Infrared stealth fabric compatible with visible light band and preparation method thereof

Abstract

The application belongs to the field of infrared stealth materials, and particularly relates to an infrared stealth fabric compatible with the visible light band and a preparation method thereof. The infrared stealth fabric is prepared by taking a polymer fiber as a base body, taking a perovskite nanocrystal as an additive, and embedding the perovskite nanocrystal into the inside of the fiber. The additive further comprises hydroxypropyl-beta-cyclodextrin. The preparation method comprises the following steps: preparation of a precursor solution; and preparation of the infrared stealth fabric from the precursor solution by using an electrostatic spinning method. The application prepares a novel stealth material which can realize dual-band stealth of the visible light and infrared, and has excellent flexibility, stability and simple processing.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of infrared stealth materials, and particularly relates to an infrared stealth fabric compatible with the visible light band and a preparation method thereof. BACKGROUND

[0002] With the continuous development of stealth technology, traditional infrared stealth materials gradually fail to meet the increasingly diversified application requirements, especially in complex environments that require simultaneous consideration of visible light and infrared band stealth. Existing single infrared stealth polymer fabrics can only achieve a certain degree of stealth in the mid-infrared band, but lack effective optical regulation under visible light, resulting in inconsistent color of the fabric in the natural environment and difficulty in blending into the background. In addition, the infrared stealth performance of existing materials is relatively weak, making it difficult to effectively shield or absorb infrared radiation. Due to the limitations of the structure and composition of the fabric itself, these materials cannot simultaneously achieve efficient infrared absorption and reflection regulation, and lack compatibility between different bands, limiting their application scenarios.

[0003] Traditional infrared stealth technology mainly relies on special coatings, low-emissivity coatings, and multilayer composite films to achieve shielding and stealth effects on infrared radiation. However, these materials often exhibit significant color differences under visible light, especially in complex environments, which greatly limits the realization of stealth effects. Metal-based multilayer films have high infrared reflection ability, but their rigidity and high density limit their performance in flexible applications, and they are easily affected in changing environments, leading to performance degradation.

[0004] Current researches mainly focus on achieving multi-band stealth through surface coloring and low-emissivity coating, but these methods have many defects, including difficulty in achieving effective coloring, complex manufacturing process, and high cost. Especially in practical applications, how to ensure stealth performance while improving the comfort, environmental adaptability, and processing simplicity of the fabric remains a challenge to be solved. SUMMARY

[0005] The present application aims to solve the problem that traditional infrared stealth fabrics cannot achieve compatible stealth in the visible light band, and provides a stealth fabric compatible with the visible light and infrared dual bands with a simple preparation process.

[0006] The technical solution for achieving the purpose of the present application is: an infrared stealth fabric compatible with the visible light band, which uses a polymer fiber as a matrix and a perovskite nanocrystal as an additive, and the perovskite nanocrystal is embedded inside the fiber.

[0007] Further, the additive also includes hydroxypropyl-beta-cyclodextrin.

[0008] Further, the polymer is polymethyl methacrylate PMMA, polyacrylonitrile PAN, polyvinylpyrrolidone PVP or polyvinylidene fluoride PVDF.

[0009] Further, the perovskite nanocrystal is selected from methylamine lead bromide perovskite MAPbBr3, cesium lead bromide perovskite CsPbBr3 or cesium lead iodide perovskite CsPbI3.

[0010] A preparation method of the above-mentioned visible light band compatible infrared stealth fabric, comprising the following steps:

[0011] Step (1): preparation of a precursor solution;

[0012] Step (2): using an electrospinning method, the precursor solution prepared in step (1) is prepared into an infrared stealth fabric.

