Preparation method of all-weather self-repairing super-hydrophobic cotton fabric

Abstract

The application discloses a kind of all-weather self-repairing super-hydrophobic cotton fabric preparation method, first using low cost, simple operation template method is prepared unique cauliflower-like polypyrrole, then using normal temperature impregnation method load TiN.Both synergies not only improve photo-thermal conversion performance, but also give fabric joule heating performance.After grafting PDMS, fabric static contact angle can reach 160.2°.The fabric has excellent photo-thermal and joule heating performance, and can be all-weather super-hydrophobic repair.When light intensity is 5 suns, fabric temperature can reach 116.3℃;When voltage reaches 8V, fabric temperature is 128.5℃.After the super-hydrophobicity of the fabric is lost, it can be restored to super-hydrophobicity after being irradiated by light with an intensity of 5 suns for 15 minutes or being electrified by a voltage of 6V for 30 minutes.

Description

Technical Field

[0001] This invention belongs to the field of self-healing superhydrophobic textile materials, and relates to thermal response repair, particularly to a method that enables all-weather superhydrophobic self-healing. Background Technology

[0002] Currently, superhydrophobic materials are widely used in self-cleaning, de-icing, corrosion prevention, drag reduction, and oil-water separation due to their excellent water repellency. Superhydrophobicity is generally considered a special surface property with a static water contact angle exceeding 150° and a dynamic roll-off angle below 10°. The principle of superhydrophobicity is based on constructing micro / nano-rough structures on low surface energy surfaces. Therefore, it is generally prepared by either constructing micro / nano-rough structures on the material surface or depositing a low surface energy layer on a material with a rough surface structure. However, superhydrophobic surfaces are easily damaged, causing current superhydrophobic materials to fail to achieve their expected service life. Therefore, the demand for developing durable superhydrophobic fabrics is rapidly increasing.

[0003] Drawing inspiration from nature's "self-healing" strategies, incorporating self-healing properties into superhydrophobic materials can extend their lifespan. Considering the causes of superhydrophobicity loss, self-healing methods can be categorized into two types: repairing micro / nano-rough structures and low surface energy layers. The principle of low surface energy repair typically involves the spontaneous migration of low surface energy substances from within the material to the surface, but this migration is extremely slow, usually taking several hours to days. Heating the material can increase the migration rate of low surface energy substances to the surface, shortening the repair time. However, this process requires sophisticated equipment and consumes excessive energy. Solar energy, as a renewable green energy source, has attracted much attention from scientists, and photothermal conversion is the most direct application of solar energy. Therefore, photothermal conversion can be introduced into self-healing to more quickly and conveniently repair materials that have lost their superhydrophobicity. However, when ambient light is insufficient (rainy days or nights), changes in light intensity inevitably affect the photothermal conversion efficiency and self-healing effect. In such cases, convenient Joule heating can compensate for these drawbacks.

[0004] Compared with traditional photothermal conversion materials, the novel photoactive material titanium nitride (TiN) has significant advantages such as good chemical stability and economic cost. The organic polymer polypyrrole (PPy) has also attracted much attention due to its excellent stability and electrothermal effect. The synergistic effect of TiN and PPy can enhance photothermal performance, and the presence of PPy allows for convenient Joule heating of the material. Due to its own π-π interactions, saffron titanium can form slightly soluble oligomers, which can then act as templates to synthesize polypyrroles with special morphologies. However, currently, no methods for preparing PPy and TiN composite coatings, nor any technologies or patents for all-weather superhydrophobic self-healing have been found. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method for preparing and self-repairing superhydrophobic cotton fabrics that can be self-repaired in all weather conditions. More specifically, it relates to a superhydrophobic fabric with photothermal conversion and Joule heating properties, and a method for repairing the superhydrophobic layer under light and low pressure conditions.

[0006] To achieve the purpose of this invention, FeCl3 was used to initiate pyrrole polymerization, and cauliflower-shaped polypyrrole was prepared using saffron T as a template. The fabric was then impregnated with TiN and grafted with polydimethylsiloxane (PDMS). The photothermal, Joule thermal and all-weather repair properties of the all-weather self-healing superhydrophobic cotton fabric were systematically studied.

[0007] The technical solution adopted in this invention is carried out according to the following steps:

[0008] (a) Prepare a 2 g / L NaOH solution, put the cotton fabric into the NaOH solution and boil it for 1-4 hours, and then dry the fabric.

[0009] (b) Prepare a saffron T solution of a certain concentration, put the cotton fabric obtained in step (a) into the saffron T solution, and let it stand for 0.5-2 hours;

[0010] (c) Add FeCl3 to the solution obtained in step (b) to make the concentration reach 0.10-0.30M, and stir until homogeneous;

[0011] (d) Add a certain amount of pyrrole to the solution obtained in step (c) and stir the mixture at room temperature for 25-30 hours. After the reaction is complete, remove the fabric and wash it three times with ethanol and deionized water, respectively.

[0012] (e) Weigh a certain amount of TiN, add it to anhydrous ethanol, and sonicate for 20-60 min to obtain TiN ethanol dispersion;

[0013] (f) Place the fabric obtained in step (d) into the TiN ethanol dispersion, stir and soak for 20-40 min, then remove and dry;

[0014] (g) Weigh the PDMS prepolymer and curing agent in a ratio of 10:1 and add them to the n-hexane solution to prepare a 1% PDMS solution;

[0015] (h) Place the fabric obtained in step (f) into a 1% PDMS solution and let it stand for 30-60 minutes. Then cure it in an oven at 80°C for 0.5-1.5 hours.

