Hollow nanosphere-iodine copper cesium composite material and preparation method and application thereof

Abstract

The invention discloses a hollow nanosphere-iodine copper cesium composite material as well as a preparation method and application thereof, and belongs to the technical field of optical anti-counterfeiting materials. The invention provides a hollow nanosphere-iodine copper cesium composite material with a fluorescence response characteristic, a unique mosaic structure is constructed by compositing hollow nanospheres and Cs3Cu2I5 crystals, and the change of fluorescence color is realized by a simple triggering mode of human respiration, so that the fluorescence response characteristic of the hollow nanosphere-iodine copper cesium composite material is realized. And finally, the human respiration triggered optical response composite material with excellent performance and relatively high stability is prepared, and has good application potential in the fields of anti-counterfeiting and optical information.

Description

Technical Field

[0001] The present invention relates to the technical field of optical anti-counterfeiting materials, and in particular to a hollow nanosphere-iodine copper cesium composite material and a preparation method and application thereof. Background Art

[0002] Traditional anti-counterfeiting methods such as QR codes, barcodes, and watermark anti-counterfeiting technologies have disadvantages such as high cost, difficulty in identification, low technical threshold, and easy copying, making it difficult to meet actual application needs and protect products. Optical anti-counterfeiting technology has great potential in intelligent anti-counterfeiting due to its advantages such as convenient design, good visibility, low cost, and strong mass production capacity. Fluorescent anti-counterfeiting materials, as one of the optically responsive materials, can achieve changes in fluorescent color or intensity when stimulated by external factors such as solvents, heat, and mechanical forces. Water, as a simple and environmentally friendly stimulus source, is widely used in stimulus-responsive anti-counterfeiting materials. However, there is little research and development on anti-counterfeiting technology using water in different physical forms to stimulate fluorescent anti-counterfeiting materials, and existing anti-counterfeiting and information encryption modes still have shortcomings in anti-counterfeiting reliability and information density. In recent years, multi-responsive optical composite materials have emerged that can effectively increase information density and anti-counterfeiting dimensions, but there are still problems such as complex preparation processes and poor stimulus source selectivity. Summary of the Invention

[0003] In order to solve the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a hollow nanosphere-iodine copper cesium composite material and its preparation method and application, so as to provide a new water-stimulated fluorescent anti-counterfeiting material that can be in different physical forms.

[0004] The present invention solves the above technical problems by providing a hollow nanosphere-iodine copper cesium composite material, comprising cerium dioxide hollow nanospheres and iodine copper cesium; wherein the cerium dioxide hollow nanospheres are embedded on the surface and inside of the iodine copper cesium.

[0005] Furthermore, the inner diameter of the shell of the hollow nanosphere-iodine copper cesium composite material is 280±4 nm, the outer diameter is 300±10 nm, and the shell thickness is 10±2 nm.

[0006] The present invention provides a method for preparing the hollow nanosphere-iodine copper cesium composite material, comprising the following steps: (1) PVP, deionized water, SiO2 nanospheres, Ce(NO3)3·6H2O and hexamethylenetetramine were mixed and stirred, centrifuged and then calcined to prepare SiO2@CeO2 nanospheres; (2) etching the SiO2@CeO2 nanospheres prepared in step (1) to obtain hollow CeO2 nanospheres; (3) performing amino modification on the hollow CeO2 nanospheres prepared in step (2) to obtain amino-modified hollow CeO2 nanospheres; (4) dispersing the amino-modified hollow CeO2 nanospheres prepared in step (3) in an organic solvent, and then adding cesium iodide, cuprous iodide and oleic acid to prepare a precursor solution; (5) The precursor solution of step (4) is quickly injected into the toluene solution, stirred and then centrifuged to obtain a hollow cerium dioxide-iodine copper cesium composite material.

[0007] Furthermore, in step (1), the volume ratio of deionized water, Ce(NO3)3·6H2O and hexamethylenetetramine is 15-25:2-3:2-3; and the mass ratio of PVP and SiO2 nanospheres is 100:9-11.

[0008] Furthermore, in step (1), the calcination temperature is 500-700°C, and the heating rate is 4-6°C / min.

