polymer materials, which have extremely high bending resistance, high sensitivity and strong flexibility.

[0003] Patent application CN116904038A discloses a flexible wearable sensor material for motion monitoring, its preparation method and its application in the preparation of wearable sensors. Specifically, it includes mixing epoxy soybean oil and 3-(4-carboxyphenyl) propionic acid, stirring at 130-150°C for 30-60 minutes to obtain mixture A; mixing borax and glycerol to obtain mixture B; adding mixture B to mixture A, stirring at 130-150°C for 40-80 minutes to obtain mixture C; cooling mixture C to 40-60°C, adding solvent to dissolve, and then pouring into a mold, and curing to obtain a flexible polymer material for monitoring sensing, that is, the flexible wearable sensor material for monitoring sensing. However, this patent does not use natural materials and is not strong enough.

[0004] At present, although great progress has been made in the development of such flexible polymer materials, their application in flexible wearable monitoring sensor devices is still hindered by problems such as insufficient tensile strength (less than 5mPa) and the high toxicity of some synthetic polymer materials that pollute the environment. Summary of the invention

[0005] In order to overcome at least one of the technical problems existing in the prior art, the present invention first provides a method for preparing a flexible polymer material for monitoring sensing, and a corresponding natural polymer material and application thereof.

[0006] The technical solution of the present invention is as follows:

[0007] The present invention first provides a method for preparing a flexible polymer material for monitoring sensing, which is prepared by the following method steps:

[0008] (1) Delignification: taking wood and soaking it in an acidic solution to delignify it, soaking the delignified material in an alkaline solution, and washing it to obtain delignified wood A; the wood is natural balsa wood;

[0009] (2) Filling wood: The delignified wood A is immersed in a sodium alginate solution to obtain heavy filling wood B;

[0010] (3) Cross-linking and curing: The heavily filled wood B is immersed in a zinc salt solution and cured to obtain a flexible polymer material for monitoring and sensing.

[0011] Specifically:

[0012] (1) Delignification: Take the wood and immerse it in NaClO2 / acetate buffer, soak it in sodium hydroxide solution, and wash it with ethanol to obtain delignified wood A; the acidic solution is NaClO2 / acetate buffer, the alkaline solution is sodium hydroxide solution, and the pH of the acidic solution is 4.2~4.9; the delignification treatment time in the acidic solution is 1~5h;

[0013] (2) Filling wood: Sodium alginate is dissolved in water and delignified wood A is immersed in the water to obtain heavy filling wood B;

[0014] (3) Cross-linking and curing: The heavily filled wood B was immersed in a zinc salt solution for 12 h and cured to obtain a flexible polymer material for monitoring and sensing.

[0015] In step (1), the natural wood is first immersed in NaClO2 / acetate buffer solution, and then sodium hydroxide solution is added. The pH of the solution for delignification treatment of the natural wood is 4.2-4.9; preferably, the pH of the solution for delignification treatment of the natural wood is 4.6.

[0016] In step (1), the duration of delignification treatment of the natural wood is 1 to 5 hours; most preferably, the duration of delignification treatment of the natural wood is 3 hours.

[0017] In step (1), the immersion time in the alkaline solution is 1 to 4 hours, that is, the delignified wood is immersed in sodium hydroxide for 1 to 4 hours, then rinsed with ethanol and freeze-dried; most preferably, the duration of the natron treatment of the natural wood is 1.5 hours.

[0018] In step (2), the obtained wood is immersed in a 1-5 wt % sodium alginate solution to obtain a heavily filled wood B. Preferably, the optimal concentration of the sodium alginate solution for immersing the wood B is 2 wt %.

[0019] In step (3), the wood B is immersed in a 0.1-0.5 mol / L zinc salt solution to solidify the flexible polymer material for monitoring and sensing. Most preferably, the optimal concentration of the zinc salt solution for immersing the wood B is 0.2 mol / L.

[0020] The zinc salt is preferably ZnCl2.

[0021] The present invention also provides a prepared flexible polymer material and its application in preparing flexible wearable monitoring sensors.

[0022] The preparation method of the wearable monitoring sensor device is as follows: the flexible polymer material for monitoring sensing is made into a long strip, and then a nickel foam current collector is connected to both sides of the strip, and conductive activated carbon is coated on the nickel foam, and the monitoring sensor device is assembled with a wire. The monitoring can be motion monitoring sensing.

