Preparation method and application of photoresponsive liquid crystal elastomer fiber

Abstract

The application belongs to the technical field of functional textiles, and relates to a preparation method and application of a light-responsive liquid crystal elastomer fiber. The preparation method is as follows: organic dyes with photo-thermal conversion performance are combined with non-light-responsive liquid crystal elastomer fibers through dyeing technology to obtain the light-responsive liquid crystal elastomer fiber; and the application is used for preparing fiber products with selective response to light wave bands. The light-responsive liquid crystal elastomer fiber and products with precise selective response to light wave bands and good reversible driving performance are successfully prepared by using organic dyes with specific photo-thermal conversion performance and normal-temperature dyeing technology.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of functional textiles, and relates to a preparation method and application of a light-responsive liquid crystal elastomer fiber. BACKGROUND

[0002] With the continuous progress of smart material technology, light-responsive liquid crystal elastomer fibers (LCE fibers) have attracted more and more attention due to their potential applications in the field of intelligent driving and response. This kind of fiber can respond to light stimulation, and through the conversion of light energy into heat energy, it can drive the fiber to deform, providing a new solution for the field of intelligent textiles, actuators, etc.

[0003] In the process of preparing light-responsive liquid crystal elastomer fibers, organic dyes are widely used as photo-thermal conversion reagents. However, the existing technology has some problems in the method of preparing light-responsive liquid crystal elastomer fibers using organic dyes. For example, as shown in patent application CN116554440A, organic dyes (such as croconium cyanine dyes) are directly dissolved in organic solvents and mixed with liquid crystal elastomer matrix materials. Although this method is simple, the mixing of dyes often affects the cross-linking reaction between the liquid crystal matrix. The cross-linking of the liquid crystal matrix is a key factor to ensure the reversible driving performance of the fiber, and the mixing of the dye will lead to incomplete cross-linking or uneven distribution of cross-linking points, thereby affecting the mechanical properties and driving performance of the fiber.

[0004] Therefore, it is necessary to propose a method for preparing light-responsive liquid crystal elastomer fibers using organic dyes that can solve the above problems.

[0005] In addition, although there have been studies that select different wavelengths of organic dyes to achieve response to specific waveband light sources, simple combination of materials that respond to different waveband light sources often cannot achieve precise driving. For example, directly mixing multiple photo-thermal conversion materials (such as different dyes), or using them separately in different layers or regions, although it can achieve multi-waveband response, due to the differences in photo-thermal conversion efficiency and response speed between different materials, as well as the energy loss and interference caused by their interaction, the overall driving effect is difficult to achieve precise control.

[0006] Therefore, it is also necessary to propose an article that can achieve precise driving of light waveband selective response. SUMMARY

[0007] The purpose of the present application is to solve the problems existing in the prior art, and to provide a preparation method and application of a light-responsive liquid crystal elastomer fiber.

[0008] To achieve the above-mentioned purpose, the technical solutions adopted by the present application are as follows:

[0009] The application discloses a preparation method of a photoresponsive liquid crystal elastomer fiber.

[0010] As a preferred technical scheme,

[0011] The preparation method of the photoresponsive liquid crystal elastomer fiber as described above, wherein the non-photoresponsive liquid crystal elastomer fiber is prepared by using a dry spinning method and a two-step crosslinking method, and the preparation steps of the non-photoresponsive liquid crystal elastomer fiber are as follows:

[0012] (1) preparing a prepolymer;

[0013] The liquid crystal monomer (RM257, RM105, RM82), the crosslinking agent (PETMP, TMPMP), the spacer (EDDET, EGBTG), the photoinitiator (for example, HHMP, Irgacure 651) and the catalyst (DPA, TEA) are dissolved in a solvent (for example, acetone, toluene, anhydrous ethanol, N, N-dimethylformamide), and then a crosslinking reaction is performed, so that the prepolymer is obtained;

[0014] (2) the prepolymer is extruded to form a fiber by using a syringe pump and a needle (with a diameter of 0.2-1 mm) at a speed of 0.1-2 mL per minute, a polytetrafluoroethylene drum is used as a receiving device, and the fiber is cured by using a convection heating method (the temperature of the convection heating is higher than the volatilization temperature of the solvent);

[0015] (3) the fiber is stretched under the irradiation of an ultraviolet lamp, so that the non-photoresponsive liquid crystal elastomer fiber is obtained.

