Lignin-mediated durable conductive cotton fabric and preparation method thereof
By using a lignin-mediated graphene oxide co-assembly method, the problem of weak bonding strength between cotton fibers and conductive components was solved, resulting in cotton fabrics with excellent conductivity and stability, suitable for smart wearables and wearable electronic devices.
Patent Information
- Application Number
- CN202511436791.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-09
- Publication Date
- 2025-12-09
AI Technical Summary
The weak interfacial bonding strength between cotton fibers and conductive components leads to a significant decline in the material's performance after long-term use or washing. Existing modification methods are complex, costly, have poor bonding strength, or offer limited functionality.
Graphene oxide was prepared using a lignin-mediated method via a modified Hummers process and co-assembled with cotton fibers. Subsequently, it was chemically reduced to reduced graphene oxide under alkaline conditions to construct a stable conductive layer.
This invention achieves cotton fabrics with excellent and stable electrical conductivity, enabling them to maintain long-term service capability under external forces such as bending, friction, and washing. The process is simple, environmentally friendly, and low-cost.
Smart Images
Figure CN121087764A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of functional textiles, in particular to a lignin-mediated durable conductive cotton fabric and a preparation method thereof. BACKGROUND
[0002] With the continuous development of modern textile technology, consumers' demand for textile functions is increasing. Cotton fiber is considered an ideal substrate material for preparing flexible wearable products due to its excellent air permeability, moisture absorption and wear comfort. In order to endow insulating cotton fibers with conductive function and expand their application in the fields of antistatic, flexible electronics, etc., the method of loading conductive components on the surface of cotton fibers is usually used for functional modification in the art. However, the problem of weak interfacial bonding strength between cotton fibers and conductive components cannot be properly solved, resulting in a significant decline in performance after long-term use or washing.
[0003] Lignin, as the second largest renewable resource next to cellulose, together with cellulose / hemicellulose forms a stable plant cell wall structure through non-covalent interactions such as ether bonds or hydrogen bonds, and plays an important role in adhesion and protection. Studies have shown that lignin molecular structure contains both hydrophilic (phenolic / alcoholic hydroxyl groups, etc.) and hydrophobic (benzene ring) groups, which exhibit excellent compatibility with a variety of different properties substrates (such as cellulose, carbon materials, etc.). Graphene oxide (GO) as an important derivative of graphene has excellent mechanical properties, high specific surface area and potential conductivity, and is often used for functional modification of textiles. However, the strong π-π interaction between GO nanosheets easily leads to aggregation in the treatment liquid, thereby affecting its uniform loading on the fabric and the final performance.
[0004] It has been found that KL can be used as a dispersant to stabilize GO in aqueous solution and prevent aggregation. There are some methods in the prior art for modifying textiles using GO or biomass materials, but often there are problems such as complex process, expensive reagents, poor bonding strength or single function. Therefore, it is of great significance to develop a modification method that is simple, low cost, environmentally friendly and can endow cotton fabric with multiple functions. SUMMARY
[0005] The present application provides a preparation method of lignin-mediated durable conductive cotton fiber, which solves the problem of weak interfacial bonding strength between cotton fibers and conductive components. The technical scheme of the method is simple, environmentally friendly, easy to operate, and has no special requirements for equipment, and has a broad application prospect.
[0006] To this end, an embodiment of the present application proposes a lignin-mediated durable conductive cotton fabric and a preparation method thereof, which is prepared by co-assembly of graphene oxide on cotton fibers induced by lignin, and then in-situ reduction.
[0007] In a first aspect, the present application provides a method for preparing graphene oxide (GO), which adopts an improved Hummers method and comprises the following steps:
[0008] (a) reacting graphite powder, phosphorus pentoxide, potassium persulfate and sulfuric acid, and then adding ultrapure water after cooling to room temperature to obtain a mixture;
[0009] (b) washing and drying the mixture of step (a), then adding sulfuric acid and potassium permanganate while stirring to react;
[0010] (c) adding ultrapure water and hydrogen peroxide while stirring in step (b), and then centrifuging and washing to obtain a precipitate;
[0011] (d) ultrasonic treatment and centrifugation of the precipitate to obtain a graphene oxide dispersion;
[0012] (e) filtering the graphene oxide dispersion and drying to obtain graphene oxide nanosheets.