[0023] Beneficial effects of the present invention:

[0024] (1) The material used to prepare the monitoring sensor device of the present invention is a natural polymer material, which has extremely high bending resistance, good biocompatibility, and can be easily recycled and reused, meeting the requirements of green, environmental protection and sustainability.

[0025] (2) The wearable monitoring sensor device prepared using the natural polymer material prepared by the present invention has good electrochemical stability and signal response performance. It has different and obvious signal response capabilities at different bending angles. It has broad application prospects and can be further used in the fields of electronic skin, signal collection fabrics, etc.

[0026] (3) In addition, the tensile strength of the natural polymer material prepared by the present invention is unprecedentedly improved, reaching more than ten times that of the same type of cellulose-based materials (about 10 mPa), and can perfectly fit into wearable monitoring sensor devices, with significant advantages in strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0028] Figure 1 Schematic diagram of the material preparation process and wearable monitoring sensor device of the present invention.

[0029] Figure 2 The signal changes of the wearable monitoring sensor device at different joint bending angles.

[0030] Figure 3 This is the SEM image of natural balsa wood in Example 1.

[0031] Figure 4 This is the SEM image of the wood after delignification in Example 1.

[0032] Figure 5 This is the SEM image of the wood after cross-linking and curing in Example 1. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] Example 1: Preparation of flexible polymer materials for monitoring and sensing

[0035] 1. Take natural balsa wood slices and immerse them in NaClO2 / acetate buffer with pH = 4.6, boil them at 120℃ for 3h, then soak the wood in 20wt% sodium hydroxide for 1.5h, and wash them with ethanol to obtain delignified wood A;

[0036] 2. Take 2g of sodium alginate and dissolve it in 100g of water, stir it at room temperature for 20 minutes, and immerse wood A in it. Treat it under vacuum at 200Pa for 1h to obtain heavy-filled wood B.

[0037] 3. Then, wood B is cured in a 0.2 mol / l zinc salt solution to obtain a flexible polymer material for monitoring and sensing.

[0038] Example 2: Preparation of flexible polymer materials for monitoring and sensing

[0039] 1. Take natural balsa wood slices and immerse them in NaClO2 / acetate buffer with pH = 4.6, boil them at 120℃ for 1h, then soak the wood in 20wt% sodium hydroxide for 1.5h, and wash them with ethanol to obtain delignified wood A;

[0040] 2. Take 2g of sodium alginate and dissolve it in 100g of water, stir it at room temperature for 20 minutes, and immerse wood A in it. Treat it under vacuum at 200Pa for 1h to obtain heavy-filled wood B.

[0041] 3. Then, wood B is cured in a 0.2 mol / l zinc salt solution to obtain a flexible polymer material for monitoring and sensing.

[0042] Example 3: Preparation of flexible polymer materials for monitoring and sensing

[0043] 1. Take natural balsa wood slices and immerse them in NaClO2 / acetate buffer with pH = 4.6, boil them at 120℃ for 2h, then soak the wood in 20wt% sodium hydroxide for 1.5h, and wash them with ethanol to obtain delignified wood A;

[0044] 2. Take 2g of sodium alginate and dissolve it in 100g of water, stir it at room temperature for 20 minutes, and immerse wood A in it. Treat it under vacuum at 200Pa for 1h to obtain heavy-filled wood B.

[0045] 3. Then, wood B is cured in a 0.2 mol / l zinc salt solution to obtain a flexible polymer material for monitoring and sensing.

[0046] Example 4: Preparation of flexible polymer materials for monitoring and sensing

[0047] 1. Take natural balsa wood slices and immerse them in NaClO2 / acetate buffer with pH = 4.6, boil them at 120℃ for 4h, then soak the wood in 20wt% sodium hydroxide for 1.5h, and wash them with ethanol to obtain delignified wood A;

[0048] 2. Take 2g of sodium alginate and dissolve it in 100g of water, stir it at room temperature for 20 minutes, and immerse wood A in it. Treat it under vacuum at 200Pa for 1h to obtain heavy-filled wood B.