[0016] The preparation method of the photoresponsive liquid crystal elastomer fiber as described above, wherein in step (1), the mass ratio of the liquid crystal monomer, the crosslinking agent, the spacer, the photoinitiator, the catalyst and the solvent is 38-40:5-10:5-10:1-5:1-5:145-150; the crosslinking reaction is performed at a temperature of 20-35 DEG C for 20-60 min.

[0017] The preparation method of the photoresponsive liquid crystal elastomer fiber as described above, wherein in step (3), the light power density of the ultraviolet lamp is 150-300 W / m -2 , and the stretching multiple is 50-300%.

[0018] The preparation method of the photoresponsive liquid crystal elastomer fiber as described above, and the specific process is as follows: first, the organic dye with photo-thermal conversion performance is dissolved in a solvent (acetone, toluene, anhydrous ethanol or N,N-dimethylformamide) by using magnetic stirring, ultrasonic dispersion and other technologies to form a dye bath, then the non-photoresponsive liquid crystal elastomer fiber is placed in the dye bath for dyeing, so that the organic dye with photo-thermal conversion performance diffuses from the dye bath to the non-photoresponsive liquid crystal elastomer fiber, thereby the non-photoresponsive liquid crystal elastomer fiber has photoresponsive properties, and after post-processing (i.e., drying to remove the solvent), the photoresponsive liquid crystal elastomer fiber is obtained.

[0019] The preparation method of the photoresponsive liquid crystal elastomer fiber as described above, and the concentration of the organic dye with photo-thermal conversion performance in the dye bath is 0.3-2 mg / ml.

[0020] The preparation method of the photoresponsive liquid crystal elastomer fiber as described above, and the mass-volume ratio of the non-photoresponsive liquid crystal elastomer fiber to the dye bath is 0.1-5 g:5-10 mL.

[0021] The preparation method of the photoresponsive liquid crystal elastomer fiber as described above, and the dyeing temperature is 20-35℃, the time is 0.5-24 h, and the pressure is 0.1013 MPa.

[0022] The preparation method of the photoresponsive liquid crystal elastomer fiber as described above, and the organic dye with photo-thermal conversion performance is Disperse Red 1 (absorbing 532 nm light source), dye800 (absorbing 800 nm light source) or dye1000 (absorbing 1000 nm light source).

[0023] The application further provides a fiber product with selective response to different light wave bands, which comprises photoresponsive liquid crystal elastomer fiber a, photoresponsive liquid crystal elastomer fiber b and photoresponsive liquid crystal elastomer fiber c.

[0024] The photoresponsive liquid crystal elastomer fiber a, the photoresponsive liquid crystal elastomer fiber b and the photoresponsive liquid crystal elastomer fiber c are all prepared by using the preparation method of the photoresponsive liquid crystal elastomer fiber as described above, and the corresponding organic dyes with photo-thermal conversion performance are Disperse Red 1 (absorbing 532 nm light source), dye800 (absorbing 800 nm light source) and dye1000 (absorbing 1000 nm light source) respectively.

[0025] The light-responsive liquid crystal elastomer fiber a, the light-responsive liquid crystal elastomer fiber b and the light-responsive liquid crystal elastomer fiber c are respectively named as DR1@LCE, 800@LCE and 1000@LCE, and the three are different in that only the DR1@LCE can convert light energy into heat energy by absorbing light of a 532 nm wave band, only the 800@LCE can convert light energy into heat energy by absorbing light of an 800 nm wave band, and only the 1000@LCE can convert light energy into heat energy by absorbing light of a 1000 nm wave band;

[0026] The fiber product with light wave band selective response has various structures, for example Figure 5 As shown in (a), the fiber product with light wave band selective response is composed of an equilateral triangle frame (formed by non-light-responsive yarns) and DR1@LCE, 800@LCE and 1000@LCE located in the equilateral triangle frame; under no light, the connection points of the three DR1@LCE, 800@LCE and 1000@LCE are located at the center of the equilateral triangle frame; after irradiation of light of a 532 nm wave band, the DR1@LCE shrinks, the 800@LCE and the 1000@LCE do not shrink, and the connection points of the three DR1@LCE, 800@LCE and 1000@LCE deviate from the center of the equilateral triangle frame; after irradiation of light of an 800 nm wave band, the 800@LCE shrinks, the DR1@LCE and the 1000@LCE do not shrink, and the connection points of the three DR1@LCE, 800@LCE and 1000@LCE deviate from the center of the equilateral triangle frame; after irradiation of light of a 1000 nm wave band, the 1000@LCE shrinks, the 800@LCE and the DR1@LCE do not shrink, and the connection points of the three DR1@LCE, 800@LCE and 1000@LCE deviate from the center of the equilateral triangle frame.

