阅读说明：本技术 抗冻水凝胶、制备方法以及应用 (Anti-freezing hydrogel, preparation method and application ) 是由 赵维巍 陈幼幼 张晨 陈国庆 于 2021-09-26 设计创作，主要内容包括：本申请涉及水凝胶技术领域,提供了一种抗冻水凝胶、制备方法以及应用,包括黏土、无机盐、交联聚合物和水的混合物,交联聚合物在水中形成三维网络结构,黏土和无机盐分散于三维网络结构中形成抗冻水凝胶。本申请提供的抗冻水凝胶,包括黏土、无机盐、交联聚合物和水,其中,交联聚合物溶解在水中,在水中形成三维网络结构,由于黏土、无机盐、交联聚合物和水的相互作用,黏土、无机盐可稳定分散于三维网络结构中。本申请的抗冻水凝胶可借助无机盐的吸水特性,使本申请的抗冻水凝胶具有低温抗冻的特性,在低温条件下仍可拉伸和可压缩,保留抗冻水凝胶的理化性质。(The application relates to the technical field of hydrogel, and provides an anti-freezing hydrogel, a preparation method and application, wherein the anti-freezing hydrogel comprises a mixture of clay, inorganic salt, a cross-linked polymer and water, the cross-linked polymer forms a three-dimensional network structure in the water, and the clay and the inorganic salt are dispersed in the three-dimensional network structure to form the anti-freezing hydrogel. The application provides an anti-freeze hydrogel, including clay, inorganic salt, cross-linked polymer and water, wherein, cross-linked polymer dissolves in water, forms three-dimensional network structure in water, because the interact of clay, inorganic salt, cross-linked polymer and water, clay, inorganic salt can stably disperse in three-dimensional network structure. The antifreeze hydrogel can be made to have the characteristic of low-temperature antifreeze by means of the water absorption characteristic of inorganic salt, can be stretched and compressed under the low-temperature condition, and keeps the physicochemical property of the antifreeze hydrogel.)

1. An antifreeze hydrogel, comprising a mixture of clay, an inorganic salt, a crosslinked polymer and water, wherein the crosslinked polymer forms a three-dimensional network structure in the water, and wherein the clay and the antifreeze agent are dispersed in the three-dimensional network structure to form the antifreeze hydrogel.

2. The antifreeze hydrogel of claim 1, wherein the mass ratio of said crosslinked polymer to water is from 0.14:1 to 0.42: 1; and/or

The mass ratio of the clay to the water is 0.01: 1-0.04: 1; and/or

The mass ratio of the inorganic salt to the water is 0.04: 1-0.24: 1.

3. The antifreeze hydrogel of claim 1, wherein said crosslinked polymer is polymerized from monomers comprising a zwitterion.

4. The antifreeze hydrogel of claim 3, wherein said zwitterionic monomer comprises sulfobetaine methacrylate.

5. The method of claim 1, wherein the clay comprises at least one of montmorillonite nanoclay and sodium magnesium lithium silicate nanoclay; and/or

The particle size of the clay is not more than 100 nm.

6. The antifreeze hydrogel of claim 1, wherein said inorganic salt comprises a chloride salt.

7. The antifreeze hydrogel of claim 6, wherein said chloride salt comprises at least one of calcium chloride, magnesium chloride, potassium chloride, sodium chloride, and lithium chloride.

8. A process for the preparation of a freeze-resistant hydrogel as claimed in any of claims 1 to 7, comprising the following steps:

performing primary mixing treatment on clay and water to obtain a clay suspension;

adding an antifreeze agent and a cross-linked polymer monomer into the clay suspension for second mixing treatment and dissolving treatment to obtain a dispersion liquid;

and adding an initiator into the dispersion liquid for third mixing treatment, and carrying out polymerization reaction to obtain the anti-freezing hydrogel.

