COMPOSITE ELECTROCHROMIC MATERIAL, AND PREPARATION METHOD THEREFOR AND APPLICATION THEREOF

Abstract

A composite electrochromic material, a preparation method therefor and an application thereof, the material comprising a core layer, a skin layer having an electrochromic function, and a light-transmitting protective layer formed by a flexible polymer material, that are arranged in sequence. The material of the core layer comprises a fluid conductive mixture, which comprises liquid metal and carboxylated carbon nanotubes. The preparation method comprises: carrying out spinning by co-extrusion using a three-channel nozzle to form hollow double-layer fibers each having a skin layer and a protective layer as well as a cavity, injecting the conductive mixture into the cavity of the hollow double-layer fiber. The material has excellent deformation ability, stable and sensitive color changing function, and a controllable deformation degree. The material has a stable color changing function even in the case of severe defomation, good fatigue resistance, and is suitable for the preparation of intelligent textiles.

Claims

1. (canceled)

2. A composite electrochromic material, wherein, the composite electrochromic material comprises a core layer, a skin layer coating on the core layer and having an electrochromic function, and a light-transmitting protective layer formed by a flexible polymer material and coating on the skin layer, the material of the core layer comprises a conductive mixture with fluidity, and the conductive mixture comprises liquid metal and carboxylated carbon nanotubes.

3. The composite electrochromic material according to claim 2, wherein, a mass ratio of the carboxylated carbon nanotubes to the liquid metal is (2-5): 100.

4. The composite electrochromic material according to claim 2, wherein, the carboxylated carbon nanotubes have a length of 15-30 m, an inner diameter of 6-10 nm, and an outer diameter of 12-20 nm.

5. The composite electrochromic material according to claim 2, wherein, the composite electrochromic material comprises a core layer, a skin layer coating on the core layer and having an electrochromic function, and a light-transmitting protective layer formed by a flexible polymer material and coating on the skin layer, the material of the core layer comprises a conductive mixture with fluidity, the conductive mixture comprises liquid metal and carboxylated carbon nanotubes, a mass ratio of the carboxylated carbon nanotubes to the liquid metal is (2-5):100, and the carboxylated carbon nanotubes have a length of 15-30 m, an inner diameter of 6-10 nm, and an outer diameter of 12-20 nm.

6. The composite electrochromic material according to claim 2, wherein, the carboxylated carbon nanotubes are carboxylated multi-walled carbon nanotubes.

7. The composite electrochromic material according to claim 6, wherein, the carboxylated multi-walled carbon nanotubes are prepared by the following method: adding multi-walled carbon nanotubes to a mixture of concentrated sulfuric acid and concentrated nitric acid in a volume ratio of 5:(1.5-2.5), with a feeding mass ratio of the multi-walled carbon nanotubes to the mixture of 1:(38-42), stirring at 55-65 C. to react, cooling, filtering, washing until neutral, and drying.

8. The composite electrochromic material according to claim 2, wherein, the liquid metal is galinstan liquid metal, with a melting point of 16 C. and a viscosity of 0.0014-0.0023 Pas at 20 C.

9. The composite electrochromic material according to claim 2, wherein, the protective layer has an outer diameter of 0.8-1.1 mm and a thickness of 0.2-0.4 mm.

10. The composite electrochromic material according to claim 2, wherein, the skin layer has an outer diameter of 0.5-0.7 mm and a thickness of 0.2-0.3 mm.

11. The composite electrochromic material according to claim 2, wherein, the core layer has a diameter of 0.3-0.5 mm.

12. The composite electrochromic material according to claim 2, wherein, the skin layer has an optical contrast ratio of 40-60% and a color brightness during stretching of 0.80-0.95.

13. The composite electrochromic material according to claim 2, wherein, the raw material of the skin layer is an organic electrochromic material or an inorganic electrochromic material.

