Visible light wave band compatible infrared stealth fabric and preparation method thereof

Abstract

The invention belongs to the field of infrared stealth materials, and particularly relates to an infrared stealth fabric compatible with visible light wave bands and a preparation method of the infrared stealth fabric. The infrared stealth fabric is prepared by taking polymer fibers as a matrix and perovskite nanocrystals as an additive and embedding the perovskite nanocrystals into the fibers. And the additive also comprises hydroxypropyl-beta-cyclodextrin. The preparation method comprises the following steps: preparing a precursor solution; and preparing the precursor solution into the infrared stealth fabric by adopting an electrostatic spinning method. The invention prepares a novel stealth material which not only can realize visible light and infrared dual-band stealth, but also has excellent flexibility and stability and is simple and convenient to process.

Description

Technical Field

[0001] The invention belongs to the field of infrared stealth materials, and in particular relates to an infrared stealth fabric compatible with a visible light band and a preparation method thereof. Background Art

[0002] With the continuous development of stealth technology, traditional infrared stealth materials are gradually unable to meet the increasingly diverse application needs, especially in complex environments where stealth in both visible light and infrared bands needs to be considered. Existing single infrared stealth polymer fabrics can usually 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 also relatively weak, and it is difficult to effectively shield or absorb infrared radiation. Due to the structural and composition limitations of the fabric itself, these materials cannot simultaneously achieve efficient infrared absorption and reflection regulation, and lack compatibility between different bands, which limits their application scenarios.

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

[0004] Current research focuses on achieving multi-band stealth through surface coloring and low-emissivity coatings, but these methods have many drawbacks, including difficulty in achieving effective coloring, complex manufacturing processes and high costs. In particular, in practical applications, how to ensure stealth performance while improving the comfort, environmental adaptability and ease of processing of fabrics remains a challenge that needs to be solved. Summary of the invention

[0005] The purpose of the present invention is to provide a visible light and infrared dual-band compatible stealth fabric with a simple preparation process in order to address the problem that traditional infrared stealth fabrics cannot achieve compatible stealth in the visible light band.

[0006] The technical solution for achieving the purpose of the present invention is: an infrared stealth fabric compatible with the visible light band, the infrared stealth fabric uses polymer fibers as a matrix, perovskite nanocrystals as an additive, and the perovskite nanocrystals are embedded in the fibers.

[0007] Furthermore, the additive also includes hydroxypropyl-β-cyclodextrin.

[0008] Furthermore, the polymer is polymethyl methacrylate (PMMA), polyacrylonitrile (PAN), polyvinyl pyrrolidone (PVP) or polyvinylidene fluoride (PVDF).

[0009] Furthermore, the perovskite nanocrystals are selected from methylamine lead bromide perovskite MAPbBr3, cesium lead bromide perovskite CsPbBr3 or cesium lead iodide perovskite CsPbI3.

[0010] A method for preparing the above-mentioned infrared stealth fabric compatible with the visible light band comprises the following steps:

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

[0012] Step (2): using an electrostatic spinning method to prepare the precursor solution obtained in step (1) into infrared stealth fabric.

[0013] Furthermore, 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 PbBr2 powder is weighed and added into 10±1 mL DMF solution for magnetic stirring, after PbBr2 is completely dissolved, 0.5-1.5 mmol CsBr powder is added and stirred continuously, after CsBr powder is completely dissolved, a certain amount of oleic acid is measured with a pipette, and a certain amount of oleylamine is added dropwise after the dispersion is complete, stirring continuously until dissolved, and then 1.5-2.0 g PMMA powder is added, and stirring continuously until a clear solution is obtained, thereby obtaining a precursor solution;

[0014] Step (2) is specifically as follows: controlling the relative humidity inside the electrospinning machine to 50±2%, drawing 5±1 mL of the precursor solution with a 10±2 mL syringe, installing a 14G right-angle needle at the front end of the syringe, installing the syringe in the electrospinning machine propeller, applying an 18 kV voltage and setting the propulsion speed to 0.02±0.002 mL / s, adjusting the distance from the syringe to the substrate to 15±1 cm and starting spinning to obtain CsPbBr3 / PMMA infrared stealth fabric.

