Composite coating based on octadecylsilane-silica-zinc oxide microcapsules-mxene / chitosan-polyacrylate, method of preparation and use

Abstract

This invention relates to a composite coating based on octadecane@silica-zinc oxide microcapsules-MXene / chitosan-polyacrylate, its preparation method, and its application. The composite coating mainly consists of the following raw materials in parts by weight: 20-100 parts chitosan-polyacrylate emulsion, 2-10 parts octadecane@silica-zinc oxide microcapsules, and 3-15 parts MXene powder. The silica-zinc oxide double-shell structure capsule prepared by this invention is constructed by in-situ growth of zinc oxide nanounits on the surface of silica microcapsules. Its rough surface helps to increase the specific surface area of ​​the material and enhance the interfacial effect, promoting improved humidity sensitivity. Furthermore, the composite coating constructed by this invention forms a hydrophilic-antibacterial composite material with a cross-linked network structure, which produces a synergistic effect with zinc oxide, thereby achieving a dual improvement in humidity sensitivity and antibacterial function. Finally, this coating is applied to fabrics for use in sportswear.

Description

Technical Field

[0001] This invention belongs to the field of smart textile technology, specifically relating to an octadecane@silica-zinc oxide microcapsule-MXene / chitosan-polyacrylate coating, its preparation method, and its application. Background Technology

[0002] In recent years, wearable electronic textiles have shown broad application prospects in areas such as human motion signal monitoring, personal protection, human-computer interaction, and real-time physiological state monitoring. Among them, epidermal perspiration monitoring, as an important means of assessing exercise status, diagnosing related diseases, and evaluating skin barrier function, is receiving increasing attention. However, traditional epidermal perspiration measurement methods are difficult to achieve real-time monitoring and are often accompanied by problems such as cumbersome sweat collection processes. Against this backdrop, a detection strategy based on humidity sensors provides an effective way to achieve real-time monitoring of human perspiration by capturing the changes in relative humidity caused by sweat evaporation.

[0003] However, electronic textiles with only a single sensing function are no longer sufficient to meet the growing demand for multifunctional integration. For example, if motion monitoring textiles could also have thermal management functions, it would significantly improve the wearing comfort of the human body during exercise. Chinese invention patent (application number: CN116672152A) prepared a high-strength electronic fabric that combines daytime radiation cooling and physiological electrical signal monitoring. It enhances the emissivity of the fabric in the mid- and far-infrared bands by uniformly blending functional Al2O3 nanoparticles, and controls the pore size of the fabric through a thermal fusion process to improve the reflectivity of the fabric in the ultraviolet, visible, and near-infrared bands, thereby obtaining an electronic fabric with radiation cooling properties. However, this method is limited to giving the fabric a cooling function, and lacks timely protection when the human body temperature drops. Chinese invention patent (application number: CN118326587A) provides a phase change thermal storage conductive sensing composite yarn. The composite yarn has a core-sheath structure, with the core layer being a polyurethane / paraffin core yarn and the sheath layer being a conductive roving covered by the core yarn. Then, the paraffin is wrapped inside the yarn by wet spinning the core yarn. However, the flexibility of the yarn obtained by this method is greatly challenged. Summary of the Invention

[0004] Objective of the Invention: To address the problems existing in the prior art, this invention provides a composite coating based on octadecane@silica-zinc oxide microcapsules-MXene / chitosan-polyacrylate. This coating is prepared by compounding these three materials onto a fabric. The resulting fabric not only has humidity monitoring capabilities, enabling real-time monitoring of human perspiration, but also provides thermal management and antibacterial functions, effectively supporting the health protection of wearers in complex environments. This invention not only solves the problem of low sensitivity of MXene as a humidity sensing material, but also addresses the integration of sensing performance, thermal management performance, and antibacterial performance in wearable electronic fabrics.

[0005] The present invention also provides a method for preparing and applying the composite coating based on octadecane@silica-zinc oxide microcapsules-MXene / chitosan-polyacrylate.

[0006] Technical solution: In order to achieve the above objectives, the present invention provides a composite coating based on octadecane@silica-zinc oxide microcapsules-MXene / chitosan-polyacrylate, which is mainly composed of the following raw materials in parts by weight: 20-100 parts of chitosan-polyacrylate emulsion, 2-10 parts of octadecane@silica-zinc oxide microcapsules, and 3-15 parts of MXene powder.

[0007] The chitosan-polyacrylate emulsion is a composite coating obtained by adding carboxymethyl chitosan aqueous solution to polyacrylate and stirring. The solid content of the carboxymethyl chitosan aqueous solution is 1-2%, and the solid content of the carboxymethyl chitosan aqueous solution accounts for 5-15% of the mass of polyacrylate.

[0008] Preferably, the chitosan-polyacrylate emulsion preparation steps are as follows: Weigh 1-10 parts of carboxymethyl chitosan and 100-1000 parts of deionized water to prepare a 1% carboxymethyl chitosan aqueous solution. Add the prepared carboxymethyl chitosan aqueous solution to the polyacrylate (the solid content of the carboxymethyl chitosan aqueous solution accounts for 10% of the mass of the polyacrylate). Stir at 25 °C for 1 hour to obtain the chitosan-polyacrylate emulsion.

[0009] The mixture comprises, by weight, 1-5 parts of fatty alcohol polyoxyethylene ether, 0.8-4 parts of sodium dodecyl sulfate, 9-45 parts of methyl methacrylate, 16-80 parts of butyl acrylate, 0.8-5 parts of acrylic acid, 4-20 parts of ethylene glycol acetoacetate methacrylate, 0.1-0.5 parts of sodium bicarbonate, 0.2-1 parts of potassium persulfate, and 50-250 parts of deionized water; fatty alcohol polyoxyethylene ether, sodium dodecyl sulfate, methyl methacrylate, butyl acrylate, acrylic acid, and ethylene glycol acetoacetate methacrylate are added to deionized water and emulsified at high speed, followed by the addition of sodium bicarbonate and potassium persulfate, and heated to react to obtain polyacrylate.

