Microcapsule color-changeable functional fabric

Abstract

The invention relates to the field of fabrics, provides a microcapsule color-changeable functional fabric, and solves the defect that a color-changeable fabric in the prior art is not washable. Which comprises a fabric body coated with a phase change microcapsule, and is characterized in that the phase change microcapsule is provided with a first cavity and a second cavity which are independently distributed at an interval, a photo-thermal double-response color-changing compound is packaged in the first cavity, and a photo-thermal double-response color-changing compound is packaged in the second cavity. The photo-thermal double-response color-changing compound is composed of a spiropyrane photosensitizer and a thermochromic liquid crystal material according to the weight ratio of 1: 1-1: 2, the color-changing response wavelength range of the photo-thermal double-response color-changing compound is 300-700 nm, and the color-changing temperature interval is 20-45 DEG C; and a temperature-adjusting and energy-storing compound is packaged in the second chamber.

Description

A microcapsule color-changing functional fabric Technical Field

[0001] This invention relates to the field of fabrics, and more particularly to a microcapsule color-changing functional fabric. Background Technology

[0002] Traditional fabrics generally do not have color-changing properties. However, as people's living standards improve, their demands for fabric performance are increasing. Fabrics with color-changing properties are becoming increasingly popular due to their color-changing effect. The color-changing function of fabrics is usually achieved by adding color-changing materials to the fabric. For example, the color-changing material can be adhered to the fabric by soaking it in a color-changing sizing solution. However, the color-changing performance obtained in this way is not long-lasting; most of the color-changing material will be washed away after multiple washes. Another method is to coat the fabric with color-changing materials. This type of fabric is also not wash-resistant; the color-changing property almost disappears after multiple washes.

[0003] Chinese Patent Publication No. CN220262242U discloses a temperature- and light-sensitive color-changing fabric, comprising: an anti-ultraviolet coating for resisting ultraviolet rays; a color-changing fabric layer one connected to the bottom of the anti-ultraviolet coating, the color-changing fabric layer one changing color according to humidity; a color-changing fabric layer two connected to the bottom of the color-changing fabric layer one, the color-changing fabric layer two changing color according to body temperature; a sweat-absorbing and waterproof membrane connected to the bottom of the color-changing fabric layer two, the sweat-absorbing and waterproof membrane for absorbing sweat and water; and an antibacterial and skin-friendly layer connected to the bottom of the sweat-absorbing and waterproof membrane, the antibacterial and skin-friendly layer containing activated carbon for absorbing odors. The color-changing fabric layer one is composed of light-sensitive and moisture-sensitive color-changing fibers, and can change color according to weather light intensity and humidity, making it more convenient for daily use. However, the color-changing fabric layer one is a structural layer connected to the bottom of the anti-ultraviolet coating, which is not washable, and the color-changing effect decreases significantly after multiple washes. Summary of the Invention

[0004] Therefore, in view of the above problems, the present invention provides a microcapsule color-changing functional fabric, which solves the defect of existing color-changing fabrics that are not washable.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a microcapsule color-changing functional fabric, comprising a fabric body coated with phase change microcapsules, wherein the phase change microcapsules have two independently spaced chambers, namely a first chamber and a second chamber. The first chamber encapsulates a photothermal dual-response color-changing composite, which is composed of a spiropyran photosensitizer and a thermochromic liquid crystal material in a weight ratio of 1:1 to 1:2, with a color-changing response wavelength range of 300nm-700nm and a color-changing temperature range of 20℃-45℃. The second chamber encapsulates a temperature-regulating energy storage composite, which is composed of a fatty acid ester phase change material with a carbon chain length of C18-C24 and a nano-graphene thermal conductive agent in a weight ratio of 1:0.5-1:2, with a phase change enthalpy ≥180 J / g and a thermal conductivity ≥2.5 W / (m·K).

[0006] Furthermore: the wall material of the first chamber is a polydopamine-titanium dioxide heterostructure with a thickness of 50nm-200nm, and the wall material of the second chamber is hydrophobically modified mesoporous silica with octadecyltrimethoxysilane grafted onto the inner wall.