14. The composite electrochromic material according to claim 2, wherein, the raw material of the skin layer consists of polyvinly alcohol and an organic electrochromic material and/or an inorganic electrochromic material, with a feeding mass ratio of the polyvinly alcohol to the organic electrochromic material and/or the inorganic electrochromic material of (0.5-1):1.

15. The composite electrochromic material according to claim 14, wherein, the polyvinly alcohol has a weight-average molecular weight of 72,600-81,400, and the organic electrochromic material is polyaniline with a weight-average molecular weight of 55,000-60,000.

16. The composite electrochromic material according to claim 2, wherein, the raw material of the protective layer is a polyolefin material with an elastic elongation of 300-500%, an elastic recovery rate of 97-99% and a softening temperature of greater than 200 C.

17. A method for preparing the composite electrochromic material according to claim 2, wherein, the preparation method comprises the following steps: (1) drying the raw material of the skin layer, the raw material of the protective layer, respectively; (2) putting the raw material of the skin layer, the raw material of the protective layer, after being treated in step (1), into a screw extruder for melting respectively, and spinning by co-extrusion method using a three-channel nozzle to make a hollow double-layer fiber with a cavity; (3) injecting the conductive mixture into the cavity of the hollow double-layer fiber to make the composite electrochromic material.

18. The method for preparing the composite electrochromic material according to claim 17, wherein, in step (2), the temperature of melting is 300-350 C.; in step (3), injecting is carried out using a syringe, its needle is inserted into the cavity of the hollow double-layer fiber, and two ends of the fiber are heated to shrink and prevent leakage.

19. Use of the composite electrochromic material according to claim 2 in intelligent textiles.

20. The composite electrochromic material according to claim 2, wherein, the composite electrochromic material comprises a core layer, a skin layer coating on the core layer and having an electrochromic function, and a light-transmitting protective layer formed by a flexible polymer material and coating on the skin layer, the material of the core layer comprises a conductive mixture with fluidity, and the conductive mixture comprises liquid metal and carboxylated carbon nanotubes, a mass ratio of the carboxylated carbon nanotubes to the liquid metal is (2-5):100, the carboxylated carbon nanotubes have a length of 15-30 m, an inner diameter of 6-10 nm, and an outer diameter of 12-20 nm, the carboxylated carbon nanotubes are carboxylated multi-walled carbon nanotubes, and the liquid metal is galinstan liquid metal with a melting point of 16 C. and a viscosity of 0.0014-0.0023 Pas at 20 C.; the protective layer has an outer diameter of 0.8-1.1 mm and a thickness of 0.2-0.4 mm; the skin layer has an outer diameter of 0.5-0.7 mm and a thickness of 0.2-0.3 mm; the core layer has a diameter of 0.3-0.5 mm; the skin layer has an optical contrast ratio of 40-60% and a color brightness during stretching of 0.80-0.95; the raw material of the skin layer consists of polyvinly alcohol and an organic electrochromic material with a feeding mass ratio of (0.5-1):1, or the raw material of the skin layer consists of polyvinly alcohol and an inorganic electrochromic material with a feeding mass ratio of (0.5-1):1, or the raw material of the skin layer consists of polyvinly alcohol, an organic electrochromic material and an inorganic electrochromic material, wherein a feeding mass ratio of the amount of the polyvinly alcohol and the total amount of the organic electrochromic material and the inorganic electrochromic material is (0.5-1):1; the raw material of the protective layer is a polyolefin material with an elastic elongation of 300-500%, an elastic recovery rate of 97-99% and a softening temperature of greater than 200 C. a method for preparing the composite electrochromic material comprises the following steps: (1) drying the raw material of the skin layer, the raw material of the protective layer, respectively; (2) putting the raw material of the skin layer, the raw material of the protective layer, after being treated in step (1), into a screw extruder for melting respectively, and spinning by co-extrusion method using a three-channel nozzle to make a hollow double-layer fiber with a cavity; (3) injecting the conductive mixture into the cavity of the hollow double-layer fiber to make the composite electrochromic material.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0042] FIG. 1 is a schematic diagram of the cross-sectional structure of the composite electrochromic material in an embodiment of the present disclosure;

[0043] Wherein, 11, protective layer; 12, skin layer; 13, core layer.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0044] In the following, the specific embodiments are combined to further explain the above solutions in detail; it should be understood that, those embodiments are to explain the basic principle, major features and advantages of the present disclosure, and the present disclosure is not limited by the scope of the following embodiments; the implementation conditions used in the embodiments may be further adjusted according to particular requirements, and undefined implementation conditions usually are conditions in conventional experiments.

