Disclosure of Invention
In order to solve the problems in the prior art, the invention aims to overcome the defects in the prior art, provides the nano tungsten oxide ink suitable for the ink-jet printing film-forming process, the preparation method and the application thereof, and provides an effective solution for large-area uniform preparation and low cost of the electrochromic film. The invention discloses a preparation method of nano tungsten oxide ink for ink-jet printing, which can be used for preparing a large-area electrochromic film by ink-jet printing, and the film layer has better electrochromic performance. The preparation process is simple, the large-scale production of the electrochromic film is facilitated, the cost is low, and the prepared film has good uniformity and excellent electrochromic performance.
In order to achieve the purpose of the invention, the invention adopts the following technical scheme:
a nano tungsten oxide ink suitable for an ink-jet printing film forming process comprises the following components: nano tungsten oxide and a solvent; according to the mass percentage, the solid content of the tungsten oxide in the nano tungsten oxide ink is 0.1-5 wt%.
Preferably, the nano tungsten oxide is at least one of tungsten oxide and alkali metal doped tungsten oxide; preferably, the solvent is any one or a mixture of isopropanol, ethanol and ethylene glycol.
Preferably, the doping element of the alkali metal doped tungsten oxide is any one or more of Li, Na, K, Ru and Cs.
Preferably, the dispersed particle size of the nano tungsten oxide in the ink is not more than 200 nm. Further preferably, the dispersion particle size of the nano tungsten oxide in the ink is 50-100 nm.
The invention relates to a preparation method of nano tungsten oxide printing ink suitable for an ink-jet printing film-forming process, which comprises the following steps:
(1) mixing the nano tungsten oxide powder with a solvent to obtain a mixed solution;
(2) grinding the mixed solution obtained in the step (1) in a ball mill to obtain uniform and stable dispersion liquid;
(3) and (3) adding a solvent into the dispersion liquid obtained in the step (2), and adjusting parameters of the dispersion liquid to obtain a tungsten oxide ink product.
The mixing is performed for the purpose of facilitating the operation of the step (2), the specific mixture does not have obvious layering within 10min, the maximum particle size in the mixture is not more than 0.1mm, in the practical process, the mixing means is conventional dispersing means under the conditions of powder state and preparation scale, and the mixing means is standard for achieving the purpose and comprises but is not limited to grinding, ball milling, ultrasound and high-speed dispersing. The preparation method of the nano tungsten oxide ink for ink-jet printing is used for preparing a large-area electrochromic film by ink-jet printing, and the film layer has better electrochromic property.
Preferably, in the step (1), the solid content of the nano tungsten oxide powder in the mixed solution is 1-20 wt% calculated according to mass percentage. Preferably, the nano tungsten oxide powder is at least one of tungsten oxide and tungsten oxide doped with alkali metal. Further preferably, the nano tungsten oxide powder is nano tungsten oxide. Preferably, the doping element of the alkali metal doped tungsten oxide is any one or more of Li, Na, K, Ru and Cs. Further preferably the doping element is Li. Preferably, the solvent is any one or a mixture of isopropanol, ethanol and ethylene glycol. Further preferably the solvent is isopropanol. Preferably, the dispersed particle size of the nano tungsten oxide in the ink is not more than 200 nm. Further preferably, the dispersion particle size of the nano tungsten oxide in the ink is 50-100 nm. Preferably, the nano tungsten oxide ink has a haze or haze of no greater than 3%. Preferably, the solid content of the nano tungsten oxide powder of the nano tungsten oxide ink is not more than 20 wt%, preferably, the solid content of the nano tungsten oxide powder is 2-20 wt%, and more preferably, 5-20 wt%. Preferably, the solid-liquid mixing ratio of the nano tungsten oxide powder to the solvent is 100 g: (400mL-500 mL).