[0010] The mixture comprises, by weight, 1-5 parts hexadecyltrimethylammonium bromide, 4-20 parts tetraethyl orthosilicate, 4-20 parts octadecane, 4-20 parts ammonia, 2-10 parts zinc acetate, 1.5-7.5 parts hexamethylenetetramine, and 100-500 parts deionized water. Hexadecyltrimethylammonium bromide, tetraethyl orthosilicate, and octadecane are added to deionized water and homogenized. Then, ammonia is added, and the mixture is heated to obtain octadecane@silica microcapsules. Subsequently, octadecane@silica microcapsule powder, zinc acetate, and hexamethylenetetramine are added to deionized water, and the mixture is heated to obtain octadecane@silica-zinc oxide microcapsules.

[0011] Wherein, the MXene is a few-layer Ti3C2T x MXene.

[0012] The preparation method of the composite coating based on octadecane@silica-zinc oxide microcapsules-MXene / chitosan-polyacrylate of the present invention includes the following steps:

[0013] Octadecylene@silica-zinc oxide microcapsules and MXene powder were dispersed in chitosan-polyacrylate emulsion and stirred to obtain a composite dispersion. The dispersion was then deposited onto a carrier and dried to obtain the desired composite coating.

[0014] The application of the octadecane@silica-zinc oxide microcapsule-MXene / chitosan-polyacrylate composite coating described in this invention in sportswear.

[0015] The present invention relates to a composite coated fabric based on octadecane@silica-zinc oxide microcapsules-MXene / chitosan-polyacrylate as described in claim 1.

[0016] The method for preparing the composite coated fabric of the present invention includes the following steps:

[0017] By weight, 2-10 parts of octadecane@silica-zinc oxide microcapsules and 3-15 parts of MXene powder are dispersed into 20-100 parts of chitosan-polyacrylate emulsion. The mixture is stirred to obtain a composite dispersion. The dispersion is then deposited onto the fabric by vacuum filtration. The resulting fabric is dried to obtain the desired composite coated fabric.

[0018] The application of the composite coated fabric described in this invention in sportswear.

[0019] The silica-zinc oxide double-shell microcapsules prepared in this invention are constructed by in-situ growth of zinc oxide nanounits on the surface of silica microcapsules. Their rough surface helps increase the specific surface area of ​​the material and enhances the interfacial effect, thus improving humidity sensitivity. Furthermore, a polyacrylate with acetoacetate groups in its side chains was synthesized, and further, by reacting the amino groups in carboxymethyl chitosan with the ester groups, a hydrophilic-antibacterial composite material with a cross-linked network structure was formed. The introduction of this composite material resin aims to leverage the hydrophilicity and antibacterial properties of the protonated amino groups in carboxymethyl chitosan to create a synergistic effect with zinc oxide, thereby achieving a dual improvement in humidity sensitivity and antibacterial function. Finally, this coating is applied to fabrics for use in sportswear.

[0020] The material prepared by this invention exhibits a dual improvement in humidity sensitivity and antibacterial function. By combining MXene material with humidity-sensitive properties with microcapsules featuring a silica-zinc oxide double-shell structure, humidity sensitivity is enhanced, and the antibacterial properties of zinc oxide further strengthen the coating's antibacterial effect. Simultaneously, this invention incorporates a cross-linked network structure of carboxymethyl chitosan and polyacrylate, endowing the composite coating with both hydrophilicity and antibacterial properties, thus achieving a dual function of excellent humidity sensitivity and antibacterial properties. The material prepared by this invention also possesses the thermal management function of phase change microcapsules. Through the design of octadecane@silica-zinc oxide microcapsules, a phase change material is introduced to provide thermal management, offering timely heat protection during human movement, regulating the wearer's body temperature, and improving wearing comfort.

[0021] This invention is the first to integrate humidity sensing, thermal management, and antibacterial functions onto fabric through a composite coating. Specifically, the synergistic effect of MXene and zinc oxide effectively enhances humidity sensitivity and antibacterial performance, while a phase change material provides thermal protection. The composite of silica-zinc oxide double-shell microcapsules and MXene enhances humidity sensitivity and thermal management. Simultaneously, the cross-linked network structure formed by carboxymethyl chitosan and polyacrylate not only improves humidity sensitivity but also strengthens antibacterial function through synergistic interaction with zinc oxide. This design provides enhanced performance in multiple dimensions, exhibiting a significant synergistic effect.

[0022] The composite coating prepared by this invention can monitor the sweating status of the human body in real time and provide heat protection, so that the wearer can stay comfortable during exercise. The antibacterial properties of zinc oxide combined with the biocompatibility of chitosan improve the hygiene of the fabric, reduce the risk of bacterial growth, and provide effective support for the health protection of the wearer in complex environments.

[0023] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0024] (1) The coating of the present invention is based on the synergistic effect of MXene and zinc oxide shell, and has superior humidity sensitivity.

[0025] (2) The composite of phase change microcapsules endows the fabric with thermal management function, which can provide timely thermal protection for the human body.

[0026] (3) Carboxymethyl chitosan has good biocompatibility, biodegradability and non-toxicity, and together with the zinc oxide shell, it imparts excellent antibacterial properties to the fabric coating.

[0027] (4) The coating preparation process in this invention is simple and environmentally friendly. Attached Figure Description

[0028] Figure 1This is a synthetic route diagram of the polyacrylate emulsion in an embodiment of the present invention.

[0029] Figure 2 The chemical equation for the reaction of carboxymethyl chitosan cross-linked polyacrylate in the embodiments of the present invention is shown below.

[0030] Figure 3 This is a test image of octadecane@silica phase change microcapsules in an embodiment of the present invention, wherein... Figure 3 (ab) are cold field emission scanning electron microscope images of octadecane@silica phase change microcapsules; Figure 3 (c) is the particle size distribution histogram of octadecane@silica phase change microcapsules; Figure 3 (d) shows the EDS energy spectrum and elemental distribution of octadecane@silica phase change microcapsules; Figure 3 (e) is the infrared spectrum of octadecane@silica phase change microcapsules.

