An ultra-small inorganic nano-heterojunction photochromic material, an erasable rewritable medium prepared by using the material, and a preparation method thereof

Abstract

The invention relates to an ultra-small inorganic nano-heterojunction photochromic material, an erasable and rewritable medium prepared by using the material and a preparation method thereof. The general structural formula of the ultra-small inorganic nano-heterojunction photochromic material is: TiO 2‑x / MO 3 ·xH 2 O, where M=W or Mo, x=0-2, the surface of the ultra-small inorganic nano-heterojunction photochromic material is modified with polyethylene glycol-polypropylene glycol-polyethylene glycol triblock copolymer. The erasable and rewritable medium is prepared by using the above-mentioned ultra-small inorganic nano-heterojunction photochromic material. The ultra-small inorganic nano-heterojunction photochromic material prepared by the invention has the characteristics of small particle size, narrow distribution, not easy to agglomerate, good stability, and high purity. The ultra-small inorganic nano-heterojunction photochromic material prepared by the invention And the erasable and rewritable medium prepared by using the material has excellent cycle performance, long cycle life, fast response speed under the stimulation of UV light, and can be flexibly used for short-term reading and long-term reading.

Description

technical field

[0001] The invention relates to an ultra-small inorganic nano-heterojunction photochromic material, an erasable and rewritable medium prepared by using the material and a preparation method thereof, belonging to the field of intelligent materials. Background technique

[0002] Photochromic materials have attracted increasing attention due to their important applications in optoelectronic devices, sensors, security and anti-counterfeiting, rewritable paper, and ultraviolet radiation indicators in sunlight. In recent decades, the research of various photochromic organic molecules has made great progress, but in practical applications, they still face the defects of slow discoloration in solid substrates and easy degradation under long-term ultraviolet irradiation; at the same time, existing materials There are problems such as complex synthesis process and toxic synthetic precursors. Compared with organic photochromic materials, inorganic photochromic material...

Examples

Embodiment 1

[0051] A method for preparing an ultra-small inorganic nano-heterojunction photochromic material, comprising the following steps:

[0052] Mix 400mg polyethylene glycol-polypropylene glycol-polyethylene glycol triblock copolymer with 260mg sodium tungstate dihydrate plus 40mL water, then add 12.8mL titanium dioxide aqueous solution with a concentration of 20mg / mL, add hydrochloric acid to adjust the pH value 1. Stir and mix evenly to obtain a mixed solution; then heat the mixed solution to 140°C, react for 8 hours, cool to 25°C after the reaction is completed, and centrifugally wash with water and acetone to obtain ultra-small inorganic nano-heterojunction photochromism Material.

[0053] The transmission diagram of the ultra-small inorganic nano-heterojunction photochromic material prepared in this embodiment, such as figure 1 shown. Depend on figure 1 It can be seen that the size of the inorganic nano-heterojunction photochromic material is 10-15 nm.

[0054] The ultra-s...

Embodiment 2

[0061] An erasable and rewritable medium, the described erasable and rewritable medium is prepared using the ultra-small inorganic nano-heterojunction photochromic material in Example 1, and the specific preparation method is as follows:

[0062] (1) Dissolve 8 g of polyvinyl alcohol (PVA) with a molecular weight of 13w in 92 mL of deionized water, and heat at 90° C. for 3 h to obtain an aqueous solution of polyvinyl alcohol (PVA);

[0063] (2) Disperse 260 mg of ultra-small inorganic nano-heterojunction photochromic material in 13 mL of deionized water, add 7 mL of ethylene glycol, mix well, continue to add 7 mL of the polyvinyl alcohol (PVA) aqueous solution obtained in step (1), and Ultrasonic oscillation and vacuum treatment make it evenly mixed to obtain a mixed solution;

[0064] (3) Drop-coat the mixed solution obtained in step (2) on the self-adhesive paper substrate, dry at 70° C. for 7 hours, and remove ethylene glycol to obtain a flexible erasable rewritable medium....