Preferably, in the step (2), the particle size of the grinding ball is not more than 0.5 mm. More preferably, the grain diameter of the grinding ball is 0.03-0.5 mm. Further preferably, the particle size of the grinding ball is 0.3-0.5 mm. Because of the grinding balls with different sizes, the preparation scales of different samples and the difference of the grinding efficiency of different devices, the grinding time and the grinding power required for reaching the optimal condition are different, the grinding balls in the invention account for 30-80% of the volume of the grinding cavity, the ball-milling linear speed is not lower than 10m/s, the optimized grinding time is 6-12h, the grinding rotating speed is 2000-4000rad/min, but do not represent the optimized technological parameters of all other working conditions.
Preferably, in the step (3), the solvent used for adjusting the parameters of the dispersion liquid adopts any one or a mixture of isopropanol, ethylene glycol and ethanol; the tungsten oxide solid content in the dispersion after dilution adjustment is 0.1-5 wt% calculated according to the mass percentage. Further preferably, the tungsten oxide solid content in the dispersion after dilution adjustment is 0.5 to 3 wt%. Preferably, the mixing volume ratio of the dispersion liquid and the solvent obtained in the step (2) is 10: (30-80).
The invention relates to application of nano tungsten oxide ink suitable for an ink-jet printing film-forming process, wherein the ink is used for preparing an electrochromic film by ink-jet printing, and the prepared electrochromic film is used for an electrochromic intelligent window or other electrochromic devices.
Compared with the prior art, the invention has the following obvious and prominent substantive characteristics and remarkable advantages:
1. the nano tungsten oxide ink is used for ink-jet printing, the prepared film is uniform, and the film layer has good electrochromic performance and is suitable for electrochromic intelligent windows and other electrochromic devices; the modulation amplitude of the electrochromic film prepared by the nano tungsten oxide ink is more than 50 percent; meanwhile, the film has better cycle stability, the coloring time is less than 13s, and the fading time is less than 20 s;
2. the nano tungsten oxide ink for ink-jet printing uses nano powder as a raw material, has simple composition and good stability, is suitable for preparing an electrochromic film by ink-jet printing, and has uniform and controllable film layer obtained by printing; the invention provides an effective solution for large-area uniform preparation and low cost of the electrochromic film;
3. the method is simple and easy to implement, low in cost and suitable for popularization and application.
Detailed Description
The present invention will be described in detail by way of examples. It is also to be understood that the following examples are illustrative of the present invention and are not to be construed as limiting the scope of the invention, and that certain insubstantial modifications and adaptations of the invention by those skilled in the art may be made in light of the above teachings. The specific process parameters and the like of the following examples are also only one example of suitable ranges, i.e., those skilled in the art can select the appropriate ranges through the description herein, and are not limited to the specific values exemplified below. The invention aims to provide a nano tungsten oxide ink for ink-jet printing and a preparation method thereof, wherein the preparation method comprises the following steps: and (3) preparing the nano tungsten oxide ink.
The above-described scheme is further illustrated below with reference to specific embodiments, which are detailed below:
the first embodiment is as follows:
in this embodiment, a method for preparing a nano tungsten oxide ink suitable for an inkjet printing film formation process includes the following steps:
(1) weighing 100g of nano tungsten oxide powder, mixing with 400mL of isopropanol, and uniformly grinding, WO3Has an average particle diameter of 50 nm; mixing the nano tungsten oxide powder with a solvent to obtain a mixed solution;
(2) placing the mixed solution obtained in the step (1) into a grinding machine for further grinding, wherein the diameter of a grinding ball is 0.5mm, the grinding ball accounts for 50% of the volume of a grinding cavity, the linear speed of the ball grinding is 10m/s, and grinding is carried out for 6 hours to obtain uniform dispersion liquid;
(3) and (3) adding 10mL of the dispersion liquid obtained in the step (2) into 30mL of isopropanol for dilution to obtain a tungsten oxide ink product.