[0013] In a second aspect, the present application proposes a method for preparing a durable conductive cotton fabric by inducing lignin to assemble the above self-prepared graphene oxide by one-step method, which comprises the following steps:
[0014] (1) immersing a pure cotton fabric in a 1-3 mol / L sodium hydroxide solution, stirring and treating at 50-80°C for 30-90 minutes, then taking it out and repeatedly washing with ultrapure water until neutral, and drying to obtain a mercerized pretreated cotton fabric; this step aims to activate the hydroxyl groups on the surface of the cotton fibers and improve their binding capacity with the subsequent composite material;
[0015] (2) according to the final KL / GO addition amount of 0-200% relative to the mass of the cotton fabric, weighing the lignosulfonate (KL), dissolving it in a 60-90% formic acid solution, and ultrasonic treatment to fully dissolve it; then, according to the KL / GO mass ratio of 1:5 to 5:1, adding the corresponding concentration of graphene oxide (GO) water dispersion, ultrasonic treatment and magnetic stirring for 20-40 minutes to obtain a uniform and stable KL / GO composite dispersion;
[0016] (3) immersing the alkali pretreated cotton fabric obtained in step (1) into the KL / GO composite dispersion prepared in step two, ultrasonic treatment and magnetic stirring for 12-36 hours at room temperature to make the KL / GO composite material fully adsorbed and physically attached to the surface of the cotton fibers;
[0017] (4) placing the whole system of step (3) in an ice water bath, slowly adding 1-3 mol / L sodium hydroxide solution under stirring to adjust the pH value of the system to 9-11 to convert it to an alkaline environment; continue stirring for 4-8 hours under this condition to make the KL / GO composite material deposit on the fiber surface and be further fixed;
[0018] (5) adding a certain amount of 10-30 mg / mL ascorbic acid solution to the alkaline system of step (4), stirring the reaction at 50-70 °C for 1-3 hours to preliminarily reduce the GO, taking out the cotton fabric after the preliminary reduction, and placing it in a sealed container with filter paper soaked in the ascorbic acid solution at the bottom to maintain the internal humidity; placing the sealed container in an oven at 60-90 °C for 24-48 hours of hydrothermal reduction treatment to fully reduce the GO to reduced graphene oxide (rGO);
[0019] (6) washing the reduced cotton fabric with ultrapure water to remove any unfirmly combined impurities, and then naturally airing or low-temperature drying to obtain the KL / GO modified cotton fabric.
[0020] Compared with the prior art, the present application has the following advantages:
[0021] The present application utilizes the natural adhesion of lignin to realize the synergistic self-assembly of lignin and graphene oxide on the surface of cotton fibers, and constructs a dense and stable conductive layer. The method has the following advantages:
[0022] (1) simple process: the uniform loading of lignin and graphene oxide on the fiber surface can be realized by one-step treatment without complex pretreatment process.
[0023] (2) environmentally friendly: abundant biomass lignin is used as a binder, which is green and sustainable.
[0024] (3) excellent conductivity: the obtained fiber shows good conductivity.