[0007] Furthermore, the pore size of the hydrophobically modified mesoporous silica is 2nm-5nm.

[0008] Further: The preparation steps of the phase change microcapsules are as follows: (1) Spiropyran photosensitizer and thermochromic liquid crystal are mixed at a weight ratio of 1:1.5-1:2, dissolved in anhydrous ethanol, and prepared into an 8wt%-13wt% solution. The solution is magnetically stirred at 30℃-45℃ until completely dissolved to obtain core material A solution; (2) Core material A solution is used as the oil phase and dispersed in a dopamine Tris-HCl buffer aqueous solution with pH=8-9, wherein the dopamine Tris-HCl buffer aqueous solution contains 1mg / mL-1.5mg / mL dopamine hydrochloride. Then, the mixture is stirred and polymerized at room temperature for 6h-7h to form a polydopamine primary capsule wall; a tetrabutyl titanate ethanol solution with a molar ratio of 1:1.8-1:2.2 to dopamine is added, and the mixture is transferred to a polytetrafluoroethylene-lined hydrothermal reactor and reacted at 80℃-85℃ for 4h-5h. Then, it is naturally cooled to room temperature and deionized. The microcapsule powder containing the photothermal dual-response color-changing complex was obtained by alternating centrifugation and washing with water and anhydrous ethanol 3-4 times, and finally dried. (3) Ethyl dodecanoate and nanographene sheets were mixed at a weight ratio of 1:1-1:1.5 and melt-blended to obtain core material B. (4) The core material B was added to an aqueous solution containing 1.55wt%-2.5wt% sodium dodecyl sulfate and reacted at 60℃-70℃ and 8000rpm-10000rpm for 15min-20min to form an O / W emulsion. Then, tetraethyl orthosilicate was slowly added, followed by the addition of ammonia water with a mass concentration of 20%-30% as a catalyst to adjust the pH of the system to 9-10. Then, the reaction was carried out at 60℃-70℃ and 300rpm-500rpm for 1h-2h to form SiO2 prepolymer and preliminarily coated. Then, octadecyltrimethoxysilane was added and reacted at 60℃-70℃ for 6h. h-7h, centrifuge, collect solid product, then wash with deionized water and anhydrous ethanol alternately 3-6 times, then dry to obtain second chamber microcapsule powder encapsulated with temperature-regulating energy storage complex; (5) mix the first chamber microcapsule powder encapsulated with photothermal dual-response color-changing complex and the second chamber microcapsule powder encapsulated with temperature-regulating energy storage complex evenly to obtain phase change microcapsules.

[0009] Furthermore, the spiropyran photosensitizer is a spiroxazine derivative.

[0010] Further: In step (5), the first chamber microcapsule powder and the second chamber microcapsule powder are fixed to the fabric body by an adhesive.

[0011] Furthermore: the adhesive is a polyurethane adhesive.

[0012] By adopting the aforementioned technical solution, the beneficial effects of the present invention are as follows: 1. The present invention, by placing the photothermal dual-response color-changing composite and the temperature-regulating energy storage composite in two independent chambers, fundamentally avoids the mutual interference that may occur between the two functional materials during long-term use, and ensures the long-term stability of color-changing sensitivity and temperature regulation capability.

[0013] 2. The wall material of the first chamber is a polydopamine-titanium dioxide heterostructure. This composite wall material combines the strong adhesion and biocompatibility of polydopamine with the photocatalytic properties and high stability of titanium dioxide. The polydopamine-titanium dioxide heterostructure can effectively improve the mechanical strength and photothermal stability of the wall material.

[0014] 3. The second chamber wall material is hydrophobically modified mesoporous silica, with the inner wall grafted with octadecyltrimethoxysilane. The mesoporous structure provides a large specific surface area and good containment. Hydrophobic modification through grafting octadecyltrimethoxysilane onto the inner wall gives the wall material a strong affinity and sealing properties for hydrophobic fatty acid ester phase change materials. This effectively prevents leakage of the phase change material during repeated solid-liquid phase transitions, significantly enhancing the thermal cycling stability of the microcapsules and thus ensuring the durability of the temperature regulation function.