[0015] Furthermore, the fabric is MAPbBr3 / PMMA infrared stealth fabric, and the preparation of the precursor solution in step (1) is specifically as follows: 0.5-1.5 mmol PbBr2 powder is weighed and added to 10±1 mL of DMF solution for magnetic stirring, and the stirring is continued until PbBr2 is completely dissolved, and 0.5-1.5 mmol CH3NHBr powder is added and stirred continuously, and after CH3NHBr is completely dissolved, oleic acid is measured with a pipette, and after the CH3NHBr is completely dispersed, 0.5±0.05 mL of oleylamine is added dropwise, and the stirring is continued until dissolved, and then 1.5-2.0 g of PMMA powder is added, and the temperature of the magnetic stirrer is set to 40±2 degrees Celsius, and the magnetic stirring is continued until a clear solution is obtained;

[0016] Step (2) is specifically as follows: controlling the relative humidity inside the electrospinning machine to 50±2%, drawing 5±1 mL of the precursor solution with a 10±2 mL syringe, installing a 14G right-angle needle at the front end of the syringe, installing the syringe in the electrospinning machine propeller, applying an 18 kV voltage and setting the propulsion speed to 0.02±0.002 mL / s, adjusting the distance from the syringe to the substrate to 15±1 cm, and then starting spinning.

[0017] Furthermore, the fabric is a CsPbI3 / PMMA infrared stealth fabric, and the preparation of the precursor solution in step (1) is specifically as follows: 0.5-1.5 mmol PbI2 powder is weighed and added into 10±1 mL DMF solution for magnetic stirring, after the PbI2 powder is completely dissolved, CsI powder is added and stirred continuously, after the CsI is completely dissolved, a certain amount of oleic acid is measured with a pipette, and a certain amount of oleylamine is added dropwise after the dispersion is complete, and after the mixture is stirred continuously until dissolved, 1.5-2.0 g PMMA powder is added and stirred continuously until a clear solution is obtained;

[0018] Step (2) is specifically as follows: controlling the relative humidity inside the electrospinning machine to 50±2%, drawing 5±1 mL of the precursor solution with a 10±2 mL syringe, installing a 14G right-angle needle at the front end of the syringe, installing the syringe in the electrospinning machine propeller, applying an 18 kV voltage and setting the propulsion speed to 0.02±0.002 mL / s, adjusting the distance from the syringe to the substrate to 15±1 cm, and then starting spinning.

[0019] Furthermore, the fabric is HP-β-CD@CsPbBr3 / PMMA infrared stealth fabric, and step (1) is specifically as follows: weigh 0.5-1.5mmol PbBr2 powder, add it into 10±1mL DMF solution, and stir it magnetically; after the PbBr2 powder is completely dissolved, add 0.5-1.5mmol CsBr powder and continue stirring; after the CsBr powder is completely dissolved, use a pipette to measure a certain amount of oleic acid, and then add a certain amount of oleylamine dropwise after it is completely dispersed; after stirring continuously until dissolved, add 0.13-1.0g HP-β-CD powder; after stirring continuously until dissolved, add 1.5-2.0g PMMA powder; and continue stirring until a clear solution is obtained;

[0020] Step (2) is specifically as follows: controlling the relative humidity inside the electrospinning machine to 50±2%, drawing 5±1 mL of the precursor solution with a 10±2 mL syringe, installing a 14G right-angle needle at the front end of the syringe, installing the syringe in the electrospinning machine propeller, applying an 18 kV voltage and setting the propulsion speed to 0.02±0.002 mL / s, adjusting the distance from the syringe to the substrate to 15±1 cm, and then starting spinning.