[0025] (4) outstanding stability: lignin as an interfacial adhesive promotes the coating of conductive graphene oxide on the surface of carbon fibers through a simple phase separation process. Based on multiple non-covalent interactions between components (i.e. hydrogen bonding between carbon fibers and lignin and π-π stacking between lignin and graphene oxide), the stable conductivity can be maintained under external forces such as bending, rubbing and washing, and has long-term service ability. BRIEF DESCRIPTION OF DRAWINGS
[0026] The above and / or additional aspects and advantages of the present application will become apparent and more readily appreciated from the following description, taken in conjunction with the following drawings, in which:
[0027] Figure 1 A schematic diagram of the preparation method of the present application, a lignin-mediated durable conductive cotton fabric and its preparation method;
[0028] Figure 2 A schematic diagram of lignin sulfate dissolved in formic acid in Example 1 of the present application;
[0029] Figure 3 Physical photos of the original cotton cloth and modified conductive cotton cloth of the present application and SEM images;
[0030] Figure 4 Physical photos of the modified conductive cotton cloth of Examples 1-3 at different KL / GO ratio concentrations;
[0031] Figure 5 Trends of the electrical conductivity of the modified conductive cotton cloth of Examples 1-3 at different KL / GO ratio concentrations;
[0032] Figure 6 Physical photos of the modified conductive cotton cloth of Examples 1-3 at different KL / GO content ratios to the original cotton cloth;
[0033] Figure 7 Trends of the electrical conductivity of the modified conductive cotton cloth of Examples 1-3 at different KL / GO content ratios to the original cotton cloth;
[0034] Figure 8 Test results of the relative resistance change of Comparative Example 1 and Example 1 for durability;
[0035] Figure 9 Comparative changes of SEM of Comparative Example 1 and Example 1 after bending (500 times), abrasion (5000 times), and washing (45 minutes). DETAILED DESCRIPTION
[0036] Embodiments of the present application are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by reference to the drawings are exemplary and are intended to explain the present application, and cannot be understood as limiting the present application.
[0037] Example 1:
[0038] The present embodiment provides a lignin-mediated durable conductive cotton fabric and a preparation method thereof, which consists of the following steps:
[0039] (1) Place 50 mg of cotton fabric in a 2 mol / L NaOH solution and stir magnetically at 60°C for 60 minutes. After taking it out, wash it with ultrapure water until it is neutral, and dry it at 60°C for standby.
[0040] (2) Set the total addition amount of KL / GO as 100% of the mass of the cotton cloth. Weigh 50 mg of sulfite lignin (KL) and dissolve it in 10 mL of 88% formic acid solution, and ultrasonic for 30 minutes until it is completely dissolved, as shown in FIG. 2. Figure 2The KL / GO composite dispersion was obtained. The KL / GO composite dispersion was obtained.
[0041] (3) The cotton fabric obtained in step (1) was immersed in the composite solution prepared in step (2), and was subjected to ultrasonic assistance and magnetic stirring at room temperature for 24 hours.
[0042] (4) The system was placed in an ice water bath, and 2 mol / L NaOH solution was slowly added dropwise under stirring until the pH was adjusted to 10. The stirring was continued for 6 hours.
[0043] (5) 45 mL of ascorbic acid aqueous solution with a concentration of 20 mg / mL was added to the system, and the stirring reaction was carried out at 60°C for 2 hours. The cotton fabric was taken out and placed in a filter paper sealed beaker wetted with ascorbic acid solution, and was placed in a 60°C oven for reaction for 48 hours.
[0044] (6) The cotton fabric was taken out and washed repeatedly with ultrapure water until the water was clear, and was naturally dried to obtain the KL / GO modified cotton fabric, as shown in FIG. 2. Figure 3
[0045] The specific test method for the electrical conductivity stability is as follows:
[0046] In the friction stability test, the sample was fixed on the surface of a magnetic stirrer, and a rotor was placed thereon. The relative change of the resistance value of the sample was measured and recorded every 1 minute under the condition of continuous stirring at 500 rpm, so as to comprehensively evaluate the anti-friction performance. In the bending stability test, the sample was repeatedly folded along the center line. After 100 bending operations were completed, the relative change of the resistance value was measured, so as to evaluate the electrical stability of the sample under the condition of repeated mechanical deformation. In the washing stability test, the sample was placed in a container containing ultrapure water, and was stirred at 500 rpm on a magnetic stirrer for 5 minutes. Then, the sample was taken out and dried at room temperature. The relative change of the resistance value was measured again, so as to characterize the water washing resistance of the sample.
