Machine-washable dustproof intelligent sensing silk fabric as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of intelligent textiles and flexible electronic materials, and particularly relates to a machine-washable dust-damage-preventing intelligent sensing silk fabric and a preparation method and application thereof. According to the preparation method, cellulose nanocrystals are subjected to alkaline activation, cyanuric chloride functional modification is utilized, in-situ oxidative polymerization of polyaniline is combined, and the machine-washable dust-damage-preventing intelligent sensing silk fabric is obtained. A chemical covalent bond combined conductive layer is formed on the fiber surface of the silk fabric; the conductive layer is tightly combined with the silk fibers, so that the fabric is endowed with high conductivity, excellent machine wash resistance and friction damage resistance, and meanwhile, the natural flexibility of the silk is reserved. The problems that a traditional conductive fabric is poor in washing fastness and prone to mechanical damage are solved, and the fabric is suitable for the fields of intelligent clothing, medical monitoring and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of smart textiles and flexible electronic materials, and specifically relates to a machine-washable dust-proof smart sensing silk fabric, a preparation method and an application thereof. Background Art

[0002] With the rapid development of smart textiles, multifunctional fabrics that combine comfort, durability, and high conductivity have shown great potential for applications in wearable electronics, medical health monitoring, motion sensing, and other fields. Silk, a natural protein fiber, is an ideal substrate for smart textiles due to its excellent flexibility, biocompatibility, and breathability. However, the preparation technology of traditional conductive silk fabrics faces significant bottlenecks, seriously restricting their long-term stability.

[0003] How to intimately integrate conductive materials with natural silk fibers to produce conductive silk fibers has always been a major research challenge. Currently explored methods primarily include conductive material doping, which involves directly incorporating conductive particles into the silk spinning solution and producing conductive fibers through wet spinning. While this method achieves internal embedding of the conductive network, it is difficult to control the uniformity of the dispersion, which can easily lead to broken conductive pathways or localized aggregation, resulting in unstable conductivity with fluctuations of up to ±15%. At the same time, doping materials may destroy the natural structure of silk protein, resulting in a decrease in mechanical properties, such as a 20-40% decrease in tensile strength; there is also a chemical grafting method, which is to introduce active groups on the surface of silk fibers through chemical modification and graft conductive polymers (such as polypyrrole and polyaniline). Although it can theoretically enhance the binding force, the existing reaction conditions are harsh and require high temperature or strong acid environment, which can easily lead to denaturation of silk protein and loss of natural flexibility and biological activity; and the functionalization efficiency is low: traditional cross-linking agents (such as glutaraldehyde) have limited modification sites, and the conductive polymer grafting rate is insufficient (usually <5%), making it difficult to form a continuous conductive network; insufficient washing resistance: there is a lack of stable covalent bond connection between the grafted chain and the fiber, and the conductive layer will still peel off after long-term washing.

[0004] Patent document CN106705829A proposes a flexible wearable fiber sensor based on an elastic spiral double-coating structure and its preparation process. By constructing a conductive functional layer on the surface of a spirally wound fiber substrate, the sensor achieves the ability to simultaneously sense multidimensional deformation signals. The sensor adopts a unique layered structure design, which can simultaneously capture complex mechanical parameters such as tensile strain, bending angle, and torsional deformation. However, in practical applications, this technology suffers from poor interfacial bonding performance. Experimental data show that the conductive layer formed solely through an impregnation process has low interfacial bonding strength with the substrate, and is prone to interlayer delamination under cyclic loads. This structural failure directly leads to a significant decrease in sensor durability, failing to meet the technical requirements for long-term stability of wearable devices.

[0005] Therefore, this field urgently needs to develop an intelligent sensing silk fabric with simple process, high conductivity, machine washability and dust damage resistance, which can monitor abnormalities in human health and other aspects in real time while ensuring the glossiness of silk, so as to be applied to human health management, smart home environment, remote monitoring and other application fields. Summary of the Invention

[0006] Based on the above-mentioned shortcomings and deficiencies in the prior art, one of the objects of the present invention is to at least solve one or more of the above-mentioned problems in the prior art, and one of the objects of the present invention is to provide a machine-washable, dust-proof, intelligent sensing silk fabric based on chemical covalent bonding that meets one or more of the above-mentioned needs, as well as a preparation method and application thereof.