[0027] Beneficial effects:

[0028] By using the organic dyes such as Disperse Red 1, dye 800 and dye 1000 with specific light-heat conversion performance, the light-responsive liquid crystal elastomer fibers (DR1@LCE, 800@LCE and 1000@LCE) capable of responding to different wave band light sources of 532 nm, 800 nm and 1000 nm respectively are successfully prepared. The light wave band selective response characteristic enables the fiber product to realize precise deformation control according to different wave length light sources, and provides a new driving mechanism for intelligent textiles and drivers.

[0029] The application adopts normal temperature (20-35 DEG C) dyeing technology to attach organic dyes to non-light response liquid crystal elastomer fibers, avoids the interference of dye mixing into the crosslinking of liquid crystal matrix, and thus ensures the reversible driving performance of liquid crystal. The preparation method is not only simple and easy to operate, but also can effectively improve the photo-thermal conversion efficiency and light response speed, so that the fiber still maintains good performance stability after multiple deformations.

[0030] The application realizes precise control of the deformation of the fiber product by combining light response liquid crystal elastomer fibers (DR1@LCE, 800@LCE, 1000@LCE) of different light response wave bands into the fiber product. The fiber product can realize different deformation modes according to different wavelengths of light sources, and provides more abundant application scenarios and more flexible driving modes for intelligent textiles and drivers.

[0031] The preparation method of the application is simple and easy to operate, and only needs to put the non-light response liquid crystal elastomer fiber into a dye bath containing photo-thermal conversion dyes for dyeing treatment. The preparation method is not only low in cost, but also easy to mass produce and popularize.

[0032] The organic dyes used in the application are all environmentally friendly materials, and no high temperature and high pressure conditions are required in the preparation process, which is conducive to environmental protection and sustainable development. At the same time, by precisely controlling the deformation and driving mode of the fiber, the application also helps to reduce energy consumption and waste of resources. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 It is a dyeing process and drying schematic diagram in the preparation of light response liquid crystal elastomer fiber of the application;

[0034] Figure 2 It is a light response schematic diagram of the light response liquid crystal elastomer fiber prepared by the application;

[0035] Figure 3 It is a UV-Vis-IR absorption spectrum diagram of the light response liquid crystal elastomer fiber prepared in examples A1-A3 and the non-light response liquid crystal elastomer fiber prepared in example A3;

[0036] Figure 4 It is a selective driving schematic diagram of the light response liquid crystal elastomer fiber prepared in examples A1-A3 to three wave bands (532nm, 980nm, 808nm) of light sources;

[0037] Figure 5 It is a light source selective driving schematic diagram of the fiber product with selective response to light wave bands prepared in example B1; wherein. Figure 5(a) is the location of the junction of the three DR1@LCE, 800@LCE, 1000@LCE in the fiber product which is selectively responsive to the light wave band in the absence of light, Figure 5 (b) is the location of the junction of the three DR1@LCE, 800@LCE, 1000@LCE in the fiber product which is selectively responsive to the light wave band after irradiation with light of 532 nm wave band, Figure 5 (c) is the location of the junction of the three DR1@LCE, 800@LCE, 1000@LCE in the fiber product which is selectively responsive to the light wave band after irradiation with light of 800 nm wave band, Figure 5 (d) is the location of the junction of the three DR1@LCE, 800@LCE, 1000@LCE in the fiber product which is selectively responsive to the light wave band after irradiation with light of 1000 nm wave band;

[0038] Figure 6 The tension-displacement curve of the LCE, the original LCE and the DR1@LCE prepared in Example A1 is mixed. DETAILED DESCRIPTION

[0039] The application will be further described in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the application and not to limit the scope of the application. Furthermore, it should be understood that those skilled in the art can make various modifications or changes to the application after reading the content taught by the application, and these equivalent forms also fall within the scope of the appended claims.

[0040] The following are the test methods for the relevant performance indicators in the examples or comparative examples:

[0041] The driving strain is: under the light source intensity of 1.2 W m -2 , the environmental temperature of 25℃, the length change of the fiber with a diameter of 250μm is observed and recorded, and the following formula is used for calculation:

[0042] The driving strain=(ΔL / L0)×100%;

[0043] In the formula, ΔL=L0-L, L0 is the initial length of the fiber, and L is the maximum length of the fiber under the light source.