[0047] Example 2:
[0048] The present embodiment provides a lignin-mediated durable conductive cotton fabric and a preparation method thereof, which comprises the following steps:
[0049] (1) 50 mg of cotton fabric was placed in 2 mol / L NaOH solution and stirred at 60°C for 60 minutes. After taking out, it was washed with ultrapure water until neutral, and was dried at 60°C for standby.
[0050] (2) Set the total amount of KL / GO added to be 200% of the mass of the cotton fabric. Take 100 mg of Kraft lignin (KL) and dissolve it in 10 mL of 88% formic acid solution, and ultrasonicate for 30 minutes until completely dissolved, as shown in FIG. 1. Then, according to the KL:GO mass ratio of 0.1:1, add 100 mL of 10 mg / mL graphene oxide aqueous solution, ultrasonicate again and magnetically stir for 30 minutes to obtain a uniform KL / GO composite dispersion. Figure 2
[0051] (3) Immerse the cotton fabric obtained in step (1) into the composite solution prepared in step (2), and ultrasonicate and magnetically stir for 24 hours at room temperature.
[0052] (4) Place the system in an ice water bath, and slowly add 2 mol / L NaOH solution dropwise under stirring until the pH is adjusted to 10. Continue stirring for 6 hours.
[0053] (5) Add 45 mL of 20 mg / mL ascorbic acid aqueous solution to the system, and stir at 60°C for 2 hours. Take out the cotton fabric, place it in a filter paper sealed beaker wetted with ascorbic acid solution, and place it in a 60°C oven for 48 hours.
[0054] (6) Take out the cotton fabric, repeatedly rinse it with ultrapure water until the water is clear, and naturally air dry to obtain the KL / GO modified cotton fabric, as shown in FIG. 1. Figure 3
[0055] Example 3
[0056] The present example provides a lignin-mediated durable conductive cotton fabric and a preparation method thereof, which comprises the following steps:
[0057] (1) Place 50 mg of cotton fabric in 2 mol / L NaOH solution, and magnetically stir at 60°C for 60 minutes. After taking it out, wash it with ultrapure water until it is neutral, and dry it at 60°C for standby use.
[0058] (2) Set the total amount of KL / GO added to be 20% of the mass of the cotton fabric. Take 10 mg of Kraft lignin (KL) and dissolve it in 10 mL of 88% formic acid solution, and ultrasonicate for 30 minutes until completely dissolved, as shown in FIG. 1. Then, according to the KL:GO mass ratio of 5:1, add 10 mL of 2 mg / mL graphene oxide aqueous solution, ultrasonicate again and magnetically stir for 30 minutes to obtain a uniform KL / GO composite dispersion. Figure 2
[0059] (3) Immerse the cotton fabric obtained in step (1) into the composite solution prepared in step (2), and ultrasonicate and magnetically stir for 24 hours at room temperature.
[0060] (4) The system was placed in an ice water bath, and 2 mol / L NaOH solution was slowly added dropwise under stirring to adjust the pH to 10. Stirring was continued for 6 hours.
[0061] (5) 45 mL of ascorbic acid aqueous solution with a concentration of 20 mg / mL was added to the system, and the reaction was stirred at 60°C for 2 hours. The cotton cloth was taken out and placed in a filter paper sealed beaker wetted with ascorbic acid solution, and was placed in a 60°C oven for reaction for 48 hours.
[0062] (6) The cotton cloth was taken out, repeatedly washed with ultrapure water until the water was clear, and naturally dried to obtain the KL / GO modified cotton cloth, as shown in FIG. 1. Figure 3
[0063] Comparative Example 1
[0064] The present embodiment provides a lignin-mediated durable conductive cotton fabric and a preparation method thereof, which consists of the following steps:
[0065] (1) 50 mg of cotton fabric was placed in 2 mol / L NaOH solution and stirred at 60°C for 60 minutes. After taking out, it was washed with ultrapure water until neutral, and was dried at 60°C for standby.