[0009] Furthermore, in step (2), the concentration of NaOH is 5-8 mol / L; the etching temperature is 50-70° C., and the etching time is 2-4 h.

[0010] Furthermore, the amino modification in step (3) is specifically performed by dispersing the hollow CeO2 nanospheres in anhydrous ethanol, and then adding 3-aminopropyltriethoxysilane and deionized water and stirring at 50-70°C for 3-5 hours to perform amino modification; wherein the volume ratio of anhydrous ethanol, 3-aminopropyltriethoxysilane and deionized water is 30-35:2:5-7.

[0011] Furthermore, in step (4), the organic solvent is N'N-dimethylformamide and dimethyl sulfoxide; and the molar ratio of cesium iodide, cuprous iodide and oleic acid is 0.4-0.5:0.25-0.35:0.4-0.8.

[0012] Furthermore, in step (5), the volume ratio of the precursor solution to the toluene solution is 1:8-12.

[0013] The present invention also provides an application of the hollow nanosphere-iodine copper cesium composite material in optical anti-counterfeiting.

[0014] The present invention has the following beneficial effects: (1) The present invention provides a hollow nanosphere-iodine copper cesium composite material with fluorescence response characteristics. A unique mosaic structure is constructed by composite hollow nanospheres and Cs3Cu2I5 crystals. The change of fluorescence color is achieved by a simple triggering method of human breathing. Finally, a human breathing-triggered optical response composite material with excellent performance and strong stability is prepared, which has good application potential in the fields of anti-counterfeiting and optical information.

[0015] (2) The hollow cerium dioxide-iodine copper cesium mosaic structure composite material of the present invention has a single-mode dual-channel anti-counterfeiting mechanism triggered by human breathing. The single-mode refers to the fluorescence mode, and the dual-channel refers to the two different light colors displayed in the wet state and the dry state under ultraviolet light respectively. When human breathing stimulates the composite material, due to the good water collection effect of the hollow CeO2 nanospheres, under the stimulation of water vapor, the water vapor condenses into water, replacing the air in the cavity. After the Cs3Cu2I5 crystals in the cavity come into contact with water, due to the good solubility of cesium ions, the water strips CsI from the Cs3Cu2I5 crystals, thereby forming CsCu2I3 and free cesium ions and iodide ions. The hollow structure provides a space that can limit the movement of cesium ions and iodide ions. When the water vapor evaporates, the cesium ions and iodide ions will be reinserted into the CsCu2I3 crystals to form Cs3Cu2I5 crystals. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a scanning electron microscope image of the hollow CeO2-Cs3Cu2I5 mosaic structure composite material of Example 1; Figure 2 Optical images of the hollow CeO2-Cs3Cu2I5 composite film of Example 1 and the solid SiO2-Cs3Cu2I5 mosaic structure composite film of the comparative example under ultraviolet light and dynamic water vapor stimulation; Figure 3 The fluorescence spectrum of the hollow CeO2-Cs3Cu2I5 mosaic structure composite material film of Example 1 under ultraviolet light and dynamic water vapor stimulation; Figure 4 This is a graph showing the fluorescence intensity variation trend of the hollow CeO2-Cs3Cu2I5 mosaic structure composite film of Example 1 when it is stimulated by dynamic water vapor for 50 consecutive times under ultraviolet light; Figure 5 This is a trend diagram of the luminescence peak position and half-peak width of the hollow CeO2-Cs3Cu2I5 mosaic structure composite material film of Example 1 under dynamic water vapor stimulation 50 times under ultraviolet light and dry conditions; Figure 6 These are optical images of the hollow CeO2-Cs3Cu2I5 mosaic structure composite film of Example 1 under ultraviolet light, static water vapor stimulation, and water mist stimulation; Figure 7 The fluorescence spectrum of the hollow CeO2-Cs3Cu2I5 mosaic structure composite material film of Example 1 under ultraviolet light and static water vapor stimulation; Figure 8 The fluorescence spectrum of the solid SiO2-Cs3Cu2I5 mosaic structure composite film of the comparative example under ultraviolet light and dynamic water vapor stimulation; Figure 9 Transmission electron microscope images of hollow CeO2 and solid SiO2. DETAILED DESCRIPTION

[0017] The following examples are intended only to illustrate the present invention and are not intended to limit the scope of the present invention. In the examples, where specific conditions are not specified, the experiments were performed under conventional conditions or those recommended by the manufacturer. Reagents or instruments used, where the manufacturer is not specified, are commercially available conventional products.

