CN105271796A - Low angle dependence blue ZnS structural color film and preparation method thereof - Google Patents

Abstract

The invention discloses a low-angle-dependent blue zinc sulfide structural color thin film and a preparation method thereof, belonging to the technical field of structural color material preparation. It includes firstly using the chemical uniform precipitation method to prepare zinc sulfide microsphere nanoparticles with uniform particle size, then preparing a thin film on the surface of the glass or ceramic substrate, and calcining under the protection of a reducing atmosphere to carbonize trace organic matter, so as to obtain a uniform distribution of carbon black. Blue structured color film. The preparation method of the invention is simple and repeatable, solves the technical problems that the chemical organic pigments are easy to fade and is harmful to the human body, and at the same time overcomes the problems that the opal structure photonic crystal has high requirements on the substrate and harsh coating conditions, and is suitable for use on the surface of various materials The construction of non-angle-flop-free structural color pigments has broad application prospects. The prepared blue zinc sulfide structural color film carbon black has uniform distribution, no angle dependence, good sphericity and uniform particle size.

Description

A kind of low angle dependence blue zinc sulfide structural color thin film and preparation method thereof

technical field

The invention belongs to the technical field of photonic crystal material preparation, and in particular relates to a low-angle-dependent blue zinc sulfide structural color thin film and a preparation method thereof.

Background technique

Materials with high and low refractive indices are alternately arranged to form a periodic structure, that is, photonic crystals, through which light of a specific wavelength cannot pass through to generate photonic band gaps, thereby producing structural colors. Structural color is a kind of physical coloration, which has the advantages of bright color, never fading, environmental friendliness, and short preparation cycle. In recent years, through the ordered self-assembly method of colloidal microspheres, opal structure photonic crystals can be formed, and finally the light forms on the surface of photonic crystals with a periodic structure through dry radiation, diffraction, scattering, etc., resulting in colorful structural colors. , but because of the iridescence effect, that is, the colors observed in different directions are different, which greatly limits the application of structural colors in wide viewing angle displays such as flat panel displays, printing media, and optical devices. Some researchers have proposed that adding a small amount of black pigment can improve the color saturation, and can effectively reduce the dependence of the structural color on the angle, and achieve the effect that the structural color remains unchanged as the viewing angle changes (CN103173039A, 102702791A, 103788770A), but the above methods The disadvantage is that in the preparation of photonic crystal structural color film, it is necessary to mix the powder with a small amount of carbon black or black pigment to form a film. Small environmental fluctuations will have a great impact on the quality of the film, so it is difficult to be widely used. Many researchers add a small amount of carbon black or melanin to silica or polystyrene colloidal solution, and use methods such as spin coating to prepare short-range ordered and long-range disordered structural color films. The role of carbon black or melanin is to be able to There is strong absorption in the visible light band, thereby reducing incoherent scattering, so that the structural color film can also show high color saturation in the state of short-range order and long-range disorder. At the same time, this short-range order and long-range disorder Because the sequence structure is isotropic, it has low angle dependence, that is, the color is basically unchanged as the viewing angle changes, and can be applied to display, printing, etc. However, the ultra-fine nano-scale carbon black used in this process has high surface energy, so it has the disadvantages of being difficult to disperse, easy to agglomerate, and difficult to dissolve in most solutions. The process is complex and the prepared organic black dye is unstable. In recent years, semiconductor sulfide (such as zinc sulfide) materials have attracted extensive attention due to their excellent properties such as sewage treatment, magneto-optical conversion, antibacterial, photonic crystals, etc.

So far, there are no reports on the use of inorganic semiconductor oxides, sulfides and other materials to prepare such short-range ordered structural color thin films.

Contents of the invention

In order to overcome the defects in the above-mentioned prior art, the object of the present invention is to provide a low-angle-dependent blue zinc sulfide structural color film and a preparation method thereof. The method is simple to operate, highly repeatable, and suitable for industrial scale production; The spherical zinc sulfide photonic crystal prepared by the method has good sphericity, uniform particle size and wide application.

