阅读说明：本技术 液晶弹性体的制备方法与液晶驱动元件 (Preparation method of liquid crystal elastomer and liquid crystal driving element ) 是由 吉岩 梁欢 于 2021-07-01 设计创作，主要内容包括：本发明提供一种液晶弹性体的制备方法与液晶驱动元件。液晶弹性体的制备方法包括以下步骤：(a)提供包含液晶单体、扩链剂和交联剂的混合溶液,其中,液晶单体选自双端丙烯酸酯类液晶单体,扩链剂选自二巯基单体,交联剂选自三巯基单体和四巯基单体中的一种或多种；(b)在混合溶液中,使液晶单体、扩链剂和交联剂发生聚合反应；(c)对步骤(b)所得反应混合物进行干燥处理,得到液晶弹性体。根据本发明的液晶弹性体在室温下可塑形,且进一步放置可实现永久塑形。(The invention provides a preparation method of a liquid crystal elastomer and a liquid crystal driving element. The preparation method of the liquid crystal elastomer comprises the following steps: (a) providing a mixed solution containing a liquid crystal monomer, a chain extender and a cross-linking agent, wherein the liquid crystal monomer is selected from a double-end acrylate liquid crystal monomer, the chain extender is selected from a dimercapto monomer, and the cross-linking agent is selected from one or more of a trimercapto monomer and a tetramercapto monomer; (b) in the mixed solution, carrying out polymerization reaction on the liquid crystal monomer, the chain extender and the cross-linking agent; (c) drying the reaction mixture obtained in the step (b) to obtain the liquid crystal elastomer. The liquid crystal elastomer according to the present invention is moldable at room temperature, and further standing can achieve permanent molding.)

1. The preparation method of the liquid crystal elastomer is characterized by comprising the following steps of:

(a) providing a mixed solution containing the liquid crystal monomer, a chain extender and a cross-linking agent, wherein the liquid crystal monomer is selected from the compound shown in the formula (I), the chain extender is selected from a dimercapto monomer, and the cross-linking agent is selected from one or more of a trimercapto monomer and a tetramercapto monomer,

in the formula (I), R is¹、R²、R³、R⁴Each independently represents hydrogen or methyl, R⁵And R⁶Each independently represents a C3-C6 alkyl group;

(b) in the mixed solution, carrying out polymerization reaction on a liquid crystal monomer, a chain extender and a cross-linking agent;

(c) drying the reaction mixture obtained in the step (b) to remove the solvent, thereby obtaining the liquid crystal elastomer.

2. The method according to claim 1, wherein the mass fraction of the liquid crystal monomer is 65% to 75% based on the total mass of the liquid crystal monomer, the chain extender and the cross-linking agent.

3. The method according to claim 1, wherein the ratio of the total molar amount of the acryloyloxy groups of the liquid crystal monomer to the total molar amount of the mercapto groups of the chain extender and the cross-linking agent is 2:3 to 3: 2.

4. The method according to claim 1, wherein the molar ratio of the cross-linking agent to the chain extender is 1.5:1 to 5: 1.

5. The method of claim 1, wherein the liquid crystal monomer is selected from one or more of 1, 4-bis [4- (3-acryloyloxypropoxy) -benzoyloxy ] -2-methyl-benzene (RM257) and 1, 4-bis [4- (6-acryloyloxyhexyloxy) benzoyloxy ] -2-methyl-benzene (RM 82).

6. The process of claim 1, wherein the chain extender is selected from one or more of 2, 2' - (1, 2-ethanediylbis-oxo) bisethanethiol (DODT), 3, 6-dioxo-1, 8-octanedithiol (EDDET), 1, 3-propanedithiol and 1, 6-hexanedithiol; and/or the presence of a gas in the gas,

the cross-linking agent is selected from one or more of 3-mercaptopropionic acid-2-ethyl-2- [ (3-mercapto-1-oxopropoxy) methyl ] -1, 3-propanediol and pentaerythritol tetrakis (3-mercaptopropionate).

7. The process of claim 1, wherein the temperature of the polymerization reaction of step (b) is from 20 ℃ to 30 ℃;

the drying treatment in the step (c) is carried out under the conditions of vacuum and the temperature of 60-100 ℃.

8. The method of any one of claims 1-7, further comprising:

(d) applying a force to the liquid crystal elastomer at 20-30 ℃ to enable the liquid crystal elastomer to generate plastic deformation;

(e) and (3) placing the liquid crystal elastomer at the temperature of between 20 and 30 ℃ for more than 7 days to obtain the single-domain liquid crystal elastomer.