9. The method for preparing the antifreeze hydrogel of claim 8, wherein the crosslinking polymer monomer and the water are mixed in a mass ratio of the generated crosslinking polymer to the water of 0.14:1 to 0.42: 1; or/and

the mass ratio of the initiator to the cross-linked polymer monomer is 0.005: 1-0.01: 1; or/and

the initiator comprises one of ammonium persulfate, potassium persulfate, benzoyl oxide, tert-butyl hydroperoxide or a photoinitiator 2959.

10. Use of a deicing hydrogel as claimed in claims 1 to 5 in soft brakes, sensors and flexible electronic energy storage devices.

Technical Field

The application belongs to the technical field of hydrogel, and particularly relates to anti-freezing hydrogel, a preparation method and application.

Background

Hydrogels are a class of high molecular polymers containing large amounts of water and having a three-dimensional network structure. Due to its special characteristics of softness and humidity, it has been widely used in the fields of electronic skin, flexible electronic devices, drivers, and biomedical applications. However, the conventional hydrogel is easy to freeze below zero degree, and the mechanical properties are reduced, which severely limits the practical application of the hydrogel in low temperature environment.

In recent years, studies have been made to introduce organic liquids such as ethylene glycol, glycerol, and dimethyl sulfoxide into hydrogels, and to obtain antifreeze hydrogels by inhibiting the formation of crystal lattices by the interaction between the organic liquids and water molecules. However, the presence of organic liquids can seriously reduce the electrical conductivity of the hydrogel, thereby failing to meet the application requirements of the hydrogel in specific fields. In addition, the toxicity, volatility and high degree of pyrophoricity of such organic compounds themselves may cause safety hazards and harm human health. In addition, it was studied to directly immerse the hydrogel in an inorganic salt solution to obtain an antifreeze hydrogel. However, the dipping time of the method is generally up to several days, and the preparation period of the hydrogel is greatly prolonged. In addition, in the dipping process, the mechanical property of the hydrogel is greatly reduced due to the water absorption swelling effect. Therefore, it is still a challenge to be solved to design a hydrogel with simple preparation method and freezing resistance, and to make the hydrogel have excellent conductivity and mechanical properties.

Disclosure of Invention

The application aims to provide an anti-freezing hydrogel, a preparation method and application, and aims to solve the problem that the mechanical strength of the hydrogel is poor under a low-temperature condition in the prior art.

In order to achieve the purpose of the application, the technical scheme adopted by the application is as follows:

in a first aspect, the present application provides a freeze-resistant hydrogel, comprising a mixture of clay, inorganic salt, a cross-linked polymer and water, wherein the cross-linked polymer forms a three-dimensional network structure in the water, and the clay and the inorganic salt are dispersed in the three-dimensional network structure to form the freeze-resistant hydrogel.

The antifreeze hydrogel provided by the application uses clay as a cross-linking agent, can prepare the cross-linked polymer in the application, and in the antifreeze hydrogel, the clay and inorganic salt can be stably dispersed in the cross-linked polymer, wherein the clay and inorganic salt can separate ions (such as sodium ions and the like) through hydrolysis, and due to the interaction between the cross-linked polymer and the ions, the ions can be uniformly and stably dispersed in the three-dimensional network structure of the cross-linked polymer. On one hand, the ions have hydrophilic characteristics, and after being dissolved in water, the ions can change the phase transition temperature of the anti-freezing hydrogel, so that the anti-freezing hydrogel can still be stretched and compressed at a low temperature state, and the physicochemical properties of the anti-freezing hydrogel are reserved, and on the other hand, the electric conductivity of the anti-freezing hydrogel can be improved through the movement of the ions.

In a second aspect, the present application provides a method for preparing a freeze-resistant hydrogel, comprising the steps of:

performing primary mixing treatment on clay and water to obtain a clay suspension;

adding inorganic salt and a cross-linked polymer monomer into the clay suspension for second mixing treatment and dissolving treatment to obtain dispersion liquid;

and adding an initiator into the dispersion liquid for third mixing treatment, and carrying out polymerization reaction to obtain the anti-freezing hydrogel.