The present invention is realized through the following technical solutions:

The invention discloses a method for preparing a low-angle-dependent blue zinc sulfide photonic crystal structural color thin film, which comprises the following steps:

1) Take Zn(NO ₃ ) ₂ ·6H ₂ O and polyvinylpyrrolidone according to the mass ratio of (3～5):1, and then add polyvinylpyrrolidone: deionized water = (0.05～0.06)g: 100mL Deionized water, mixed thoroughly to obtain a uniform solution;

2) According to the ratio of (0.3～0.5) g: 50mL, dissolve thioacetamide in deionized water, and perform ultrasonic mixing treatment to obtain an aqueous solution of thioacetamide;

3) Mix the homogeneous solution prepared in step 1) with the aqueous solution of thioacetamide prepared in step 2) according to the volume ratio of (2-2.5): 1, and react in a water bath at 70-85°C for 5-8 hours , making an emulsion containing zinc sulfide microspheres, and then washing and ultrasonically dispersing to obtain an ethanol solution of monodisperse zinc sulfide microspheres;

4) Put the substrate in the ethanol solution of monodisperse zinc sulfide microspheres and dry it in vacuum to obtain a zinc sulfide film, and then calcine the zinc sulfide film at 300-500°C under a protective atmosphere to obtain a blue zinc sulfide photonic crystal structure color material.

Step 1) Mix well and evenly by using a magnetic stirrer to stir for 25-30 minutes.

The ultrasonic mixing treatment time in step 2) is 10-20 minutes.

The washing in step 3) is to wash the emulsion containing zinc sulfide microspheres for 2 to 4 times with deionized water, and then wash with absolute ethanol for 2 to 4 times.

Step 4) The protective atmosphere is nitrogen or argon.

Step 4) The vacuum drying is carried out at 50-65°C.

The invention also discloses the low-angle-dependent blue zinc sulfide photonic crystal structural color film prepared by the above method. The carbon black of the low-angle-dependent blue zinc sulfide photonic crystal structural color film is evenly distributed, has no angle dependence, and is spherical. Good degree, uniform particle size.

Compared with the prior art, the present invention has the following beneficial technical effects:

The preparation method of the low-angle-dependent blue zinc sulfide structural color film disclosed by the present invention first adopts the chemical uniform precipitation method, and strictly controls the reaction ratio of Zn(NO ₃ ) ₂ ·6H ₂ O and polyvinylpyrrolidone (3～ 5:1), and the amount of deionized water, to prepare zinc sulfide microsphere nanoparticles with uniform particle size, and then calcined in a protective atmosphere to carbonize trace organic matter, so as to obtain the blue crystal with carbon black evenly distributed in the microspheres. Color structural color film, the color of this kind of carbon-containing zinc sulfide microsphere film pigment will not change with the change of viewing angle, the color is stable, and it is not easy to fade. The preparation method of the present invention is simple, and the repeatability is strong. Due to the presence of C produced by the carbonization of a small amount of organic matter, the intensity of incoherent scattered light is reduced, while the intensity of coherent scattering is more prominent, so that the non-opal structure with short-range order on the rough surface still has relatively high High color saturation. It not only solves the technical problems that chemical organic pigments are easy to fade and is harmful to the human body, but also solves the technical problems such as the strict requirements of the opal structure on the substrate and the harsh coating environment. Semiconductors and sulfide (such as zinc sulfide) materials have many excellent properties and can be used in sewage treatment, magneto-optical conversion, antibacterial, photonic crystals, etc., and can be prepared into multifunctional materials. So far, there are no reports on the use of inorganic semiconductor oxides, sulfides and other materials to prepare such short-range ordered structural color thin films.

The carbon black in the blue zinc sulfide photonic crystal structural color film prepared by a novel method of the present invention is evenly distributed, has no angle dependence, good sphericity, and uniform particle size. It can be used in display materials, sensing, catalysis and various The field of surface coloring of similar materials has broad application prospects.

Description of drawings

Fig. 1 is the X-ray diffraction figure of embodiment 1 gained;

Fig. 2 is the scanning electron micrograph of embodiment 1 gained;

Fig. 3 is the EDS figure of zinc sulfide microspheres after calcining;

Fig. 4 is the optical photograph of the structural color film of embodiment 1 gained;

FIG. 5 is a 30-fold magnified photo of the structural color thin film obtained in Example 1 under an optical microscope.

detailed description

The present invention will be further described in detail below in conjunction with specific embodiments, which are explanations of the present invention rather than limitations.