Experimental test analysis:
the crystallinity of the nano tungsten oxide powder selected in the above example steps is good, as shown in the XRD chart of fig. 1, and in addition, as shown in fig. 2 and 3, the particle size distribution of the powder is uniform, and the average particle size is 52.58 nm. The tungsten oxide ink prepared by the method of the embodiment uses ITO transparent conductive glass as a substrate to prepare an electrochromic film in an ink-jet printing mode. The prepared tungsten oxide electrochromic film has better uniformity as shown in figure 4. The films prepared by the methods of the above examples were subjected to an electrochromic property test, and were colored at-0.8V for 30s and bleached at +0.8V for 30s, respectively. The results are shown in fig. 5, from which it can be seen that the maximum modulation amplitude of the film at 708nm wavelength is 65%, which is superior to most literature reports. The change of the in-situ transmittance of the film is tested at a fixed wavelength of 633nm, and the voltage is changed to-0.8V for 30s and 0.8V for 30 s. As a result, as shown in FIG. 6, it was found that the film had a coloring time of 11s and a fading time of 16.5 s.
The nano tungsten oxide ink for ink-jet printing prepared by the method uses nano powder as a raw material, has simple composition and good stability, is suitable for preparing an electrochromic film by ink-jet printing, and has uniform and controllable film layer obtained by printing. The method of the embodiment provides an effective solution for large-area uniform preparation and low cost of the electrochromic film. The ink prepared by the preparation method of the nano tungsten oxide ink for ink-jet printing can be used for preparing large-area electrochromic films by ink-jet printing, and the film layer has good electrochromic performance.
Example two
In this embodiment, a method for preparing a nano tungsten oxide ink suitable for an inkjet printing film formation process includes the following steps:
(1) weighing 100g of nano tungsten oxide powder, mixing with 400mL of isopropanol, and uniformly grinding, WO3Has an average particle diameter of 50 nm; mixing the nano tungsten oxide powder with a solvent to obtain a mixed solution;
(2) placing the mixed solution obtained in the step (1) into a grinding machine for further grinding, wherein the diameter of a grinding ball is 0.3mm, the grinding ball accounts for 60% of the volume of a grinding cavity, the linear speed of the ball grinding is 10m/s, and grinding is carried out for 6 hours to obtain uniform dispersion liquid;
(3) and (3) adding 10mL of the dispersion liquid obtained in the step (2) into 60mL of isopropanol for dilution to obtain a tungsten oxide ink product.
Experimental test analysis:
the nano tungsten oxide powder selected in the method steps of the above examples had good crystallinity, as shown in the XRD chart of fig. 1, and the powder had a uniform particle size distribution and an average particle size of 52.58nm as shown in fig. 2 and 3.
The tungsten oxide ink prepared by the method of the embodiment is used for preparing an electrochromic film by taking ITO transparent conductive glass as a substrate in an ink-jet printing mode. The prepared tungsten oxide electrochromic film has better uniformity. The film prepared by the method of the embodiment is subjected to an electrochromic performance test, the film is colored for 30s at-0.1V and bleached for 30s at +0.1V respectively, and the test result shows that the maximum modulation amplitude of the film at the wavelength of 678nm is 69.7%, which is superior to most literature reports. The change of in-situ transmittance of the film was tested at a fixed wavelength of 633nm, and the voltage was changed to-1V for 30s and 1V for 30 s. From the test results, the film had a coloration time of 9.2s and a fading time of 14.6 s.
The nano tungsten oxide ink for ink-jet printing prepared by the method uses nano powder as a raw material, has simple composition and good stability, is suitable for preparing an electrochromic film by ink-jet printing, and has uniform and controllable film layer obtained by printing.
EXAMPLE III
In this embodiment, a method for preparing a nano tungsten oxide ink suitable for an inkjet printing film formation process includes the following steps:
(1) weighing 100g of doped tungsten oxide powder, mixing with 400mL of isopropanol, and uniformly grinding, wherein the average particle size of the doped tungsten oxide is 50nm, and the doping element of the doped tungsten oxide powder is Li; mixing the nano tungsten oxide powder with a solvent to obtain a mixed solution;
(2) placing the mixed solution obtained in the step (1) into a grinding machine for further grinding, wherein the diameter of a grinding ball is 0.5mm, the grinding ball accounts for 80% of the volume of a grinding cavity, the linear speed of the ball grinding is 10m/s, and grinding is carried out for 6 hours to obtain uniform dispersion liquid;
(3) and (3) adding 10mL of the dispersion liquid obtained in the step (2) into 80mL of isopropanol for dilution to obtain a tungsten oxide ink product.
