阅读说明：本技术 多功能液晶聚合物网络/液态金属制备方法及应用 (Preparation method and application of multifunctional liquid crystal polymer network/liquid metal ) 是由 余黎 于 2020-05-20 设计创作，主要内容包括：本发明涉及一种多功能液态金属/液晶交联聚合物网络柔性驱动器件及其制备方法,制备原料包含液晶单体、链增长剂、交联剂、催化剂、光引发剂和液态金属,制备方法包括溶剂成型和机械编程。所制备的多功能液态金属/液晶交联聚合物网络柔性驱动器件具备超高导电率3.4×10～(6)S/m和较大的可逆形变200％,可作为抗疲劳性优异的热响应智能电子开关。此外,液晶交联聚合物网络管驱动器件的表面结构可调,且此法适用于不同的液晶体系,包括丙烯酸酯、聚硅氧烷、环氧树脂和聚氨酯。(The invention relates to a multifunctional liquid metal/liquid crystal cross-linked polymer network flexible driving device and a preparation method thereof. The prepared multifunctional liquid metal/liquid crystal cross-linked polymer network flexible driving device has ultrahigh conductivity of 3.4 multiplied by 10 6 S/m and larger reversible deformation is 200%, and the product can be used as a thermal response intelligent electronic switch with excellent fatigue resistance. In addition, the surface structure of the liquid crystal cross-linked polymer network tube driving device is adjustable, and the method is suitable for different liquid crystal systems including acrylate, polysiloxane, epoxy resin and polyurethane.)

1. A multifunctional liquid metal/liquid crystal cross-linked polymer network flexible driving device is designed and prepared by taking a liquid crystal cross-linked polymer network pipe driver prepared by solvent forming and mechanical programming as a subject frame and taking low-melting-point liquid metal as a conductive functional component, and the preparation method of the flexible driving device with ultrahigh conductivity and larger reversible deformation comprises the following steps:

(1) adding a liquid crystal monomer, a chain extender, a cross-linking agent, a catalyst and a photoinitiator into a solvent, uniformly mixing, adding into a self-made mould, and forming to obtain multi-domain (non-oriented) liquid crystal cross-linked polymer network pipes with different sizes;

(2) obtaining a single-domain (oriented) liquid crystal cross-linked polymer network tube driving device by a mechanical programming method, adopting mechanical stretching to enable a multi-domain (non-oriented) liquid crystal cross-linked polymer network tube to be oriented along the stretching direction, and fixing the orientation mode of liquid crystal in the liquid crystal cross-linked polymer network by ultraviolet light cross-linking;

(3) the prepared low-melting-point liquid metal is directly injected into a liquid crystal cross-linked polymer network tube driving device to obtain the multifunctional flexible driving device with ultrahigh conductivity and larger reversible deformation, and the multifunctional flexible driving device can be applied to a thermal response intelligent electronic switch.

2. The flexible multifunctional liquid metal/liquid crystal crosslinked polymer network driver device of claim 1 wherein the liquid crystal monomer is a difunctional polymerizable liquid crystal molecule.

3. The flexible multifunctional liquid metal/liquid crystal polymer network driver device of claim 1, wherein the liquid crystal polymer network tube driver device is fabricated by mechanical programming.

4. The flexible driver device of claim 1 wherein the liquid metal is a simple metal or alloy with a melting point below room temperature.

5. The multifunctional liquid metal/liquid crystal polymer network flexible driver device of claim 1, wherein the multifunctional liquid metal/liquid crystal polymer network flexible driver device functions as a thermally responsive intelligent electronic switch.

Technical Field

The invention relates to a multifunctional liquid metal/liquid crystal cross-linked polymer network flexible driving device and a preparation method thereof.