According to the antifreeze hydrogel preparation method, on one hand, clay is used as a physical cross-linking agent, under the action of an initiator, a cross-linked polymer monomer is subjected to free reaction and then is cross-linked into a cross-linked polymer, and the cross-linked polymer, inorganic salt and the clay are mixed together to form the antifreeze hydrogel, wherein the free reaction process is carried out, the reaction conditions are not strictly limited, and then the method for preparing the antifreeze hydrogel is simple in process and convenient for large-scale production. On the other hand, in the preparation process, the addition amount of the inorganic salt can be flexibly adjusted according to requirements, and the anti-freezing hydrogel with different phase transition temperatures can be prepared.

In a third aspect, the present application provides the use of a freeze resistant hydrogel in soft brakes, sensors, and flexible electronic energy storage devices.

The application provides an anti-freeze aquogel deformability is strong, and electric conductive property is good, therefore the application provides an anti-freeze aquogel deformability can be used to soft stopper, sensor and flexible electron energy storage equipment device by force.

Drawings

FIG. 1 results of differential scanning calorimetry on the antifreeze hydrogel prepared in example 1 of the present invention;

FIG. 2 tensile stress-strain curve at 25 ℃ of the antifreeze hydrogel prepared in example 1 of the invention;

FIG. 3 compressive stress-strain curve at 25 ℃ of the antifreeze hydrogel prepared in example 1 of the invention;

FIG. 4 is a drawing of a tensile deformation of the antifreeze hydrogel prepared in example 1 of the invention at-50 ℃;

FIG. 5 is a conductivity scatter plot of the freeze resistant hydrogels prepared in example 1 of the present invention.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects to be solved by the present application more clearly apparent, the present application is further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

In this application, the term "and/or" describes an association relationship of associated objects, meaning that there may be three relationships, e.g., a and/or B, which may mean: a is present alone, A and B are present simultaneously, and B is present alone. Wherein A and B can be singular or plural. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship.

In the present application, "at least one" means one or more, "a plurality" means two or more. "at least one of the following" or similar expressions refer to any combination of these items, including any combination of the singular or plural items. For example, "at least one (a), b, or c", or "at least one (a), b, and c", may each represent: a, b, c, a-b (i.e., a and b), a-c, b-c, or a-b-c, wherein a, b, and c may be single or plural, respectively.

It should be understood that, in various embodiments of the present application, the sequence numbers of the above-mentioned processes do not mean the execution sequence, some or all of the steps may be executed in parallel or executed sequentially, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

The terminology used in the embodiments of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in the examples of this application and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

The weight of the related components mentioned in the description of the embodiments of the present application may not only refer to the specific content of each component, but also represent the proportional relationship of the weight among the components, and therefore, the content of the related components is scaled up or down within the scope disclosed in the description of the embodiments of the present application as long as it is scaled up or down according to the description of the embodiments of the present application. Specifically, the mass described in the specification of the embodiments of the present application may be a mass unit known in the chemical industry field such as μ g, mg, g, kg, etc.

The terms "first" and "second" are used for descriptive purposes only and are used for distinguishing purposes such as substances from one another, and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. For example, a first XX may also be referred to as a second XX, and similarly, a second XX may also be referred to as a first XX, without departing from the scope of embodiments of the present application. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

In a first aspect, embodiments of the present application provide a freeze resistant hydrogel. The antifreeze hydrogel of the embodiment of the application comprises a mixture of clay, inorganic salt, a cross-linked polymer and water, wherein the cross-linked polymer forms a three-dimensional network structure in the water, and the clay and the inorganic salt are dispersed in the three-dimensional network structure to form the antifreeze hydrogel.