[0031] Figure 4 This is a test image of octadecane@silica-zinc oxide phase change microcapsules in an embodiment of the present invention, wherein... Figure 4 (ab) are cold field emission scanning electron microscope images of octadecane@silica-zinc oxide phase change microcapsules; Figure 4 (c) is the particle size distribution histogram of octadecane@silica-zinc oxide phase change microcapsules; Figure 4 (d) shows the EDS energy spectrum and elemental distribution of octadecane@silica-zinc oxide phase change microcapsules; Figure 4 (e) shows the XRD patterns of the silica shell and the silica-zinc oxide shell.

[0032] Figure 5 This is a graph from an embodiment of the present invention, wherein, Figure 5 (a) is the differential scanning calorimeter curve of the core material and the microcapsule; Figure 5 (b) Comparison of phase transition enthalpy values ​​between the core material and the microcapsule; Figure 5 (c) Comparison of encapsulation parameters for microcapsules; Figure 5 (de) shows the DSC cycle curve of the phase change microcapsules and the changes in phase change temperature and phase change enthalpy during the cycle.

[0033] Figure 6 This is a test diagram of carboxymethyl chitosan crosslinked polyacrylate in an embodiment of the present invention, wherein, Figure 6 (a) Infrared spectra of carboxymethyl chitosan and carboxymethyl chitosan cross-linked polyacrylate; Figure 6 (b) Water contact angles of composite membranes with different carboxymethyl chitosan contents; Figure 6 (c) Elongation at break curves of composite films with different carboxymethyl chitosan contents; Figure 6(d) Cold field emission scanning electron microscope images of composite films with different carboxymethyl chitosan contents.

[0034] Figure 7 This is a test image of the coated fabric in an embodiment of the present invention, wherein, Figure 7 (a) is a schematic diagram of the electrostatic adsorption of carboxymethyl chitosan cross-linked polyacrylate with MXene; Figure 7 (b) is a photograph of the mixed dispersion of carboxymethyl chitosan cross-linked polyacrylate and MXene; Figure 7 (c) is a cold field emission scanning electron microscope image of a polyester fabric; Figure 7 (de) is a cold field emission scanning electron microscope image and a further magnified view of the composite coated fabric; Figure 7 (fg) shows the EDS energy spectrum and elemental distribution of the coated fabric; Figure 7 (hi) is a picture of the coated fabric.

[0035] Figure 8 The above is a test image of the composite coated fabric in an embodiment of the present invention, wherein, Figure 8 (a) shows the humidity sensing characteristic curves of fabrics with different coatings; Figure 8 (b) The real-time humidity response curve of the coated fabric when the microcapsule content is 6%; Figure 8 (c) shows the response time curve for 11-97%RH; Figure 8 (d) shows the humidity response signal fitting curves of the coated fabric under different RH conditions; Figure 8 (e) shows the moisture retention curve of the coated fabric; Figure 8 (f) shows the repeated response curves of the coated fabric at 33, 57, and 97%RH.

[0036] Figure 9 The antibacterial properties of the composite coated fabric in this embodiment of the invention are as follows: Figure 9 (a) Photographs showing the antibacterial effects of untreated blank fabric, carboxymethyl chitosan cross-linked polyacrylate / MXene coated fabric (Sample 1), polyacrylate / MXene / double-shell microcapsule coated fabric (Sample 2), and carboxymethyl chitosan cross-linked polyacrylate / MXene / double-shell microcapsule coated fabric (Sample 3) against Escherichia coli and Staphylococcus aureus. Figure 9 (b) is a comparison chart of antibacterial rates of different samples.

[0037] Figure 10 This invention relates to the thermal management application of composite coated fabrics in an embodiment of the invention, wherein... Figure 10 (ab) show the surface temperature change curves of the untreated blank fabric (S0), the coated fabric with octadecane@silica microcapsules (S1), and the fabric with octadecane@silica-zinc oxide double-shell microcapsules (S2) during the heating and cooling processes; Figure 10 (cd) are infrared thermal images of different samples during the heating and cooling process.

[0038] Figure 11 This invention relates to the application of composite coated fabrics in wet management, wherein... Figure 11 (ab) shows the humidity detection signal of the coated fabric to the human body during walking and resting, as well as temperature monitoring images. Detailed Implementation

[0039] The present invention will be further described below with reference to the embodiments.

[0040] Unless otherwise specified, the experimental methods described in the embodiments are conventional methods; unless otherwise specified, the reagents and materials are commercially available.

[0041] In the examples, the MXene powder was few-layer Ti3C2T x Mxene, titanium carbide (Ti3C2T) purchased from Xi'an Qiyue Biotechnology Co., Ltd. x MXene few-layer nanosheets, similar few-layer Ti3C2T from other companies. x All Mxene products are acceptable, such as the few-layer Ti3C2T from Shanghai Titan Technology Co., Ltd. x MXene, CAS No.: 196506-01-1.

[0042] Example 1

[0043] (1) Preparation of polyacrylate: According to the weight, 1.1 parts of fatty alcohol polyoxyethylene ether (Mw 400-500), 0.8 parts of sodium dodecyl sulfate, 9 parts of methyl methacrylate, 16 parts of butyl acrylate, 1 part of acrylic acid, and 4 parts of ethylene glycol acetoacetate methacrylate were added to 50 parts of deionized water and emulsified at 10000 rpm for 5 minutes; then 0.1 parts of sodium bicarbonate and 0.2 parts of potassium persulfate were added, and the temperature was raised to 80 ℃ and reacted for 2 hours to obtain polyacrylate;

[0044] (2) Preparation of chitosan-polyacrylate: 1 part by weight of carboxymethyl chitosan (Maclean, catalog number: C832672) was dissolved in 100 parts by weight of deionized water to prepare a 1% carboxymethyl chitosan aqueous solution. The solution was stirred continuously at 60 °C until completely dissolved. Subsequently, the two were mixed at 25 °C and stirred for 1 h to obtain a chitosan-polyacrylate emulsion, with the carboxymethyl chitosan solid content being 6% of the polyacrylate mass.