[0044] Example A1

[0045] A preparation method of a light-responsive liquid crystal elastomer fiber, the specific steps are as follows:

[0046] (1) Preparation of raw materials;

[0047] Liquid crystal monomer: RM257 (CAS No. 174063-87-7);

[0048] Crosslinking agent: PETMP (CAS No. 7575-23-7);

[0049] Spacer: EDDET (CAS No. 14970-87-7);

[0050] Photoinitiator: HHMP (CAS No. 106797-53-9);

[0051] Catalyst: DPA (CAS No. 142-84-7);

[0052] Solvent: Acetone (CAS No. 67-64-1);

[0053] Organic dye with photo-thermal conversion performance: Disperse Red 1 (CAS No. 2872-52-8);

[0054] (2) Preparation of non-photo-responsive liquid crystal elastomer fiber;

[0055] (2.1) After the liquid crystal monomer, crosslinking agent, spacer, photoinitiator, catalyst are dissolved in the solvent, crosslinking reaction is carried out at a temperature of 30℃ for 45min to obtain a prepolymer; wherein the mass ratio of the liquid crystal monomer, crosslinking agent, spacer, photoinitiator, catalyst, solvent is 38:6:7:1:1:147;

[0056] (2.2) The prepolymer is extruded to form a fiber at a speed of 1mL per minute by using a syringe pump and a needle (diameter 0.5mm), and a polytetrafluoroethylene drum is used as a receiving device, and the fiber is cured by using a convection heating method (the temperature of the convection heating is higher than the volatilization temperature of the solvent);

[0057] (2.3) The fiber is stretched by 200% under the irradiation of a UV lamp with a light power density of 150W m -2 to obtain a non-photo-responsive liquid crystal elastomer fiber (named as original LCE);

[0058] (3) Dyeing;

[0059] First, the organic dye with photo-thermal conversion performance is dissolved in the solvent to form a dye bath with a concentration of 1mg / ml, and then the non-photo-responsive liquid crystal elastomer fiber is placed in the dye bath for dyeing at a temperature of 30℃ and a pressure of 0.1013MPa for 24h, and after treatment (i.e. drying to remove the solvent), a photo-responsive liquid crystal elastomer fiber (named as DR1@LCE) is obtained; wherein the mass-volume ratio of the non-photo-responsive liquid crystal elastomer fiber to the dye bath is 3g:5mL.

[0060] As shown in Figure 2 , the finally prepared DR1@LCE has photo-responsive characteristics; the driving strain of the DR1@LCE is 52%.

[0061] Comparative Example 1

[0062] A method for preparing a liquid crystal elastomer fiber, the specific steps are as follows:

[0063] (1) Preparation of raw materials;

[0064] Liquid crystal monomer: RM257 (CAS No. 174063-87-7);

[0065] Crosslinking agent: PETMP (CAS No. 7575-23-7);

[0066] Spacer: EDDET (CAS No. 14970-87-7);

[0067] Photoinitiator: HHMP (CAS No. 106797-53-9);

[0068] Catalyst: DPA (CAS No. 142-84-7);

[0069] Solvent: Acetone (CAS No. 67-64-1);

[0070] Organic dye with photo-thermal conversion performance: Disperse Red 1 (CAS No. 2872-52-8);

[0071] (2) Preparation of liquid crystal elastomer fiber;

[0072] (2.1) After dissolving the liquid crystal monomer, crosslinking agent, spacer, photoinitiator, catalyst, and Disperse Red 1 in the solvent, crosslinking reaction was carried out at a temperature of 30°C for 45 min to obtain a prepolymer; wherein the mass ratio of the liquid crystal monomer, crosslinking agent, spacer, photoinitiator, catalyst, solvent, and Disperse Red 1 is 38:6:7:1:1:147:1;

[0073] (2.2) The prepolymer was extruded to form a fiber at a speed of 1 mL per minute using a syringe pump and a needle (diameter 0.5 mm), and a polytetrafluoroethylene drum was used as a receiving device, and the fiber was cured by convection heating (the temperature of convection heating is higher than the volatilization temperature of the solvent);

[0074] (2.3) The fiber was stretched by 200% under the irradiation of a UV lamp with a light power density of 150 W m -2

[0075] The driving strain of the prepared mixed LCE is 25%.