[0016] (i) The fabric obtained in step (h) is subjected to plasma cleaning for 5 minutes, causing the fabric to lose its superhydrophobicity. After being treated under light or low pressure for a period of time, the fabric can regain its superhydrophobicity. Therefore, an all-weather self-healing superhydrophobic cotton fabric can be prepared.

[0017] The features of this all-weather self-healing superhydrophobic fabric are:

[0018] (1) The optimal conditions for preparing this all-weather self-healing superhydrophobic cotton fabric are as follows: boiling in NaOH solution for 2 hours, standing in 4 mM saffron T solution for 1 hour, selecting FeCl3 concentration of 0.15 M, reacting for 25 hours under pyrrole concentration of 0.075 M, TiN ethanol dispersion concentration of 2 g / L, impregnation for 30 minutes, PDMS grafting time of 30 minutes, and curing time of 1 hour.

[0019] (2) The optimal conditions for photothermal, Joule thermal and self-repair are: when the light intensity is 5 solar hours, the temperature can reach 116.3℃; when the voltage reaches 8V, the temperature can reach 128.5℃; when the light intensity is 5 solar hours, the fabric can restore its superhydrophobicity after 15 minutes of irradiation.

[0020] This invention first utilizes a low-cost and simple template method to prepare a unique cauliflower-shaped polypyrrole, and then loads TiN using a room-temperature impregnation method. The synergistic effect of these two methods not only enhances photothermal conversion performance but also endows the fabric with Joule heating properties. After grafting PDMS, the fabric's static contact angle reaches 160.2°. This fabric exhibits all-weather superhydrophobic self-healing properties. Attached Figure Description

[0021] Appendix Figure 1 It is a TEM image of cauliflower-shaped polypyrrole on a fabric.

[0022] Appendix Figure 2 It measures the temperature changes of all-weather self-healing superhydrophobic cotton fabric under different light intensities.

[0023] Appendix Figure 3 It measures the temperature change of all-weather self-healing superhydrophobic cotton fabric under different voltages.

[0024] Appendix Figure 4 It is the temperature change of all-weather self-healing superhydrophobic fabric under the heating of light source and DC power conversion.

[0025] Best practice

[0026] The implementation methods and steps of the present invention are described in detail below with specific embodiments.

[0027] Example 1

[0028] (1) Prepare a 2g / L NaOH solution, put the cotton fabric into the NaOH solution and boil it for 2 hours, and then dry the fabric.

[0029] (2) Prepare a 4 mM saffron T solution. Place the cotton fabric obtained in step (1) into the saffron T solution and let it stand for 1 hour. (3) Add FeCl3 to the solution obtained in step (2) to make the concentration reach 0.15 M, and stir evenly;

[0030] (4) Add pyrrole to the solution from step (3) to a concentration of 0.075 M, and then stir the reaction at room temperature for 25 h. After the reaction is complete, remove the fabric and wash it three times with ethanol and deionized water, respectively.

[0031] (5) Prepare a 2 g / L TiN ethanol solution and sonicate it for 30 min to obtain a TiN ethanol dispersion;

[0032] (6) Place the fabric obtained in step (4) into the TiN ethanol dispersion, stir and soak for 30 minutes, then take it out and dry it.

[0033] (7) Weigh the PDMS prepolymer and curing agent in a ratio of 10:1 and add them to the n-hexane solution to prepare a 1% PDMS solution;

[0034] (8) Add the fabric obtained in step (6) to a 1% PDMS solution and let it stand for 30 minutes. Then cure it in an oven at 80°C for 1 hour.

[0035] (9) The fabric obtained in step (8) is subjected to plasma cleaning for 5 minutes, and the fabric loses its superhydrophobicity. The superhydrophobicity can be restored after being exposed to 5 suns for 15 minutes or after being subjected to a 6V voltage for 30 minutes.

[0036] The all-weather self-healing superhydrophobic fabric prepared by this invention has good photothermal conversion and Joule heating properties, and can quickly repair the superhydrophobic layer under light or low pressure. In addition, the preparation method of this fabric is simple and safe.

[0037] The above description is an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent process transformations made using the content of the present invention specification, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method for preparing an all-weather self-healing superhydrophobic cotton fabric, comprising the following steps: (a) Prepare a 2 g / L NaOH solution, put the cotton fabric into the NaOH solution and boil it for 1-4 hours, then dry the fabric. (b) Prepare a saffron T solution of a certain concentration, put the cotton fabric obtained in step (a) into the saffron T solution, and let it stand for 0.5-2 hours; (c) Add FeCl3 to the solution obtained in step (b) to make the concentration reach 0.10-0.30M, and stir until homogeneous; (d) Add a certain amount of pyrrole to the solution obtained in step (c) and stir the reaction at room temperature for 25-30 hours; after the reaction is completed, take out the fabric and wash it three times with ethanol and deionized water respectively. (e) Weigh a certain amount of TiN, add it to anhydrous ethanol, and sonicate for 20-60 min to obtain TiN ethanol dispersion; (f) Place the fabric obtained in step (d) into the TiN ethanol dispersion, stir and soak for 20-40 min, then remove and dry; (g) Weigh the PDMS prepolymer and curing agent in a ratio of 10:1 and add them to the n-hexane solution to prepare a 1% PDMS solution; (h) Place the fabric obtained in step (f) into a 1% PDMS solution and let it stand for 30-60 min; then cure it in an oven at 80℃ for 0.5-1.5 h; (i) The fabric obtained in step (h) is subjected to plasma cleaning for 5 minutes, and the fabric loses its superhydrophobicity. After being treated under light or low pressure for a period of time, the fabric can regain its superhydrophobicity and prepare an all-weather self-healing superhydrophobic cotton fabric.

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