[0049] 3. Then, wood B is cured in a 0.2 mol / l zinc salt solution to obtain a flexible polymer material for monitoring and sensing.

[0050] Example 5: Preparation of flexible polymer materials for monitoring and sensing

[0051] 1. Take natural balsa wood slices and immerse them in NaClO2 / acetate buffer with pH = 4.6, boil them at 120℃ for 3h, then soak the wood in 20wt% sodium hydroxide for 1.5h, and wash them with ethanol to obtain delignified wood A;

[0052] 2. Take 1g of sodium alginate and dissolve it in 100g of water, stir it at room temperature for 20 minutes, and immerse wood A in it. Treat it under vacuum at 200Pa for 1h to obtain heavy-filled wood B.

[0053] 3. Then, wood B is cured in a 0.2 mol / l zinc salt solution to obtain a flexible polymer material for monitoring and sensing.

[0054] Example 6: Preparation of flexible polymer materials for monitoring and sensing

[0055] 1. Take natural balsa wood slices and immerse them in NaClO2 / acetate buffer with pH = 4.6, boil them at 120℃ for 3h, then soak the wood in 20wt% sodium hydroxide for 1.5h, and wash them with ethanol to obtain delignified wood A;

[0056] 2. Take 3g of sodium alginate and dissolve it in 100g of water, stir it at room temperature for 20 minutes, and immerse wood A in it. Treat it under vacuum at 200Pa for 1h to obtain heavy-filled wood B.

[0057] 3. Then, wood B is cured in a 0.2 mol / l zinc salt solution to obtain a flexible polymer material for monitoring and sensing.

[0058] Example 7: Preparation of flexible polymer materials for monitoring and sensing

[0059] 1. Take natural balsa wood slices and immerse them in NaClO2 / acetate buffer with pH = 4.6, boil them at 120℃ for 3h, then soak the wood in 20wt% sodium hydroxide for 1.5h, and wash them with ethanol to obtain delignified wood A;

[0060] 2. Take 4g of sodium alginate and dissolve it in 100g of water, stir it at room temperature for 20 minutes, and immerse wood A in it. Treat it under vacuum at 200Pa for 1h to obtain heavy-filled wood B.

[0061] 3. Then, wood B is cured in a 0.2 mol / l zinc salt solution to obtain a flexible polymer material for monitoring and sensing.

[0062] Example 8: Preparation of flexible polymer materials for monitoring and sensing

[0063] 1. Take natural balsa wood slices and immerse them in NaClO2 / acetate buffer with pH = 4.6, boil them at 120℃ for 3h, then soak the wood in 20wt% sodium hydroxide for 1.5h, and wash them with ethanol to obtain delignified wood A;

[0064] 2. Take 2g of sodium alginate and dissolve it in 100g of water, stir it at room temperature for 20 minutes, and immerse wood A in it. Treat it under vacuum at 200Pa for 1h to obtain heavy-filled wood B.

[0065] 3. Then, wood B is cured in a 0.1 mol / l zinc salt solution to obtain a flexible polymer material for monitoring and sensing.

[0066] Example 9: Preparation of flexible polymer materials for monitoring and sensing

[0067] 1. Take natural balsa wood slices and immerse them in NaClO2 / acetate buffer with pH = 4.6, boil them at 120℃ for 3h, then soak the wood in 20wt% sodium hydroxide for 1.5h, and wash them with ethanol to obtain delignified wood A;

[0068] 2. Take 2g of sodium alginate and dissolve it in 100g of water, stir it at room temperature for 20 minutes, and immerse wood A in it. Treat it under vacuum at 200Pa for 1h to obtain heavy-filled wood B.

[0069] 3. Then, wood B is cured in a 0.3 mol / l zinc salt solution to obtain a flexible polymer material for monitoring and sensing.

[0070] Comparative Example 1: Preparation of flexible polymer materials for monitoring and sensing

[0071] 1. Take 1g of sodium alginate and dissolve it in 100g of water, stir it at room temperature for 20 minutes, and mix it with commercially available cellulose I. Treat it under vacuum at 200Pa for 1h to obtain a mixture C.

[0072] 2. Then, the mixture C is solidified in a 0.2 mol / l zinc salt solution to obtain a flexible polymer material for monitoring and sensing.

