Organic gel as well as preparation method and application thereof

Abstract

The invention provides an organogel and a preparation method and application thereof. The organogel comprises a prepolymerization solution; the prepolymerization solution is prepared from the following components in parts by mass: 1.0 part of propylene glycol, 0.5 to 1.3 parts of acrylic acid, 0.6 to 1.3 parts of methacrylic acid-2-aminoethyl ester hydrochloride and 0.0055 to 0.026 part of a photoinitiator; the invention discloses organic gel as well as a preparation method and application thereof. The organic gel provided by the invention has the advantages of biological safety, environmental stability, super-stretchability, recoverability and the like. The preparation method of the organic gel provided by the invention is simple and easy to implement and efficient in production; the application provides a basis for developing biologically safe and recoverable flexible conductive materials.

Description

Technical Field

[0001] The present invention relates to the technical field of gel materials, and in particular, to an organic gel and a preparation method and application thereof. Background Art

[0002] With the rapid development of flexible electronics technology, the preparation and design of flexible materials have attracted extensive attention and have important application values in fields such as soft robots, human-computer interaction, and medical health monitoring. Compared with the methods of achieving flexibility by structurally designing traditional rigid conductive materials or by compounding conductive media with elastic networks, intrinsically flexible organic gels have gradually become the research focus of flexible conductive materials.

[0003] Intrinsically flexible conductive organic gels can achieve a wider range of electrical and mechanical property adjustments to meet actual application requirements. In recent years, hydrogels have been very popular due to their excellent biocompatibility, but their environmental stability greatly limits their application scenarios. Ionic gels based on ionic liquids can effectively avoid the dehydration problem of hydrogels. However, in practical applications, most ionic liquids (such as imidazolium and pyridinium-based ionic liquids) are costly and have low biocompatibility.

[0004] Currently, the strategy of replacing water solvents with polyol small molecule solvents with high boiling points and low melting points can improve the stability of gels. Compared with ionic liquids, these solvents are inexpensive and easily available. The prior art discloses an ethylene glycol organic gel using polyacrylic acid and gelatin as raw materials. The ionic liquid selected for this organic gel is 1-hexyl-3-methylimidazolium chloride, 1-butyl-3-methylimidazolium chloride, or 1-hexyl-3-methylimidazolium hexafluorophosphate, which effectively avoids the dehydration problem of hydrogels, and the raw materials are cheap and easily available. At the same time, it can achieve super stretchability and strain electrical response at low temperatures. However, this material adds toxic ionic liquids as conductive media, and there is a risk of ionic liquid leakage, with poor biosafety, and the biological toxicity of ethylene glycol is relatively high, which greatly limits the actual application scope of the material.

[0005] Based on the above deficiencies of the prior art, there is an urgent need for an organic gel with biosafety at present. Summary of the Invention

[0006] Aiming at the deficiencies of the prior art, the present application provides an organic gel and a preparation method and application thereof. The organic gel provided by the present application has the advantages of biosafety, environmental stability, super stretchability, and recyclability, etc.; the preparation method of the organic gel provided by the present invention is simple and easy to implement, and the production is efficient; its application provides a basis for the development of biosafe and recyclable flexible conductive materials.

[0007] An organic gel disclosed in the present application includes: a prepolymer solution; by mass, the prepolymer solution includes 1.0 part of propylene glycol, 0.5 - 1.3 parts of acrylic acid, 0.6 - 1.3 parts of 2-aminoethyl methacrylate hydrochloride, and 0.0055 - 0.026 part of a photoinitiator.

[0008] According to an embodiment of the present invention, in the prepolymer solution, the mass ratio of propylene glycol, acrylic acid, and 2-aminoethyl methacrylate hydrochloride is 1:1:1.

[0009] According to an embodiment of the present invention, the mass of the photoinitiator is 0.5% - 1.0% of the total mass of acrylic acid and 2-aminoethyl methacrylate hydrochloride.

[0010] According to an embodiment of the present invention, the mass of the photoinitiator is 1.0% of the total mass of acrylic acid and 2-aminoethyl methacrylate hydrochloride.

[0011] A preparation method of an organic gel disclosed in the present application: prepare a prepolymer solution; add the prepolymer solution to a mold and carry out polymerization under ultraviolet light to obtain the organic gel.