[0013] Further, the fabric is a CsPbBr3 / PMMA infrared stealth fabric, and the preparation of the precursor solution in step (1) is specifically as follows: 0.5-1.5 mmol of PbBr2 powder is added into 10±1 mL of DMF solution for magnetic stirring, after PbBr2 is completely dissolved, 0.5-1.5 mmol of CsBr powder is added for continuous stirring, after the CsBr powder is completely dissolved, a certain amount of oleic acid is taken by a syringe, after complete dispersion, a certain amount of oleylamine is added dropwise, continuous stirring is carried out until dissolution, then 1.5-2.0 g of PMMA powder is added, and continuous magnetic stirring is carried out until a clear solution is obtained, thereby obtaining the precursor solution;

[0014] Step (2) is specifically as follows: the relative humidity inside the electrospinning machine is controlled to be 50±2%, 5±1 mL of the precursor solution is taken by a 10±2 mL syringe, a 14G right-angle needle head is installed at the front end of the syringe, the syringe is installed in the pusher of the electrospinning machine, a voltage of 18 kV is applied and the push speed is set to be 0.02±0.002 mL / s, the distance between the syringe and the substrate is adjusted to be 15±1 cm, and then the spinning is started, thereby obtaining the CsPbBr3 / PMMA infrared stealth fabric.

[0015] Further, the fabric is a MAPbBr3 / PMMA infrared stealth fabric, and the preparation of the precursor solution in step (1) is specifically as follows: 0.5-1.5 mmol of PbBr2 powder is added into 10±1 mL of DMF solution for magnetic stirring, after PbBr2 is completely dissolved, 0.5-1.5 mmol of CH3NHBr powder is added for continuous stirring, after the CH3NHBr is completely dissolved, oleic acid is taken by a syringe, after complete dispersion, 0.5±0.05 mL of oleylamine is added dropwise, continuous stirring is carried out until dissolution, then 1.5-2.0 g of PMMA powder is added, the temperature of the magnetic stirrer is set to be 40±2 degrees Celsius, and continuous magnetic stirring is carried out until a clear solution is obtained.

[0016] Step (2) is specifically: control the relative humidity in the electrospinning machine to be 50±2%, use a 10±2mL syringe to suck 5±1mL of the precursor solution, and install a 14G right-angle needle at the front end of the syringe, install the syringe in the electrospinning machine pusher, apply a voltage of 18kV and set the push speed to be 0.02±0.002mL / s, adjust the distance between the syringe and the substrate to be 15±1cm, and then start spinning.

[0017] Further, the fabric is CsPbI3 / PMMA infrared stealth fabric, and step (1) is specifically: 0.5-1.5mmol of PbI2 powder is weighed and added into 10±1mL of DMF solution for magnetic stirring, after the PbI2 powder is completely dissolved, CsI powder is added for continuous stirring, after the CsI is completely dissolved, a certain amount of oleic acid is measured by a pipette, after complete dispersion, a certain amount of oleylamine is added dropwise, continuous stirring is carried out until the solution is dissolved, 1.5-2.0g of PMMA powder is added, and continuous stirring is carried out until a clear solution is obtained.

[0018] Step (2) is specifically: control the relative humidity in the electrospinning machine to be 50±2%, use a 10±2mL syringe to suck 5±1mL of the precursor solution, and install a 14G right-angle needle at the front end of the syringe, install the syringe in the electrospinning machine pusher, apply a voltage of 18kV and set the push speed to be 0.02±0.002mL / s, adjust the distance between the syringe and the substrate to be 15±1cm, and then start spinning.

[0019] Further, the fabric is HP-β-CD@CsPbBr3 / PMMA infrared stealth fabric, and step (1) is specifically: 0.5-1.5mmol of PbBr2 powder is weighed and added into 10±1mL of DMF solution for magnetic stirring, after the PbBr2 powder is completely dissolved, 0.5-1.5mmol of CsBr powder is added for continuous stirring, after the CsBr powder is completely dissolved, a certain amount of oleic acid is measured by a pipette, after complete dispersion, a certain amount of oleylamine is added dropwise, continuous stirring is carried out until the solution is dissolved, 0.13-1.0g of HP-β-CD powder is added, continuous stirring is carried out until the solution is dissolved, 1.5-2.0g of PMMA powder is added, and continuous stirring is carried out until a clear solution is obtained.

