CN112980425B

CN112980425B - Solid powder color-changing material for non-contact induction quick response and preparation method thereof

Info

Publication number: CN112980425B
Application number: CN202110212634.3A
Authority: CN
Inventors: 王东升; 孙梵熙; 郑永豪
Original assignee: University of Electronic Science and Technology of China
Current assignee: University of Electronic Science and Technology of China
Priority date: 2021-02-25
Filing date: 2021-02-25
Publication date: 2023-03-24
Anticipated expiration: 2041-02-25
Also published as: CN112980425A

Abstract

The invention discloses a solid powder color-changing material with non-contact induced quick response and a preparation method thereof, wherein the preparation method comprises the following steps: s1, preparing a DASAs molecular intermediate; s2, preparing DASA-1 molecules; s3, preparing DASA-2 molecules; s4, preparing a porous material A; s5, preparing a porous material B; and S6, integrating. The invention uses porous material as carrier, imitates the state of molecule in solution, distributes donor-acceptor Steinhaos adduct evenly in the pore canal of porous material, separates the originally piled molecule separately, overcomes the problem of no color change under solid state caused by molecule piling effect.

Description

Solid powder color-changing material for non-contact induction quick response and preparation method thereof

Technical Field

The invention belongs to the technical field of color-changing solid materials, and particularly relates to a solid powder color-changing material for non-contact induction and quick response and a preparation method thereof.

Background

Nowadays, with the development of science and technology and the continuous efforts of the academic world, the color-changing solid material has been widely applied in the industries of information processing, automobiles, buildings, electronics, textile printing and dyeing and the like. According to different induction conditions, the color-changing materials are mainly divided into five types, namely light, heat, electricity, gas and liquid stimulation. The photochromic material has the characteristics of remote and accurate control, and can efficiently and cleanly regulate and control the physical and chemical properties of the material.

Photochromic solid is mainly divided into two categories of organic photochromic and inorganic photochromic, and the principle is that when the material is irradiated by light with certain intensity and wavelength, the material generates a special physical and chemical process, so that the absorption peak value of the material to the light is changed. Research on inorganic color-changing materials has been continued for nearly 100 years, and a series of convenient applications represented by color-changing sunglasses have been developed. But is mainly limited to rare earth elements, transition metal oxides, halides, oxyacid salts, etc. due to its core additives. The inherent problems of high use cost, large industrialization difficulty, difficult degradation of raw materials, environment-friendliness and the like are inevitably caused. Compared with organic color-changing materials, inorganic color-changing materials usually involve the change of the electronic state of matter when the two states are switched, and the process usually needs to introduce higher excitation energy and longer radiation time, so that the efficient and rapid state switching cannot be realized while a large amount of energy is wasted.

The solid color-changing material taking the organic color-changing molecules as the core can well solve the problems and has the performances of rapidness, low energy induction, accurate regulation and control and the like. At present, the core of the application of the organic color-changing solid material is mainly based on a spiropyran compound, molecules can be converted from a closed-loop spiropyran state to an open-loop merocyanine state under the irradiation of ultraviolet light, and due to the fact that ultraviolet light and strong heat are generally required to be introduced in the process, the solid color-changing material designed based on the molecules generally has the defects of poor fatigue resistance, easiness in oxidation, color-changing performance loss under the conditions of strong light or high heat and the like. The specific main problems are as follows: and (1) triggering by ultraviolet light. The introduction of ultraviolet light inevitably brings irreversible molecular structure damage, ultraviolet light is not easily available in a civil range, and the generation of artificial ultraviolet light introduces a large amount of energy consumption, thereby greatly limiting the application range of the artificial ultraviolet light. And (2) a photobleaching process. The traditional color-changing process of the color-changing solid powder is a forward color-changing process generally, when the color-changing solid powder is used as a high-concentration additive to be prepared into a thick solid material, the color-changing process is completed by molecules on the outer layer or the outer surface, the molecules on the outer layer can block light rays outside the light rays, the ultraviolet light does not have strong penetrating power, and the molecules distributed on the inner layer are difficult to generate color-changing reaction. And (3) the synthesis is complex and the cost is high. Therefore, the traditional organic color-changing molecules are required to be prepared by the problems of expensive raw materials, difficult purification, complex synthesis and the like. These pain points greatly limit the application scenarios.

Disclosure of Invention

The invention aims to: aiming at the defects of the organic color-changing solid material in the prior art, the solid powder color-changing material with non-contact induction and quick response and the preparation method thereof are provided.