[0045] In the following, unless otherwise specified, all raw materials are basically commercially available or prepared by conventional methods in the field. Polyaniline was purchased from Guangdong Wengjiang Chemical Reagent Co., Ltd, CAS No. 25233-30-1, with a weight-average molecular weight of 55,000-60,000; polyvinyl alcohol was purchased from Shanghai Jinshan Petrochemical, CAS No.: 9002-89-5, PVA 088-20 (1788), with a weight-average molecular weight of 72,600-81,400.

[0046] In the following embodiments, carboxylated multi-walled carbon nanotubes were prepared by the following steps: adding multi-walled carbon nanotubes (purchased from Shenzhen Turing Evolution Technology Co., Ltd., with a length of 15-30 m, an inner diameter of 6-10 nm, and an outer diameter of 12-15 nm, CAS No. 308068-56-6) into concentrated sulfuric acid/concentrated nitric acid in a volume ratio of 5:2 (the concentrated sulfuric acid is commercially available sulfuric acid with a mass percentage of 98, the concentrated nitric acid is commercially available nitric acid with a mass percentage of 75) with an adding mass ratio of 1:40, stirring at 60 C. for 15 min to react, cooling, filtering and washing until neutral, and drying at 80 C. for 24 h.

[0047] In the following description, the three-channel nozzle used had the following dimensions: an outer diameter of 1.20 mm and an inner diameter of 0.95 mm for the outer channel, an outer diameter of 0.80 mm and inner diameter of 0.50 mm for the middle channel, and a diameter of 0.30 mm for the inner channel.

Embodiment 1

[0048] This embodiment provided a composite electrochromic material, as shown in FIG. 1, which was formed by a core layer 11, a skin layer 12 having an electrochromic function, and a light-transmitting protective layer 13 formed by a flexible polymer material that were arranged in sequence from inside to outside, the material of the core layer comprised a conductive mixture with fluidity, and the conductive mixture comprised liquid metal and carboxylated carbon nanotubes, a mass ratio of the carboxylated carbon nanotubes to the liquid metal was 3:100, wherein the liquid metal consisted of gallium, indium and tin in a mass ratio of of 68.5:21.5:10.

[0049] A composite material obtained by mixing polyaniline and polyvinly alcohol with a mass ratio of 2:1 was used as the raw material of the skin layer having an electrochromic function.

[0050] The raw material of the light-transmitting protective layer formed by a flexible polymer material was polyolefin elastomer purchased from The DowChemical Company (USA), with a melt index of 30 g/10 min.

[0051] The method for preparing the composite electrochromic material, which comprised the following steps:

[0052] (1) Polyaniline and polyvinyl alcohol were mixed at a mass ratio of 2:1 using a mixer at 2500 rmp for 10 hours, and mixed well and dried for use, and the polyolefin material was dried for use.

[0053] (2) The treated polyolefin material and polyaniline/polyvinyl alcohol were put into the screw extruder for high-temperature melt treatment at 350 C., respectively, the spinning solutions after melt treatment were respectively introduced into the middle channel and the outer channel, wherein the polyolefin material was introduced into the outer channel with a flow rate of 0.2 ml/min, polyaniline/polyvinyl alcohol was introduced into the middle channel with a flow rate of 0.8 ml/min, the spinning temperature was 230 C., the three-channel nozzle was used for co-extrusion spinning to form a new hollow double-layer fiber, the new hollow double-layer fiber was shaped in a gel bath, and then dried naturally for 24 hours to produce a hollow double-layer fiber with a cavity.