[0020] Step (2) is specifically: control the relative humidity in the electrospinning machine to be 50±2%, use a 10±2mL syringe to suck 5±1mL of the precursor solution, and install a 14G right-angle needle at the front end of the syringe, install the syringe in the electrospinning machine pusher, apply a voltage of 18kV and set the push speed to be 0.02±0.002mL / s, adjust the distance between the syringe and the substrate to be 15±1cm, and then start spinning.

[0021] Compared with the prior art, the present application has the following advantages:

[0022] The additive of the present application can add hydroxypropyl-β-cyclodextrin (HP-β-CD) in addition to perovskite nanocrystals to improve the water environment stability of inorganic perovskite / polymer infrared stealth fabric. Because the metal halide bond of inorganic perovskite crystal is easy to react with water molecules, leading to the dissolution and degradation of the crystal, the crystal structure of inorganic perovskite is extremely vulnerable to moisture and water, resulting in rapid decline of its optical properties and crystallinity. HP-β-CD is a cyclic oligosaccharide with a special molecular structure. Its structure characteristics of hydrophilic outside and hydrophobic inside enable it to coat perovskite nanocrystals, thereby forming a physical barrier on the surface of perovskite to prevent water molecules from eroding the crystal. Moreover, HP-β-CD forms a chemical bond with the uncoordinated metal ions (such as Pb 2 +) on the surface of perovskite through the hydroxyl group, stabilizing the structure of perovskite. This effective coating and passivation reduces surface defects and avoids decomposition caused by contact with water, also helping to enhance the luminous brightness. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 Photographs of perovskite / PMMA fabrics of different types and different concentrations under normal light.

[0024] Figure 2 Scanning electron microscope images of the internal nanocrystals of CsPbBr3 / PMMA fibers of different concentrations of CsPbBr3: (a) 0.5 mmol, (b) 1.0 mmol, (c) 1.5 mmol; nanocrystal particle size distribution graphs: (d) 0.5 mmol, (e) 1.0 mmol, (f) 1.5 mmol.

[0025] Figure 3 Infrared transmission spectrum and reflectance spectrum of CsPbBr3 / PMMA fabric of different concentrations of CsPbBr3: (a) infrared transmission spectrum, (b) reflectance spectrum.

[0026] Figure 4 Thermal conductivity graph of CsPbBr3 / PMMA fabric with different CsPbBr3 contents.

[0027] Figure 5 CsPbBr3 / PMMA fabric of different CsPbBr3 concentrations photographed under an infrared camera.

[0028] Figure 6 Images of CsPbBr3 / PMMA fabric with different contents of HP-β-CD (0 g, 0.13 g, 0.5 g, 1.0 g) under 365 nm ultraviolet light irradiation and normal light irradiation with soaking time change in water environment.

[0029] Figure 7Different HP-β-CD content of HP-β-CD@CsPbBr3 / PMMA fabric was taken by infrared camera. DETAILED DESCRIPTION

[0030] The application is further described by the following specific examples, which are only intended to illustrate the application and not to limit the scope of the application.

[0031] Example 1

[0032] The preparation of infrared stealth fabric CsPbBr3 / PMMA is as follows.

[0033] Preparation of precursor solution: weigh 0.183505 g of PbBr2 powder into 10 mL of DMF solution and perform magnetic stirring, continue stirring for 30 min until PbBr2 is completely dissolved, then add 0.106405 g of CsBr powder and continue stirring for 2 h, after CsBr is completely dissolved, use a syringe to take 1 mL of oleic acid, drop DMF solution during magnetic stirring, stir for 5 min, then drop 0.5 mL of oleylamine, continue stirring for 5 min, then add 2.25 g of PMMA powder, set the temperature of the magnetic stirrer to 40 degrees Celsius, continue magnetic stirring for 24 h until a clear solution is obtained.