[0007] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions:

[0008] A method for preparing a machine-washable dust-proof intelligent sensing silk fabric comprises the following steps:

[0009] (1) Ultrasonic modification of cellulose nanocrystals in an alkaline environment, followed by centrifugal filtration, to obtain activated cellulose nanocrystals;

[0010] (2) Adding activated cellulose nanocrystals to an acetone solution of cyanuric chloride, stirring for several minutes, first adding water, then adding glacial acetic acid to quench the reaction, and then centrifuging, washing, and freeze-drying to obtain a conjugate of cellulose nanocrystals and cyanuric chloride, CNC-CC;

[0011] (3) The conjugate CNC-CC was dispersed in HCl solution and ultrasonically treated to form a uniform suspension. Aniline monomer was slowly added to the suspension and stirred in an ice-water bath. Then, an initiator was added to initiate the oxidative polymerization of aniline. After the reaction, the mixture was centrifuged, washed, and freeze-dried to obtain black powder CCP.

[0012] (4) dispersing the black powder CCP in DMF solution to obtain a modified slurry;

[0013] (5) The silk fabric is alkalized and then immersed in a modified slurry, and then dried to obtain a machine-washable, dust-proof, and intelligent sensing silk fabric.

[0014] As a preferred embodiment, the step (1) specifically comprises: adding cellulose nanocrystals to a sodium hydroxide solution, ultrasonicating for 20 to 40 minutes, centrifugally filtering once without washing, to obtain activated cellulose nanocrystals.

[0015] As a preferred solution, the mass fraction of the modified cellulose nanocrystals in the sodium hydroxide solution is 0.4-1.0%, and the density of the sodium hydroxide solution is 1-1.5M.

[0016] As a preferred embodiment, in step (2), the solid-liquid ratio of cyanuric chloride to acetone is (4.5-5) g:130 mL.

[0017] As a preferred solution, the mass ratio of the activated cellulose nanocrystals to cyanuric chloride is 1:(4.5-5).

[0018] As a preferred embodiment, in step (3), the solid-liquid ratio of the conjugate CNC-CC to the HCl solution is (0.05-0.15) g:100 mL, and the concentration of the HCl solution is 1-1.5 M.

[0019] As a preferred embodiment, in step (3), the ratio of the conjugate CNC-CC, the aniline monomer, and the initiator is 0.1 g: (1-5) mL: (2-2.5) g.

[0020] As a preferred embodiment, in step (3), the initiator is AlCl3, FeCl3 or ammonium persulfate.

[0021] The present invention also provides a machine-washable dust-stain-resistant intelligent sensing silk fabric prepared by the preparation method described in any of the above schemes.

[0022] The present invention also provides the use of the machine-washable dust-proof smart sensing silk fabric as described above as a sensing element, which can be used for real-time monitoring of human health, body temperature changes, and environmental gases.

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

[0024] (1) The silk fabric used in the present invention has the advantages of a wide range of raw material sources, simple preparation process, low energy consumption, and biodegradability. In terms of structure, it has porous breathable holes and is rich in amino polar groups on the surface, making it an excellent flexible substrate.

[0025] (2) The present invention utilizes the abundant amino groups on the surface of silk and modified cellulose nanocrystals to react with polyaniline to form a chemical covalent bond, so that the two are tightly bound, not easy to fall off, and can be machine washed;

[0026] (3) The present invention utilizes an initiator to initiate aniline polymerization, and the resulting polyaniline has the advantages of good environmental stability, high conductivity, easy synthesis, high adhesion, and non-toxicity, and can be used as an excellent conductive component;

[0027] (4) The present invention utilizes an initiator to allow the remaining hydroxyl groups of the modified cellulose nanocrystals to undergo a chemical bonding reaction with the free radicals of aniline, so that the conductive component is tightly bonded to the silk fabric, making it less likely to agglomerate and fall off, further improving the machine wash resistance.

[0028] (5) The machine-washable, dust-proof, and highly conductive intelligent sensing silk fabric of the present invention is prepared by multiple covalent bonds and reaction methods. The method is simple, the technology is mature, and it is easy to mass-produce. The sensing silk fabric has the advantages of high conductivity, machine washability, and stable conductive performance. Its conductive performance and stability are better than those of silk fabrics modified with non-covalent bonds. Its real-time monitoring of gas, temperature, human movement, and health can be used in health management, human-computer interaction, smart home, and other fields. It has a large market demand and has considerable social and economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a field emission scanning electron microscope image of the highly conductive dust-scar-proof intelligent sensing silk fabric of Example 1 of the present invention;

[0030] Figure 2 This is a comparison chart of the conductive properties of the highly conductive dust-scratch-proof intelligent sensing silk fabric of Example 1 of the present invention and the silk fabrics of Comparative Examples 1, 2, and 3;

[0031] Figure 3 This is a sensing diagram of the machine-washable dust-proof intelligent sensing silk fabric according to Example 1 of the present invention;

[0032] Figure 4 This is a comparison chart of the degree of dust damage of the machine-washable dust-proof intelligent sensor silk fabric of Example 1 of the present invention after 50 washes compared with the original sample. DETAILED DESCRIPTION

[0033] The machine-washable dust-proof intelligent sensing silk fabric of the present invention, as well as its preparation method and application are described in detail below.