Background

The intelligent material is a material which can generate shape change under the stimulation of external environment, and comprises piezoelectric ceramics, shape memory alloy and the like. The intelligent high polymer material is widely concerned by the scientific research field and the industrial field because of the characteristics of easy processing and forming, light weight, flexibility, corrosion resistance and the like, and is expected to be applied to the fields of robots, flexible solar cells, anti-counterfeiting, camouflage and the like.

The intelligent polymer materials are various in types and comprise hydrogel, shape memory polymer, electroactive polymer and elastomer. Compared with the above intelligent high molecular materials, the liquid crystal crosslinked polymer network is gradually a research hotspot due to a series of unique properties. 1. Under the stimulation of external conditions, the liquid crystal cross-linked polymer network can deform under different harsh environments such as water, vacuum and the like. 2. The liquid crystal cross-linked polymer network can generate reversible deformation under the action of various external stimuli such as temperature, humidity, light, electric field and magnetic field, and the deformation quantity is large. 3. The orientation mode of the liquid crystal is adjusted through the self-assembly behavior of the liquid crystal, so that the deformation behavior of the liquid crystal cross-linked polymer network can be effectively adjusted and controlled. Currently, many flexible driving devices have been developed using liquid crystal cross-linked polymer networks. However, designing and fabricating multifunctional flexible actuation devices based on liquid crystal cross-linked polymer networks still presents significant challenges. For example, when the conductive material is added into the liquid crystal cross-linked polymer network to endow the liquid crystal cross-linked polymer network with the conductive performance, the original stimulation response deformation behavior of the liquid crystal cross-linked polymer network can be sacrificed, and the flexibility and the larger reversible deformation of the liquid crystal cross-linked polymer network are obviously reduced.

Disclosure of Invention

The invention aims to solve the problems that in the design and preparation of a multifunctional liquid crystal cross-linked polymer network flexible driving device, ultrahigh conductivity is difficult to realize, and better mechanical property and larger reversible deformation of the device are maintained. The liquid crystal cross-linked polymer network tube with larger reversible deformation is prepared by adopting a mechanical programming method, and the liquid metal with low melting point is directly poured into the liquid crystal cross-linked polymer network tube to obtain the multifunctional flexible driving device with ultrahigh conductivity and larger reversible deformation. The invention provides a preparation method of a multifunctional liquid crystal cross-linked polymer network flexible driving device with simple process and adjustable performance.

The preparation method comprises the following steps:

(1) adding a liquid crystal monomer, a chain extender, a crosslinking agent, a catalyst and a photoinitiator into a solvent, uniformly mixing, adding into a self-made mould, and molding to obtain the multi-domain (non-oriented) liquid crystal crosslinked polymer network pipes (figure 1) with different sizes.

(2) The monodomain (oriented) liquid crystal cross-linked polymer network tube driving device is obtained by a mechanical programming method (figure 2). The multi-domain (non-oriented) liquid crystal cross-linked polymer network tube is oriented along the stretching direction by adopting mechanical stretching, and the ultraviolet light cross-links and fixes the orientation mode of the liquid crystal in the liquid crystal cross-linked polymer network.

(3) The prepared low-melting-point liquid metal is directly injected into a liquid crystal cross-linked polymer network tube driving device to obtain a multifunctional flexible driving device (figure 3) with ultrahigh conductivity and large reversible deformation, and the multifunctional flexible driving device can be applied to a thermal response intelligent electronic switch (figure 4).

The invention has the characteristics that:

the invention adopts a mechanical programming method to prepare the liquid crystal cross-linked polymer network tube with larger reversible deformation, and directly injects the liquid metal with low melting point into the liquid crystal cross-linked polymer network tube to obtain the multifunctional flexible driving device with ultrahigh conductivity and larger reversible deformation. The invention has the advantages that:

(1) the single-domain (oriented) liquid crystal cross-linked polymer network tube driving device obtained by a mechanical programming method has large reversible deformation, and the deformation amount in the length direction can reach 200%.

(2) Mechanical programming is applicable to different liquid crystal systems including acrylates, silicones, epoxies and polyurethanes.