[0034] Preparation of perovskite nanocrystal / PMMA fabric: electrospinning method is adopted, the relative humidity inside the electrospinning machine is controlled to be 50%, 5 mL of precursor solution is taken with a 10 mL syringe, a 14G right-angle needle is installed at the front end of the syringe, the syringe is installed in the pusher of the electrospinning machine, an 18 kV voltage is applied and the push speed is set to 0.02 mL / s, the distance between the syringe and the substrate is adjusted to 15 cm, and then the spinning is started.

[0035] Example 2

[0036] The preparation of infrared stealth fabric MAPbBr3 / PMMA is as follows.

[0037] Preparation of precursor solution: weigh 0.183505 g of PbBr2 powder into 10 mL of DMF solution and perform magnetic stirring, continue stirring for 30 min until PbBr2 is completely dissolved, then add 0.106405 g of CsBr powder and continue stirring for 2 h, after CsBr is completely dissolved, use a syringe to take 1 mL of oleic acid, drop DMF solution during magnetic stirring, stir for 5 min, then drop 0.5 mL of oleylamine, continue stirring for 5 min, then add 2.25 g of PMMA powder, set the temperature of the magnetic stirrer to 40 degrees Celsius, continue magnetic stirring for 24 h until a clear solution is obtained.

[0038] Perovskite nanocrystal / PMMA fabric preparation: electrospinning method was adopted, the relative humidity inside the electrospinning machine was controlled to be 50%, 5 mL of precursor solution was taken by 10 mL syringe, and 14G right-angle needle was installed at the front end of the syringe, the syringe was installed in the electrospinning machine pusher, 18 kV voltage was applied and the push speed was set to 0.02 mL / s, the distance between the syringe and the substrate was adjusted to 15 cm, and then the spinning was started.

[0039] Example 3

[0040] The preparation of infrared stealth fabric CsPbI3 / PMMA is as follows.

[0041] Preparation of precursor solution: 0.46101 g of PbI2 powder was weighed and added to 10 mL of DMF solution for magnetic stirring, and the stirring was continued for 30 min until PbI2 was completely dissolved, then 0.25981 g of CsI powder was added and stirred for 2 h, and then 1 mL of oleic acid was taken by a pipette, and DMF solution was added dropwise during magnetic stirring, and then 0.5 mL of oleylamine was added after stirring for 5 min, and 2.25 g of PMMA powder was added after stirring for 5 min, and the temperature of the magnetic stirrer was set to 40 degrees Celsius, and the magnetic stirring was continued for 24 h until a clear solution was obtained.

[0042] Perovskite nanocrystal / PMMA fabric preparation: electrospinning method was adopted, the relative humidity inside the electrospinning machine was controlled to be 50%, 5 mL of precursor solution was taken by 10 mL syringe, and 14G right-angle needle was installed at the front end of the syringe, the syringe was installed in the electrospinning machine pusher, 18 kV voltage was applied and the push speed was set to 0.02 mL / s, the distance between the syringe and the substrate was adjusted to 15 cm, and then the spinning was started.

[0043] Example 4

[0044] The preparation of infrared stealth fabric HP-β-CD@CsPbBr3 / PMMA is as follows.

[0045] Preparation of precursor solution: 0.183505 g of PbBr2 powder was weighed and added to 10 mL of DMF solution for magnetic stirring, and the stirring was continued for 30 min until PbBr2 was completely dissolved, then 0.106405 g of CsBr powder was added and stirred for 2 h, and then 1 mL of oleic acid was taken by a pipette, and DMF solution was added dropwise during magnetic stirring, and then 0.5 mL of oleylamine was added after stirring for 5 min, and a certain amount of HP-β-CD powder was added after stirring for 5 min, and the stirring was continued for 30 min, and then 2.25 g of PMMA powder was added, and the temperature of the magnetic stirrer was set to 40 degrees Celsius, and the magnetic stirring was continued for 24 h until a clear solution was obtained.