[0066] (2) No KL was added, only 10 ml of 10 mg / ml graphene oxide aqueous solution was added.
[0067] (3) The cotton cloth obtained in step (1) was immersed in the composite solution prepared in step (2), and was ultrasonically assisted and magnetically stirred at room temperature for 24 hours.
[0068] (4) The system was placed in an ice water bath, and 2 mol / L NaOH solution was slowly added dropwise under stirring to adjust the pH to 10. Stirring was continued for 6 hours.
[0069] (5) 45 mL of ascorbic acid aqueous solution with a concentration of 20 mg / mL was added to the system, and the reaction was stirred at 60°C for 2 hours. The cotton cloth was taken out and placed in a filter paper sealed beaker wetted with ascorbic acid solution, and was placed in a 60°C oven for reaction for 48 hours.
[0070] (6) The cotton cloth was taken out, repeatedly washed with ultrapure water until the water was clear, and naturally dried to obtain the KL / GO modified cotton cloth, as shown in FIG. 1. Figure 3
[0071] Comparative Example 2
[0072] The present embodiment provides a lignin-mediated durable conductive cotton fabric and a preparation method thereof, which consists of the following steps:
[0073] (1) Place 50 mg of cotton fabric in a 2 mol / L NaOH solution and stir magnetically at 60°C for 60 minutes. After removal, wash with ultrapure water until neutral and dry at 60°C for later use.
[0074] (2) Without adding GO, weigh 50 mg of sulfate lignin (KL), dissolve it in 10 mL of 88% formic acid solution, and sonicate for 30 minutes until completely dissolved, as shown in the attached figure. Figure 2 As shown.
[0075] (3) Immerse the cotton cloth obtained in step (1) into the composite liquid prepared in step (2) and stir it with ultrasound and magnetic force at room temperature for 24 hours.
[0076] (4) Place the system in an ice-water bath and slowly add 2 mol / L NaOH solution dropwise while stirring to adjust the pH to 10. Continue stirring for 6 hours.
[0077] (5) Add 45 mL of 20 mg / mL ascorbic acid aqueous solution to the system and stir at 60°C for 2 hours. Take out the cotton cloth and place it in a sealed beaker with filter paper moistened with ascorbic acid solution. Place it in a 60°C oven for 48 hours.
[0078] (6) Remove the cotton cloth, rinse it repeatedly with ultrapure water until the water is clear, and let it air dry naturally to obtain KL / GO modified cotton cloth, as shown in the attached document. Figure 3 As shown.
[0079] The lignin-induced graphene oxide one-step assembly method for durable conductive cotton fabric prepared in this invention exhibits excellent stability in long-term reliability tests. (See attached diagram.) Figure 6 As shown, the effects of external conditions such as bending, abrasion, and washing on the conductive layer were further investigated to simulate damage to cotton fabrics during daily use. The resulting modified cotton fabric exhibited excellent durability, with no significant change in relative resistance under repeated bending (500 cycles), abrasion (5000 cycles), and washing cycles (45 minutes). (See attached image.) Figure 7 Further SEM images confirmed the structural integrity of the fabric after rigorous treatment. The images show that even under the aforementioned mechanical and chemical effects, the rGO sheets remained firmly attached to the fiber surface without significant peeling or structural damage, indicating the excellent durability of its conductive network. Experiments demonstrate that this modified cotton fabric maintains stable and reliable sensing performance under simulated real-world usage conditions, showing significant application potential in smart wearables, human motion monitoring, and long-term wearable electronic devices.
[0080] Although the present application has been described with reference to the embodiments above, various changes and modifications can be suggested to one skilled in the art, and it is intended that the present application encompass such changes and modifications as fall within the scope of the appended claims. None of the features to be bound by the claims are essential to the application, unless the claims specifically indicate or state otherwise. Furthermore, no item or component is essential unless the claims specifically indicate or state otherwise. Thus, the scope of the application is not intended to be bound by the specific disclosed embodiments, but is intended to be bound by the scope of the claims appended hereto.