The antifreeze hydrogel provided by the embodiment of the application comprises clay, inorganic salt, a cross-linked polymer and water, wherein the clay is used as a cross-linking agent, the cross-linked polymer of the embodiment of the application can be prepared, and in the antifreeze hydrogel, the clay and the inorganic salt can be stably dispersed in the cross-linked polymer, wherein the clay and the inorganic salt can separate ions (such as sodium ions and the like) through hydrolysis, the ions can be uniformly and stably dispersed in a three-dimensional network structure of the cross-linked polymer due to the interaction of the cross-linked polymer and the ions, in addition, the ions have hydrophilic characteristics, and after being dissolved in water, the phase transition temperature of the antifreeze hydrogel can be changed, so that the antifreeze hydrogel can be still stretched and compressible in a low-temperature state, the physicochemical properties of the antifreeze hydrogel can be reserved, and in addition, the electric conductivity of the antifreeze hydrogel can be improved through the movement of the ions.

In some embodiments, in order to further improve the conductivity and low-temperature freezing resistance of the freezing-resistant hydrogel, researchers have studied the components of the freezing-resistant hydrogel in the embodiments, and the experimental results show that the mass ratio of the cross-linked polymer to the water is 0.14: 1-0.42: 1; the mass ratio of the clay to the water is 0.01: 1-0.04: 1; the mass ratio of the inorganic salt to the water is 0.04: 1-0.24: 1, and the conductivity and the low-temperature freezing resistance of the anti-freezing hydrogel disclosed by the embodiment of the application can be improved by controlling and adjusting the proportion of at least one of the inorganic salt, the water and the water. Further, when the mass ratio of the inorganic salt to water in the system is 0.04:1 to 0.24:1, the phase transition temperature decreases as the mass ratio of the salt to water in the system increases.

In some embodiments, the crosslinked polymer is polymerized from monomers including zwitterions, such that the crosslinked polymer in the antifreeze hydrogel of the embodiments of the present application has positive and negative ions, which can improve the conductivity of the antifreeze hydrogel on the one hand, and can improve the dispersibility of clay and inorganic salts in the antifreeze hydrogel and improve the thermal stability and mechanical stability of the antifreeze hydrogel on the other hand. Illustratively, crosslinked polymers are mostly hydrophilic materials that form gels when mixed with water. The cross-linked polymer synthesized by the zwitterionic monomer through free radicals has positive ions and negative ions, the positive ions and the negative ions of the cross-linked polymer can improve the stability of the cross-linked polymer in inorganic salt, the viscosity of the cross-linked polymer in the inorganic salt cannot be reduced, but can be increased, namely the cross-linked polymer can generate reverse polyelectrolyte solution behavior in a salt solution.

In an embodiment, the zwitterionic monomer includes a sulfobetaine methacrylate, wherein the sulfobetaine methacrylate is more difficult to deprotonate, and has high thermal and mechanical stability than typical zwitterionic monomers.

In some embodiments, the inorganic salt comprises a chloride salt, wherein the chloride salt comprises at least one of calcium chloride, magnesium chloride, potassium chloride, sodium chloride, and lithium chloride, and the inorganic salt can improve the anti-freeze properties of the anti-freeze hydrogels of the embodiments.

In the examples, in order to further improve the stability of the antifreeze hydrogel, researchers have studied various chloride salts, and the studies show that, when the chloride salt includes lithium chloride, the antifreeze hydrogel has better antifreeze performance, and the lithium chloride can be stably dispersed in the cross-linked polymer, so that the antifreeze performance of the antifreeze hydrogel in the examples can be improved.