9. The method of claim 8, wherein the deformation in step (d) is a tensile deformation, and the liquid crystal elastomer undergoes a tensile deformation at a deformation rate of 5% to 70%, or 10% to 50%.

10. A liquid crystal driving device, wherein the liquid crystal elastomer obtained by the method according to any one of claims 1 to 9 is used.

Technical Field

The invention belongs to the technical field of liquid crystal materials, and particularly relates to a preparation method of a liquid crystal elastomer and a liquid crystal driving element.

Background

Liquid Crystal Elastomers (LCEs) are a class of novel smart materials that respond to external stimuli, such as reversible deformation under external stimuli such as light, heat, magnetic fields, and the like. This property of liquid crystal elastomers makes them potentially useful as actuators and sensors in the fields of artificial muscles, microfluidic valves, flexible robots, blind displays, and the like.

The liquid crystal elastomer can be permanently shaped and temporarily shaped without changing the crosslinking density of the network. Permanent shaping is often achieved by introducing dynamic covalent bonds in the system. For example, the liquid crystal elastomer is deformed by applying an external force and heated to the topological freezing transformation temperature T_vKeeping the temperature above for a period of time, and then reducing the temperature to T_vPermanent shaping can be achieved as follows. For the majorityIn order to realize temporary shaping, a liquid crystal elastomer is often deformed at a temperature higher than the glass transition temperature, and the temporary deformation is maintained by lowering the temperature of the deformation to a temperature lower than the glass transition temperature. When the liquid crystal elastomer is heated again to a temperature higher than the glass transition temperature, the deformation disappears and the original shape is recovered. Therefore, for most liquid crystal elastomers, to realize reshaping, temperature-dependent change is required, i.e., deformation occurs at a higher temperature, and deformation is maintained at a lower temperature.

Disclosure of Invention

The invention provides a liquid crystal elastomer which can be shaped at room temperature, and can realize permanent shaping by further placing, and the process does not need any change of external conditions or additional energy input.

The first aspect of the present invention provides a method for preparing a liquid crystal elastomer, comprising the steps of:

(a) providing a mixed solution containing the liquid crystal monomer, a chain extender and a cross-linking agent, wherein the liquid crystal monomer is selected from the compound shown in the formula (I), the chain extender is selected from a dimercapto monomer, and the cross-linking agent is selected from one or more of a trimercapto monomer and a tetramercapto monomer,

in the formula (I), R is¹、R²、R³、R⁴Each independently represents hydrogen or methyl, R⁵And R⁶Each independently represents a C3-C6 alkyl group;

(b) in the mixed solution, carrying out polymerization reaction on a liquid crystal monomer, a chain extender and a cross-linking agent;

(c) drying the reaction mixture obtained in the step (b) to obtain the liquid crystal elastomer.

A second aspect of the present invention provides a liquid crystal driving device in which the liquid crystal elastomer according to the present invention is employed.

The invention adopts proper liquid crystal monomer, chain extender and cross linker to carry out polymerization reaction, and the liquid crystal elastomer obtained by drying treatment can be temporarily shaped at room temperature, and can realize permanent shaping by further placing, and the process does not need external stimulation. The permanently shaped liquid crystal elastomer can achieve reversible driving. In addition, compared with the problem that the single domain preparation by the two-step method is difficult to control the cross-linking density of the first step and the operation of pulling the sample off is easy to carry out by the dynamic covalent bond method, the method for shaping and fixing the single domain at room temperature is easy to control, simple to operate, mild in condition and good in stability.

Detailed Description

In order to make the objects, technical solutions and advantageous effects of the present invention more clear, the present invention is described in detail with reference to specific embodiments below. It should be understood that the embodiments described in this specification are only for the purpose of explaining the present invention and are not intended to limit the present invention.

For the sake of brevity, only some numerical ranges are explicitly disclosed herein. However, any lower limit may be combined with any upper limit to form ranges not explicitly recited; and any lower limit may be combined with any other lower limit to form a range not explicitly recited, and similarly any upper limit may be combined with any other upper limit to form a range not explicitly recited. Also, although not explicitly recited, each point or individual value between endpoints of a range is encompassed within the range. Thus, each point or individual value can form a range not explicitly recited as its own lower or upper limit in combination with any other point or individual value or in combination with other lower or upper limits.