[0015] 4. The preparation of phase change microcapsules of the present invention involves first preparing first chamber microcapsule powder and second chamber microcapsule powder independently to avoid cross-influence of functional components during the preparation process. The photothermal dual-response unit uses polydopamine-titanium dioxide heterostructure wall material, and the temperature regulation and energy storage unit uses hydrophobic modified mesoporous silica. Both wall materials have strong sealing properties. Then, an adhesive is used to fix the phase change microcapsules to the fabric body. The adhesive is made of polyurethane material, which can form a strong cross-linking network between the phase change microcapsules and fibers, making the three more firmly bonded and ultimately improving the washability of the fabric. Detailed Implementation

[0016] Example 1

[0017] A microcapsule-encapsulated color-changing functional fabric includes a fabric body coated with phase change microcapsules. Each phase change microcapsule has two independently spaced chambers, designated as a first chamber and a second chamber. The first chamber encapsulates a photothermal dual-response color-changing composite material, which is composed of a spiropyran photosensitizer and a thermochromic liquid crystal material in a 1:1 weight ratio. The color-changing response wavelength range is 300nm-700nm, and the color-changing temperature range is 20℃-45℃. The second chamber encapsulates a temperature-regulating energy storage composite material, which is composed of a fatty acid ester phase change material with a carbon chain length of C18-C24 and a nano-graphene thermal conductive agent in a 1:0.5 weight ratio. The phase change enthalpy is ≥180 J / g, and the thermal conductivity is ≥2.5 W / (m·K).

[0018] The first chamber wall material is a polydopamine-titanium dioxide heterostructure with a thickness of 50 nm. The second chamber wall material is hydrophobically modified mesoporous silica with octadecyltrimethoxysilane grafted onto the inner wall. The pore size of the hydrophobically modified mesoporous silica is 2 nm.

[0019] The preparation steps of the phase change microcapsules are as follows: (1) Spiroxazine derivative and thermochromic liquid crystal are mixed at a weight ratio of 1:1.5, dissolved in anhydrous ethanol, and prepared into an 8wt%t% solution. The solution is magnetically stirred at 30°C until completely dissolved to obtain core material A solution; (2) Core material A solution is used as the oil phase and dispersed in a dopamine Tris-HCl buffer aqueous solution with pH=8, wherein the dopamine Tris-HCl buffer aqueous solution contains 1mg / mL of dopamine hydrochloride. Then, the mixture is stirred and polymerized at room temperature for 6h to form a polydopamine primary capsule wall; a tetrabutyl titanate ethanol solution with a molar ratio of 1:1.8 to dopamine is added, and the mixture is transferred to a hydrothermal reactor with a polytetrafluoroethylene liner and reacted at 80°C for 4h, and then naturally cooled to At room temperature, the first chamber microcapsule powder containing the photothermal dual-response color-changing complex was obtained by alternating centrifugation and washing with deionized water and anhydrous ethanol three times, and finally dried. (3) Ethyl dodecanoate and nanographene sheets were mixed at a weight ratio of 1:1 and melt-blended to obtain core material B. (4) The core material B was added to an aqueous solution containing 1.55wt% sodium dodecyl sulfate and reacted at 60℃ and 8000rpm for 15min to form an O / W emulsion. Then, tetraethyl orthosilicate was slowly added, followed by the addition of 20% ammonia water as a catalyst to adjust the pH of the system to 9. Then, the reaction was carried out at 60℃ and 300rpm for 1h to form SiO2 prepolymer and preliminarily coated. Then, octadecyltrimethoxysilane was added and reacted at 60℃ for 6 hours. h, centrifuge, collect solid product, wash three times alternately with deionized water and anhydrous ethanol, and then dry to obtain second chamber microcapsule powder encapsulated with temperature-regulating energy storage complex; (5) mix the first chamber microcapsule powder encapsulated with photothermal dual-response color-changing complex and the second chamber microcapsule powder encapsulated with temperature-regulating energy storage complex evenly to obtain phase change microcapsules.