[0034] The present invention innovatively adopts cyanuric chloride-mediated chemical covalent bond grafting technology, combined with an in-situ oxidative polymerization strategy, and utilizes the high reactivity of cyanuric chloride to covalently anchor it on the surface of nanocellulose crystal CNC through a nucleophilic substitution reaction to form a conjugate CNC-CC, which provides dense and stable grafting sites for subsequent conductive polymers. Aniline monomers are adsorbed on the CNC-CC surface at low temperatures and form a polyaniline PANI conductive network through oxidative polymerization. It is doubly bonded to CNC through covalent bonds and [-[ stacking effects, significantly improving the interface strength; and through infiltration technology, the polyaniline chains are penetrated through the microporous structure of silk fibers in the silk fabric to form a three-dimensional conductive path, while retaining the multi-level porosity of silk to ensure the flexibility and breathability of the fabric.

[0035] Specifically, the preparation method of machine-washable dust-proof intelligent sensing silk fabric comprises the following steps:

[0036] (1) Ultrasonic modification of cellulose nanocrystals in an alkaline environment, followed by centrifugal filtration, to obtain activated cellulose nanocrystals;

[0037] (2) Adding activated cellulose nanocrystals to an acetone solution of cyanuric chloride, stirring for several minutes, first adding water, then adding glacial acetic acid to quench the reaction, and then centrifuging, washing, and freeze-drying to obtain a conjugate of cellulose nanocrystals and cyanuric chloride, CNC-CC;

[0038] (3) The conjugate CNC-CC was dispersed in HCl solution and ultrasonically treated to form a uniform suspension. Aniline monomer was slowly added to the suspension and stirred in an ice-water bath. Then, an initiator was added to initiate the oxidative polymerization of aniline. After the reaction, the mixture was centrifuged, washed, and freeze-dried to obtain black powder CCP.

[0039] (4) dispersing the black powder CCP in DMF solution to obtain a modified slurry;

[0040] (5) The silk fabric is alkalized and then immersed in a modified slurry, and then dried to obtain a machine-washable, dust-proof, and intelligent sensing silk fabric.

[0041] In one or more embodiments, the above step (1) specifically includes: adding cellulose nanocrystals to sodium hydroxide solution, ultrasonicating for 20 to 40 minutes, centrifugally filtering once without washing, to obtain activated cellulose nanocrystals.

[0042] In one or more embodiments, the mass fraction of the modified cellulose nanocrystals in the sodium hydroxide solution is 0.4-1.0%, and the density of the sodium hydroxide solution is 1-1.5M.

[0043] In one or more embodiments, in the above step (2), the solid-liquid ratio of cyanuric chloride to acetone is (4.5-5) g:130 mL.

[0044] In one or more embodiments, the mass ratio of the activated cellulose nanocrystals to cyanuric chloride is 1:(4.5-5).

[0045] In one or more embodiments, in the above step (3), the solid-liquid ratio of the conjugate CNC-CC to the HCl solution is (0.05-0.15) g:100 mL, and the concentration of the HCl solution is 1-1.5 M.

[0046] In one or more embodiments, in the above step (3), the ratio of the conjugate CNC-CC, the aniline monomer, and the initiator is 0.1 g: (1-5) mL: (2-2.5) g.

[0047] In one or more embodiments, in the above step (3), the initiator is AlCl3, FeCl3 or ammonium persulfate.

[0048] The present invention also provides machine-washable dust-stain-resistant intelligent sensing silk fabric prepared by the above-mentioned preparation method.

[0049] The present invention also provides the application of the above-mentioned machine-washable dust-proof intelligent sensing silk fabric as a sensing element. It can be used for real-time monitoring of human health, body temperature changes and environmental gases.

[0050] Through chemical bonding and structural optimization, the present invention overcomes long-standing technical difficulties such as easy shedding of the conductive layer and poor washability, providing a reliable solution for the practical application of smart silk fabrics.