In the description herein, it is to be noted that, unless otherwise specified, "above" and "below" are inclusive, and "one or more" of "plural" means two or more.

The above summary of the present invention is not intended to describe each disclosed embodiment or every implementation of the present invention. The following description more particularly exemplifies illustrative embodiments. At various points throughout this application, guidance is provided through a list of embodiments that can be used in various combinations. In various embodiments, the lists are provided as representative groups and should not be construed as exhaustive.

The invention provides a preparation method of a liquid crystal elastomer, which comprises a step (a) of providing a mixed solution, a polymerization reaction step (b) and a drying step (c).

In the step (a) of providing a mixed solution, a mixed solution including the liquid crystal monomer, the chain extender, and the cross-linking agent is provided.

In the step (a), the liquid crystal monomer is selected from double-ended acrylate liquid crystal monomers. In some embodiments, both ends of the backbone of the double-ended acrylate-based liquid crystal monomer are acrylate groups. In some embodiments, preferably, the liquid crystal monomer is selected from compounds described by formula (I).

In the formula (I), R¹、R²、R³、R⁴Each independently represents hydrogen or methyl, R⁵And R⁶Each independently represents a C3-C6 alkylene group.

In some embodiments, R¹、R²、R³、R⁴At least one of them represents a methyl group. Alternatively, R¹、R²、R³、R⁴One of them represents a methyl group, and the others represent hydrogen. For example, R¹Represents a methyl group, R²、R³And R⁴All represent hydrogen.

In any of the embodiments of the present invention, the alkylene group having C3-C6 represents an alkylene group having 3-6 carbon atoms. Examples of the alkylene group of C3 to C6 may include n-propylene, isopropylene, n-butylene, isobutylene, sec-butylene, tert-butylene, n-pentylene, isopentylene, n-hexylene and the like. One or more of the hydrogens of the C3-C6 alkylene groups may be replaced with other elements or groups. Other elements may be, but are not limited to, F, Cl, O, and the like. Other groups may be, but are not limited to, hydroxyl, amino, phenyl, methoxy, and the like.

In some embodiments, R⁵And R⁶Can respectively and independently representN-propylene, n-butylene, n-pentylene, or n-hexylene.

In some embodiments, the liquid crystal monomer may be selected from one or more of 1, 4-bis [4- (3-acryloyloxypropyl) -benzoyloxy ] -2-methyl-benzene (RM257) and 1, 4-bis [4- (6-acryloyloxyhexyloxy) benzoyloxy ] -2-methyl-benzene (RM 82).

In step (a), the chain extender is selected from dimercapto monomers. In some embodiments, both ends of the backbone of the dimercapto monomer are mercapto. As an example, the chain extender may be selected from one or more of 2, 2' - (1, 2-ethanediylbis-oxo) bisethanethiol (DODT), 3, 6-dioxo-1, 8-octanedithiol (EDDET), 1, 3-propanedithiol and 1, 6-hexanedithiol.

In step (a), the crosslinking agent is selected from one or more of a trimercapto monomer and a tetramercapto monomer. By way of example, the cross-linking agent may be selected from one or more of 3-mercaptopropionic acid-2-ethyl-2- [ (3-mercapto-1-oxopropoxy) methyl ] -1, 3-propanediol and pentaerythritol tetrakis (3-mercaptopropionate).

In some preferred embodiments, in step (a), the mass fraction of the liquid crystal monomer is 65% to 75%, preferably 70% to 75%, based on the total mass of the liquid crystal monomer, the chain extender and the cross-linker. The content of the liquid crystal monomer is in a proper range, so that the performance of the liquid crystal elastomer for realizing temporary shaping at room temperature and further realizing permanent shaping after being placed at room temperature can be further improved. In particular, the reversible driving performance of the permanently shaped liquid crystal elastomer can also be improved.

In this context, the temporary shaping is that the liquid crystal elastomer is deformed under the action of external force, and the deformation is maintained after the external force is removed; and heating the deformed liquid crystal elastomer to a temperature higher than the isotropic phase transition temperature, and cooling to room temperature to recover the liquid crystal elastomer to the original shape. Taking the temporary shaping under uniaxial tension deformation as an example, the liquid crystal elastomer with the original length of L0 is subjected to tension deformation under the action of external force until the length is L1, and then the external force is removed, so that the liquid crystal elastomer maintains the length of L1 after the tension deformation. The stretched liquid crystalline elastomer was heated to above the isotropic phase transition temperature and cooled to room temperature, and the liquid crystalline elastomer was restored to the original length L0.