[0020] In step (5) of the present invention, the first chamber microcapsule powder and the second chamber microcapsule powder are fixed onto the fabric body by polyurethane adhesive.

[0021] Example 2

[0022] A microcapsule-encapsulated color-changing functional fabric includes a fabric body coated with phase change microcapsules. Each phase change microcapsule has two independently spaced chambers, designated as a first chamber and a second chamber. The first chamber encapsulates a photothermal dual-response color-changing composite material composed of a spiroxazine derivative and a thermochromic liquid crystal material in a weight ratio of 1:1.5, with a color-changing response wavelength range of 300nm-700nm and a color-changing temperature range of 20℃-45℃. The second chamber encapsulates a temperature-regulating energy storage composite material composed of a fatty acid ester phase change material with a carbon chain length of C18-C24 and a nano-graphene thermal conductive agent in a weight ratio of 1:1.2, with a phase change enthalpy ≥180J / g and a thermal conductivity ≥2.5 W / (m·K). The first chamber wall material is a polydopamine-titanium dioxide heterostructure with a thickness of 150 nm. The second chamber wall material is hydrophobically modified mesoporous silica with a pore size of 4 nm and octadecyltrimethoxysilane grafted onto the inner wall.

[0023] The preparation steps of the phase change microcapsules are as follows: (1) a spiropyran photosensitizer and a thermochromic liquid crystal are mixed at a weight ratio of 1:1.5-1:2, dissolved in anhydrous ethanol, and a solution of 8wt%-13wt% is prepared. The solution is then magnetically stirred at 30℃-45℃ until completely dissolved to obtain core material A solution; (2) the core material A solution is used as the oil phase and dispersed in a dopamine Tris-HCl buffer aqueous solution with pH=8-9, wherein the dopamine Tris-HCl buffer aqueous solution contains 1 Dopamine hydrochloride at concentrations of mg / mL-1.5 mg / mL was added, followed by stirring and polymerization at room temperature for 6-7 hours to form the primary polydopamine capsule wall. A tetrabutyl titanate ethanol solution with a dopamine molar ratio of 1:1.8 was added, and the mixture was transferred to a polytetrafluoroethylene-lined hydrothermal reactor and reacted at 83°C for 4.5 hours. After natural cooling to room temperature, the mixture was washed four times alternately by centrifugation with deionized water and anhydrous ethanol, and finally dried to obtain the first chamber microstructure encapsulated with the photothermal dual-response color-changing composite. (3) Ethyl dodecanoate and nanographene sheets are mixed at a weight ratio of 1:1.3 and melt-blended to obtain core material B; (4) The core material B is added to an aqueous solution containing 2wt% sodium dodecyl sulfate and reacted at 65℃ and 9000rpm for 18min to form an O / W emulsion. Then, tetraethyl orthosilicate is slowly added, followed by the addition of 25% ammonia as a catalyst to adjust the pH of the system to 9. Then, the reaction is carried out at 65℃ and 400rpm for 1.5h to form SiO2 prepolymer and preliminarily encapsulate it. Then, octadecyltrimethoxysilane is added and reacted at 65℃ for 6.5h. After centrifugation, the solid product is collected and washed 5 times alternately with deionized water and anhydrous ethanol. After drying, the second chamber microcapsule powder encapsulated with temperature-regulating energy storage composite is obtained; (5) The first chamber microcapsule powder encapsulated with photothermal dual-response color-changing composite and the second chamber microcapsule powder encapsulated with temperature-regulating energy storage composite are mixed evenly to obtain phase change microcapsules.

[0024] In step (5), the first chamber microcapsule powder and the second chamber microcapsule powder are fixed to the fabric body by polyurethane adhesive.