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

[0022] In addition to perovskite nanocrystals, the additive of the present invention can also add hydroxypropyl-β-cyclodextrin (HP-β-CD) to improve the water environment stability of inorganic perovskite / polymer infrared stealth fabric. Since the metal halide bonds of inorganic perovskite crystals easily react with water molecules, resulting in the dissolution and degradation of the crystals, the crystal structure of inorganic perovskite is extremely susceptible to moisture and water erosion, resulting in rapid decline of its optical properties and crystallinity. HP-β-CD is a cyclic oligosaccharide with a special molecular structure. Its structural characteristics of hydrophilic exterior and hydrophobic interior enable it to coat perovskite nanocrystals, thereby forming a physical barrier on the perovskite surface to prevent water molecules from corroding the crystals. In addition, HP-β-CD binds to uncoordinated metal ions (such as Pb) on the surface of the perovskite through hydroxyl groups. 2 +) to form chemical bonds, stabilizing the structure of the perovskite. This effective coating and passivation reduces surface defects, avoids decomposition caused by contact with moisture, and also helps to enhance luminescence brightness. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

[0025] Figure 3 Infrared transmission spectrum and reflection spectrum of CsPbBr3 / PMMA fabrics with different CsPbBr3 concentrations; (a) infrared transmission spectrum, (b) reflection spectrum.

[0026] Figure 4 Thermal conductivity diagram of CsPbBr3 / PMMA fabrics with different CsPbBr3 contents.

[0027] Figure 5 CsPbBr3 / PMMA fabrics with different CsPbBr3 concentrations were photographed under an infrared camera.

[0028] Figure 6 These are the images of samples with different contents of HP-β-CD (0 g, 0.13 g, 0.5 g, 1.0 g) added in water environment under 365 nm ultraviolet light and normal light.

[0029] Figure 7HP-β-CD@CsPbBr3 / PMMA fabrics with different HP-β-CD contents were photographed under an infrared camera. DETAILED DESCRIPTION

[0030] The present invention is further described below by means of specific examples. These embodiments are only intended to illustrate the present invention but are not intended to limit the scope of the present invention.

[0031] Example 1

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

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

[0034] Preparation of perovskite nanocrystal / PMMA fabric: The electrospinning method was used, and the relative humidity inside the electrospinning machine was controlled at 50%. 5 mL of the precursor solution was drawn with a 10 mL syringe, and a 14 G right-angle needle was installed at the front end of the syringe. The syringe was installed in the electrospinning machine propeller, 18 kV voltage was applied, and the propulsion speed was set to 0.02 mL / s. The distance from the syringe to the substrate was adjusted to 15 cm before starting spinning.

[0035] Example 2

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

[0037] Preparation of precursor solution: Weigh 0.550515g PbBr2 powder and add it to 10mL DMF solution for magnetic stirring. Continue stirring for 30 minutes until PbBr2 is completely dissolved, then add 0.167955g CH3NHBr powder and continue stirring for 2 hours. After CH3NHBr is completely dissolved, use a pipette to measure 1mL of oleic acid, add DMF solution dropwise during magnetic stirring, stir for 5 minutes, then add 0.5mL of oleylamine dropwise, continue stirring for 5 minutes, then add 2.25g PMMA powder, set the magnetic stirrer temperature to 40 degrees Celsius, and continue magnetic stirring for 24 hours until a clear solution is obtained.

[0038] Preparation of perovskite nanocrystal / PMMA fabric: The electrospinning method was used, and the relative humidity inside the electrospinning machine was controlled at 50%. 5 mL of the precursor solution was drawn with a 10 mL syringe, and a 14 G right-angle needle was installed at the front end of the syringe. The syringe was installed in the electrospinning machine propeller, 18 kV voltage was applied, and the propulsion speed was set to 0.02 mL / s. The distance from the syringe to the substrate was adjusted to 15 cm before starting spinning.

[0039] Example 3

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

[0041] Preparation of precursor solution: Weigh 0.46101g PbI2 powder and add it to 10mL DMF solution for magnetic stirring. Continue stirring for 30min until PbI2 is completely dissolved, then add 0.25981g CsI powder and continue stirring for 2h. After CsI is completely dissolved, use a pipette to measure 1mL oleic acid, add DMF solution dropwise during magnetic stirring, stir for 5min, then add 0.5mL oleylamine dropwise, continue stirring for 5min, then add 2.25g PMMA powder, set the magnetic stirrer temperature to 40 degrees Celsius, and continue magnetic stirring for 24h until a clear solution is obtained.