The permanent shaping is that the liquid crystal elastomer is deformed under the action of external force, and the deformation is kept after the external force is removed; and heating the deformed liquid crystal elastomer to a temperature higher than the isotropic phase transition temperature, and cooling to room temperature to keep the deformation. Taking permanent shaping under uniaxial tension deformation as an example, the liquid crystal elastomer with the original length of L0 is subjected to tension deformation under the action of external force until the length is L1, and then the external force is removed, so that the liquid crystal elastomer keeps the length L1 after the tension deformation. The stretched liquid crystal elastomer is heated to a temperature higher than the isotropic phase transition temperature, and then cooled to room temperature, so that the stretched liquid crystal elastomer still maintains the length L1 after stretching deformation.

In some preferred embodiments, in the step (a), the ratio of the total molar amount of the acryloyloxy groups of the liquid crystal monomer to the total molar amount of the mercapto groups of the chain extender and the crosslinking agent is 2:3 to 3: 2. The total molar amount of the acryloyloxy groups of the liquid crystal monomers refers to the total amount of acryloyloxy groups contained in all the liquid crystal monomers in moles. The total molar amount of the mercapto groups of the chain extender and the crosslinking agent is the sum of the molar amount of the mercapto groups contained in all the chain extenders and the molar amount of the mercapto groups contained in all the crosslinking agents. The ratio of the total molar amount of the acryloyloxy groups of the liquid crystal monomer to the total molar amount of the mercapto groups of the chain extender and the cross-linking agent is in a proper range, so that the reaction is more sufficient, and fewer impurities are generated, thereby further improving the performance of temporary shaping of the liquid crystal elastomer at room temperature and permanent shaping of the liquid crystal elastomer after being further placed at room temperature. In particular, the reversible driving performance of the permanently shaped liquid crystal elastomer is further improved. More preferably, the ratio of the total molar amount of the acryloyloxy groups in the liquid crystal monomer to the total molar amount of the mercapto groups in the chain extender and the crosslinking agent is 4:5 to 5:4, and still more preferably 5:5 to 5: 4.

In some preferred embodiments, in step (a), the molar ratio of the cross-linker to the chain extender is from 1.5:1 to 5: 1. The molar ratio of the cross-linking agent to the chain extender is in a proper range, so that the reaction is more sufficient, and fewer impurities are generated, thereby further improving the performance of the liquid crystal elastomer for realizing temporary shaping at room temperature and further realizing permanent shaping after being placed at room temperature. In particular, the reversible driving performance of the permanently shaped liquid crystal elastomer is further improved. More preferably, the molar ratio of the cross-linking agent to the chain extender is 1:3 to 1: 5.

In some embodiments, preferably, in the step (a), the total mass percentage content of the liquid crystal monomer, the chain extender and the cross-linking agent in the mixed solution is 20 wt% to 60 wt%, and more preferably 30 wt% to 50 wt%. The total concentration of the liquid crystal monomer, the chain extender and the cross-linking agent in the mixed solution is in a proper range, which is beneficial to the final permanently-shaped liquid crystal elastomer to obtain higher driving performance.

In the step (a), the liquid crystal monomer, the chain extender and the cross-linking agent may be added to a solvent to form a mixed solution. The solvent may be an organic solvent. The organic solvent can dissolve the liquid crystal monomer, the chain extender and the cross-linking agent. Preferably, the organic solvent is also readily volatile. For example, the organic solvent has a boiling point of 120 ℃ or lower, 100 ℃ or lower, 80 ℃ or lower, 70 ℃ or lower, or 60 ℃ or lower. In some embodiments, the organic solvent has a boiling point of 30 ℃ to 120 ℃. In some embodiments, the organic solvent has a boiling point of 30 ℃ to 80 ℃. In some embodiments, the organic solvent has a boiling point of 35 ℃ to 70 ℃. As a specific example, the solvent may be selected from one or more of dichloromethane, tetrahydrofuran, toluene, chloroform.

In some embodiments, the mixed solution of step (a) further optionally contains a catalyst. The catalyst is used for catalyzing the polymerization reaction of the liquid crystal monomer, the chain extender and the cross-linking agent. This can improve the reaction efficiency. The catalyst can be selected from catalysts known in the art for catalyzing the polymerization reaction of the acrylate liquid crystal monomer with the mercapto chain extender and the mercapto crosslinking agent. Such as one or more of dipropylamine, triethylamine, and n-hexylamine.