(3) The surface structure of the liquid crystal cross-linked polymer network tube driving device prepared by the mechanical programming method is adjustable (figure 5).

(4) The multifunctional liquid metal/liquid crystal cross-linked polymer network flexible driving device has the ultrahigh conductivity of 3.4 multiplied by 10⁶S/m and a large reversible deformation of 200%.

(5) The multifunctional liquid metal/liquid crystal cross-linked polymer network flexible driving device can be used as a thermal response intelligent electronic switch with excellent fatigue resistance.

Drawings

FIG. 1 is a photograph of tubes of liquid crystal cross-linked polymer network of varying internal diameters.

FIG. 2 is a photograph of reversible thermal driving behavior of a liquid crystal cross-linked polymer network tube.

FIG. 3 shows the conductivity and reversible thermal driving behavior of a liquid metal/liquid crystal cross-linked polymer network flexible driving device at different temperatures.

Figure 4 a liquid metal/liquid crystal cross-linked polymer network flexible actuation device is used as a thermally responsive electrical switch.

FIG. 5 shows the control of the surface structure of the driving device of the liquid crystal cross-linked polymer network tube by a mechanical programming method.

Detailed description of the preferred embodiments

Example 1

(1) Adding a liquid crystal monomer, a chain extender, a cross-linking agent, a catalyst and a photoinitiator into a solvent, uniformly mixing, pouring into a self-made mould, and drying at 80 ℃ for 12-24 hours to obtain the multi-domain (non-oriented) liquid crystal cross-linked polymer network tube.

(2) Mechanically stretching the multidomain (non-oriented) liquid crystalline cross-linked polymer network tube at a strain of 200% and at a light intensity of 30mW/cm²And irradiating for 15-30 minutes under ultraviolet light to obtain the single domain (oriented) liquid crystal cross-linked polymer network tube driving device.

(3) And directly injecting the prepared indium-gallium alloy with the melting point of 15 ℃ into a liquid crystal cross-linked polymer network tube driving device to prepare the multifunctional liquid metal/liquid crystal cross-linked polymer network flexible driving device.

Example 2

(1) Adding a liquid crystal monomer, a chain extender, a cross-linking agent, a catalyst and a photoinitiator into a solvent, uniformly mixing, pouring into a self-made mould, and drying at 80 ℃ for 12-24 hours to obtain the multi-domain (non-oriented) liquid crystal cross-linked polymer network tube.

(2) Mechanically stretching the multidomain (non-oriented) liquid crystalline cross-linked polymer network tube at a strain of 200% and at a light intensity of 30mW/cm²And irradiating for 15-30 minutes under ultraviolet light to obtain the single domain (oriented) liquid crystal cross-linked polymer network tube driving device.

(3) And directly injecting the prepared indium-gallium alloy with the melting point of 15 ℃ into a liquid crystal cross-linked polymer network tube driving device to prepare the multifunctional liquid metal/liquid crystal cross-linked polymer network flexible driving device.

Example 3

(1) Adding a liquid crystal monomer, a chain extender, a cross-linking agent, a catalyst and a photoinitiator into a solvent, uniformly mixing, pouring into a self-made mould, and drying at 80 ℃ for 12-24 hours to obtain the multi-domain (non-oriented) liquid crystal cross-linked polymer network tube.

(2) Mechanically stretching the multidomain (non-oriented) liquid crystalline cross-linked polymer network tube at a strain of 200% and at a light intensity of 30mW/cm²And irradiating for 15-30 minutes under ultraviolet light to obtain the single domain (oriented) liquid crystal cross-linked polymer network tube driving device.

(3) And directly injecting the prepared indium-gallium alloy with the melting point of 5 ℃ into a liquid crystal cross-linked polymer network tube driving device to prepare the multifunctional liquid metal/liquid crystal cross-linked polymer network flexible driving device.