[0076] The tension-displacement curves of the mixed LCE, the original LCE, and the DR1@LCE prepared in Example A1 are shown in Figure 6 . ​

[0077] Compared with Example A1, the driving performance and mechanical properties (decrease in mechanical properties can be seen from Figure 6 Compared with Example A1, the driving performance and mechanical properties (decrease in mechanical properties can be seen from

[0078] Example A2

[0079] A method for preparing a photoresponsive liquid crystal elastomer fiber, the specific steps are as follows:

[0080] (1) Preparation of raw materials;

[0081] Liquid crystal monomer: RM257 (CAS No. 174063-87-7);

[0082] Crosslinking agent: PETMP (CAS No. 7575-23-7);

[0083] Spacer: EDDET (CAS No. 14970-87-7);

[0084] Photoinitiator: HHMP (CAS No. 106797-53-9);

[0085] Catalyst: DPA (CAS No. 142-84-7);

[0086] Solvent: Acetone (CAS No. 67-64-1);

[0087] Organic dye with photo-thermal conversion performance: dye800 (manufacturer: Shanghai Yujia Chemical Technology Co., Ltd.);

[0088] (2) Preparation of non-photoresponsive liquid crystal elastomer fiber;

[0089] (2.1) After dissolving the liquid crystal monomer, crosslinking agent, spacer, photoinitiator, and catalyst in the solvent, crosslinking reaction was carried out at a temperature of 30°C for 45 min to obtain a prepolymer; wherein the mass ratio of the liquid crystal monomer, crosslinking agent, spacer, photoinitiator, catalyst, and solvent is 38:6:7:1:1:147;

[0090] (2.2) Using a syringe pump and a needle (diameter 0.5 mm), the prepolymer was extruded at a speed of 1 mL per minute to form a fiber, a polytetrafluoroethylene drum was used as a receiving device, and the fiber was cured by convection heating (the temperature of convection heating is higher than the volatilization temperature of the solvent)

[0091] (2.3) When the optical power density is 150W m -2 The fiber was stretched 200% under the irradiation of ultraviolet light to obtain a non-photoresponsive liquid crystal elastomer fiber;

[0092] (3) Staining;

[0093] like Figure 1 As shown, an organic dye with photothermal conversion properties is first dissolved in a solvent to form a dye bath with a concentration of 1 mg / ml. Then, the non-photoresponsive liquid crystal elastomer fiber is placed in the dye bath and dyed for 24 hours at a temperature of 30°C and a pressure of 0.1013 MPa. After post-treatment (i.e., drying to remove the solvent), the photoresponsive liquid crystal elastomer fiber (named 800@LCE) is obtained; wherein, the mass volume ratio of the non-photoresponsive liquid crystal elastomer fiber to the dye bath is 3 g:5 mL.

[0094] Example A3

[0095] A method for preparing a light-responsive liquid crystal elastomer fiber, comprising the following steps:

[0096] (1) Preparation of raw materials;

[0097] Liquid crystal monomer: RM257 (CAS No. 174063-87-7);

[0098] Cross-linking agent: PETMP (CAS No. 7575-23-7);

[0099] Spacer: EDDET (CAS No. 14970-87-7);

[0100] Photoinitiator: HHMP (CAS No. 106797-53-9);

[0101] Catalyst: DPA (CAS No. 142-84-7);

[0102] Solvent: acetone (CAS No. 67-64-1);

[0103] Organic dye with photothermal conversion performance: dye1000 (manufacturer: Shanghai Yujia Chemical Technology Co., Ltd.);

[0104] (2) Preparation of non-photoresponsive liquid crystal elastomer fibers;

[0105] (2.1) Dissolving a liquid crystal monomer, a cross-linking agent, a spacer, a photoinitiator, and a catalyst in a solvent and subjecting the mixture to a cross-linking reaction at 30°C for 45 minutes to obtain a prepolymer; wherein the mass ratio of the liquid crystal monomer, the cross-linking agent, the spacer, the photoinitiator, the catalyst, and the solvent is 38:6:7:1:1:147;

[0106] (2.2) Using a syringe pump and a needle (0.5 mm in diameter), the prepolymer is extruded to form a fiber at a speed of 1 mL per minute, a polytetrafluoroethylene drum is used as a receiving device, and the fiber is cured by convection heating (the temperature of convection heating is higher than the volatilization temperature of the solvent);

[0107] (2.3) The fiber is stretched by 200% under the irradiation of a 150 W m -2 UV light lamp with a light power density of 150 W m

[0108] (3) Dyeing;

[0109] As shown in Figure 1 , first, an organic dye with photo-thermal conversion performance is dissolved in a solvent to form a dye bath with a concentration of 1 mg / ml, then the non-photo-responsive liquid crystal elastomer fiber is placed in the dye bath for dyeing at a temperature of 30°C and a pressure of 0.1013 MPa for 24 hours, and after treatment (i.e. drying to remove the solvent), a photo-responsive liquid crystal elastomer fiber (named 1000@LCE) is obtained; wherein the mass-volume ratio of the non-photo-responsive liquid crystal elastomer fiber to the dye bath is 3g:5mL.