[0051] The machine-washable dust-proof intelligent sensing silk fabric of the present invention and its preparation method and application are further explained below through specific examples.

[0052] Example 1:

[0053] The preparation method of the machine-washable dust-proof intelligent sensing silk fabric of this embodiment comprises the following steps:

[0054] (1) Dissolve 8 g of sodium hydroxide in 200 mL of deionized water to obtain a 1 M sodium hydroxide solution;

[0055] (2) Add 1 g of cellulose nanocrystals (CNC) to the above sodium hydroxide solution, sonicate for 30 min, centrifuge once (without washing) to obtain alkaline CNC, and centrifuge to remove excess alkali solution to obtain activated CNC;

[0056] (3) 4.5 g of cyanuric chloride was added to 130 mL of acetone and stirred until homogeneous. 1 g of activated CNC was added and stirred for 5 minutes. 130 mL of deionized water was quickly added. After 15 seconds, the reaction was quenched with 20% glacial acetic acid to stop the reaction. The mixture was washed by centrifugation until neutral and freeze-dried to obtain the conjugate CNC-CC.

[0057] (4) 0.1 g of the conjugate CNC-CC was dispersed in 100 mL of 1 M HCl, and 1 mL of aniline monomer was added first, and stirred at 5 °C for 1 hour. Then, 2.5 g of ammonium persulfate was added dropwise to initiate the oxidative polymerization of the aniline monomer. The reaction was carried out at 5 °C for 4 hours, and then the temperature was raised to 25 °C and stirred for 8 hours. The mixture was centrifuged, washed, and freeze-dried to obtain black powder CCP1.

[0058] (5) Disperse 0.1 g of black powder CCP1 in 1.5 mL of DMF solution to obtain a modified slurry;

[0059] (6) Take 0.4g of sodium hydroxide and dissolve it in 100mL of deionized water. Take 1*1cm silk fabric and put it into the NaOH solution. Let it stand at room temperature or stir it gently for 15 minutes. After treatment, rinse it with a large amount of deionized water until it is neutral. Then, place the alkalized silk fabric in the modified slurry and soak it for 12 hours. Then, dry it in an oven to obtain a machine-washable, dust-proof, and intelligent sensing silk fabric.

[0060] Example 2:

[0061] The preparation method of the machine-washable dust-proof intelligent sensing silk fabric of this embodiment differs from that of Example 1 in that: the amount of aniline monomer used is different;

[0062] Specifically, the amount of aniline monomer used is 3 mL of aniline monomer; other steps are the same as in Example 1.

[0063] Example 3:

[0064] The preparation method of the machine-washable dust-proof intelligent sensing silk fabric of this embodiment differs from that of Example 1 in that: the amount of aniline monomer used is different;

[0065] Specifically, the amount of aniline monomer used is 5 mL of aniline monomer; other steps are the same as in Example 1.

[0066] Comparative Example 1:

[0067] The preparation method of the silk fabric of this comparative example is different from that of Example 1 in that:

[0068] A 1*1 cm silk fabric was placed in 1 mL of aniline monomer, and 2.5 g of ammonium persulfate was slowly added at 5°C to allow the reaction to proceed evenly. After the reaction, the fabric was taken out and dried to obtain the silk fabric.

[0069] Comparative Example 2:

[0070] The preparation method of the silk fabric of this comparative example is different from that of Example 1 in that:

[0071] Steps (3) to (4) were omitted, and the activated CNC was directly dispersed in the DMF solution to obtain a modified slurry. The other steps were the same as in Example 1 to obtain a silk fabric.

[0072] Comparative Example 3:

[0073] The preparation method of the silk fabric of this comparative example is different from that of Example 1 in that:

[0074] A 1*1cm silk fabric was directly placed in 1mL of aniline monomer, and 2.5g of ammonium persulfate was added to allow a small amount of active groups on the silk surface to react with the free radicals of aniline to produce a silk fabric with in-situ polymerization of aniline.

[0075] 0.1 g of the conjugate CNC-CC prepared in Example 1 was dispersed in 100 mL of 1 M HCl, and then the silk fabric prepared by in-situ polymerization of aniline was placed in the dispersion, soaked for 12 hours, and dried at room temperature to obtain the silk fabric.