[0054] (3) The components of the conductive mixture were mixed by ultrasonic oscillation according to the ratio, then one end of the dried hollow double-layer fiber was connected to the needle, and the conductive mixture was filled into the cavity of the hollow double-layer fiber by syringe injection to obtain the composite electrochromic material.

[0055] This composite electrochromic material has excellent deformation ability, and a color change response speed of 1.7 s [the test method was measuring the time interval from when the material is energized to when a green color is visible to the naked eye after a 12 V of voltage is applied to a length of one meter of material], [the color change response speeds were 2.0 s, 2.7 s and 3.4 s when deforming by 45, 90 and 135, respectively];

[0056] The color changes to green or blue, and the material is not easy to bend and break with the number of bending fatigue resistance times of 1.910.sup.5 [tested by JWQ06 bending fatigue tester, with a pre-tension of 0.750.05 cn/dtex, and a repeated bending angle of 100], and can be applied to the field of intelligent textiles.

Embodiment 2

[0057] This embodiment provided a composite electrochromic material, which was formed by a core layer, a skin layer having an electrochromic function, and a light-transmitting protective layer formed by a flexible polymer material that were arranged in sequence from inside to outside, the material of the core layer comprised a conductive mixture with fluidity, and the conductive mixture comprised liquid metal and carboxylated carbon nanotubes, a mass ratio of the carboxylated carbon nanotubes to the liquid metal was 3:100, wherein the liquid metal consisted of gallium, indium and tin in a mass ratio of of 63.5:24:12.5.

[0058] A composite material obtained by mixing polyaniline and polyvinly alcohol with a mass ratio of 1:1 was used as the raw material of the skin layer having an electrochromic function.

[0059] The raw material of the light-transmitting protective layer formed by a flexible polymer material was polyolefin elastomer purchased from The DowChemical Company (USA), with a melt index of 30 g/10 min.

[0060] The method for preparing the composite electrochromic material, which comprised the following steps:

[0061] (1) Polyaniline and polyvinyl alcohol were mixed at a mass ratio of 1:1 using a mixer at 2000 rmp for 10 hours, and mixed well and dried for use, and the polyolefin material was dried for use.

[0062] (2) The treated polyolefin material and polyaniline/polyvinyl alcohol were put into the screw extruder for high-temperature melt treatment at 350 C., respectively, the spinning solutions after melt treatment were respectively introduced into the middle channel and the outer channel, wherein the polyolefin material was introduced into the outer channel with a flow rate of 0.3 ml/min, polyaniline/polyvinyl alcohol was introduced into the middle channel with a flow rate of 0.8 ml/min, the spinning temperature was 200 C., the three-channel nozzle was used for co-extrusion spinning to form a new hollow double-layer fiber, the new hollow double-layer fiber was shaped in a gel bath, and then dried naturally for 24 hours to produce a hollow double-layer fiber with a cavity.

[0063] (3) The components of the conductive mixture were mixed by ultrasonic oscillation according to the ratio, then one end of the dried hollow double-layer fiber was connected to the needle, and the conductive mixture was filled into the cavity of the hollow double-layer fiber by syringe injection to obtain the composite electrochromic material.

[0064] This composite electrochromic material has excellent deformation ability, and a color change response speed of 1.4 s [the test method was measuring the time interval from when the material is energized to when a green color is visible to the naked eye after a 12 V of voltage is applied to a length of one meter of material], [the color change response speeds were 1.5 s, 2.1 s and 2.9 s when deforming by 45, 90 and 135, respectively];

[0065] The color changes to green or blue, and the material is not easy to bend and break with the number of bending fatigue resistance times of 2.410.sup.5 [tested by JWQ06 bending fatigue tester, with a pre-tension of 0.750.05 cn/dtex, and a repeated bending angle of 100], and can be applied to the field of intelligent textiles.