[0110] The UV-visible-infrared absorption spectrum of the photo-responsive liquid crystal elastomer fiber prepared in Examples A1-A3 and the non-photo-responsive liquid crystal elastomer fiber prepared in Example A3 is shown in Figure 3 , and the selective driving graph of the photo-responsive liquid crystal elastomer fiber prepared in Examples A1-A3 to light sources of 532 nm, 980 nm and 808 nm is shown in Figure 4 .

[0111] Example A4

[0112] A method for preparing a photo-responsive liquid crystal elastomer fiber, the specific steps are as follows:

[0113] (1) Preparation of raw materials;

[0114] Liquid crystal monomer: RM105 (CAS No. 82200-53-1);

[0115] Crosslinking agent: TMPMP (CAS No. 33007-83-9);

[0116] Spacer: EGBTG (CAS No. 123-81-9);

[0117] Photoinitiator: Irgacure 651 (CAS No. 24650-42-8);

[0118] Catalyst: TEA (CAS No. 121-44-8);

[0119] Solvent: Toluene (CAS No. 108-88-3);

[0120] Organic dye with photo-thermal conversion performance: dye800 (manufacturer: Shanghai Yujia Chemical Technology Co., Ltd.);

[0121] (2) Preparation of non-photo-responsive liquid crystal elastomer fiber;

[0122] (2.1) After dissolving the liquid crystal monomer, crosslinking agent, spacer, photoinitiator and catalyst in the solvent, crosslinking reaction was carried out at a temperature of 35°C for 60 min to obtain a prepolymer; wherein the mass ratio of the liquid crystal monomer, crosslinking agent, spacer, photoinitiator, catalyst and solvent is 38:5:5:2:2:145;

[0123] (2.2) The prepolymer was extruded to form a fiber at a speed of 0.7 mL per minute using a syringe pump and a needle (diameter 0.2 mm), and a polytetrafluoroethylene drum was used as a receiving device, and the fiber was cured by convection heating (the temperature of convection heating is higher than the volatilization temperature of the solvent);

[0124] (2.3) The fiber was stretched by 100% under the irradiation of a UV lamp with a light power density of 200 W m -2 to obtain a non-photo-responsive liquid crystal elastomer fiber;

[0125] (3) Dyeing;

[0126] As shown in Figure 1 , first, the organic dye with photo-thermal conversion performance was dissolved in the solvent to form a dye bath with a concentration of 0.3 mg / ml, and then the non-photo-responsive liquid crystal elastomer fiber was placed in the dye bath at a temperature of 25°C and a pressure of 0.1013 MPa for dyeing for 8 h, and after treatment (i.e. drying to remove the solvent), a photo-responsive liquid crystal elastomer fiber (named 800@LCE) was obtained; wherein the mass-volume ratio of the non-photo-responsive liquid crystal elastomer fiber to the dye bath is 0.1 g:5 mL.

[0127]

[0128] A preparation method of a photo-responsive liquid crystal elastomer fiber, the specific steps are as follows:

[0129] (1) Preparation of raw materials;

[0130] Liquid crystal monomer: RM82 (CAS No. 125248-71-7);

[0131] Crosslinking agent: PETMP (CAS No. 7575-23-7);

[0132] Spacer: EGBTG (CAS No. 123-81-9);

[0133] Photoinitiator: Irgacure 651 (CAS No. 24650-42-8);

[0134] Catalyst: TEA (CAS No. 121-44-8);

[0135] Solvent: N,N-dimethylformamide (CAS No. 68-12-2);

[0136] Organic dye with photothermal conversion performance: dye1000 (manufacturer: Shanghai Yujia Chemical Technology Co., Ltd.);

[0137] (2) Preparation of non-photoresponsive liquid crystal elastomer fibers;

[0138] (2.1) Dissolving a liquid crystal monomer, a cross-linking agent, a spacer, a photoinitiator, and a catalyst in a solvent and subjecting the mixture to a cross-linking reaction at 35°C for 35 minutes to obtain a prepolymer; wherein the mass ratio of the liquid crystal monomer, the cross-linking agent, the spacer, the photoinitiator, the catalyst, and the solvent is 40:10:10:5:5:150;

[0139] (2.2) Using a syringe pump and a needle (0.7 mm diameter), extrude the prepolymer at a rate of 0.1 mL / min to form fibers. A polytetrafluoroethylene drum is used as a receiving device, and the fibers are cured by convection heating (the convection heating temperature can be higher than the evaporation temperature of the solvent).