In an embodiment, the clay comprises at least one of montmorillonite nano clay and sodium silicate magnesium lithium nano clay, wherein the montmorillonite nano clay and the sodium silicate magnesium lithium nano clay are commercially available, and active hydroxyl groups rich in the montmorillonite nano clay and the sodium silicate magnesium lithium nano clay interact with the cross-linked polymer by adding the montmorillonite nano clay and/or the sodium silicate magnesium lithium nano clay, so that the montmorillonite nano clay and the sodium silicate magnesium lithium nano clay can be stably dispersed in a three-dimensional structure of the cross-linked polymer, the internal cross-linking density of the hydrogel is enhanced, the movement of molecular chains of the cross-linked polymer is limited, and the anti-freezing hydrogel has larger breaking elongation and breaking strength, thereby playing a role of enhancing the toughness and mechanical property of the hydrogel material, and improving the practicability and durability of the anti-freezing hydrogel material in an actual application process.

In a second aspect, embodiments of the present application provide a method for preparing a freeze-resistant hydrogel, comprising the following steps:

step S1, mixing clay and water for the first time to obtain a clay suspension;

step S2, adding inorganic salt and a cross-linked polymer monomer into the clay suspension to perform secondary mixing treatment and dissolving treatment to obtain dispersion liquid;

and step S3, adding an initiator into the dispersion liquid for third mixing treatment, and carrying out polymerization reaction to obtain the antifreeze hydrogel.

According to the first aspect of the antifreeze hydrogel preparation method, clay is used as a physical cross-linking agent, cross-linked polymer monomers are cross-linked into cross-linked polymers under the action of an initiator, and the cross-linked polymers, inorganic salt and the clay are mixed together to form the antifreeze hydrogel. In addition, in the preparation process of the embodiment of the application, the addition of the inorganic salt can be flexibly adjusted according to requirements to prepare the antifreeze hydrogel with different phase transition temperatures.

In the embodiment, in step S1, the suspended particle size of the clay in the clay suspension is not greater than 100nm, and after the clay and water are mixed in the embodiment of the present application, the suspended particle size in the clay suspension is not greater than 100nm, and after the free polymerization, the clay can stably exist in the antifreeze gel at a nanometer level.

In an embodiment, in step S2, the mass ratio of the cross-linked polymer monomer to water is 0.14:1 to 0.42:1, and the cross-linked polymer monomer is well soluble in water after mixing the cross-linked polymer monomer, the cross-linked polymer monomer and water and before the radical polymerization reaction. After the free radical polymerization reaction, water can be dispersed in the three-dimensional network structure of the cross-linking polymerization, and the stability of the antifreeze hydrogel can be further improved.

In the embodiment, in step S3, the mass ratio of the initiator to the crosslinked polymer monomer is 0.005:1 to 0.01:1, and after the initiator and the crosslinked polymer monomer are mixed, the degree of crosslinking of the polymer monomer is increased, thereby improving the stability of the antifreeze hydrogel.

In an embodiment, the initiator comprises one of ammonium persulfate, potassium persulfate, benzoyl oxide, t-butyl hydroperoxide, or a photoinitiator 2959, provided in embodiments herein to initiate polymerization of the cross-linked polymer monomer.

In a third aspect, embodiments of the present application provide a use of a freeze resistant hydrogel in a soft brake, a sensor, and a flexible electronic energy storage device, wherein the sensor includes a wearable sensor.

Just because the frost-resistant hydrogel that this application embodiment provided deformability is strong, and electric conductive property is good, therefore the frost-resistant hydrogel that this application embodiment provided deformability is strong can be used to soft stopper, sensor and flexible electronic energy storage equipment device.

The following description will be given with reference to specific examples.

Example 1

This example provides a freeze resistant hydrogel and a method for making the same, comprising the steps of:

preparing 2 wt% of sodium magnesium lithium silicate nano clay suspension by using the sodium magnesium lithium silicate nano clay and water according to the mass ratio of 1: 49;

weighing 1.6g of lithium chloride, stirring and dissolving the lithium chloride in 10mL of 2 wt% sodium magnesium lithium silicate nano clay suspension, and weighing 2.8g of sulfobetaine methacrylate, and adding the sulfobetaine methacrylate into the sodium magnesium lithium silicate nano clay/lithium chloride suspension;

then ammonium persulfate with the concentration of 0.2 wt% is added, the mixture is fully stirred, and the antifreeze hydrogel is formed through free radical polymerization.