In some embodiments, the catalyst is used in an amount of 0.1 to 2 wt%, preferably 0.5 to 1.5 wt%, such as 1 wt%, based on the total mass of the liquid crystal monomer, the chain extender, and the cross-linker in the mixed solution.

In the step (b), the liquid crystal monomer, the chain extender and the crosslinking agent are subjected to a polymerization reaction in the mixed solution to obtain a reaction mixture containing the liquid crystal elastomer. And (b) carrying out polymerization reaction, and connecting the liquid crystal monomer, the chain extender and the cross-linking agent with each other to form a polymer.

In step (b), the polymerization temperature may be selected from 20 ℃ to 30 ℃, or 23 ℃ to 28 ℃, for example 25 ℃. The time for the polymerization reaction may be selected from 5 to 20 hours, or 10 to 15 hours, such as 12 hours.

In some embodiments, the polymerization of step (b) may be carried out in a mold to obtain the desired shape of the resulting liquid crystalline elastomer. During the reaction, care should be taken to remove bubbles so as not to affect the material properties. The liquid crystal elastomer can be in any shape and can be selected according to actual requirements. For example, the liquid crystal elastomer may have a film shape, a polyhedral shape (for example, a rectangular parallelepiped, a square, a cross shape, or the like), a cylindrical shape, or the like. Of course, the liquid crystal elastic body may be subjected to a post-process such as cutting to obtain a desired shape.

In the drying step (c), the reaction mixture obtained in the step (b) is dried to obtain a liquid crystal elastomer. The polymer is completely dried by the drying treatment of the step (c) to remove the solvent. The reaction mixture may be dried by methods known in the art, such as by heat drying. Preferably by vacuum heat drying.

In some embodiments, step (c) comprises: drying the reaction mixture obtained in the step (b) under vacuum at a temperature of 60-100 ℃. In some embodiments, the temperature of the drying process is from 70 ℃ to 90 ℃, such as 80 ℃.

In some embodiments, the drying treatment in step (c) may be performed for 10 to 48 hours, or 15 to 30 hours, such as 24 hours.

According to the invention, the liquid crystal elastomer is obtained by adopting a proper liquid crystal monomer, a chain extender and a cross-linking agent to perform polymerization reaction and drying treatment, and can be temporarily shaped after deformation treatment at room temperature, and permanent shaping can be realized after further placement, and no external condition change or additional energy input is needed in the process. The permanently shaped liquid crystal elastomer can achieve reversible driving.

In some embodiments, the preparation method of the present invention further comprises: (d) at 20-30 ℃, the liquid crystal elastomer is subjected to plastic deformation; (e) the liquid crystal elastomer is placed at 20-30 ℃ to fix the orientation, and the single-domain liquid crystal elastomer is obtained.

In some embodiments, the liquid crystal elastomer is plastically deformed in the step (d) in various ways, for example, by applying a force to the liquid crystal elastomer to plastically deform the liquid crystal elastomer. The applied force may act as one or a combination of uniaxial stretching, multidirectional stretching, folding, or the like of the liquid crystal elastomer. By multi-directional stretching, the driving performance of different directions of orientation can be completed on the same sample.

In the step (d), the permanently shaped liquid crystal elastomer can be oriented to different degrees by controlling the degree of plastic deformation of the liquid crystal elastomer. For example, the liquid crystal elastomer may be uniaxially stretched at a deformation rate of 5% to 70%, 5% to 50%, 10% to 50%, 20% to 40%, or 25% to 35%. For example, the liquid crystal elastomer is stretched in multiple directions, and the deformation rate in each direction is independently selected from 5% to 70%, 5% to 50%, 10% to 50%, 20% to 40%, 25% to 35%, or the like. The deformation rate is the percentage of the increase in the dimension of the liquid crystal elastomer in the direction of the stretching to the original dimension of the liquid crystal elastomer in the direction of the stretching.

The liquid crystal elastomer can also be folded in half or folded for multiple times, and the folded liquid crystal elastomer is clamped between two pieces of glass so as to fix the orientation. The number of times may be selected as desired, e.g., 2, 3, 4, 5, 6, etc.

The appropriate deformation rate of plastic deformation can be selected according to the reversible driving deformation rate of the needed single-domain liquid crystal elastomer. The larger the deformation rate of plastic deformation in an appropriate range, the larger the reversible drive deformation rate of the monodomain liquid crystalline elastomer is.