[0046] Perovskite nanocrystals / PMMA fabric preparation: using electrospinning method, control the relative humidity inside the electrospinning machine to be 50%, use a 10 mL syringe to suck 5 mL of precursor solution, and install a 14G right-angle needle at the front end of the syringe, install the syringe in the pusher of the electrospinning machine, apply a voltage of 18 kV and set the push speed to 0.02 mL / s, adjust the distance between the syringe and the substrate to 15 cm, and then start spinning.

[0047] As shown in Figure 1 , after adding perovskite nanocrystals of different contents and different types, the color of the PMMA fabric changed from white to light green, green, yellow-green, yellow, and brown-yellow. These color tones are very close to the colors of plants in nature. This rich color change provides a variety of choices for the camouflage effect of the fabric in the vegetation environment, making it better integrated with the surrounding environment and enhancing its concealment in sunlight.

[0048] As shown in Figure 2 , after adding perovskite nanocrystals (CsPbBr3 = 0, 0.5, 1, 1.5 mmol) of different contents, the size of the nanocrystals inside the fiber became smaller as the content of perovskite nanocrystals increased. This is because, as the concentration increases, the number of precursor molecules in the solution increases, leading to an increase in the nucleation density of nanocrystals, and the excessive growth of crystal nuclei is inhibited, resulting in the formation of smaller and more uniform nanocrystals.

[0049] As shown in Figure 3 , after adding perovskite nanocrystals (CsPbBr3 = 0, 0.5, 1, 1.5 mmol) of different contents, the infrared transmittance of the PMMA fabric decreased significantly, and the reflectivity changed within a small range. This is because, as the concentration of nanocrystals increases and the size decreases, the quantum confinement effect is enhanced, the specific surface area of small-size quantum dots increases, the path of light absorption becomes longer, and more infrared radiation is scattered or absorbed, thereby significantly reducing the transmittance.

[0050] As shown in Figure 4 , after adding perovskite nanocrystals (CsPbBr3 = 0, 0.5, 1, 1.5 mmol) of different contents, the thermal conductivity of the PMMA fabric decreased significantly from 0.1922 to 0.03942. This is because, as the concentration of CsPbBr3 in the precursor increases, the size of the CsPbBr3 nanocrystals in the PMMA fiber gradually decreases, and the interface scattering and thermal resistance effect of the material become more significant, which limits the effective conduction of heat.

[0051] As shown in Figure 5As shown, the body temperature is 34.6℃ under the infrared camera shooting, and the temperature can be reduced to 30.9℃, 29.5℃, 26.8℃ and 25.0℃ after covering by the CsPbBr3 / PMMA fabric with different CsPbBr3 concentrations, which shows good infrared stealth performance.

Claims

1. A method for preparing an infrared stealth fabric compatible with the visible light band, characterized in that, The infrared stealth fabric is made by using polymer fibers as the matrix and perovskite nanocrystals as an additive, with the perovskite nanocrystals embedded inside the fibers. The specific steps include the following: Step (1): Preparation of precursor solution; Step (2): The precursor solution obtained in step (1) is prepared into infrared stealth fabric by electrospinning. The fabric is a CsPbBr3 / PMMA infrared stealth fabric. The preparation of the precursor solution in step (1) is as follows: Weigh 0.5-1.5 mmol of PbBr2 powder and add it to 10±1 mL of DMF solution and stir magnetically. After PbBr2 is completely dissolved, add 0.5-1.5 mmol of CsBr powder and continue stirring. After CsBr powder is completely dissolved, use a pipette to measure a certain amount of oleic acid, disperse it completely, and then add a certain amount of oleylamine. Continue stirring until dissolved, then add 1.5-2.0 g of PMMA powder and continue stirring until a clear solution is obtained, thus obtaining the precursor solution. Step (2) is as follows: control the relative humidity inside the electrospinning machine to be 50±2%, use a 10±2mL syringe to draw 5±1mL of precursor solution, attach a 14G right-angle needle to the front end of the syringe, install the syringe in the electrospinning machine pusher, apply an 18kV voltage and set the pusher speed to 0.02±0.002mL / s, adjust the distance between the syringe and the substrate to 15±1cm and start spinning to obtain CsPbBr3 / PMMA infrared stealth fabric.