[0073] Tensile strength test method:

[0074] The tensile strength tests of different hydrogel materials were carried out using an electronic universal testing machine (SANSCMT4503) at a test speed of 5 mm / min (ASTM F2512-20a).

[0075] Signal response performance retention test:

[0076] Use tweezers to bend the sample 180° 1000 times, record the signal intensities S1 and S2 before and after bending, and calculate the signal response performance retention rate according to the formula S2 / S1*100%.

[0077] Table 1: Performance test results of the flexible polymer material used for monitoring sensing of the present invention

[0078]

[0079] It can be seen from the experimental data in Table 1 that the flexible polymer material for monitoring and sensing prepared by using delignified wood and sodium alginate as raw materials in the present invention has good tensile stress and bending resistance.

[0080] It can be seen from the experimental data in Table 1 that the bending performance of the flexible polymer material for monitoring and sensing prepared in Example 1 is significantly higher than that of the flexible polymer material for monitoring and sensing prepared in Examples 2, 3, and 4; the conductivity of the flexible polymer material for monitoring and sensing prepared in Example 1 is significantly higher than that of Examples 2 and 3, while the tensile strength is significantly greater than that of Example 4 and the ionic conductivity is basically the same. This shows that the tensile strength and ionic conductivity of the material can be accurately controlled by accurately controlling the delignification time.

[0081] It can be seen from the experimental data in Table 1 that the ionic conductivity and bending resistance of the flexible polymer material for monitoring sensing prepared in Example 1 are significantly better than those in Examples 5, 6, and 7, which shows that selecting a suitable amount of sodium alginate can significantly improve the molecular cross-linking level and ionic conductivity, and improve the sensitivity of the monitoring sensor device.

[0082] It can be seen from the experimental data in Table 1 that the ionic conductivity and bending resistance of the flexible polymer material for monitoring sensing prepared in Example 1 are significantly better than those in Examples 8 and 9, which shows that selecting a suitable cross-linking zinc salt concentration can significantly improve the molecular cross-linking level and the bending resistance of the gel, thereby increasing the service life of the monitoring sensor device.

[0083] It can be seen from the experimental data in Table 1 that the tensile strength value, post-bending performance and ionic conductivity of the flexible polymer material for monitoring and sensing prepared in Example 1 are significantly higher than those of the flexible polymer material for monitoring and sensing prepared in Comparative Example 1 without adding wood. This shows that the strategy of using delignified wood as the internal skeleton of the polymer material in the present invention is extremely successful, which can not only improve the mechanical and bending resistance of the flexible polymer material, but also improve its conductivity, making it more suitable for monitoring life activities, broadening the development prospects for its further application, and contributing to the development and application of green materials.

[0084] In addition, regarding the Figure 3-5 Compared with logs, delignified wood has larger pores, and after cross-linking and curing, the lumen is completely filled.

[0085] Each embodiment of this specification focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referenced to each other.

[0086] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing a flexible polymer material for monitoring sensing, characterized in that: The preparation was carried out by the following steps: (1) taking natural balsa wood slices and immersing them in a NaClO2 / acetate buffer solution with a pH of 4.6, boiling them at 120°C for 3 hours, then soaking the wood in 20 wt% sodium hydroxide for 1.5 hours, and washing them with ethanol to obtain delignified wood A; (2) 2 g of sodium alginate was dissolved in 100 g of water, stirred at room temperature for 20 minutes, and wood A was immersed therein, and treated under vacuum at 200 Pa for 1 hour to obtain heavily filled wood B; (3) Then, wood B is solidified in a 0.2 mol / l zinc salt solution to obtain a flexible polymer material for monitoring and sensing.

2. The flexible polymer material for monitoring and sensing prepared by the preparation method according to claim 1.

3. Use of the flexible polymer material for monitoring sensing according to claim 2 in the preparation of a wearable monitoring sensor device.

4. The use according to claim 3, characterized in that: The preparation method of the wearable monitoring sensor device is as follows: the flexible polymer material for monitoring sensing described in claim 2 is made into a long strip sample, and then a foam nickel current collector is connected on both sides of the sample, conductive activated carbon is coated on the foam nickel, and the monitoring sensor device is assembled with a wire.

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