Example 2

This example provides a freeze resistant hydrogel and a method for making the same, comprising the steps of: preparing 2 wt% of sodium magnesium lithium silicate nano clay suspension by using the sodium magnesium lithium silicate nano clay and water according to the mass ratio of 1: 49;

weighing 2g of sodium chloride, stirring and dissolving the sodium chloride in 10mL of 2 wt% sodium magnesium lithium silicate nano clay suspension, and weighing 2.8g of sulfobetaine methacrylate, and adding the sulfobetaine methacrylate into the sodium magnesium lithium silicate nano clay/lithium chloride suspension;

then ammonium persulfate with the concentration of 0.2 wt% is added, the mixture is fully stirred, and the antifreeze hydrogel is formed through free radical polymerization.

Example 3

This example provides a freeze resistant hydrogel and a method for making the same, comprising the steps of: preparing 2 wt% of sodium magnesium lithium silicate nano clay suspension by using the sodium magnesium lithium silicate nano clay and water according to the mass ratio of 1: 49;

weighing 2.2g of sodium chloride, stirring and dissolving in 10mL of 2 wt% sodium magnesium lithium silicate nano clay suspension, and weighing 2.8g of sulfobetaine methacrylate, and adding into the sodium magnesium lithium silicate nano clay/lithium chloride suspension;

then adding potassium persulfate with the concentration of 0.2 wt%, fully stirring, and forming the antifreeze hydrogel through free radical polymerization.

Example 4

This example provides a freeze resistant hydrogel and a method for making the same, comprising the steps of: preparing 2 wt% of sodium magnesium lithium silicate nano clay suspension by using the sodium magnesium lithium silicate nano clay and water according to the mass ratio of 1: 49;

weighing 2.8g of potassium chloride, stirring and dissolving in 10mL of 2 wt% sodium magnesium lithium silicate nano clay suspension, and weighing 2.8g of sulfobetaine methacrylate, and adding into the sodium magnesium lithium silicate nano clay/lithium chloride suspension;

then adding potassium persulfate with the concentration of 0.2 wt%, fully stirring, and forming the antifreeze hydrogel through free radical polymerization.

Example 5

This example provides a freeze resistant hydrogel and a method for making the same, comprising the steps of: preparing 2 wt% of sodium magnesium lithium silicate nano clay suspension by using the sodium magnesium lithium silicate nano clay and water according to the mass ratio of 1: 49;

weighing 2.8g of potassium chloride, stirring and dissolving in 10mL of montmorillonite nano clay suspension consisting of 2 wt% of aluminosilicate layer, and weighing 2.8g of sulfobetaine methacrylate, and adding into the sodium silicate magnesium lithium nano clay/lithium chloride suspension;

then adding potassium persulfate with the concentration of 0.2 wt%, fully stirring, and forming the antifreeze hydrogel through free radical polymerization.

Example 6

This example provides a freeze resistant hydrogel and a method for making the same, comprising the steps of: preparing 2 wt% of sodium magnesium lithium silicate nano clay suspension by using the sodium magnesium lithium silicate nano clay and water according to the mass ratio of 1: 49;

weighing 2.8g of potassium chloride, and stirring and dissolving in 10mL of 2 wt% sodium magnesium lithium silicate nano clay suspension; weighing 2.8g of sulfobetaine methacrylate and adding the sulfobetaine methacrylate into the sodium magnesium lithium silicate nano clay/lithium chloride suspension;

then adding benzoyl oxide with the concentration of 0.2 wt%, fully stirring, and forming the antifreeze hydrogel through free radical polymerization.