[0045] (3) Preparation of octadecane@silica-zinc oxide microcapsules: By weight, 1 part hexadecyltrimethylammonium bromide, 4 parts tetraethyl orthosilicate, and 4 parts octadecane were added to 100 parts deionized water and homogenized at 10,000 rpm for 3 minutes. Then, 4 parts of 28% ammonia water were added and reacted at 60 °C for 8 hours. The precipitate was collected by centrifugation and then freeze-dried to obtain octadecane@silica microcapsules. Subsequently, 1 part octadecane@silica microcapsule powder, 2.2 parts zinc acetate, and 1.6 parts hexamethylenetetramine were added to 100 parts deionized water and reacted at 75 °C for 4 hours. The precipitate was collected by centrifugation and then freeze-dried to obtain octadecane@silica-zinc oxide microcapsule powder.

[0046] (4) Disperse 2 parts of octadecane@silica-zinc oxide microcapsules and 3 parts of MXene powder into 20 parts of chitosan-polyacrylate emulsion by weight, stir for 3 minutes to obtain a composite dispersion, and then deposit the dispersion onto the fabric by vacuum filtration. The resulting fabric is dried at 60 °C to obtain the desired composite coated fabric.

[0047] The synthetic route of the polyacrylate emulsion in this embodiment is as follows: Figure 1 The chemical equation for the reaction of carboxymethyl chitosan cross-linked polyacrylate is as follows: Figure 2 .

[0048] Example 2

[0049] (1) Preparation of polyacrylate: According to the weight, 1.0 part of fatty alcohol polyoxyethylene ether, 0.8 part of sodium dodecyl sulfate, 9.0 part of methyl methacrylate, 16.0 part of butyl acrylate, 0.8 part of acrylic acid, and 4.0 part of ethylene glycol acetoacetate methacrylate were added to 50 parts of deionized water and emulsified at 10,000 rpm for 5 minutes; then 0.1 part of sodium bicarbonate and 0.2 part of potassium persulfate were added, and the temperature was raised to 80 °C and reacted for 2 hours to obtain polyacrylate;

[0050] (2) Preparation of chitosan-polyacrylate: 1 part of carboxymethyl chitosan was dissolved in 100 parts of deionized water to prepare a 1% carboxymethyl chitosan aqueous solution, and stirred continuously at 60 °C until completely dissolved. Then, the two were mixed at room temperature and stirred for 1 h at a ratio of carboxymethyl chitosan solid content to polyacrylate solid content of 6% to obtain chitosan-polyacrylate emulsion;

[0051] (3) Preparation of octadecane@silica-zinc oxide microcapsules: By weight, 1 part hexadecyltrimethylammonium bromide, 4 parts tetraethyl orthosilicate, and 4 parts octadecane were added to 100 parts deionized water and homogenized at 10,000 rpm for 3 minutes. Then, 4 parts of 28% ammonia water were added and reacted at 60 °C for 8 hours. The precipitate was collected by centrifugation and then freeze-dried to obtain octadecane@silica microcapsules. Subsequently, 1 part octadecane@silica microcapsule powder, 2 parts zinc acetate, and 1.5 parts hexamethylenetetramine were added to 100 parts deionized water and reacted at 75 °C for 4 hours. The precipitate was collected by centrifugation and then freeze-dried to obtain octadecane@silica-zinc oxide microcapsule powder.

[0052] (4) Disperse 5 parts of octadecane@silica-zinc oxide microcapsules and 4 parts of MXene powder into 30 parts of chitosan-polyacrylate emulsion by weight, stir for 3 minutes to obtain a composite dispersion, and then deposit the dispersion onto the fabric by vacuum filtration. The resulting fabric is dried at 60 °C to obtain the desired composite coated fabric.

[0053] Example 3

[0054] (1) Preparation of polyacrylate by weight: 1.0 part of fatty alcohol polyoxyethylene ether, 0.8 part of sodium dodecyl sulfate, 9.0 part of methyl methacrylate, 16.0 part of butyl acrylate, 0.8 part of acrylic acid, and 4.0 part of ethylene glycol acetoacetate methacrylate were added to 50 parts of deionized water and emulsified at 10,000 rpm for 5 minutes; then 0.1 part of sodium bicarbonate and 0.2 part of potassium persulfate were added, and the mixture was heated to 80 °C and reacted for 2 hours to obtain chitosan-polyacrylate emulsion;

[0055] (2) Preparation of chitosan-polyacrylate by weight: Dissolve 1 part of carboxymethyl chitosan in 100 parts of deionized water to prepare a 1% carboxymethyl chitosan aqueous solution, and stir continuously at 60 °C until completely dissolved. Then, mix the two at 25 °C and stir for 1 h to obtain a chitosan-polyacrylate emulsion, with the carboxymethyl chitosan solid content being 6% of the polyacrylate solid content.

[0056] (3) Preparation of octadecane@silica-zinc oxide microcapsules by weight: 1 part hexadecyltrimethylammonium bromide, 4 parts tetraethyl orthosilicate, and 4 parts octadecane were added to 100 parts deionized water and homogenized at 10,000 rpm for 3 minutes. Then, 4 parts of 28% ammonia water were added and reacted at 60 °C for 8 hours. The precipitate was collected by centrifugation and then freeze-dried to obtain octadecane@silica microcapsules. Subsequently, 1 part octadecane@silica microcapsule powder, 2 parts zinc acetate, and 1.5 parts hexamethylenetetramine were added to 100 parts deionized water and reacted at 75 °C for 4 hours. The precipitate was collected by centrifugation and then freeze-dried to obtain octadecane@silica-zinc oxide microcapsule powder.