Claims
1. A lignin-mediated durable conductive cotton fabric and its preparation method, characterized in that, Includes the following steps: Step 1: The cotton fabric is stirred in a sodium hydroxide solution, repeatedly washed with ultrapure water until neutral, and dried to obtain mercerized modified cotton fabric. Step 2: Dissolve an appropriate amount of sulfate lignin in formic acid solution, sonicate to ensure complete dissolution, add graphene oxide dispersion, sonicate again and stir magnetically to obtain KL / GO composite dispersion; Step 3: Immerse the cotton sample treated in Step 1 into the KL / GO composite solution obtained in Step 2, and sonicate and stir to complete the adsorption process. Step 4: Place the system from Step 3 in an ice-water bath, slowly add NaOH solution to adjust to an alkaline environment, and continue stirring to promote the deposition and fixation of the composite components; Step 5: Add a certain amount of ascorbic acid solution to the system in Step 4, stir to achieve preliminary reduction treatment, then take out the cotton cloth and put it into a sealed glass container, with ascorbic acid-soaked filter paper at the bottom to maintain humidity, and perform wet heat reduction for a certain period of time. Step 6: Wash the cotton fabric obtained in Step 5 with ultrapure water, and then let it air dry to obtain KL / GO modified cotton fabric.
2. The method for preparing a lignin-mediated durable conductive cotton fabric as described in claim 1, characterized in that... In step one, the concentration of the sodium hydroxide solution is 1-3 mol / L, and the treatment time is 30-90 min.
3. The lignin-mediated durable conductive cotton fabric and its preparation method as described in claim 1, characterized in that... In the KL / GO composite dispersion described in step two, the mass ratio of KL to GO is 1:5 to 5:1; the total mass of KL and GO added relative to the mass of the cotton fabric is 0%-200%.
4. The lignin-mediated durable conductive cotton fabric and its preparation method as described in claim 1, characterized in that, The method for preparing the graphene oxide nanosheets includes: (a) Graphite powder, phosphorus pentoxide, potassium persulfate and sulfuric acid were reacted, cooled to room temperature and then ultrapure water was added and allowed to stand to obtain a mixture; (b) After washing and drying the mixture from step (a), add sulfuric acid and add potassium permanganate while stirring to react; (c) Add ultrapure water and hydrogen peroxide to step (b) while stirring, and centrifuge and wash to obtain the precipitate; (d) The precipitate was ultrasonically treated and centrifuged to obtain a graphene oxide dispersion.
5. The lignin-mediated durable conductive cotton fabric and its preparation method as described in claim 1, characterized in that... The concentration of the formic acid solution mentioned in step two is 60-90 vol.
6. The lignin-mediated durable conductive cotton fabric and its preparation method as described in claim 1, characterized in that... The adsorption treatment in step three takes 12-36 hours and is performed with ultrasound.
7. The lignin-mediated durable conductive cotton fabric and its preparation method as described in claim 1, characterized in that... Step four is as follows: Place the system in an ice-water bath, slowly add sodium hydroxide solution to adjust the pH value to 9-11, and continue stirring for 4-8 hours.
8. The lignin-mediated durable conductive cotton fabric and its preparation method as described in claim 1, characterized in that, The preliminary reduction in step five specifically involves adding an ascorbic acid solution with a concentration of 10-30 mg / mL and stirring the reaction at 50-70°C for 1-3 hours. The wet heat reduction specifically involves placing the cotton fabric in a sealed container with ascorbic acid-wetted filter paper at the bottom and treating it at 60-90°C for 12-24 hours.
9. A lignin-mediated durable conductive cotton fabric prepared by the method according to any one of claims 1 to 7.
10. The conductive cotton fabric according to claim 9, characterized in that, The fibers maintain stable electrical conductivity even under bending, friction, and washing conditions.