Example 7

This example provides a freeze resistant hydrogel and a method for making the same, comprising the steps of: preparing 2 wt% of sodium magnesium lithium silicate nano clay suspension by using the sodium magnesium lithium silicate nano clay and water according to the mass ratio of 1: 49;

weighing 2.8g of lithium chloride, and stirring and dissolving the lithium chloride in 10mL of 2 wt% sodium magnesium lithium silicate nano clay suspension; weighing 2.8g of sulfobetaine methacrylate and adding the sulfobetaine methacrylate into the sodium magnesium lithium silicate nano clay/lithium chloride suspension;

then adding tert-butyl hydroperoxide with the concentration of 0.2 wt%, fully stirring, and forming the antifreeze hydrogel through free radical polymerization.

Example 8

This example provides a freeze resistant hydrogel and a method for making the same, the method comprising the steps of: preparing 2 wt% of sodium magnesium lithium silicate nano clay suspension by using the sodium magnesium lithium silicate nano clay and water according to the mass ratio of 1: 49;

weighing 2.2g of lithium chloride, stirring and dissolving the lithium chloride in 10mL of 2 wt% sodium magnesium lithium silicate nano clay suspension, and weighing 2.8g of sulfobetaine methacrylate, and adding the sulfobetaine methacrylate into the sodium magnesium lithium silicate nano clay/lithium chloride suspension;

then, 0.2 wt% of a photoinitiator 2959 was added thereto, and the mixture was sufficiently stirred to form a hydrogel by radical polymerization.

Example 9

This example provides a freeze resistant hydrogel and a method for making the same, comprising the steps of:

preparing 2.5 wt% of sodium magnesium lithium silicate nano clay suspension by using the sodium magnesium lithium silicate nano clay and water according to the mass ratio of 1: 40;

weighing 2.2g of lithium chloride, stirring and dissolving the lithium chloride in 10mL of 2 wt% sodium magnesium lithium silicate nano clay suspension, and weighing 2.8g of sulfobetaine methacrylate, and adding the sulfobetaine methacrylate into the sodium magnesium lithium silicate nano clay/lithium chloride suspension;

then, 0.2 wt% of a photoinitiator 2959 was added thereto, and the mixture was sufficiently stirred to form a hydrogel by radical polymerization.

Example 10

This example provides a freeze resistant hydrogel and a method for making the same, comprising the steps of:

preparing 2 wt% of sodium magnesium lithium silicate nano clay suspension by using the sodium magnesium lithium silicate nano clay and water according to the mass ratio of 1: 49;

weighing 2.2g of lithium chloride, stirring and dissolving the lithium chloride in 10mL of 2 wt% sodium magnesium lithium silicate nano clay suspension, and weighing 2.8g of sulfobetaine methacrylate, and adding the sulfobetaine methacrylate into the sodium magnesium lithium silicate nano clay/lithium chloride suspension;

then, 0.2 wt% of a photoinitiator 2959 was added thereto, and the mixture was sufficiently stirred to form a hydrogel by radical polymerization.

Example 11

This example provides a freeze resistant hydrogel and a method for making the same, the method comprising the steps of:

preparing 2 wt% of sodium magnesium lithium silicate nano clay suspension by using the sodium magnesium lithium silicate nano clay and water according to the mass ratio of 1: 49;

weighing 2.2g of lithium chloride, stirring and dissolving the lithium chloride in 10mL of 2 wt% sodium magnesium lithium silicate nano clay suspension, and weighing 2.8g of sulfobetaine methacrylate, and adding the sulfobetaine methacrylate into the sodium magnesium lithium silicate nano clay/lithium chloride suspension;

then, 0.2 wt% of a photoinitiator 2959 was added thereto, and the mixture was sufficiently stirred to form a hydrogel by radical polymerization.