[0012] According to an embodiment of the present invention, preparing the prepolymer solution includes: ultrasonically dissolving acrylic acid, 2-aminoethyl methacrylate hydrochloride, and the photoinitiator in propylene glycol to obtain the prepolymer solution.

[0013] According to an embodiment of the present invention, the ultrasonic dissolution time is 2 - 10 min.

[0014] According to an embodiment of the present invention, the polymerization time is 20 - 40 min.

[0015] An application of an organic gel disclosed in the present application, the organic gel is applied to flexible conductive materials.

[0016] An application of an organic gel disclosed in the present application, applied to the fields of flexible wearable sensing devices, soft robots, human-computer interaction, or medical health monitoring.

[0017] The beneficial effects of the present application are as follows: First, the organic gel provided by the present application has excellent biocompatibility, will not cause harm to the skin, and is safe and reliable during application.

[0018] Second, the organic gel provided by the present application has intrinsic conductivity, endows the gel with conductivity by in-situ polymerizing electrolyte monomers, is more reliable and stable than the traditional method of achieving flexible conductivity by compounding conductive media and elastic networks, avoids the problem of peeling at the interface between the conductor and the substrate, and thus overcomes the problem of leakage of ionic liquids.

[0019] III. The organic gel provided by this application has excellent tensile properties and will not break even when stretched to 104 times its original length.

[0020] IV. The organic gel provided by this application has excellent environmental stability. Propylene glycol has an extremely low freezing point (-59 °C), which is lower than that of most common polar organic solvents and ionic liquids, and thus has more advantages in applications in extremely low-temperature environments.

[0021] V. The organic gel provided by this application has excellent recyclability. It can be completely dissolved in water, and the organic gel can be obtained after the water in which the organic gel is dissolved evaporates.

[0022] VI. The preparation method and process of the organic gel provided by this application are simple. The commercially available 99.5% propylene glycol costs 6,000 - 8,000 yuan per ton, which is cheap and easily available, and the one-pot method can achieve rapid and large-scale preparation. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings described herein are used to provide a further understanding of this application and constitute a part of this application. The schematic embodiments of this application and their descriptions are used to explain this application and do not constitute an improper limitation to this application. In the drawings: Figure 1 It is a schematic structural diagram of the organic gel in Example 1; Figure 2 It is a demonstration schematic diagram and an actual adhesion diagram of the organic gel in Example 1 adhering to the human skin surface; Figure 3 It is a demonstration schematic diagram and an actual diagram after washing of the organic gel in Example 1 during the water washing process on the human skin surface; Figure 4 It is an epidermal comparison diagram of the organic gel in Example 1 in the mouse epidermal adhesion experiment; Figure 5 It is the H&E staining result of the tissue section of the corresponding area of the mouse epidermis; Figure 6 It is a graph of the mass change of the organic gel in Example 1 when placed in the air for different times; Figure 7 It is a stress-strain curve of the organic gel in Example 1 at a tensile rate of 5 mm / min at -25 °C, 0 °C, 25 °C, and 50 °C environments respectively; Figure 8 It is a stress-strain curve of the organic gels in Examples 1 - 5 at a tensile rate of 20 mm / min; Figure 9 It is a stress-strain curve graph of the organic gel in Example 1 at a tensile rate of 5 mm / min; Figure 10Experimental demonstration diagrams of the organogel in Example 1 before and after being stretched 104 times at a stretching rate of 5 mm / min; Figure 11 Physical diagram showing the recyclability of the organogel in Example 1. Detailed implementation manners

[0024] The following will disclose multiple implementation manners of the present application through diagrams. For the sake of clear illustration, many practical details will be described together in the following narrative. However, it should be understood that these practical details are not used to limit the present application. That is to say, in some implementation manners of the present application, these practical details are not necessary. In addition, for the purpose of simplifying the diagrams, some conventional structures and components will be shown in a simple schematic manner in the diagrams.

[0025] In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the premise that those skilled in the art can implement them. When the combination of technical solutions conflicts with each other or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present application.

[0026] In addition, unless otherwise specified, the experimental methods used in the following embodiments are all conventional methods.