In some embodiments, the temperature at which plastic deformation occurs in step (d) may be selected to be in the range of 23 ℃ to 28 ℃, such as 25 ℃.

In some embodiments, the temperature of the step (e) may be selected to be from 23 ℃ to 28 ℃, such as 25 ℃.

In some embodiments, in the step (e), the liquid crystal elastomer may be left for more than 7 days, such as 7 to 50 days, 20 to 50 days, or 25 to 40 days, such as 30 days.

If the liquid crystal elastomer is subjected to plastic deformation by applying a force to the liquid crystal elastomer in the step (d), since the liquid crystal elastomer of the present invention can temporarily maintain the deformation rate, the force can be removed in the step (e) to allow the liquid crystal elastomer to stand at 20 to 30 ℃ to obtain a single-domain liquid crystal elastomer. In another example, the liquid crystal elastomer may be left at 20 ℃ to 30 ℃ under the action of the retaining force without removing the action of the force in step (e), so as to obtain the monodomain liquid crystal elastomer.

The liquid crystal elastomer capable of being molded at room temperature can be temporarily or permanently fixed in various shapes according to the length of the storage time. Different from the existing liquid crystal elastomer preparation method, the process is independent of temperature change and can be realized without external stimulation. The liquid crystal elastomer has the characteristics of being used for fixing liquid crystal orientation and preparing a flexible driver, and is simple to operate, high in success rate and stable in driving.

The present invention also provides a liquid crystal driving device in which the liquid crystal elastomer according to the present invention is employed. The liquid crystal elastomer can be applied to any field or device needing a flexible driver, such as a display screen for the blind, a flexible robot, artificial muscles, artificial pupils, a bionic device and the like. Further, since the liquid crystal driving element employs the liquid crystal elastomer of the present invention, it can have high driving stability.

Examples

The present disclosure is more particularly described in the following examples that are intended as illustrations only, since various modifications and changes within the scope of the present disclosure will be apparent to those skilled in the art. Unless otherwise indicated, all parts, percentages, and ratios reported in the following examples are on a weight basis, and all reagents used in the examples are commercially available or synthesized according to conventional methods and can be used directly without further treatment, and the equipment used in the examples is commercially available.

Example 1

1mmol of liquid crystal monomer RM257, 0.6mmol of chain extender 3, 6-dioxo-1, 8-octanedithiol and 0.2mmol of cross-linking agent pentaerythritol tetrakis (3-mercaptopropionate) were added to dichloromethane at 25 ℃ to obtain a mixed solution. The total mass fraction of the liquid crystal monomer, the chain extender and the cross-linking agent in the mixed solution is 40 wt%. Based on the total mass of the liquid crystal monomer, the chain extender and the cross-linking agent in the mixed solution, 1 wt% of catalyst dipropylamine is dropwise added into the mixed solution, wherein the dipropylamine is diluted by 100 times by using dichloromethane. Pouring the mixed solution containing the catalyst into a polytetrafluoroethylene mold with an inner groove of 40mm long, 40mm wide and 4mm deep, and carrying out polymerization reaction for 12 hours at 25 ℃. And after the reaction is finished, demolding the polymer, drying the polymer in a vacuum drying oven at the temperature of 80 ℃ for 24 hours, and completely drying the polymer to obtain the liquid crystal elastomer capable of being molded at room temperature.

The liquid crystal elastomer was cut into a strip having a length of 25mm, a width of 0.25mm and a thickness of 0.12mm at 25 ℃ and uniaxially stretched in the longitudinal direction, wherein the stretch deformation rate was 50%. After the external force is removed, the liquid crystal elastomer can temporarily keep 50% of deformation rate. And continuously placing the liquid crystal elastomer at 25 ℃ for 30 days, and permanently fixing the deformation to obtain the single-domain liquid crystal elastomer.

In the embodiment, the average driving deformation rate of the obtained single-domain liquid crystal elastomer is about 60-70% by adopting the preparation method of the invention, and the single-domain liquid crystal elastomer has high driving stability.

The above description is only an embodiment of the present invention, but the scope of the present invention is not limited thereto. Those skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope of the present disclosure, and such modifications or substitutions are intended to be included within the scope of the present disclosure. Therefore, the protection scope of the present invention shall be subject to the protection scope defined by the claims.