The technical scheme adopted by the invention is as follows:

a preparation method of a solid powder color-changing material with non-contact induced quick response comprises the following steps:

s1, preparation of DASAs molecular intermediates: stirring the cyclopropyl (methylene) acrylate and furfural at 30-40 ℃ for 4-5h, and then sequentially carrying out water washing, suction filtration, extraction, drying, secondary suction filtration, column chromatography purification and rotary evaporation to obtain an intermediate;

s2, preparing DASA-1 molecules: reacting the intermediate obtained in the step S1 with dipropylamine, and then purifying and rotary-steaming the intermediate through column chromatography to obtain DASA-1 molecules;

s3, preparing DASA-2 molecules: stirring the intermediate obtained in the step S1 and N-propylaniline at the temperature of 30-35 ℃ for reacting for 2-3h, and then purifying and rotary steaming the intermediate by using column chromatography under the condition of keeping out of the sun to obtain a DASA-2 molecule;

s4, preparing a porous material A: mixing aluminum chloride hexahydrate and terephthalic acid, heating to 120-145 ℃, stirring for reaction for 15-20h, cooling, and performing suction filtration to obtain a porous material A;

s5, preparing a porous material B: mixing chromium nitrate nonahydrate, terephthalic acid and hydrofluoric acid, stirring at room temperature for 15-45min, heating at 200-240 ℃ for 15-20h, cooling, and filtering to obtain porous material B;

s6, integration: under the condition of keeping out of the sun, activating the porous material A obtained in the step S4 or the porous material B obtained in the step S5 at the temperature of 80-180 ℃ for 5-10 hours in static vacuum, and cooling to room temperature; dissolving DASA-1 molecules obtained from S2 or DASA-2 molecules obtained from S3 in dichloromethane solvent, adding into activated porous material A obtained from S4 or porous material B obtained from S5, stirring vigorously for 10-15h, centrifuging, and drying.

The invention relates to the design of solid powder materials starting from donor-acceptor Steinhaos adducts (DASAs). Under natural conditions of drying, donor-acceptor Stanhaus adducts (DASAs) are strongly intermolecular powders, tightly packed from molecule to molecule due to the attraction of hydrogen bonds and conjugated structures. Because the nature of the molecular discoloration comes from the change of the molecular structure, in the pure solid state, the energy brought by visible light is difficult to overcome the mutual attraction among molecules, and the space required for generating the structural change is also greatly limited due to the high-density molecular stacking. Thus, the current applications and research on donor-acceptor stent adducts (DASAs) are largely limited to liquid and polymer systems.

Based on the above, the invention designs a host-guest mixed system, which takes a porous material as a carrier, simulates the state of molecules in a solution, uniformly distributes donor-acceptor Steinhaos adducts (DASAs) in pores of the porous material, and individually separates originally stacked molecules, thereby fundamentally overcoming the problem of no color change caused by the molecular stacking effect.

In addition, in the aspect of color change rate, due to the fact that the donor-acceptor Steinhaos adducts (DASAs) are completely different in performance in two different porous material systems, the fast light response solid color change powder, the fast thermal response solid color change powder and the bidirectional fast response solid color change powder can be prepared according to different requirements, various color change schemes with high identification degree can be provided, including red to white, purple to white, brown to green, reddish brown to green and the like, and application scenes are further widened.

Further, the molar ratio of the S1 malonic acid cyclic (isopropylidene) ester to the furfural is 1-3:1; preferably 1:1.

Further, the molar ratio of the S2 intermediate to dipropylamine is 1-3:1; preferably 1:1.

Further, the S2 intermediate is dissolved in anhydrous dichloromethane or anhydrous tetrahydrofuran solvent, and then dipropylamine is added for reaction.

Further, the reaction conditions of S2 are: stirring for 2-3h at normal temperature.

Further, the reaction conditions of S2 are: stirring for 1.5-2h at 30-35 ℃.

Further, the molar ratio of the S3 intermediate to the N-propylaniline is 1-3:1; preferably 1:1.

Further, the S3 intermediate is dissolved in an anhydrous dichloromethane or anhydrous tetrahydrofuran solvent, and N-propylaniline is added for reaction.

Further, the mass ratio of the S4 aluminum chloride hexahydrate to the terephthalic acid is 2-5:2-4; preferably 3.5.

Further, respectively dissolving aluminum chloride hexahydrate and terephthalic acid in a DMF solvent, and mixing for reaction; after the porous material A is prepared, the solvent is replaced.

Further, the ratio of S5 chromium nitrate nonahydrate, terephthalic acid and hydrofluoric acid is 3-5g; preferably 4 g.

Further, aluminum chloride nonahydrate, terephthalic acid and hydrofluoric acid are mixed in deionized water for reaction.

Further, the concentration of DASA-1 molecule or DASA-2 molecule in S6 is 1-3mg/mL; the mass ratio of the porous material A or the porous material B to the DASA-1 molecules or the DASA-2 molecules is 80-120, preferably 100.

The solid powder color-changing material with non-contact induction and quick response prepared by the method.