[0018] Example 1: A method for preparing a hollow CeO2-Cs3Cu2I5 mosaic structure composite material, comprising the following steps: (1) Take 1g PVP, 40mL deionized water, 100mg SiO2 nanospheres, 5mL Ce(NO3)3·6H2O solution and 5mL hexamethylenetetramine (HMTA) solution, where the concentration of Ce(NO3)3·6H2O solution is 0.5mol / L and the concentration of hexamethylenetetramine (HMTA) solution is 0.5mol / L, stir at 95℃ for 2h, centrifuge and calcine at 600℃ (heating rate of 5℃ / min) for 100min to prepare SiO2@CeO2 nanospheres; (2) The SiO2@CeO2 nanospheres prepared in step (1) were etched in 8 mol / L NaOH solution at 60°C for 3 h to remove the SiO2 template. The hollow CeO2 nanospheres were collected by centrifugation and washed with deionized water to obtain hollow CeO2 nanospheres with an outer diameter of about 300 nm and a shell thickness of about 10 nm (see Figure 9 A); (3) The hollow CeO2 nanospheres prepared in step (2) were dispersed in 35 mL of anhydrous ethanol, and then 2 mL of 3-aminopropyltriethoxysilane and 5 mL of deionized water were added and stirred at 50 °C for 3 h for amino modification; (4) The amino-modified hollow CeO2 nanospheres prepared in step (3) were dispersed in 3.0 mL of N'N-dimethylformamide (DMF), and then 0.45 mmol of cesium iodide (CsI), 0.3 mmol of cuprous iodide (CuI), 200 μL of oleic acid (OA), and 3 mL of dimethyl sulfoxide (DMSO) were added and mixed to prepare a precursor solution. (5) 1.0 mL of the precursor solution prepared in step (4) was quickly injected into 10.0 mL of toluene solution. After stirring for 2 min, the precipitate was separated by centrifugation to obtain a hollow CeO2-Cs3Cu2I5 heterostructure composite material. A hollow CeO2-Cs3Cu2I5 mosaic structure composite material was obtained by simple dynamic water vapor pretreatment (the composite material was spin-coated into a thin film on the surface of a glass sheet and subjected to ten dynamic water vapor responses).

[0019] Depend on Figure 1 It can be seen that the hollow CeO2-Cs3Cu2I5 mosaic structure composite material prepared in this embodiment has a morphology in which Cs3Cu2I5 partially wraps hollow CeO2, and CeO2 hollow nanospheres are embedded on the surface and inside of Cs3Cu2I5.

[0020] Example 2: A method for preparing a hollow CeO2-Cs3Cu2I5 composite material, comprising the following steps: (1) Take 1g PVP, 30mL deionized water, 90mg SiO2 nanospheres, 4mL Ce(NO3)3·6H2O solution and 4mL hexamethylenetetramine (HMTA) solution, where the concentration of Ce(NO3)3·6H2O solution is 0.5mol / L and the concentration of hexamethylenetetramine (HMTA) solution is 0.5mol / L, stir at 95℃ for 2h, centrifuge and calcine at 500℃ (heating rate of 4℃ / min) for 100min to prepare SiO2@CeO2 nanospheres; (2) The SiO2@CeO2 nanospheres prepared in step (1) were etched in a 5 mol / L NaOH solution at 60°C for 3 h to remove the SiO2 template, and the hollow CeO2 nanospheres were collected by centrifugation and washed with deionized water to obtain hollow CeO2 nanospheres with an outer diameter of approximately 300 nm and a shell thickness of approximately 10 nm. (3) The hollow CeO2 nanospheres prepared in step (2) were dispersed in 30 mL of anhydrous ethanol, and then 2 mL of 3-aminopropyltriethoxysilane and 7 mL of deionized water were added and stirred at 70 °C for 5 h for amino modification; (4) The amino-modified hollow CeO2 nanospheres prepared in step (3) were dispersed in 2.0 mL of N'N-dimethylformamide (DMF), and then 0.5 mmol of cesium iodide (CsI), 0.25 mmol of cuprous iodide (CuI), 150 μL of oleic acid (OA), and 2 mL of dimethyl sulfoxide (DMSO) were added and mixed to prepare a precursor solution. (5) 1.0 mL of the precursor solution prepared in step (4) was quickly injected into 10.0 mL of toluene solution. After stirring for 2 min, the precipitate was separated by centrifugation to obtain a hollow CeO2-Cs3Cu2I5 heterostructure composite material. A hollow CeO2-Cs3Cu2I5 mosaic structure composite material was obtained by simple dynamic water vapor pretreatment (the composite material was spin-coated into a thin film on the surface of a glass sheet and subjected to ten dynamic water vapor responses).