Embodiment 3

[0066] This embodiment provided a composite electrochromic material, which was formed by a core layer, a skin layer having an electrochromic function, and a light-transmitting protective layer formed by a flexible polymer material that were arranged in sequence from inside to outside, the material of the core layer comprised a conductive mixture with fluidity, and the conductive mixture comprised liquid metal and carboxylated carbon nanotubes, a mass ratio of the carboxylated carbon nanotubes to the liquid metal was 5:100, wherein the liquid metal consisted of gallium, indium and tin in a mass ratio of of 63.5:24:12.5.

[0067] A composite material obtained by mixing polyaniline and polyvinly alcohol with a mass ratio of 1:1 was used as the raw material of the skin layer having an electrochromic function.

[0068] The raw material of the light-transmitting protective layer formed by a flexible polymer material was polyolefin elastomer purchased from The DowChemical Company (USA), with a melt index of 30 g/10 min.

[0069] The method for preparing the composite electrochromic material, which comprised the following steps:

[0070] (1) Polyaniline and polyvinyl alcohol were mixed at a mass ratio of 1:1 using a mixer at 2500 rmp for 10 hours, and mixed well and dried for use, and the polyolefin material was dried for use.

[0071] (2) The treated polyolefin material and polyaniline/polyvinyl alcohol were put into the screw extruder for high-temperature melt treatment at 350 C., respectively, the spinning solutions after melt treatment were respectively introduced into the middle channel and the outer channel, wherein the polyolefin material was introduced into the outer channel with a flow rate of 0.2 ml/min, polyaniline/polyvinyl alcohol was introduced into the middle channel with a flow rate of 0.7 ml/min, the spinning temperature was 200 C., the three-channel nozzle was used for co-extrusion spinning to form a new hollow double-layer fiber, the new hollow double-layer fiber was shaped in a gel bath, and then dried naturally for 24 hours to produce a hollow double-layer fiber with a cavity.

[0072] (3) The components of the conductive mixture were mixed by ultrasonic oscillation according to the ratio, then one end of the dried hollow double-layer fiber was connected to the needle, and the conductive mixture was filled into the cavity of the hollow double-layer fiber by syringe injection to obtain the composite electrochromic material.

[0073] This composite electrochromic material has excellent deformation ability, and a color change response speed of 1.5 s [the test method was measuring the time interval from when the material is energized to when a green color is visible to the naked eye after a 12 V of voltage is applied to a length of one meter of material], [the color change response speeds were 1.8 s, 2.5 s and 3.1 s when deforming by 45, 90 and 135, respectively];

[0074] The color changes to green or blue, and the material is not easy to bend and break with the number of bending fatigue resistance times of 2.210.sup.5 [tested by JWQ06 bending fatigue tester, with a pre-tension of 0.750.05 cn/dtex, and a repeated bending angle of 100], and can be applied to the field of intelligent textiles.

Comparative Example 1

[0075] It was basically the same as Embodiment 1, except that the conductive mixture was replaced by a separate liquid metal consisting of gallium, indium and tin in a mass ratio of 68.5:21.5:10, without the addition of carboxylated multi-walled carbon nanotubes.

[0076] This composite electrochromic material has excellent deformation ability, and a color change response speed of 1.9 s [the test method was measuring the time interval from when the material is energized to when a green color is visible to the naked eye after a 12 V of voltage is applied to a length of one meter of material], [the color change response speeds were 2.8 s, 4.0 s and 5.2 s when deforming by 45, 90 and 135, respectively];

[0077] The number of bending fatigue resistance times was 1.710.sup.5 [tested by JWQ06 bending fatigue tester, with a pre-tension of 0.750.05 cn/dtex, and a repeated bending angle of 100].

[0078] The embodiments described above are only for illustrating the technical concepts and features of the present disclosure, and are intended to make those skilled in the art being able to understand the present disclosure and thereby implement it, and should not be concluded to limit the protective scope of this disclosure. Any equivalent variations or modifications according to the spirit of the present disclosure should be covered by the protective scope of the present disclosure.