[0027] In addition, the materials, reagents, etc. used in the following embodiments, unless otherwise specified, can all be obtained through commercial channels.

[0028] In addition, in the following embodiments, the unit of "parts" is in mg.

[0029] In order to further understand the application content, features and effects of the present application, the following examples are hereby cited and described in detail in conjunction with the attached diagrams as follows.

[0030] Example 1 Please refer to Figure 1 , Figure 1 which is the structural schematic diagram of the organogel in this example. In this example, the organogel is obtained by polymerizing a prepolymer solution.

[0031] The prepolymer solution is prepared from the following raw materials in parts by weight: 1000.00 parts of propylene glycol, 1000.00 parts of acrylic acid, 1000.00 parts of 2-aminoethyl methacrylate hydrochloride, and 20.00 parts of I-2959.

[0032] Among them, propylene glycol is used as the solution, acrylic acid and 2-aminoethyl methacrylate hydrochloride are used as polymers, 2-aminoethyl methacrylate hydrochloride is used as the conductive medium, and the photoinitiator is selected as I-2959, and its CAS number is: 106797-53-9.

[0033] The method for preparing the organic gel from the above raw materials includes: at room temperature, mixing acrylic acid, 2-aminoethyl methacrylate hydrochloride and a photoinitiator with propylene glycol, and obtaining a clear prepolymer solution after ultrasonic treatment for 5 min; dropping the clear prepolymer solution onto a mold and performing ultraviolet light polymerization treatment for 30 min to obtain the organic gel.

[0034] In this example, the photoinitiator can be replaced by I-1173 or I-184; when mixing acrylic acid, 2-aminoethyl methacrylate hydrochloride and the photoinitiator with propylene glycol, acrylic acid, 2-aminoethyl methacrylate hydrochloride and the photoinitiator can be added to propylene glycol step by step for mixing, or acrylic acid, 2-aminoethyl methacrylate hydrochloride and the photoinitiator can be added to propylene glycol simultaneously for mixing; when dropping the clear prepolymer solution onto a mold, the mold can be selected according to the shape of the organic gel to be prepared; the ultraviolet light polymerization process can be realized by a UV irradiator or other ultraviolet light curing equipment.

[0035] The organic gel provided by this application is a propylene glycol-based organic gel, which has the following beneficial effects: First, the organic gel provided by this application has excellent biocompatibility, and the organic gel will not cause harm to the skin, and is safe and reliable during application.

[0036] Second, the organic gel provided by this application has intrinsic conductivity, and the gel's conductivity is imparted by in-situ polymerization of electrolyte monomers, which is more reliable and stable than the traditional method of achieving flexible conductivity by compounding conductive media and elastic networks, avoiding the problem of peeling at the interface between the conductor and the substrate, and thus overcoming the problem of ion liquid leakage.

[0037] Third, the organic gel provided by this application has super tensile properties and will not break even when stretched to 104 times the original length of the organic gel.

[0038] Fourth, the organic gel provided by this application has excellent environmental stability. Propylene glycol has an extremely low freezing point (-59°C), which is lower than most common polar organic solvents and ionic liquids, and has more advantages in applications in extremely low temperature environments.

[0039] Fifth, the organic gel provided by this application has excellent recyclability. It can be completely dissolved in water, and the organic gel can be obtained after the water in which the organic gel is dissolved evaporates.

[0040] Sixth, the preparation method and process of the organic gel provided by this application are simple. The market price of 99.5% propylene glycol is 6000 - 8000 yuan / ton, which is cheap and easily available, and the one-pot method can achieve rapid and large-scale preparation.

[0041] Example 2 In this example, the organogel is also obtained by pre-polymerization solution polymerization. Different from Example 1, in the raw materials for preparing the pre-polymerization solution, the amount of acrylic acid is adjusted to 700.00 parts.

[0042] In this example, the preparation method of the organogel is the same as that in Example 1.

[0043] Example 3 In this example, the organogel is also obtained by pre-polymerization solution polymerization. Different from Example 1, in the raw materials for preparing the pre-polymerization solution, the amount of acrylic acid is adjusted to 1300.00 parts.

[0044] In this example, the preparation method of the organogel is the same as that in Example 1.