[0021] Depend on Figure 1It can be seen that the hollow CeO2-Cs3Cu2I5 composite material prepared in this embodiment has a morphology in which Cs3Cu2I5 partially wraps hollow CeO2, and CeO2 hollow nanospheres are embedded on the surface and inside of Cs3Cu2I5.

[0022] Comparative Example: A method for preparing a solid SiO2-Cs3Cu2I5 composite material comprises the following steps: (1) Disperse 25 mg of SiO2 nanospheres in 3.0 mL of DMF, add 0.45 mmol of CsI, 0.3 mmol of CuI, 200 μL of OA, and 2 mL of DMSO, and mix well to prepare a precursor solution.

[0023] (2) 1.0 mL of the above precursor solution was quickly injected into 10.0 mL of toluene solution. After stirring for 2 min, the precipitate was separated by centrifugation to obtain a solid SiO2-Cs3Cu2I5 heterostructure composite material. A solid SiO2-Cs3Cu2I5 mosaic structure composite material was obtained by simple dynamic water vapor pretreatment (the composite material was spin-coated into a thin film on the surface of a glass sheet and subjected to ten dynamic water vapor responses).

[0024] Transmission electron microscope image of solid SiO2 Figure 9 B.

[0025] Test example: The hollow CeO2-Cs3Cu2I5 mosaic structure composite material of Example 1 and the solid SiO2-Cs3Cu2I5 mosaic structure composite material of Control Example 1 were respectively subjected to continuous stimulation of dynamic water vapor, static water vapor and water mist under ultraviolet light for multiple times to measure the cyclic performance of each composite material.

[0026] (1) Figure 2 It shows that the hollow CeO2-Cs3Cu2I5 mosaic structure composite material of Example 1 undergoes a fluorescence color change under the action of dynamic water vapor, changing from dry blue light to wet yellow light, and returns to blue light after the water vapor evaporates. The solid SiO2-Cs3Cu2I5 mosaic structure composite material of the comparative example does not undergo a fluorescence color change, indicating that the fluorescence color change is caused by the hollow CeO2-Cs3Cu2I5 mosaic structure.

[0027] (2) Figure 3 It shows that the photoluminescence wavelength of the hollow CeO2-Cs3Cu2I5 mosaic structure composite material of Example 1 shifts from 445nm to 550nm and the intensity decreases under ultraviolet light and dynamic water vapor, and the spectrum is basically restored after the water vapor evaporates, indicating that the hollow CeO2-Cs3Cu2I5 mosaic structure composite material has good reversibility.

[0028] (3) Figure 4 It shows that the photoluminescence intensity of the hollow CeO2-Cs3Cu2I5 mosaic structure composite material of Example 1 remains basically unchanged under continuous stimulation of dynamic water vapor under ultraviolet light, indicating that the hollow CeO2-Cs3Cu2I5 mosaic structure composite material has strong stability in response to dynamic water vapor stimulation.

[0029] (4) Figure 5 It shows that the dry wavelength and half-peak width of the hollow CeO2-Cs3Cu2I5 composite material of Example 1 remain basically unchanged under ultraviolet light and continuous multiple stimulations of dynamic water vapor, indicating that the hollow CeO2-Cs3Cu2I5 mosaic structure composite material has strong stability in response to dynamic water vapor stimulation.