[0042] Preparation of perovskite nanocrystal / PMMA fabric: The electrospinning method was used, and the relative humidity inside the electrospinning machine was controlled at 50%. 5 mL of the precursor solution was drawn with a 10 mL syringe, and a 14 G right-angle needle was installed at the front end of the syringe. The syringe was installed in the electrospinning machine propeller, 18 kV voltage was applied, and the propulsion speed was set to 0.02 mL / s. The distance from the syringe to the substrate was adjusted to 15 cm before starting spinning.

[0043] Example 4

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

[0045] Preparation of precursor solution: Weigh 0.183505g PbBr2 powder and add it to 10mL DMF solution for magnetic stirring. Continue stirring for 30min until PbBr2 is completely dissolved, then add 0.106405g CsBr powder and continue stirring for 2h. After CsBr is completely dissolved, use a pipette to measure 1mL of oleic acid, add DMF solution dropwise during magnetic stirring, stir for 5min, then add 0.5mL of oleylamine dropwise, continue stirring for 5min, add a certain amount of HP-β-CD powder, continue stirring for 30min, add 2.25g PMMA powder, set the temperature of the magnetic stirrer to 40 degrees Celsius, and continue magnetic stirring for 24h until a clear solution is obtained.

[0046] Preparation of perovskite nanocrystal / PMMA fabric: The electrospinning method was used, and the relative humidity inside the electrospinning machine was controlled at 50%. 5 mL of the precursor solution was drawn with a 10 mL syringe, and a 14 G right-angle needle was installed at the front end of the syringe. The syringe was installed in the electrospinning machine propeller, 18 kV voltage was applied, and the propulsion speed was set to 0.02 mL / s. The distance from the syringe to the substrate was adjusted to 15 cm before starting spinning.

[0047] like Figure 1 As shown in the figure, after adding different types of perovskite nanocrystals with different contents, the PMMA fabric changes from the original white to light green, green, yellow-green, yellow, and brown-yellow tones. These tones are very close to the colors of plants in nature. This rich color change provides a variety of options for the invisible effect of the fabric in the vegetation environment, allowing it to better integrate with the surrounding environment and enhance its concealment in sunlight.

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

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

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

[0051] like Figure 5As shown, when photographed by an infrared camera, the human body temperature is 34.6°C. After being covered with CsPbBr3 / PMMA fabrics with different CsPbBr3 concentrations, the temperature can be reduced to 30.9°C, 29.5°C, 26.8°C, and 25.0°C, demonstrating good infrared stealth performance.

Claims

1. An infrared stealth fabric compatible with the visible light band, characterized in that: The infrared stealth fabric is made of polymer fibers as a matrix and perovskite nanocrystals as additives, and the perovskite nanocrystals are embedded inside the fibers.

2. The infrared stealth fabric according to claim 1, characterized in that: Additives also include hydroxypropyl-β-cyclodextrin.

3. The infrared stealth fabric according to claim 2, characterized in that: The polymer is polymethyl methacrylate PMMA, polyacrylonitrile PAN, polyvinyl pyrrolidone PVP or polyvinylidene fluoride PVDF.

4. The infrared stealth fabric according to claim 3, characterized in that: The perovskite nanocrystals are selected from methylamine lead bromide perovskite MAPbBr3, cesium lead bromide perovskite CsPbBr3 or cesium lead iodide perovskite CsPbI3.

5. A method for preparing the infrared stealth fabric compatible with the visible light band as claimed in claim 4, characterized in that: The steps include: Step (1): preparation of precursor solution; Step (2): using an electrostatic spinning method to prepare the precursor solution obtained in step (1) into infrared stealth fabric.

6. The method according to claim 5, characterized in that The fabric is CsPbBr3 / PMMA infrared stealth fabric. The preparation of the precursor solution in step (1) is specifically as follows: 0.5-1.5 mmol PbBr2 powder is weighed and added into 10±1 mL DMF solution for magnetic stirring. After PbBr2 is completely dissolved, 0.5-1.5 mmol CsBr powder is added and stirred continuously. After CsBr powder is completely dissolved, a certain amount of oleic acid is measured with a pipette. After the CsBr powder is completely dissolved, a certain amount of oleylamine is added dropwise. After the mixture is completely dispersed, 1.5-2.0 g PMMA powder is added and stirred continuously until the mixture is dissolved. The mixture is stirred continuously until a clear solution is obtained to obtain a precursor solution. Step (2) is specifically as follows: controlling the relative humidity inside the electrospinning machine to 50±2%, drawing 5±1 mL of the precursor solution with a 10±2 mL syringe, installing a 14G right-angle needle at the front end of the syringe, installing the syringe in the electrospinning machine propeller, applying an 18 kV voltage and setting the propulsion speed to 0.02±0.002 mL / s, adjusting the distance from the syringe to the substrate to 15±1 cm and starting spinning to obtain CsPbBr3 / PMMA infrared stealth fabric.