[0025] Example 3

[0026] A microcapsule-encapsulated color-changing functional fabric includes a fabric body coated with phase change microcapsules. Each phase change microcapsule has two independently spaced chambers, designated as a first chamber and a second chamber. The first chamber encapsulates a photothermal dual-response color-changing composite material, which is composed of a spiroxazine derivative and a thermochromic liquid crystal material in a 1:2 weight ratio. The color-changing response wavelength range is 300nm-700nm, and the color-changing temperature range is 20℃-45℃. The second chamber encapsulates a temperature-regulating energy storage composite material, which is composed of a fatty acid ester phase change material with a carbon chain length of C18-C24 and a nano-graphene thermal conductive agent in a 1:2 weight ratio. The phase change enthalpy is ≥180 J / g, and the thermal conductivity is ≥2.5 W / (m·K).

[0027] The first chamber wall material is a polydopamine-titanium dioxide heterostructure with a thickness of 200 nm, and the second chamber wall material is hydrophobically modified mesoporous silica with octadecyltrimethoxysilane grafted onto the inner wall.

[0028] The hydrophobic modified mesoporous silica has a pore size of 5 nm.

[0029] The preparation steps of the phase change microcapsules are as follows: (1) Spiropyran photosensitizer and thermochromic liquid crystal are mixed at a weight ratio of 1:2, dissolved in anhydrous ethanol, and prepared into a 13wt% solution. The solution is magnetically stirred at 45°C until completely dissolved to obtain core material A solution; (2) Core material A solution is used as the oil phase and dispersed in a dopamine Tris-HCl buffer aqueous solution with pH=9. The dopamine Tris-HCl buffer aqueous solution contains 1.5mg / mL of dopamine hydrochloride. Then, it is stirred and polymerized at room temperature for 7h to form a polydopamine primary capsule wall; tetrabutyl titanate ethanol solution with a molar ratio of 1:2.2 to dopamine is added, and the mixture is transferred to a hydrothermal reactor with a polytetrafluoroethylene liner and reacted at 85°C for 5h. Then, it is naturally cooled to room temperature, washed 4 times by alternating centrifugation with deionized water and anhydrous ethanol, and finally dried to obtain the first chamber microcapsule powder encapsulated with photothermal dual-response color-changing complex; (3) ethyl icosinate is added to the oil phase and dispersed in a dopamine Tris-HCl buffer aqueous solution containing 1.5mg / mL of dopamine hydrochloride. The ester and the nano-graphene sheet were mixed at a weight ratio of 1:1.5 and melt-blended to obtain core material B; (4) The core material B was added to an aqueous solution containing 2.5wt% sodium dodecyl sulfate and reacted at 70℃ and 10000rpm for 20min to form an O / W emulsion. Then, tetraethyl orthosilicate was slowly added, followed by the addition of 30% ammonia water as a catalyst to adjust the pH of the system to 10. Then, the reaction was carried out at 70℃ and 500rpm for 2h to form SiO2 prepolymer and preliminarily coated. Then, octadecyltrimethoxysilane was added and reacted at 70℃ for 7h. After centrifugation, the solid product was collected and washed 6 times alternately with deionized water and anhydrous ethanol. After drying, the second chamber microcapsule powder encapsulated with temperature-regulating energy storage composite was obtained; (5) The first chamber microcapsule powder encapsulated with photothermal dual-response color-changing composite and the second chamber microcapsule powder encapsulated with temperature-regulating energy storage composite were mixed evenly to obtain phase change microcapsules.

[0030] In step (5), the first chamber microcapsule powder and the second chamber microcapsule powder are fixed to the fabric body by polyurethane adhesive.

[0031] The thermochromic liquid crystal used in this invention is based on chiral compounds or sterol ester derivatives of non-sterols, such as (S)-4-(2-methylbutyl)phenol ester derivatives, which have chiral nematic or cholesteric phase structures. These are materials known in the prior art and will not be described in detail here.

[0032] Although the invention has been specifically shown and described in conjunction with preferred embodiments, those skilled in the art should understand that various changes in form and detail may be made to the invention without departing from the spirit and scope of the invention as defined in the appended claims, all of which shall be within the scope of protection of the invention.