[0057] (4) Disperse 5 parts of octadecane@silica-zinc oxide microcapsules and 6 parts of MXene powder into 40 parts of chitosan-polyacrylate emulsion by weight, stir for 3 minutes to obtain a composite dispersion, and then deposit the dispersion onto the fabric by vacuum filtration. The resulting fabric is dried at 60 °C to obtain the desired composite coated fabric.

[0058] Example 4

[0059] (1) Preparation of polyacrylate by weight: 1.0 part of fatty alcohol polyoxyethylene ether, 0.8 part of sodium dodecyl sulfate, 9.0 part of methyl methacrylate, 16.0 part of butyl acrylate, 0.8 part of acrylic acid, and 4.0 part of ethylene glycol acetoacetate methacrylate were added to 50 parts of deionized water and emulsified at 10,000 rpm for 5 minutes; then 0.1 part of sodium bicarbonate and 0.2 part of potassium persulfate were added, and the temperature was raised to 80 °C and reacted for 2 hours to obtain chitosan-polyacrylate emulsion;

[0060] (2) Preparation of chitosan-polyacrylate by weight: Dissolve 1 part of carboxymethyl chitosan in 100 parts of deionized water to prepare a 1% carboxymethyl chitosan aqueous solution, and stir continuously at 60 °C until completely dissolved. Then, mix the two at room temperature and stir for 1 h at a ratio of carboxymethyl chitosan solid content to polyacrylate solid content of 6% to obtain chitosan-polyacrylate emulsion;

[0061] (3) Preparation of octadecane@silica microcapsules by weight: 1 part hexadecyltrimethylammonium bromide, 4 parts tetraethyl orthosilicate, and 4 parts octadecane were added to 100 parts deionized water and homogenized at 10,000 rpm for 3 minutes. Then, 4 parts of 28% ammonia water were added and reacted at 60 °C for 8 hours. The precipitate was collected by centrifugation and then freeze-dried to obtain octadecane@silica microcapsules. Subsequently, 1 part octadecane@silica microcapsule powder, 2 parts zinc acetate, and 1.5 parts hexamethylenetetramine were added to 100 parts deionized water and reacted at 75 °C for 4 hours. The precipitate was collected by centrifugation and then freeze-dried to obtain octadecane@silica-zinc oxide microcapsule powder.

[0062] (4) Disperse 5 parts of octadecane@silica-zinc oxide microcapsules and 5 parts of MXene powder into 25 parts of chitosan-polyacrylate emulsion by weight, stir for 3 minutes to obtain a composite dispersion, and then deposit the dispersion onto the fabric by vacuum filtration. The resulting fabric is dried at 60 °C to obtain the desired composite coated fabric.

[0063] Example 5

[0064] (1) Preparation of polyacrylate by weight: 1.0 part of fatty alcohol polyoxyethylene ether, 0.8 part of sodium dodecyl sulfate, 9.0 part of methyl methacrylate, 16.0 part of butyl acrylate, 0.8 part of acrylic acid, and 4.0 part of ethylene glycol acetoacetate methacrylate were added to 50 parts of deionized water and emulsified at 10,000 rpm for 5 minutes; then 0.1 part of sodium bicarbonate and 0.2 part of potassium persulfate were added, and the temperature was raised to 80 °C and reacted for 2 hours to obtain chitosan-polyacrylate emulsion;

[0065] (2) Preparation of chitosan-polyacrylate by weight: Dissolve 1 part of carboxymethyl chitosan in 100 parts of deionized water to prepare a 1% carboxymethyl chitosan aqueous solution, and stir continuously at 60 °C until completely dissolved. Then, mix the two at room temperature and stir for 1 h at a ratio of carboxymethyl chitosan solid content to polyacrylate solid content of 6% to obtain chitosan-polyacrylate emulsion;

[0066] (3) Preparation of octadecane@silica-zinc oxide microcapsules by weight: 1 part hexadecyltrimethylammonium bromide, 4 parts tetraethyl orthosilicate, and 4 parts octadecane were added to 100 parts deionized water and homogenized at 10,000 rpm for 3 minutes. Then, 4 parts ammonia water with a concentration of 28% were added and reacted at 60 °C for 8 hours. The precipitate was collected by centrifugation and then freeze-dried to obtain octadecane@silica microcapsules. Subsequently, 1 part octadecane@silica microcapsule powder, 2 parts zinc acetate, and 1.5 parts hexamethylenetetramine were added to 100 parts deionized water and reacted at 75 °C for 4 hours. The precipitate was collected by centrifugation and then freeze-dried to obtain octadecane@silica-zinc oxide microcapsule powder.

[0067] (4) Disperse 7 parts by weight of octadecane@silica-zinc oxide microcapsules and 10 parts by weight of MXene powder into 100 parts by weight of chitosan-polyacrylate emulsion, stir for 3 minutes to obtain a composite dispersion, and then deposit the dispersion onto the fabric by vacuum filtration. The resulting fabric is dried at 60 °C to obtain the desired composite coated fabric.

[0068] Example 6

[0069] (1) Preparation of polyacrylate by weight: 1.0 part of fatty alcohol polyoxyethylene ether, 0.8 part of sodium dodecyl sulfate, 9.0 part of methyl methacrylate, 16.0 part of butyl acrylate, 0.8 part of acrylic acid, and 4.0 part of ethylene glycol acetoacetate methacrylate were added to 50 parts of deionized water and emulsified at 10,000 rpm for 5 minutes; then 0.1 part of sodium bicarbonate and 0.2 part of potassium persulfate were added, and the temperature was raised to 80 °C and reacted for 2 hours to obtain chitosan-polyacrylate emulsion;

[0070] (2) Preparation of chitosan-polyacrylate by weight: Dissolve 1 part of carboxymethyl chitosan in 100 parts of deionized water to prepare a 1% carboxymethyl chitosan aqueous solution, and stir continuously at 60 °C until completely dissolved. Then, mix the two at room temperature and stir for 1 h according to the ratio of carboxymethyl chitosan solid content to polyacrylate solid content of 6%.