[0045] Example 4 In this example, the organogel is also obtained by pre-polymerization solution polymerization. Different from Example 1, in the raw materials for preparing the pre-polymerization solution, the amount of 2-aminoethyl methacrylate hydrochloride is adjusted to 700.00 parts.

[0046] In this example, the preparation method of the organogel is the same as that in Example 1.

[0047] Example 5 In this example, the organogel is also obtained by pre-polymerization solution polymerization. Different from Example 1, in the raw materials for preparing the pre-polymerization solution, the amount of 2-aminoethyl methacrylate hydrochloride is adjusted to 1300.00 parts.

[0048] In this example, the preparation method of the organogel is the same as that in Example 1.

[0049] Example 6 In this example, the organogel is also obtained by pre-polymerization solution polymerization. Different from Example 1, in the raw materials for preparing the pre-polymerization solution, the amount of acrylic acid is adjusted to 500.00 parts, the amount of 2-aminoethyl methacrylate hydrochloride is adjusted to 600.00 parts, and the amount of I-2959 is adjusted to 5.50 parts.

[0050] In this example, the preparation method of the organogel is the same as that in Example 1.

[0051] Example 7 In this example, the organogel is also obtained by pre-polymerization solution polymerization. Different from Example 1, in the raw materials for preparing the pre-polymerization solution, the amount of acrylic acid is adjusted to 1300.00 parts, the amount of 2-aminoethyl methacrylate hydrochloride is adjusted to 1300.00 parts, and the amount of I-2959 is adjusted to 26.00 parts.

[0052] In this example, the preparation method of the organogel is the same as that in Example 1.

[0053] Example 8 In this example, the organogel is also obtained by pre-polymerization solution polymerization, and the raw materials for preparing the pre-polymerization solution are the same as those in Example 1.

[0054] In the preparation method of the organogel in this example, the ultrasonic dissolution time is adjusted to 2 min, and the polymerization time is adjusted to 20 min. The remaining steps are the same as those in Example 1.

[0055] Example 9 In this example, the organogel is also obtained by pre-polymerization solution polymerization, and the raw materials for preparing the pre-polymerization solution are the same as those in Example 1.

[0056] In the preparation method of the organogel in this example, the ultrasonic dissolution time is adjusted to 10 min, and the polymerization time is adjusted to 40 min. The remaining steps are the same as those in Example 1.

[0057] Example 10 The flexible conductive material in this example includes an organogel.

[0058] Example 11 The organogel in this example is applied to fields such as flexible wearable sensing devices, soft robots, human-computer interaction, or medical health monitoring.

[0059] The following analysis method is used to test and analyze the biosafety performance of the organogel in Example 1: (1) Please refer to Figure 2 , Figure 2 For the demonstration schematic diagram and the adhesion physical diagram of the organogel in Example 1 on the human skin surface, the organogel prepared in Example 1 is completely dissolved in water, and then the aqueous solution containing the organogel is patterned on the human skin surface using a spray bottle and masking paper. After the water evaporates, the organogel directly adheres to the skin surface; after briefly rinsing the position of the human skin adhered with the organogel with distilled water, the organogel can be directly wiped off with a tissue paper, and observe whether there are any adverse reaction phenomena on the skin or discomfort in the human body.

[0060] (2) The organogel prepared in Example 1 is completely dissolved in water, and then the water containing the organogel is patterned on the surface of the mouse epidermis using a spray bottle and masking paper. After the water evaporates, the organogel directly adheres in situ to the mouse epidermis; a long-term adhesion test is carried out, and the adhesion test time is 7 days. After 7 days, the epidermis section of the corresponding area of the mouse is stained by hematoxylin-eosin staining (H&E) to analyze whether there is inflammation in the mouse epidermis tissue.

[0061] (3) By comparing the median lethal dose (lnLD 50 ) of common organic solvents and the median lethal concentration (lgEC 50 ) of common ionic liquids, the biocompatibility of propylene glycol is analyzed.

[0062] Biosecurity performance test results: (1) Please refer to Figure 3 , Figure 3 which is a demonstration diagram of the organic gel in Example 1 during the water washing process on the human skin surface and a physical picture after water washing. It is found through observation that no adverse reactions occur on the human skin and no discomfort phenomena occur to the human body.