Experimental test analysis:
the tungsten oxide ink prepared by the method of the embodiment takes ITO transparent conductive glass as a substrate to prepare an electrochromic film in an ink-jet printing mode. The prepared tungsten oxide electrochromic film has better uniformity. The film prepared by the method of the embodiment is subjected to an electrochromic performance test, the film is colored for 30s at-0.8V and bleached for 30s at +0.8V, and the test result shows that the maximum modulation amplitude of the film at the wavelength of 667nm is 56.8%. The change of in-situ transmittance of the film was tested at a fixed wavelength of 633nm, and the voltage was changed to-1V for 30s and 1V for 30 s. From the test results, the film had a coloration time of 12.3s and a fading time of 17.4 s.
The nano tungsten oxide ink for ink-jet printing prepared by the method uses nano powder as a raw material, has simple composition and good stability, is suitable for preparing an electrochromic film by ink-jet printing, and has uniform and controllable film layer obtained by printing.
Example four
In this embodiment, a method for preparing a nano tungsten oxide ink suitable for an inkjet printing film formation process includes the following steps:
(1) weighing 100g of doped tungsten oxide powder, mixing with 400mL of isopropanol, and uniformly grinding, wherein the average particle size of the doped tungsten oxide is 50nm, and the doping element of the doped tungsten oxide powder is Na; mixing the nano tungsten oxide powder with a solvent to obtain a mixed solution;
(2) placing the mixed solution obtained in the step (1) into a grinding machine for further grinding, wherein the diameter of a grinding ball is 0.5mm, the grinding ball accounts for 60% of the volume of a grinding cavity, the linear speed of the ball grinding is 10m/s, and grinding is carried out for 6 hours to obtain uniform dispersion liquid;
(3) and (3) adding 10mL of the dispersion liquid obtained in the step (2) into 30mL of isopropanol for dilution to obtain a tungsten oxide ink product.
Experimental test analysis:
the tungsten oxide ink prepared by the method of the embodiment takes ITO transparent conductive glass as a substrate to prepare an electrochromic film in an ink-jet printing mode. The prepared tungsten oxide electrochromic film has better uniformity. The film prepared by the method of the embodiment is subjected to an electrochromic performance test, the film is colored for 30s at-0.8V and bleached for 30s at +0.8V, and the test result shows that the maximum modulation amplitude of the film at the wavelength of 721nm is 58.7%. The change of in-situ transmittance of the film was tested at a fixed wavelength of 633nm, and the voltage was changed to-1V for 30s and 1V for 30 s. From the test results, the film had a coloration time of 11.8s and a fading time of 17.2 s.
The nano tungsten oxide ink for ink-jet printing prepared by the method uses nano powder as a raw material, has simple composition and good stability, is suitable for preparing an electrochromic film by ink-jet printing, and has uniform and controllable film layer obtained by printing.
EXAMPLE five
In this embodiment, a method for preparing a nano tungsten oxide ink suitable for an inkjet printing film formation process includes the following steps:
(1) weighing 100g of doped tungsten oxide powder, mixing with 500mL of isopropanol, and uniformly grinding, wherein the average particle size of the doped tungsten oxide is 50nm, and the doping element of the doped tungsten oxide powder is K; mixing the nano tungsten oxide powder with a solvent to obtain a mixed solution;
(2) placing the mixed solution obtained in the step (1) into a grinding machine for further grinding, wherein the diameter of a grinding ball is 0.3mm, the grinding ball accounts for 80% of the volume of a grinding cavity, the linear speed of the ball grinding is 10m/s, and grinding is carried out for 6 hours to obtain uniform dispersion liquid;
(3) and (3) adding 10mL of the dispersion liquid obtained in the step (2) into 30mL of isopropanol for dilution to obtain a tungsten oxide ink product.