Example 1

The present invention is realized through the following technical solutions:

A preparation method for blue zinc sulfide structural color pigment, comprising the following steps:

1) Weigh several grams of Zn(NO ₃ ) ₂ 6H ₂ O and polyvinylpyrrolidone (PVP) according to the mass ratio of 3:1, and add them to the beaker. Stir to fully dissolve and mix evenly, and stir for 30 minutes to obtain a uniform solution;

2) Accurately weigh 0.3 g of thioacetamide, add 50 mL of deionized water and ultrasonically mix for 10-20 minutes to obtain an aqueous solution of thioacetamide;

3) Stir the above two homogeneous solutions of 1) and 2) respectively, add them into the same beaker, and react in a water bath at 80°C for 6 hours under magnetic stirring to obtain an emulsion containing zinc sulfide microspheres, and then wash with water , alcohol washing three times and ultrasonic dispersion to obtain monodisperse zinc sulfide microsphere ethanol solution.

4) Place the glass or ceramic substrate on the ethanol solution of monodisperse zinc sulfide microspheres prepared in step 3) and dry in a vacuum oven at 60°C to prepare a short-programmed zinc sulfide film, and then place the film under nitrogen protection After heat treatment at 300°C, a blue zinc sulfide photonic crystal structural color film with no angle dependence and uniform distribution of carbon black can be obtained.

The samples of the blue zinc sulfide structural color film prepared in this embodiment are shown in Figure 4 and Figure 5, and it can be clearly seen that it appears blue. Its XRD analysis is shown in Figure 1, and its XRD analysis is shown in Figure 1. 2θ=28.2°, 47.7°, and 56.6° correspond to (111), (220), and (311) crystal planes of ZnS respectively, and in addition to ZnS features Except for the peak, no other impurity peaks appear, indicating that the prepared sample is pure ZnS. The scanning electron micrograph is shown in Figure 2, as can be seen from the figure, the surface of the zinc sulfide microspheres is rough, highly monodisperse, and the particle size is uniform (230 ± 10nm). Energy spectrum analysis is shown in Figure 3. It can be seen from the figure that in addition to the peaks of Zn and S, there are also characteristic peaks of C element, indicating that there is a trace amount of C element in ZnS microspheres, and it can be seen from the SEM image It can be seen that the C element is uniformly distributed in the monodisperse microspheres without agglomeration phenomenon.

Example 2

1) Weigh several grams of Zn(NO ₃ ) ₂ 6H ₂ O and polyvinylpyrrolidone (PVP) according to a mass ratio of 3.5:1, and add them to a beaker. Stir to fully dissolve and mix evenly, and stir for 30 minutes to obtain a uniform solution;

2) Accurately weigh 0.3 g of thioacetamide, add 50 mL of deionized water and ultrasonically mix for 10-20 minutes to obtain an aqueous solution of thioacetamide;

3) Stir the above two homogeneous solutions of 1) and 2) evenly, add them into the same beaker, and react in a water bath at 80° C. for 7 hours under magnetic stirring to obtain an emulsion containing zinc sulfide microspheres. After washing with water and washing with alcohol for three times, ultrasonic dispersion is carried out to obtain an ethanol solution of monodisperse zinc sulfide microspheres;

4) Place the glass or ceramic substrate on the ethanol solution of monodisperse zinc sulfide microspheres prepared in step 3) and dry it in a vacuum oven at 50°C, and then heat-treat the film at 500°C under the protection of nitrogen to obtain Low angle dependence, evenly distributed carbon black blue zinc sulfide structural color film.

Example 3

1) Weigh several grams of Zn(NO ₃ ) ₂ 6H ₂ O and polyvinylpyrrolidone (PVP) according to the mass ratio of 4:1, and add them to the beaker. Stir to fully dissolve and mix evenly, and stir for 30 minutes to obtain a uniform solution;

2) Accurately weigh 0.4 g of thioacetamide, add 50 mL of deionized water and ultrasonically mix for 10-20 minutes to obtain an aqueous solution of thioacetamide;

3) Stir the above two homogeneous solutions of 1) and 2) respectively, add them into the same beaker, and react in a water bath at 85° C. for 5 hours under magnetic stirring to obtain an emulsion containing zinc sulfide microspheres. After washing with water and washing with alcohol for three times, ultrasonic dispersion is carried out to obtain an ethanol solution of monodisperse zinc sulfide microspheres;

4) Place the glass or ceramic substrate on the ethanol solution of monodisperse zinc sulfide microspheres prepared in step 3) and dry it in a vacuum oven at 55°C, and then heat-treat the film at 400°C under the protection of nitrogen to obtain Low angle dependence, evenly distributed carbon black blue zinc sulfide structural color film.