Example 12

This example provides a freeze resistant hydrogel and a method for making the same, the method comprising the steps of:

preparing 1.6 wt% of sodium magnesium lithium silicate nano clay suspension by using sodium magnesium lithium silicate nano clay and water according to the mass ratio of 1: 25;

weighing 2.2g of lithium chloride, stirring and dissolving the lithium chloride in 10mL of 1.6 wt% sodium magnesium lithium silicate nano clay suspension, and weighing 2.8g of sulfobetaine methacrylate, and adding the sulfobetaine methacrylate into the sodium magnesium lithium silicate nano clay/lithium chloride suspension;

then adding a photoinitiator 2959 with the concentration of 0.2 wt%, fully stirring, and forming the antifreeze hydrogel through free radical polymerization.

Performance testing of antifreeze hydrogels

The performance tests were carried out on the deicing hydrogels prepared in examples 1 to 12.

(1) The differential scanning calorimetry analysis test method comprises the following steps:

the differential scanning calorimetry analysis of the hydrogel samples was performed in a differential scanning calorimetry analyzer (Perkin Elmer DSC8000), the samples were first cooled from 20 ℃ to-80 ℃ and then returned from-80 ℃ to 20 ℃, the temperature rise and drop rates were both 5 ℃/min, the sample mass was about 5mg, and the test results are shown in fig. 1.

(1) The tensile property test method comprises the following steps:

the hydrogel thus prepared was cut into 20mm × 10mm × 1mm specimens, and subjected to a tensile test using a material testing machine (mark-10) at an effective distance of 10mm and a tensile rate of 20mm/min, as shown in FIGS. 2 to 3.

(2) The compression performance test method comprises the following steps:

the hydrogel thus prepared was cut into a cylinder having a diameter of 15mm × 2mm, and subjected to a compression test using a Material testing machine (mark-10) at a compression rate of 1mm/min, as shown in FIG. 4.

(4) The conductivity testing method comprises the following steps:

soaking the anti-freezing gel in deionized water, wiping off the water on the surface, fixing copper wires, coating silver glue, and testing the conductivity of the sample by a four-electrode method, wherein the test result is shown in fig. 5.

FIG. 1 is a plot of heat flow versus temperature for a hydrogel, where the temperature corresponding to the freezing peak in the plot can be considered to be the freezing point of the hydrogel at-56.4 deg.C, further illustrating the freezing resistance of the freeze-resistant hydrogel provided in example 1 of the present application.

FIGS. 2 and 3 are tensile and compressive stress-strain curves, respectively, for the antifreeze hydrogel prepared in this example. As can be seen from FIG. 2, the freeze resistant hydrogel provided in example 1 of the present application is shown to have a maximum tensile stress of 241.4kPa and a tensile elongation of 2275%. As can be seen from FIG. 3, the hydrogel reached a stress of 45kPa at a compressive strain of 80%.

FIG. 4 is a drawing of a tensile deformation of a freeze-resistant hydrogel at-50 ℃, wherein FIG. 4A corresponds to a state diagram of the freeze-resistant hydrogel in example 1 of the present application in a natural state, FIG. 4B is a state diagram of the freeze-resistant hydrogel in example 1 of the present application after being knotted, FIG. 4C is a state diagram after tensile forces are applied to two ends of the freeze-resistant hydrogel in example 1 of the present application after being knotted, and the processes of FIG. 4A, FIG. 4B and FIG. 4C can illustrate that the freeze-resistant hydrogel provided in example 1 of the present application can be arbitrarily tensile deformed at-50 ℃ and still maintain the properties of the hydrogel.

FIG. 5 is a conductivity scatterplot of the freeze resistant hydrogel provided in example 1 of the present application, the experimental results show that the hydrogel provided in example 1 of the present application has a conductivity of 14.9mS.cm^-1，Has excellent conductivity.

In addition, the antifreeze hydrogels provided according to examples 2 to 12 have good conductivity and antifreeze properties compared to those of example 1, and can be applied to soft actuators, sensors, and flexible electronic energy storage devices.

The present invention is not intended to be limited to the particular embodiments shown and described, but is to be accorded the widest scope consistent with the principles and novel features herein disclosed.