Experimental test analysis:
the tungsten oxide ink prepared by the method of the embodiment takes ITO transparent conductive glass as a substrate to prepare an electrochromic film in an ink-jet printing mode. The prepared tungsten oxide electrochromic film has better uniformity. The film prepared by the method of the embodiment is subjected to an electrochromic performance test, the film is colored for 30s at-1.2V and bleached for 30s at +1.2V, and the test result shows that the maximum modulation amplitude of the film at a wavelength of 693nm is 62.5%. The change of the in-situ transmittance of the film was tested at a fixed wavelength of 633nm and the change of the voltage was-1.2V for 30s and 1.2V for 30 s. From the test results, the film had a coloration time of 11.6s and a fading time of 16.8 s.
The nano tungsten oxide ink for ink-jet printing prepared by the method uses nano powder as a raw material, has simple composition and good stability, is suitable for preparing an electrochromic film by ink-jet printing, and has uniform and controllable film layer obtained by printing.
EXAMPLE six
In this embodiment, a method for preparing a nano tungsten oxide ink suitable for an inkjet printing film formation process includes the following steps:
(1) weighing 100g of doped tungsten oxide powder, mixing with 500mL of isopropanol, and uniformly grinding, wherein the average particle size of the doped tungsten oxide is 50nm, and the doping element of the doped tungsten oxide powder is Cs; mixing the nano tungsten oxide powder with a solvent to obtain a mixed solution;
(2) placing the mixed solution obtained in the step (1) into a grinding machine for further grinding, wherein the diameter of a grinding ball is 0.5mm, the grinding ball accounts for 50% of the volume of a grinding cavity, the linear speed of the ball grinding is 10m/s, and grinding is carried out for 6 hours to obtain uniform dispersion liquid;
(3) and (3) adding 10mL of the dispersion liquid obtained in the step (2) into 30mL of isopropanol for dilution to obtain a tungsten oxide ink product.
Experimental test analysis:
the tungsten oxide ink prepared by the method of the embodiment takes ITO transparent conductive glass as a substrate to prepare an electrochromic film in an ink-jet printing mode. The prepared tungsten oxide electrochromic film has better uniformity. The film prepared by the method of the embodiment is subjected to an electrochromic performance test, the film is colored for 30s at-1V and bleached for 30s at +1V, and the test result shows that the maximum modulation amplitude of the film at the wavelength of 684nm is 63.2%. The change of in-situ transmittance of the film was tested at a fixed wavelength of 633nm, and the voltage was changed to-1V for 30s and 1V for 30 s. From the test results, the film had a coloration time of 12.8s and a fading time of 17.6 s.
The nano tungsten oxide ink for ink-jet printing prepared by the method uses nano powder as a raw material, has simple composition and good stability, is suitable for preparing an electrochromic film by ink-jet printing, and has uniform and controllable film layer obtained by printing.
In summary, the nano tungsten oxide ink for inkjet printing and the preparation method thereof in the above embodiments are obtained by mixing the nano tungsten oxide powder and the solvent, dispersing and grinding the mixture uniformly by ball milling, and then adding the solvent to blend the mixture. The nano tungsten oxide ink prepared by the method of the embodiment is suitable for ink-jet printing and has a good printing effect. The tungsten oxide film with electrochromic property can be directly prepared by adopting the ink through ink-jet printing, and an effective solution is provided for large-area uniform preparation and low cost of the electrochromic film.
The embodiments of the present invention have been described with reference to the accompanying drawings, but the present invention is not limited to the embodiments, and various changes and modifications can be made according to the purpose of the invention, and any changes, modifications, substitutions, combinations or simplifications made according to the spirit and principle of the technical solution of the present invention shall be equivalent substitutions, as long as the purpose of the present invention is met, and the present invention shall fall within the protection scope of the present invention without departing from the technical principle and inventive concept of the present invention.