Example 4

1) Weigh several grams of Zn(NO ₃ ) ₂ 6H ₂ O and polyvinylpyrrolidone (PVP) at a mass ratio of 5:1, and add them to a beaker. Stir to fully dissolve and mix evenly, and stir for 30 minutes to obtain a uniform solution;

2) Accurately weigh 0.5 g of thioacetamide, add 50 mL of deionized water and ultrasonically mix for 10-20 minutes to obtain an aqueous solution of thioacetamide;

3) Stir the above two homogeneous solutions of 1) and 2) respectively, add them into the same beaker, and react in a water bath at 75° C. for 6 hours under magnetic stirring to obtain an emulsion containing zinc sulfide microspheres. After washing with water and washing with alcohol for three times, ultrasonic dispersion is carried out to obtain an ethanol solution of monodisperse zinc sulfide microspheres;

4) Place the glass or ceramic substrate on the ethanol solution of monodisperse zinc sulfide microspheres prepared in step 3) and dry in a vacuum oven at 50°C to obtain a short-range ordered zinc sulfide film, and then pass the film under nitrogen protection. Heat treatment at 350°C, low angle dependence, carbon black evenly distributed zinc sulfide blue powder pigment can be obtained.

In summary, the present invention discloses a method for preparing a blue low-angle dependent zinc sulfide structural color film, including the preparation of nano-zinc sulfide microspheres; the preparation of a short-range ordered structural color film, the zinc sulfide film is reduced Calcination under the atmosphere; finally a blue structural color film without color flop is obtained. The method is low in cost, simple and easy to implement, is suitable for constructing non-angle-dependent structural color pigments on the surface of various materials, and has a simple preparation method, strong repeatability, and easy large-scale preparation. By controlling the particle size of the microspheres, various colors such as blue-green, blue-violet, and purple-blue can be obtained. It has broad application prospects in the fields of display materials, sensing, catalysis, and surface coloring of various materials.

Claims (7)

1. A method for preparing a low-angle-dependent blue zinc sulfide photonic crystal structural color film, characterized in that, comprising the following steps: 1) Take Zn(NO ₃ ) ₂ ·6H ₂ O and polyvinylpyrrolidone according to the mass ratio of (3～5):1, and then add polyvinylpyrrolidone: deionized water = (0.05～0.06)g: 100mL Deionized water, mixed thoroughly to obtain a uniform solution; 2) According to the ratio of (0.3～0.5) g: 50mL, dissolve thioacetamide in deionized water, and perform ultrasonic mixing treatment to obtain an aqueous solution of thioacetamide; 3) Mix the homogeneous solution prepared in step 1) with the aqueous solution of thioacetamide prepared in step 2) according to the volume ratio of (2-2.5): 1, and react in a water bath at 70-85°C for 5-8 hours , making an emulsion containing zinc sulfide microspheres, and then washing and ultrasonically dispersing to obtain an ethanol solution of monodisperse zinc sulfide microspheres; 4) Put the substrate in the ethanol solution of monodisperse zinc sulfide microspheres and dry it in vacuum to obtain a zinc sulfide film, and then calcine the zinc sulfide film at 300-500°C under a protective atmosphere to obtain a blue zinc sulfide photonic crystal structure color material. 2. The method for preparing the low-angle-dependent blue zinc sulfide photonic crystal structural color thin film according to claim 1, characterized in that, step 1) fully mixes evenly by using a magnetic stirrer to stir for 25 to 30 minutes. 3. The method for preparing the low-angle-dependent blue zinc sulfide photonic crystal structural color thin film according to claim 1, characterized in that the ultrasonic mixing treatment time in step 2) is 10-20 minutes. 4. the preparation method of low angle dependence blue zinc sulfide photonic crystal structural color thin film according to claim 1, it is characterized in that, the washing described in step 3) is that the emulsion that contains zinc sulfide microspheres is passed through first Wash with deionized water for 2 to 4 times, and then wash with absolute ethanol for 2 to 4 times. 5. The preparation method of the low-angle-dependent blue zinc sulfide photonic crystal structural color thin film according to claim 1, characterized in that, the protective atmosphere in step 4) adopts nitrogen or argon. 6. The method for preparing the low-angle-dependent blue zinc sulfide photonic crystal structural color thin film according to claim 1, characterized in that the vacuum drying in step 4) is carried out at 50-65°C. 7. The low-angle-dependent blue zinc sulfide photonic crystal structural color thin film prepared by the method according to any one of claims 1 to 6, characterized in that the low-angle-dependent blue zinc sulfide photonic crystal structural color The film carbon black is evenly distributed, has no angle dependence, good sphericity, and uniform particle size.