[0140] (2.3) When the optical power density is 260 W m -2 The fiber was stretched 300% under the irradiation of ultraviolet light to obtain a non-photoresponsive liquid crystal elastomer fiber;

[0141] (3) Staining;

[0142] like Figure 1 As shown, an organic dye with photothermal conversion properties is first dissolved in a solvent to form a dye bath with a concentration of 1.5 mg / ml. Then, the non-photoresponsive liquid crystal elastomer fiber is placed in the dye bath and dyed for 16 hours at a temperature of 20°C and a pressure of 0.1013 MPa. After post-treatment (i.e., drying to remove the solvent), the photoresponsive liquid crystal elastomer fiber (named 1000@LCE) is obtained; wherein, the mass volume ratio of the non-photoresponsive liquid crystal elastomer fiber to the dye bath is 5 g:10 mL.

[0143] Example A6

[0144] A method for preparing a light-responsive liquid crystal elastomer fiber, comprising the following steps:

[0145] (1) Preparation of raw materials;

[0146] Liquid crystal monomer: RM105 (CAS No. 82200-53-1);

[0147] Cross-linking agent: PETMP (CAS No. 7575-23-7);

[0148] Spacer: EDDET (CAS No. 14970-87-7);

[0149] Photoinitiator: HHMP (CAS No. 106797-53-9);

[0150] Catalyst: DPA (CAS No. 142-84-7);

[0151] Solvent: anhydrous ethanol (CAS No. 64-17-5);

[0152] Organic dye with photothermal conversion properties: Disperse Red 1 (CAS No. 2872-52-8);

[0153] (2) Preparation of non-photoresponsive liquid crystal elastomer fibers;

[0154] (2.1) Dissolving a liquid crystal monomer, a cross-linking agent, a spacer, a photoinitiator, and a catalyst in a solvent and subjecting the mixture to a cross-linking reaction at 20°C for 20 minutes to obtain a prepolymer; wherein the mass ratio of the liquid crystal monomer, the cross-linking agent, the spacer, the photoinitiator, the catalyst, and the solvent is 39:7:7:3:3:148;

[0155] (2.2) Using a syringe pump and a needle (1 mm diameter), extrude the prepolymer at a rate of 2 mL / min to form fibers. A polytetrafluoroethylene drum is used as a receiving device, and the fibers are cured by convection heating (the convection heating temperature can be higher than the evaporation temperature of the solvent).

[0156] (2.3) When the optical power density is 300W m -2 The fiber was stretched by 50% under the irradiation of ultraviolet light to obtain a non-photoresponsive liquid crystal elastomer fiber;

[0157] (3) Staining;

[0158] like Figure 1 As shown, an organic dye with photothermal conversion properties is first dissolved in a solvent to form a dye bath with a concentration of 2 mg / ml. Then, the non-photoresponsive liquid crystal elastomer fiber is placed in the dye bath and dyed for 0.5 h at a temperature of 35°C and a pressure of 0.1013 MPa. After post-treatment (i.e., drying to remove the solvent), the photoresponsive liquid crystal elastomer fiber (named DR1@LCE) is obtained; wherein, the mass volume ratio of the non-photoresponsive liquid crystal elastomer fiber to the dye bath is 4 g:8 mL.

[0159] Example B1

[0160] An application of a photoresponsive liquid crystal elastomer fiber, first fix DR1@LCE (prepared from Example A1), 800@LCE (prepared from Example A2), 1000@LCE (prepared from Example A3) together, then fix DR1@LCE, 800@LCE and 1000@LCE on a equilateral triangle frame composed of non-photoresponsive yarn (polypropylene, CAS No. 9003-07-0), to obtain a fiber product with selective response to light waveband.

[0161] As shown in (a) of Figure 5 The prepared fiber product with selective response to light waveband is in the case of no light, the connection point of DR1@LCE, 800@LCE, 1000@LCE is located at the center position of the equilateral triangle frame; as shown in (b) of Figure 5 After irradiation with 532nm waveband light, DR1@LCE shrinks, 800@LCE and 1000@LCE do not shrink, the connection point of DR1@LCE, 800@LCE, 1000@LCE deviates from the center position of the equilateral triangle frame; as shown in (c) of Figure 5 After irradiation with 800nm waveband light, 800@LCE shrinks, DR1@LCE and 1000@LCE do not shrink, the connection point of DR1@LCE, 800@LCE, 1000@LCE deviates from the center position of the equilateral triangle frame; as shown in (d) of Figure 5 After irradiation with 1000nm waveband light, 1000@LCE shrinks, 800@LCE and DR1@LCE do not shrink, the connection point of DR1@LCE, 800@LCE, 1000@LCE deviates from the center position of the equilateral triangle frame.