[0063] (2) Please refer to Figure 4 and Figure 5 , Figure 4 which is a comparison diagram of the epidermis in the organic gel adhesion experiment on the mouse epidermis in Example 1, Figure 5 and Figure 4 is the H&E staining result of the tissue section of the corresponding area of the mouse epidermis. In

[0064] Figure 6 Figure 6 , is an Ashby diagram for the quantitative comparison of the melting points and toxicities of common organic solvents and ionic liquids. Among them, the lnLD 50 of ethylene glycol is 1.55, the median lethal dose lnLD 50 of glycerol is 2.53, and the lnLD 50 of propylene glycol is 2.99. It can be seen that propylene glycol has better biocompatibility than ethylene glycol.

[0065] The following analysis method is used to conduct environmental stability test analysis on the organic gel in Example 1: (1) Place the organic gel in Example 1 in the air and measure the mass change of the organic gel within the time period of 0 - 12 days.

[0066] (2) Under the conditions of -25 °C, 0 °C, 25 °C, and 50 °C respectively, conduct stress-strain tests on the organic gel at a tensile rate of 5 mm / min by DMA850 (10 mm×5 mm×1 mm), where DMA850 is a dynamic thermomechanical analyzer produced by TA Instruments.

[0067] Environmental stability test results: (1) Please refer to Figure 6 , Figure 6It is the mass change curve of the organogel in Example 1 placed in the air for different times. The mass of the organogel hardly changes after 12 days. It can be seen that after a long time, the propylene glycol and ionic liquid in the organogel hardly volatilize, and the component content of the organogel is stable.

[0068] (2) Please refer to Figure 7 , Figure 7 It is the stress-strain curve of the organogel in Example 1 at -25 °C, 0 °C, 25 °C, and 50 °C with a tensile rate of 5 mm / min. It can be seen that the tensile strain of the organogel in Example 1 at -25 °C, 0 °C, 25 °C, and 50 °C is greater than 200%, proving that it still has good mechanical properties in a wide temperature range.

[0069] The following analysis method is used to test and analyze the tensile properties of the organogel: (1) At room temperature, the strip-shaped samples (30 mm × 10 mm × 1 mm) of the organogel in Examples 1 to 5 are stretched by Instron LEGEND 2367 at a tensile rate of 20 mm / min until the material breaks. Among them, Instron LEGEND 2367 is an Instron 2360 series double-column bench-top test system.

[0070] (2) At room temperature, the strip-shaped sample (30 mm × 10 mm × 1 mm) of the organogel in Example 1 is stretched by Instron LEGEND 2367 at a tensile rate of 5 mm / min for the tensile experiment.

[0071] Tensile property test results: (1) Please refer to Figure 8 , Figure 8 It is the stress-strain curve of the organogel in Examples 1 to 5 at a tensile rate of 20 mm / min. Among the organogels in Examples 1 to 5, all the organogels can be stretched to more than 1800%. Among them, the organogel in Example 1 has the best tensile property, the organogel in Example 2 has the second-best tensile property, and the organogel in Example 4 has the weakest tensile property among Examples 1 to 5. It can be seen that when the mass ratio of propylene glycol, acrylic acid, and 2-aminoethyl methacrylate hydrochloride is 1:1:1, the organogel has the best tensile property. When the mass ratio of propylene glycol, acrylic acid, and 2-aminoethyl methacrylate hydrochloride is adjusted within the range of 1:0.5~1.3:0.6~1.3 and the mass ratio of the three is not 1:1:1, the organogel does not reach the best tensile property.

[0072] (2) Please refer to Figure 9 and Figure 10 ,Figure 9 The stress-strain curve of the organogel in Example 1 at a stretching rate of 5 mm / min. Figure 10 The experimental demonstration diagrams of the organogel in Example 1 before and after being stretched 104 times at a stretching rate of 5 mm / min. It can be seen that when the organogel is stretched at a stretching rate of 5 mm / min, the stress of the organogel gradually increases. When the strain of the organogel reaches 10400%, its stress still does not decrease. It can be seen that the organogel in Example 1 does not break after being stretched 104 times. The organogel provided by this application has excellent stretching performance.