Claims

1. A microcapsule-coated color-changing functional fabric, comprising a fabric body, wherein phase change microcapsules are coated within the fabric body, characterized in that: The phase change microcapsule has two independently spaced chambers, a first chamber and a second chamber. The first chamber encapsulates a photothermal dual-response color-changing composite, which is composed of a spiropyran photosensitizer and a thermochromic liquid crystal material in a weight ratio of 1:1 to 1:

2. Its color-changing response wavelength range is 300nm-700nm, and its color-changing temperature range is 20℃-45℃. The second chamber encapsulates a temperature-regulating energy storage composite, which is composed of a fatty acid ester phase change material with a carbon chain length of C18-C24 and a nano-graphene thermal conductive agent in a weight ratio of 1:0.5 to 1:

2. The phase change enthalpy is ≥180 J / g, and the thermal conductivity is ≥2.5 W / (m·K).

2. The microcapsule color-changing functional fabric according to claim 1, characterized in that: The first chamber wall material is a polydopamine-titanium dioxide heterostructure with a thickness of 50nm-200nm, and the second chamber wall material is hydrophobically modified mesoporous silica with octadecyltrimethoxysilane grafted onto the inner wall.

3. The microcapsule color-changing functional fabric according to claim 2, characterized in that: The hydrophobically modified mesoporous silica has a pore size of 2nm-5nm.

4. The microcapsule color-changing functional fabric according to claim 1, characterized in that: The preparation steps of the phase change microcapsules are as follows: (1) Spiropyran photosensitizer and thermochromic liquid crystal are mixed at a weight ratio of 1:1.5-1:2, dissolved in anhydrous ethanol, and prepared into an 8wt%-13wt% solution. The solution is magnetically stirred at 30℃-45℃ until completely dissolved to obtain core material A solution; (2) Core material A solution is used as the oil phase and dispersed in a dopamine Tris-HCl buffer aqueous solution with pH=8-9, wherein the dopamine Tris-HCl buffer aqueous solution contains 1mg / mL-1.5mg / mL dopamine hydrochloride. Then, the mixture is stirred and polymerized at room temperature for 6h-7h to form a polydopamine primary capsule wall; a tetrabutyl titanate ethanol solution with a molar ratio of 1:1.8-1:2.2 to dopamine is added, and the mixture is transferred to a polytetrafluoroethylene-lined hydrothermal reactor and reacted at 80℃-85℃ for 4h-5h. Then, it is naturally cooled to room temperature and treated with deionized water and (2) Wash the product with anhydrous ethanol by alternating centrifugation 3-4 times, and finally dry it to obtain the first chamber microcapsule powder encapsulated with photothermal dual-response color-changing complex; (3) Mix ethyl dodecanoate and nanographene sheets at a weight ratio of 1:1-1:1.5 and melt blend to obtain core material B; (4) Add the core material B to an aqueous solution containing 1.55wt%-2.5wt% sodium dodecyl sulfate, and react at 60℃-70℃ and 8000rpm-10000rpm for 15min-20min to form an O / W emulsion, then slowly add tetraethyl orthosilicate, and then dropwise add ammonia water with a mass concentration of 20%-30% as a catalyst to adjust the pH of the system to 9-10; then react at 60℃-70℃ and 300rpm-500rpm for 1h-2h to form SiO2 prepolymer and initially coat it, and then add octadecyltrimethoxysilane and react at 60℃-70℃ for 6 hours. h-7h, centrifuge, collect solid product, then wash with deionized water and anhydrous ethanol alternately 3-6 times, then dry to obtain second chamber microcapsule powder encapsulated with temperature-regulating energy storage complex; (5) mix the first chamber microcapsule powder encapsulated with photothermal dual-response color-changing complex and the second chamber microcapsule powder encapsulated with temperature-regulating energy storage complex evenly to obtain phase change microcapsules.

5. The microcapsule color-changing functional fabric according to claim 1, characterized in that: The spiropyran photosensitizer is a spiroxazine derivative.

6. The microcapsule color-changing functional fabric according to claim 4, characterized in that: In step (5), the first chamber microcapsule powder and the second chamber microcapsule powder are fixed to the fabric body by an adhesive.

7. The microcapsule color-changing functional fabric according to claim 6, characterized in that: The adhesive is a polyurethane adhesive.