[0030] (5) Figure 6 It shows that the hollow CeO2-Cs3Cu2I5 mosaic structure composite material of Example 1 does not undergo fluorescence color change under the stimulation of ultraviolet light, static water vapor and water mist, indicating that the hollow CeO2-Cs3Cu2I5 mosaic structure composite material does not respond to static water vapor and water mist. Figure 2 It shows that the hollow CeO2-Cs3Cu2I5 mosaic structure composite material has unique selectivity for dynamic water vapor.

[0031] (6) Figure 7 It shows that under ultraviolet light and static water vapor stimulation, the fluorescence spectrum wavelength of the hollow CeO2-Cs3Cu2I5 mosaic structure composite material of Example 1 basically does not shift, indicating that the hollow CeO2-Cs3Cu2I5 mosaic structure composite material does not respond to static water vapor.

[0032] (7) Figure 8 It shows that the fluorescence spectrum wavelength of the hollow CeO2-Cs3Cu2I5 mosaic structure composite material of Example 1 does not shift substantially under ultraviolet light and water mist stimulation, indicating that the hollow CeO2-Cs3Cu2I5 mosaic structure composite material does not respond to water mist.

[0033] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A hollow nanosphere-iodine copper cesium composite material, characterized in that: The hollow nanosphere-iodine copper cesium composite material comprises cerium dioxide hollow nanospheres and iodine copper cesium; wherein the cerium dioxide hollow nanospheres are embedded on the surface and inside of the iodine copper cesium.

2. The hollow nanosphere-iodine copper cesium composite material according to claim 1, characterized in that The inner diameter of the shell layer of the hollow nanosphere-iodine copper cesium composite material is 280±4 nm, the outer diameter is 300±10 nm, and the shell thickness is 10±2 nm.

3. The method for preparing the hollow nanosphere-iodine copper cesium composite material according to claim 1 or 2, characterized in that: The following steps are involved: (1) PVP, deionized water, SiO2 nanospheres, Ce(NO3)3·6H2O and hexamethylenetetramine were mixed and stirred, centrifuged and then calcined to prepare SiO2@CeO2 nanospheres; (2) etching the SiO2@CeO2 nanospheres prepared in step (1) to obtain hollow CeO2 nanospheres; (3) performing amino modification on the hollow CeO2 nanospheres prepared in step (2) to obtain amino-modified hollow CeO2 nanospheres; (4) dispersing the amino-modified hollow CeO2 nanospheres prepared in step (3) in an organic solvent, and then adding cesium iodide, cuprous iodide and oleic acid to prepare a precursor solution; (5) The precursor solution of step (4) is quickly injected into the toluene solution, stirred and then centrifuged to obtain a hollow cerium dioxide-iodine copper cesium composite material.

4. The preparation method according to claim 3, characterized in that The volume ratio of deionized water, Ce(NO3)3·6H2O and hexamethylenetetramine in step (1) is 15-25:2-3:2-3; the mass ratio of PVP and SiO2 nanospheres is 100:9-11.

5. The preparation method according to claim 3, characterized in that The calcination temperature in step (1) is 500-700°C, and the heating rate is 4-6°C / min.

6. The preparation method according to claim 3, characterized in that The concentration of NaOH in step (2) is 5-8 mol / L; the etching temperature is 50-70° C., and the etching time is 2-4 h.

7. The preparation method according to claim 3, characterized in that The amino modification described in step (3) is specifically to disperse the hollow CeO2 nanospheres in anhydrous ethanol, and then add 3-aminopropyltriethoxysilane and deionized water and stir at 50-70°C for 3-5h to carry out amino modification; wherein the volume ratio of anhydrous ethanol, 3-aminopropyltriethoxysilane and deionized water is 30-35:2:5-7.

8. The preparation method according to claim 3, characterized in that The organic solvent in step (4) is N'N-dimethylformamide and dimethyl sulfoxide; the molar ratio of cesium iodide, cuprous iodide and oleic acid is 0.4-0.5:0.25-0.35:0.4-0.

8.

9. The preparation method according to claim 3, characterized in that The volume ratio of the precursor solution to the toluene solution in step (5) is 1:8-12.

10. Use of the hollow nanosphere-iodine copper cesium composite material according to claim 1 or 2 in optical anti-counterfeiting.

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