[0162] Example B2

[0163] An application of a photoresponsive liquid crystal elastomer fiber, first fix DR1@LCE (prepared from Example A6), 800@LCE (prepared from Example A4), 1000@LCE (prepared from Example A5) together, then fix DR1@LCE, 800@LCE and 1000@LCE on a equilateral triangle frame composed of non-photoresponsive yarn (polypropylene, CAS No. 9003-07-0), to obtain a fiber product with selective response to light waveband.

[0164] The prepared fiber product with selective response to light wave band is located at the center of the equilateral triangle frame in the absence of light; after irradiation of 532 nm wave band, DR1@LCE shrinks, 800@LCE and 1000@LCE do not shrink, and the connection points of DR1@LCE, 800@LCE and 1000@LCE deviate from the center of the equilateral triangle frame; after irradiation of 800 nm wave band, 800@LCE shrinks, DR1@LCE and 1000@LCE do not shrink, and the connection points of DR1@LCE, 800@LCE and 1000@LCE deviate from the center of the equilateral triangle frame; after irradiation of 1000 nm wave band, 1000@LCE shrinks, 800@LCE and DR1@LCE do not shrink, and the connection points of DR1@LCE, 800@LCE and 1000@LCE deviate from the center of the equilateral triangle frame.

Claims

1. A method for preparing a photoresponsive liquid crystal elastomer fiber, characterized by, The specific process is that: first, the organic dye with photo-thermal conversion performance is dissolved in a solvent to form a dye bath, then the non-photo-responsive liquid crystal elastomer fiber is put into the dye bath for dyeing, and after post-processing, the photo-responsive liquid crystal elastomer fiber is obtained; the dyeing temperature is 20-35℃, the time is 0.5-24h, and the pressure is 0.1013MPa.

2. The method of claim 1, wherein the photoresponsive liquid crystal elastomer fiber is prepared by the steps of: The preparation steps of the non-photo-responsive liquid crystal elastomer fiber are as follows: (1) preparing a prepolymer; After the liquid crystal monomer, the crosslinking agent, the spacer, the photoinitiator and the catalyst are dissolved in the solvent, crosslinking reaction is carried out, and the prepolymer is obtained; (2) using a syringe pump and a needle, the prepolymer is extruded to form a fiber, and the fiber is cured by convection heating; (3) the fiber is stretched under the irradiation of an ultraviolet lamp, and the non-photo-responsive liquid crystal elastomer fiber is obtained.

3. A method of preparing a photoresponsive liquid crystal elastomer fiber according to claim 2, wherein, In step (1), the mass ratio of the liquid crystal monomer, the crosslinking agent, the spacer, the photoinitiator, the catalyst and the solvent is 38-40:5-10:5-10:1-5:1-5:145-150; the crosslinking reaction temperature is 20-35℃, and the time is 20-60min.

4. The method for preparing a light-responsive liquid crystal elastomer fiber according to claim 2, wherein: In step (3), the light power density of the UV light lamp is 150-300 W m -2 , and the stretching multiple is 50-300%.

5. The method for preparing a light-responsive liquid crystal elastomer fiber according to claim 1, characterized in that: The concentration of the organic dye with photo-thermal conversion performance in the dye bath is 0.3-2mg / ml.

6. The method of claim 1, wherein the photoresponsive liquid crystal elastomer fiber is prepared by the steps of: The mass-volume ratio of the non-photo-responsive liquid crystal elastomer fiber to the dye bath is 0.1-5g:5-10mL.

7. The method for preparing a light-responsive liquid crystal elastomer fiber according to claim 1, characterized in that: The organic dye with photo-thermal conversion performance is Disperse Red 1, dye800 or dye1000.

8. A fiber product that is selectively responsive to a wavelength of light, characterized by, The photo-responsive liquid crystal elastomer fiber a, the photo-responsive liquid crystal elastomer fiber b and the photo-responsive liquid crystal elastomer fiber c; The photo-responsive liquid crystal elastomer fiber a, the photo-responsive liquid crystal elastomer fiber b and the photo-responsive liquid crystal elastomer fiber c are all prepared by the preparation method of the photo-responsive liquid crystal elastomer fiber according to any one of claims 1-7, and the corresponding organic dyes with photo-thermal conversion performance are Disperse Red 1, dye800 and dye1000 respectively.

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