[0076] like Figure 1As shown, Example 1 successfully prepared a highly conductive smart sensing material based on chemical covalent bonding, where the conductive material grew on the fiber surface to form a unique dense spherical structure;

[0077] like Figure 2 As shown, the conductivity of the machine-washable dust-proof smart sensing silk fabric of Example 1 is significantly improved compared with the conductivity of the silk fabrics of Comparative Examples 1 to 3, reaching as high as 1.114 S / m;

[0078] like Figure 3 As shown, the Agilent Truevolt 34461A digital multimeter (DMM) was used to test the real-time resistance signal change and voltage signal change of the machine-washable dust-proof smart sensing silk fabric of Example 1 as a sensor. The results showed that the output resistance signal was stable when the human body performed a series of actions such as bending the elbow, leg, finger, ankle, neck, and swallowing the throat, indicating excellent sensing performance and suitability for use as a sensing element.

[0079] like Figure 4 As shown in the figure, microscopic images with a magnification of 150 times were taken using a Zeiss microscope Discovery.V20 stereo before and after 50 machine washings. The results show that the degree of dust damage did not increase much before and after. This is attributed to the fact that each silk thread is loaded with conductive material on the silk surface, which reduces the degree of filament breakage and can effectively prevent the external environment from corroding the material, thereby reducing the occurrence of dust damage.

[0080] In view of the numerous embodiments of the present invention, each embodiment can be determined according to actual application requirements within the limited range of each parameter. The experimental data is huge and it is not suitable to list them one by one here. However, the content that needs to be verified and the final conclusions obtained in each embodiment are similar.

[0081] The above description is only a detailed description of the preferred embodiments and principles of the present invention. For ordinary technicians in this field, based on the ideas provided by the present invention, there may be changes in the specific implementation methods, and these changes should also be considered as the scope of protection of the present invention.

Claims

1. A method for preparing machine-washable dust-proof intelligent sensing silk fabric, characterized in that: The following steps are involved: (1) Ultrasonic modification of cellulose nanocrystals in an alkaline environment, followed by centrifugal filtration, to obtain activated cellulose nanocrystals; (2) Adding activated cellulose nanocrystals to an acetone solution of cyanuric chloride, stirring for several minutes, first adding water, then adding glacial acetic acid to quench the reaction, and then centrifuging, washing, and freeze-drying to obtain a conjugate of cellulose nanocrystals and cyanuric chloride, CNC-CC; (3) The conjugate CNC-CC was dispersed in HCl solution and ultrasonically treated to form a uniform suspension. Aniline monomer was slowly added to the suspension and stirred in an ice-water bath. Then, an initiator was added to initiate the oxidative polymerization of aniline. After the reaction, the mixture was centrifuged, washed, and freeze-dried to obtain black powder CCP. (4) dispersing the black powder CCP in DMF solution to obtain a modified slurry; (5) The silk fabric is alkalized and then immersed in a modified slurry, and then dried to obtain a machine-washable, dust-proof, and intelligent sensing silk fabric.

2. The preparation method according to claim 1, characterized in that The step (1) specifically comprises: adding cellulose nanocrystals to a sodium hydroxide solution, ultrasonicating for 20 to 40 minutes, centrifugally filtering once without washing, and obtaining activated cellulose nanocrystals.

3. The preparation method according to claim 2, characterized in that The mass fraction of the modified cellulose nanocrystals in the sodium hydroxide solution is 0.4-1.0%, and the density of the sodium hydroxide solution is 1-1.5M.

4. The preparation method according to claim 1, characterized in that In the step (2), the solid-liquid ratio of cyanuric chloride to acetone is (4.5-5) g:130 mL.

5. The preparation method according to claim 4, characterized in that The mass ratio of the activated cellulose nanocrystals to cyanuric chloride is 1:(4.5-5).

6. The preparation method according to claim 1, characterized in that In the step (3), the solid-liquid ratio of the conjugate CNC-CC to the HCl solution is (0.05-0.15) g:100 mL, and the concentration of the HCl solution is 1-1.5M.

7. The preparation method according to claim 1, characterized in that In the step (3), the ratio of the conjugate CNC-CC, the aniline monomer, and the initiator is 0.1 g: (1-5) mL: (2-2.5) g.

8. The preparation method according to claim 1, characterized in that In the step (3), the initiator is AlCl3, FeCl3 or ammonium persulfate.

9. A machine-washable dust-proof intelligent sensor silk fabric prepared by the preparation method according to any one of claims 1 to 8.

10. The use of the machine-washable dust-proof intelligent sensor silk fabric according to claim 9, characterized in that: As a sensing element.

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