2. The method according to claim 1, characterized in that, The fabric is MAPbBr3 / PMMA infrared stealth fabric. The preparation of the precursor solution in step (1) is as follows: Weigh 0.5-1.5 mmol of PbBr2 powder and add it to 10±1 mL of DMF solution for magnetic stirring. After stirring continuously until PbBr2 is completely dissolved, add 0.5-1.5 mmol of CH3NHBr powder and continue stirring. After CH3NHBr is completely dissolved, use a pipette to measure oleic acid, disperse it completely, and then add 0.5±0.05 mL of oleylamine. Continue stirring until dissolved, and then add 1.5-2.0 g of PMMA powder. Set the temperature of the magnetic stirrer to 40±2 degrees Celsius and continue magnetic stirring until a clear solution is obtained. Step (2) is as follows: control the relative humidity inside the electrospinning machine to be 50±2%, use a 10±2mL syringe to draw 5±1mL of precursor solution, attach a 14G right-angle needle to the front end of the syringe, install the syringe in the electrospinning machine pusher, apply an 18kV voltage and set the pusher speed to 0.02±0.002mL / s, adjust the distance between the syringe and the substrate to 15±1cm and start spinning.

3. The method according to claim 1, characterized in that, The fabric is a CsPbI3 / PMMA infrared stealth fabric. The preparation of the precursor solution in step (1) is as follows: Weigh 0.5-1.5 mmol of PbI2 powder and add it to 10±1 mL of DMF solution and stir magnetically. After the PbI2 powder is completely dissolved, add CsI powder and continue stirring. After the CsI is completely dissolved, use a pipette to measure a certain amount of oleic acid, disperse it completely, and then add a certain amount of oleylamine. Continue stirring until dissolved, then add 1.5-2.0 g of PMMA powder and continue stirring until a clear solution is obtained. Step (2) is as follows: control the relative humidity inside the electrospinning machine to be 50±2%, use a 10±2mL syringe to draw 5±1mL of precursor solution, attach a 14G right-angle needle to the front end of the syringe, install the syringe in the electrospinning machine pusher, apply an 18kV voltage and set the pusher speed to 0.02±0.002mL / s, adjust the distance between the syringe and the substrate to 15±1cm and start spinning.

4. The method according to claim 1, characterized in that, The fabric is HP-β-CD@CsPbBr3 / PMMA infrared stealth fabric. Step (1) is as follows: Weigh 0.5-1.5 mmol of PbBr2 powder and add it to 10±1 mL of DMF solution and stir magnetically. After the PbBr2 powder is completely dissolved, add 0.5-1.5 mmol of CsBr powder and continue stirring. After the CsBr powder is completely dissolved, use a pipette to measure a certain amount of oleic acid. After it is completely dispersed, add a certain amount of oleylamine. Continue stirring until dissolved, then add 0.13-1.0 g of HP-β-CD powder and continue stirring until dissolved. Then add 1.5-2.0 g of PMMA powder and continue stirring until a clear solution is obtained. Step (2) is as follows: control the relative humidity inside the electrospinning machine to be 50±2%, use a 10±2mL syringe to draw 5±1mL of precursor solution, attach a 14G right-angle needle to the front end of the syringe, install the syringe in the electrospinning machine pusher, apply an 18kV voltage and set the pusher speed to 0.02±0.002mL / s, adjust the distance between the syringe and the substrate to 15±1cm and start spinning.

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