[0073] The following analysis method is used to test and analyze the recyclability of the organogel in Example 1: At room temperature, place the organogel strip sample (30 mm×10 mm×1 mm) in a petri dish containing 5 mL of distilled water. Wait until the organogel completely dissolves in the distilled water, and then drop the solution into a mold. Observe whether there is organogel in the mold after the distilled water has completely evaporated.

[0074] Recyclability test results: Please refer to Figure 11 , Figure 11 The physical diagram showing the recyclability of the organogel in Example 1. It can be seen from Figure 11 that this material can completely dissolve in water; when the water droplet containing the organogel is dropped into the mold, the organogel material can be obtained again after the distilled water has completely evaporated. It can be seen that the organogel provided by this application has excellent recyclability.

[0075] In summary, the present invention has the following advantages: 1. The organogel provided by this application has excellent biocompatibility and will not cause harm to the skin, and is safe and reliable during application.

[0076] 2. The organogel provided by this application has intrinsic conductivity. By in-situ polymerizing electrolyte monomers, the gel is given the ability to conduct electricity, which is more reliable and stable than the traditional method of achieving flexible conductivity by compounding conductive media and elastic networks, avoiding the problem of peeling at the interface between the conductor and the substrate, and thus overcoming the problem of leakage of ionic liquids.

[0077] 3. The organogel provided by this application has excellent stretching performance and will not break even when stretched to 104 times its original length.

[0078] 4. The organogel provided by this application has excellent environmental stability. Propylene glycol has an extremely low freezing point (-59°C), which is lower than most common polar organic solvents and ionic liquids, and has more advantages in applications in extremely low temperature environments.

[0079] V. The organic gel provided by this application has excellent recyclability. It can be completely dissolved in water, and the organic gel can be obtained after the water in which the organic gel is dissolved evaporates.

[0080] VI. The preparation method and process of the organic gel provided by this application are simple. The market price of 99.5% propylene glycol is 6,000 - 8,000 yuan per ton, which is cheap and easily available. Moreover, the one-pot method can achieve rapid and large-scale preparation.

[0081] The above are only the embodiments of this application and are not used to limit this application. For those skilled in the art, various changes and modifications can be made to this application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this application shall be included within the scope of the claims of this application.

Claims

1. An organogel, characterized in that: include: Prepolymer solution; in parts by mass, the prepolymer solution includes 1.0 part of propylene glycol, 0.5-1.3 parts of acrylic acid, 0.6-1.3 parts of methacrylate-2-aminoethyl ester hydrochloride and 0.0055-0.026 parts of photoinitiator.

2. The organogel according to claim 1, characterized in that In the prepolymerization solution, the mass ratio of the propylene glycol, the acrylic acid and the 2-aminoethyl methacrylate hydrochloride is 1:1:

1.

3. The organogel according to claim 1 or 2, characterized in that: The mass of the photoinitiator is 0.5%-1.0% of the total mass of the acrylic acid and the 2-aminoethyl methacrylate hydrochloride.

4. The organogel according to claim 3, characterized in that The mass of the photoinitiator is 1.0% of the total mass of the acrylic acid and the 2-aminoethyl methacrylate hydrochloride.

5. A method for preparing an organogel, characterized in that: include: Prepare the prepolymer solution according to any one of claims 1 to 4; The prepolymerization solution is dripped onto the mold and polymerized under ultraviolet light to obtain an organic gel.

6. The method for preparing the organogel according to claim 5, characterized in that: The preparation of the prepolymerization solution comprises: ultrasonically dissolving the acrylic acid, the methacrylic acid-2-aminoethyl ester hydrochloride and the photoinitiator into the propylene glycol to obtain the prepolymerization solution.

7. The method for preparing the organogel according to claim 6, characterized in that: The ultrasonic dissolution time is 2-10 min.

8. The method for preparing an organogel according to any one of claims 5 to 7, characterized in that: The polymerization time is 20-40 min.

9. An application of an organogel, characterized in that: Applicable to flexible conductive materials.

10. An application of an organogel, characterized in that: It is used in flexible wearable sensing devices, soft robots, human-computer interaction or medical health monitoring.

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