[0071] (3) Preparation of octadecane@silica-zinc oxide microcapsules by weight: 1 part hexadecyltrimethylammonium bromide, 4 parts tetraethyl orthosilicate, and 4 parts octadecane were added to 100 parts deionized water and homogenized at 10,000 rpm for 3 minutes. Then, 4 parts ammonia water with a concentration of 28% were added and reacted at 60 °C for 8 hours. The precipitate was collected by centrifugation and then freeze-dried to obtain octadecane@silica microcapsules. Subsequently, 1 part octadecane@silica microcapsule powder, 2 parts zinc acetate, and 1.5 parts hexamethylenetetramine were added to 100 parts deionized water and reacted at 75 °C for 4 hours. The precipitate was collected by centrifugation and then freeze-dried to obtain octadecane@silica-zinc oxide microcapsule powder.

[0072] (4) Disperse 8 parts of octadecane@silica-zinc oxide microcapsules and 7 parts of MXene powder into 80 parts of chitosan-polyacrylate emulsion by weight, stir for 3 minutes to obtain a composite dispersion, and then deposit the dispersion onto the fabric by vacuum filtration. The resulting fabric is dried at 60 °C to obtain the desired composite coated fabric.

[0073] Experimental Example 1

[0074] The octadecane@silica microcapsules prepared in Example 1 of this invention were tested, wherein... Figure 3 (ab) are cold field emission scanning electron microscope images of octadecane@silica microcapsules; Figure 3 (c) is the particle size distribution histogram of octadecane@silica microcapsules; Figure 3 (d) shows the EDS energy spectrum and elemental distribution of octadecane@silica microcapsules; Figure 3 (e) is the infrared spectrum of octadecane@silica microcapsules. Figure 4 (ab) are cold field emission scanning electron microscope images of octadecane@silica-zinc oxide microcapsules; Figure 4 (c) is the particle size distribution histogram of octadecane@silica-zinc oxide microcapsules; Figure 4 (d) shows the EDS energy spectrum and elemental distribution of octadecane@silica-zinc oxide microcapsules; Figure 4 (e) shows the XRD patterns of the silica shell and the silica-zinc oxide shell.

[0075] The phase transition properties of the microcapsules were systematically studied using DSC analysis, and the results are as follows: Figure 5 As shown. Figure 5 (a) Differential scanning calorimetry curves of the core material and the octadecane@silica-zinc oxide microcapsule powder prepared in step (3) of Example 1. The melting temperature and crystallization temperature of the octadecane core material are 30.77℃. o C and 23.76 oC. After coating, the phase transition temperatures of octadecane@silica and octadecane@silica-zinc oxide microcapsules are similar to those of the core material, but both show a slight decreasing trend. This phenomenon can be attributed to the good thermal conductivity of the silica and zinc oxide shells, which promotes heat transfer to the core material during heating and, to some extent, delays heat loss during cooling, thus leading to a decrease in crystallization temperature; from the perspective of the change in phase transition enthalpy ( Figure 5 (b) The energy storage capacity of microcapsules is significantly reduced compared to pure octadecane, mainly because the introduction of shell material reduces the proportion of phase change core material per unit mass. Figure 5 The decrease in encapsulation efficiency shown in (c) also confirms this result. It is noteworthy that both types of microcapsules exhibited high energy storage efficiency, indicating that they can still effectively achieve phase change energy storage and release functions; Figure 5 (de) shows the differential scanning calorimeter cycle curve of the phase change microcapsule (octadecane@silica-zinc oxide microcapsule prepared in step (3) of Example 1), and the changes in phase change temperature and phase change enthalpy during the cycle. After 15 heating and cooling cycles, the phase change temperature fluctuation does not exceed 0.15 °C, and the phase change enthalpy change is less than 0.33 J / g, showing excellent cycle stability, proving that the double-shell structure microcapsule is suitable for long-term energy storage applications.

[0076] Figure 6 The image shows the test pattern of the carboxymethyl chitosan cross-linked polyacrylate prepared in step (2) of Example 1 of this invention. The cross-linking structure was verified by Fourier transform infrared spectroscopy. Figure 6 a). 3450 cm -1 The broad absorption peak at 1650 cm⁻¹ originates from the stretching vibrations of hydroxyl, carboxyl, and amino groups in the system; in the polyacrylate spectrum, the peak at 1650 cm⁻¹ is... -1 The absorption peak at [location] is attributed to the C=C stretching vibration resulting from the keto-enol tautomerism in the acetoacetate group. In the spectrum of the carboxymethyl chitosan crosslinked polyacrylate composite, the peak at 1600-1670 cm⁻¹ is [missing information]. -1 The double peaks observed within the range can be considered characteristic vibrations of the C=N and conjugated C=C structures in the enamine bond, confirming the successful conduct of the crosslinking reaction. Further investigation was conducted on the effects of different carboxymethyl chitosan contents on the hydrophilicity and mechanical properties of the composite membrane. Figure 6 (b) The water contact angle of composite membranes with different contents of carboxymethyl chitosan (the solid content of carboxymethyl chitosan was adjusted from 6% to 0-10% of the solid mass of polyacrylate according to the method of step (2) in Example 1) is as follows: as the content of carboxymethyl chitosan increases, the water contact angle of the composite membrane gradually decreases and the hydrophilicity is significantly enhanced. This is mainly due to the introduction of a large number of hydrophilic groups in the carboxymethyl chitosan molecule. Figure 6(c) shows the elongation at break curves of composite films with different contents of carboxymethyl chitosan. When the content of carboxymethyl chitosan does not exceed 6%, the tensile strength and elongation at break of the composite film increase simultaneously. However, when the content of carboxymethyl chitosan continues to increase to 8% and 10%, the elongation at break decreases sharply and the brittleness of the material increases significantly. Figure 6 (d) Cold field emission scanning electron microscope images of composite films with different contents of carboxymethyl chitosan. High contents of carboxymethyl chitosan will make the coating surface rough and lead to a decrease in the compatibility between the two phases. Combined with the electron microscope images, it can be seen that the optimal addition amount of carboxymethyl chitosan is 6%.