Embodiment 3

[0067] An erasable and rewritable medium, the described erasable and rewritable medium is prepared using the ultra-small inorganic nano-heterojunction photochromic material in Example 1, and the specific preparation method is as follows:

[0068] (1) Dissolve 20 g of polyvinylpyrrolidone (PVP) with a molecular weight of 13w in 80 mL of deionized water, and heat at 90° C. for 8 hours to obtain an aqueous solution of polyvinylpyrrolidone (PVP);

[0069] (2) Disperse 260 mg of ultra-small inorganic nano-heterojunction photochromic material in 13 mL of deionized water, add 7 mL of ethylene glycol, mix well, continue to add 7 mL of polyvinylpyrrolidone (PVP) aqueous solution obtained in step (1), and Ultrasonic oscillation and vacuum treatment make it evenly mixed to obtain a mixed solution;

[0070] (3) Drop-coat the mixed solution obtained in step (2) on the back glue, dry at 70° C. for 7 hours, and remove ethylene glycol to obtain a flexible erasable rewritable medium.

[0071]...

technical field

[0001] The invention relates to an ultra-small inorganic nano-heterojunction photochromic material, an erasable and rewritable medium prepared by using the material and a preparation method thereof, belonging to the field of intelligent materials. Background technique

[0002] Photochromic materials have attracted increasing attention due to their important applications in optoelectronic devices, sensors, security and anti-counterfeiting, rewritable paper, and ultraviolet radiation indicators in sunlight. In recent decades, the research of various photochromic organic molecules has made great progress, but in practical applications, they still face the defects of slow discoloration in solid substrates and easy degradation under long-term ultraviolet irradiation; at the same time, existing materials There are problems such as complex synthesis process and toxic synthetic precursors. Compared with organic photochromic materials, inorganic photochromic material...

Examples

Embodiment 1

[0051] A method for preparing an ultra-small inorganic nano-heterojunction photochromic material, comprising the following steps:

[0052] Mix 400mg polyethylene glycol-polypropylene glycol-polyethylene glycol triblock copolymer with 260mg sodium tungstate dihydrate plus 40mL water, then add 12.8mL titanium dioxide aqueous solution with a concentration of 20mg / mL, add hydrochloric acid to adjust the pH value 1. Stir and mix evenly to obtain a mixed solution; then heat the mixed solution to 140°C, react for 8 hours, cool to 25°C after the reaction is completed, and centrifugally wash with water and acetone to obtain ultra-small inorganic nano-heterojunction photochromism Material.

[0053] The transmission diagram of the ultra-small inorganic nano-heterojunction photochromic material prepared in this embodiment, such as figure 1 shown. Depend on figure 1 It can be seen that the size of the inorganic nano-heterojunction photochromic material is 10-15 nm.

[0054] The ultra-s...

Embodiment 2

[0061] An erasable and rewritable medium, the described erasable and rewritable medium is prepared using the ultra-small inorganic nano-heterojunction photochromic material in Example 1, and the specific preparation method is as follows:

[0062] (1) Dissolve 8 g of polyvinyl alcohol (PVA) with a molecular weight of 13w in 92 mL of deionized water, and heat at 90° C. for 3 h to obtain an aqueous solution of polyvinyl alcohol (PVA);

[0063] (2) Disperse 260 mg of ultra-small inorganic nano-heterojunction photochromic material in 13 mL of deionized water, add 7 mL of ethylene glycol, mix well, continue to add 7 mL of the polyvinyl alcohol (PVA) aqueous solution obtained in step (1), and Ultrasonic oscillation and vacuum treatment make it evenly mixed to obtain a mixed solution;

[0064] (3) Drop-coat the mixed solution obtained in step (2) on the self-adhesive paper substrate, dry at 70° C. for 7 hours, and remove ethylene glycol to obtain a flexible erasable rewritable medium....

Embodiment 3

[0067] An erasable and rewritable medium, the described erasable and rewritable medium is prepared using the ultra-small inorganic nano-heterojunction photochromic material in Example 1, and the specific preparation method is as follows:

[0068] (1) Dissolve 20 g of polyvinylpyrrolidone (PVP) with a molecular weight of 13w in 80 mL of deionized water, and heat at 90° C. for 8 hours to obtain an aqueous solution of polyvinylpyrrolidone (PVP);

[0069] (2) Disperse 260 mg of ultra-small inorganic nano-heterojunction photochromic material in 13 mL of deionized water, add 7 mL of ethylene glycol, mix well, continue to add 7 mL of polyvinylpyrrolidone (PVP) aqueous solution obtained in step (1), and Ultrasonic oscillation and vacuum treatment make it evenly mixed to obtain a mixed solution;

[0070] (3) Drop-coat the mixed solution obtained in step (2) on the back glue, dry at 70° C. for 7 hours, and remove ethylene glycol to obtain a flexible erasable rewritable medium.

[0071]...

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