7. The method according to claim 5, characterized in that The fabric is MAPbBr3 / PMMA infrared stealth fabric. The preparation of the precursor solution in step (1) is specifically as follows: 0.5-1.5 mmol PbBr2 powder is weighed and added to 10±1 mL of DMF solution for magnetic stirring. After continuous stirring until PbBr2 is completely dissolved, 0.5-1.5 mmol CH3NHBr powder is added and continuously stirred. After CH3NHBr is completely dissolved, oleic acid is measured with a pipette. After complete dispersion, 0.5±0.05 mL of oleylamine is added dropwise. After continuous stirring until dissolved, 1.5-2.0 g of PMMA powder is added. The temperature of the magnetic stirrer is set to 40±2 degrees Celsius. Continuous magnetic stirring is performed until a clear solution is obtained. Step (2) is specifically as follows: controlling the relative humidity inside the electrospinning machine to 50±2%, drawing 5±1 mL of the precursor solution with a 10±2 mL syringe, installing a 14G right-angle needle at the front end of the syringe, installing the syringe in the electrospinning machine propeller, applying an 18 kV voltage and setting the propulsion speed to 0.02±0.002 mL / s, adjusting the distance from the syringe to the substrate to 15±1 cm, and then starting spinning.

8. The method according to claim 5, characterized in that The fabric is CsPbI3 / PMMA infrared stealth fabric. The preparation of the precursor solution in step (1) is specifically as follows: 0.5-1.5 mmol PbI2 powder is weighed and added into 10±1 mL DMF solution for magnetic stirring. After the PbI2 powder is completely dissolved, CsI powder is added and stirred continuously. After the CsI is completely dissolved, a certain amount of oleic acid is measured with a pipette. After the dispersion is complete, a certain amount of oleylamine is added dropwise. After the stirring is continued until the solution is dissolved, 1.5-2.0 g PMMA powder is added and stirred continuously until a clear solution is obtained. Step (2) is specifically as follows: controlling the relative humidity inside the electrospinning machine to 50±2%, drawing 5±1 mL of the precursor solution with a 10±2 mL syringe, installing a 14G right-angle needle at the front end of the syringe, installing the syringe in the electrospinning machine propeller, applying an 18 kV voltage and setting the propulsion speed to 0.02±0.002 mL / s, adjusting the distance from the syringe to the substrate to 15±1 cm, and then starting spinning.

9. The method according to claim 5, characterized in that The fabric is HP-β-CD@CsPbBr3 / PMMA infrared stealth fabric, and the step (1) is specifically as follows: weigh 0.5-1.5mmol PbBr2 powder, add it into 10±1mL DMF solution, and stir it magnetically; after the PbBr2 powder is completely dissolved, add 0.5-1.5mmol CsBr powder and continue stirring; after the CsBr powder is completely dissolved, use a pipette to measure a certain amount of oleic acid, and then add a certain amount of oleylamine dropwise after it is completely dispersed; after stirring continuously until dissolved, add 0.13-1.0g HP-β-CD powder; after stirring continuously until dissolved, add 1.5-2.0g PMMA powder; and continue stirring until a clear solution is obtained; Step (2) is specifically as follows: controlling the relative humidity inside the electrospinning machine to 50±2%, drawing 5±1 mL of the precursor solution with a 10±2 mL syringe, installing a 14G right-angle needle at the front end of the syringe, installing the syringe in the electrospinning machine propeller, applying an 18 kV voltage and setting the propulsion speed to 0.02±0.002 mL / s, adjusting the distance from the syringe to the substrate to 15±1 cm, and then starting spinning.

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