[0077] Figure 7 This is a test image of the coated fabric in Embodiment 1 of the present invention, wherein, Figure 7 (a) is a schematic diagram of the electrostatic adsorption of carboxymethyl chitosan cross-linked polyacrylate with MXene; Figure 7 (b) is a physical image of the mixed dispersion of chitosan cross-linked polyacrylate and MXene in step (4) of Example 1. After mixing, the MXene dispersion changed from a uniform state to flocculation and precipitation, indicating that the electrostatic composite reaction was carried out. This process promotes the combination of MXene nanosheets and polymer chains, effectively inhibits the stacking behavior of nanosheets, and improves its dispersion stability in the composite system; Figure 7 (c) is a cold field emission scanning electron microscope image of a polyester fabric (uncoated original fabric); Figure 7 (de) is a cold field emission scanning electron microscope image and a further magnified view of the composite coated fabric; Figure 7 (fg) shows the EDS energy spectrum and elemental distribution of the coated fabric; Figure 7 (hi) is a picture of the coated fabric.

[0078] Figure 8 The above is a test image of the composite coated fabric in an embodiment of the present invention, wherein, Figure 8(a) shows the humidity sensing characteristic curves of different coated fabrics. The humidity sensitivity of the polyacrylate and MXene composite coating (0% microcapsules, i.e., without octadecane@silica-zinc oxide microcapsules in step (4) of Example 1) was significantly higher than that of the control group. This is mainly attributed to the fact that the introduction of CMCS enhanced the hydrophilicity of the coating and improved its adsorption capacity for water molecules. On this basis, the addition of double-shell microcapsules further improved the humidity response performance of the coating. The high specific surface area of ​​the microcapsules and the abundant hydroxyl groups on their surface provide more adsorption sites for water molecules. At the same time, the rough porous structure formed by the microcapsules and the matrix also promotes the diffusion and adhesion of water molecules. When the microcapsule content is 6%, the coating sensitivity reaches a maximum of 10186%. However, when the microcapsule content continued to increase to 9% and 12%, the humidity sensitivity showed a decreasing trend. Specifically, the number of octadecane@silica-zinc oxide microcapsules in step (4) of Example 1 was changed to 0.8 parts (3%), 1.5 parts (6%), 2.3 parts (9%), and 3.5 parts (12%), respectively. This was because excessive microcapsules accumulated in the coating, partially blocking the conductive pathway formed by MXene, resulting in a weakening of the electrical signal change. Based on the above experimental results, the optimal microcapsule content was finally determined to be 6%. Figure 8 (b) shows the real-time humidity response curve of the coated fabric when the microcapsule content is 6%. It can be seen that the sensor can stably respond to changes in humidity levels, and the response signal is significantly enhanced under higher humidity conditions, indicating that it has higher detection sensitivity in high humidity environments. Figure 8 (c) shows the response time curve for 11-97%RH, with both response and recovery times of approximately 1 min, demonstrating a good dynamic response speed. Figure 8 (d) shows the humidity response signal fitting curves of the coated fabric under different RH conditions. The sensor response value shows an exponential growth trend with increasing humidity, indicating that the adsorption capacity of the coating material for water molecules is significantly enhanced in a high humidity environment, thus causing more obvious changes in the electrical signal. Figure 8 (e) is the moisture retention curve of the coated fabric. This value reflects the equilibrium characteristics of the material during the moisture absorption and desiccation process. Figure 8 (f) shows the repeated response curves of the coated fabric at 33, 57, and 97%RH. The sensor maintains stable response performance in five consecutive cycles, demonstrating good reusability.

[0079] Figure 9 The antibacterial properties of the composite coated fabric in this embodiment of the invention are as follows: Figure 9(a) Photographs showing the antibacterial effects of untreated blank fabric, carboxymethyl chitosan cross-linked polyacrylate / MXene coated fabric (Sample 1), polyacrylate / MXene / double-shell microcapsule coated fabric (Sample 2), and carboxymethyl chitosan cross-linked polyacrylate / MXene / double-shell microcapsule coated fabric (Sample 3) against Escherichia coli and Staphylococcus aureus. Figure 9 (b) This diagram compares the antibacterial rates of different samples. Compared with the untreated blank fabric, all three functionally coated fabrics exhibited varying degrees of antibacterial effects. Sample 1 (carboxymethyl chitosan cross-linked polyacrylate / MXene coated fabric) showed antibacterial rates of 63.85% and 50.19% against the two bacteria, respectively; Sample 2 (carboxymethyl chitosan cross-linked polyacrylate / double-shell microcapsule coated fabric) showed a significantly improved antibacterial rate, reaching 98.32% and 99.81%, respectively; while Sample 3 (carboxymethyl chitosan cross-linked polyacrylate / MXene / double-shell microcapsule coated fabric) exhibited the best antibacterial performance, with antibacterial rates as high as 99.78% and 99.99% against the two bacteria, respectively. These results indicate that the introduction of carboxymethyl chitosan not only enhances coating stability as a cross-linking agent, but its protonated amino groups can also interact with the negatively charged bacterial cell membranes, disrupting membrane structural integrity and thus exerting an antibacterial effect. Simultaneously, the zinc oxide on the surface of the double-shell microcapsules can release zinc ions in an aqueous environment, disrupting bacterial intracellular homeostasis and leading to bacterial death. Under the synergistic antibacterial mechanism of carboxymethyl chitosan and zinc oxide, Sample3 exhibits a near-complete antibacterial effect, demonstrating excellent comprehensive antibacterial performance.

[0080] Figure 10 This invention relates to the thermal management application of composite coated fabrics in an embodiment of the invention, wherein... Figure 10 (ab) show the surface temperature change curves of the untreated blank fabric (S0), the coated fabric with octadecane@silica microcapsules (S1), and the fabric with octadecane@silica-zinc oxide double-shell microcapsules (S2) during the heating and cooling processes; Figure 10(cd) shows the infrared thermal images of different samples during the heating and cooling processes. During the heating stage, S0's temperature rose rapidly, while S1 and S2 both exhibited significant temperature response lag. This is because the phase change core material absorbs heat and undergoes a solid-liquid phase transition within a specific temperature range, delaying the temperature rise. The maximum temperature difference between S0 and S1 was 8.43 ℃, and the maximum temperature difference between S0 and S2 was 4.14 ℃, a decrease of 4.29 ℃. During the cooling stage, the phase change material released heat of crystallization, slowing the temperature decrease. The maximum temperature differences between S0 and S1 and S2 were 6.42 ℃ and 5.23 ℃, respectively. Notably, during the regeneration cooling process, the lag of S2 was less than that of S1. This is because, for the same mass, the double-shell structure further reduced the proportion of the phase change core material, resulting in a corresponding decrease in its energy storage capacity.

[0081] Figure 11 This is an example of the wet management application of the composite coated fabric in Embodiment 1 of the present invention, wherein... Figure 11 (ab) shows the humidity detection signal of the coated fabric to the human body during walking and rest, as monitored by temperature. As walking time increased, the humidity response signal of the coated fabric gradually strengthened, indicating increased perspiration. After stopping exercise, the signal gradually returned to its initial level, demonstrating the fabric's good reversible moisture response. During the initial skin temperature rise phase of exercise, the coated fabric melted due to the heat absorption of the phase change microcapsules, resulting in a significantly lower surface temperature than the control fabric. However, during the cooling phase after exercise, the phase change material released its stored heat, causing the fabric surface temperature to be higher than the control sample, exhibiting excellent thermal insulation performance. These results demonstrate that the coated fabric can regulate the microenvironment temperature in real time according to the human body's activity level, possessing both heat dissipation and heat preservation functions in its thermal management.

Claims

1. A composite coating based on octadecane@silica-zinc oxide microcapsules-MXene / chitosan-polyacrylate, characterized in that, The raw material composition includes the following parts by weight: Chitosan-polyacrylate emulsion 20-100 parts, octadecane@silica-zinc oxide microcapsules 2-10 parts, MXene powder 3-15 parts.

2. The composite coating based on octadecane@silica-zinc oxide microcapsules-MXene / chitosan-polyacrylate according to claim 1, characterized in that, The chitosan-polyacrylate emulsion is formed by adding an aqueous solution of carboxymethyl chitosan to polyacrylate. The solid content of the aqueous solution of carboxymethyl chitosan is 1-2%, and the solid content of the aqueous solution of carboxymethyl chitosan accounts for 5-15% of the mass of polyacrylate.

3. The composite coating based on octadecane@silica-zinc oxide microcapsules-MXene / chitosan-polyacrylate according to claim 2, characterized in that, By weight, take 1-5 parts of fatty alcohol polyoxyethylene ether, 0.8-4 parts of sodium dodecyl sulfate, 9-45 parts of methyl methacrylate, 16-80 parts of butyl acrylate, 1-5 parts of acrylic acid, 4-20 parts of ethylene glycol acetoacetate methacrylate, 0.1-0.5 parts of sodium bicarbonate, 0.2-1 parts of potassium persulfate, and 50-250 parts of deionized water; add fatty alcohol polyoxyethylene ether, sodium dodecyl sulfate, methyl methacrylate, butyl acrylate, acrylic acid, and ethylene glycol acetoacetate methacrylate to deionized water and emulsify at high speed, then add sodium bicarbonate and potassium persulfate, and heat to react to obtain polyacrylate.

4. The composite coating based on octadecane@silica-zinc oxide microcapsules-MXene / chitosan-polyacrylate according to claim 2, characterized in that, By weight, 1-5 parts hexadecyltrimethylammonium bromide, 4-20 parts tetraethyl orthosilicate, 4-20 parts octadecane, 4-20 parts ammonia, 2-10 parts zinc acetate, 1.5-7.5 parts hexamethylenetetramine, and 100-500 parts deionized water are used. Hexadecyltrimethylammonium bromide, tetraethyl orthosilicate, and octadecane are added to deionized water and homogenized. Then ammonia is added, and the mixture is heated to obtain octadecane@silica microcapsules. Subsequently, octadecane@silica microcapsule powder, zinc acetate, and hexamethylenetetramine are added to deionized water, and the mixture is heated to obtain octadecane@silica-zinc oxide microcapsules.

5. The composite coating based on octadecane@silica-zinc oxide microcapsules-MXene / chitosan-polyacrylate according to claim 1, characterized in that, The MXene is a few-layer Ti3C2T x MXene.

6. A method for preparing the composite coating based on octadecane@silica-zinc oxide microcapsules-MXene / chitosan-polyacrylate as described in claim 1, characterized in that, Includes the following steps: Octadecylene@silica-zinc oxide microcapsules and MXene powder were dispersed in chitosan-polyacrylate emulsion and stirred to obtain a composite dispersion. The dispersion was then deposited onto a carrier and dried to obtain the desired composite coating.

7. The application of the octadecane@silica-zinc oxide microcapsule-MXene / chitosan-polyacrylate composite coating claimed in claim 1 in sportswear.

8. A composite coated fabric based on the octadecane@silica-zinc oxide microcapsule-MXene / chitosan-polyacrylate as described in claim 1.

9. A method for preparing the composite coated fabric according to claim 8, characterized in that, Includes the following steps: By weight, 2-10 parts of octadecane@silica-zinc oxide microcapsules and 3-15 parts of MXene powder are dispersed into 20-100 parts of chitosan-polyacrylate emulsion. The mixture is stirred to obtain a composite dispersion. The dispersion is then deposited onto the fabric by vacuum filtration. The resulting fabric is dried to obtain the desired composite coated fabric.

10. The application of the composite coated fabric of claim 6 in sportswear.

Images