In summary, due to the adoption of the technical scheme, the invention has the beneficial effects that:

1. the invention takes donor-acceptor Steinhaos adducts (DASAs) as a starting point, and the obtained solid powder color-changing material only needs 40mW/cm ² The green light triggering not only avoids the damage of ultraviolet light to the internal structure of the molecule, and ensures that the molecule has good fatigue resistance, but also can not cause a large amount of energy waste when regulating and controlling color change, and simultaneously greatly widens the application scenes of the material;

2. the donor-acceptor Steinhaos adducts (DASAs) are used as reverse photochromic molecules, are different from photochromic molecules, and when the DASAs are used as additives to be designed into solid block-shaped materials, the limitation that outer-layer molecules block inner-layer molecules is avoided, and the problem that light is limited in space conduction can be perfectly avoided in the heat-control coloring process, so that the effective depth of color change of the color change materials is greatly increased when the color change materials are overlapped at high concentration, and the color change performance of the color change materials with fixed shapes can be realized by visible light and heat control;

3. the invention realizes the color change of solid powder taking donor-acceptor Steinhaos adducts (DASAs) as cores by taking color-changing DASA molecules as color-changing main bodies and dispersing the color-changing DASA molecules in porous material carriers, wherein the visible light induced color-changing stimulation time is less than 10s, the speed is high, the conversion rate is high, the color can be repeatedly utilized, and the color change range span is large;

4. the raw materials adopted in the production and synthesis process of the invention, such as furfural, common metal salts, and terephthalic acid which is already industrially produced, are cheap and easily available, and have great potential of low-cost industrial application.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

FIG. 1 is a schematic flow chart of the integration process of the present invention;

FIG. 2 is a schematic representation of the material of example 2 (reddish brown) before irradiation;

FIG. 3 is a schematic diagram of the material of example 2 under green illumination;

FIG. 4 is a schematic representation of the material of example 2 (green) after illumination with green light;

FIG. 5 is a schematic representation of the material (reddish brown) of example 2 after heating by a heat gun;

FIG. 6 is a color chart of the material produced in the example; DASA-1 collar red, DASA-2 purple, porous material A white, porous material B green; DASA-1+ porous material A (example 1) bright red; DASA-2+ porous material A (example 3) purple; DASA-1+ porous material B (example 2) brown; DASA-2+ porous material B (example 4) reddish brown;

FIG. 7 is a schematic view of a solid block; the left is before green irradiation (brown), the middle is after green irradiation (green), and the right is after heat treatment (brown).

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort, shall fall within the protection scope of the present invention.

It is noted that relational terms such as "first" and "second," and the like, may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising a … …" does not exclude the presence of another identical element in a process, method, article, or apparatus that comprises the element.

The features and properties of the present invention are described in further detail below with reference to examples.

Example 1

The preferred embodiment of the invention provides a preparation method of a solid powder color-changing material with non-contact induction and rapid response, which comprises the following specific steps:

(1) Preparation of DASAs molecular intermediates: and mixing the cyclopropane-isopropyl (methylene) malonate and the furfural, and stirring at 35 ℃ for about 4 hours to obtain a yellow intermediate product. And then washing and filtering the obtained yellow product to remove water in the yellow product. And then, extracting the intermediate product by using saturated sodium bisulfite and saturated sodium chloride aqueous solution to remove impurities in the intermediate product, further removing moisture in the intermediate product by using anhydrous magnesium sulfate or anhydrous sodium sulfate, and removing the anhydrous magnesium sulfate by suction filtration. Finally, the intermediate is finally purified by column chromatography, eluting with Dichloromethane (DCM). And finally, removing the solvent from the purified intermediate by rotary evaporation to obtain a yellow solid for later use.

(2) Preparation of DASA-1 molecule: taking the intermediate obtained in the last step as an acceptor part to react with Dipropylamine (Dipropylamine) as a donor part, firstly dissolving 5mmol of yellow intermediate in 10ml of anhydrous Dichloromethane (DCM) solvent, then adding 5mmol of Dipropylamine, and stirring and reacting for 2.5h at normal temperature. After the reaction is finished, purifying the product by a column chromatography method, wherein an eluent adopts DCM: EA is 1:3, a proportioning mode. And removing the solvent by rotary evaporation to obtain the purified DASA-1 molecule for later use.

(3) Preparation of porous material A: first, 3.34g of aluminum chloride hexahydrate and 3.28g of terephthalic acid were dissolved in 50mL of DMF solvent, respectively, which took about 30 minutes. After the two parts were completely dissolved, the two solutions were mixed in a 500mL round bottom flask, and a magnetic stirring rotor was placed in the flask, connected to a condensing reflux unit, and stabilized on a heating stir table. The heating stage was set at 135 ℃ and heating was continued with stirring for 18 hours. And (3) cooling the reaction product to room temperature, and separating white solid powder by using a suction filtration device. Subsequently, the obtained porous material is subjected to a solvent substitution treatment, specifically operated as follows: the white solid powder was washed three times with 50mL of DMF, stirred for 3 hours each time, and isolated by suction filtration. The same operation steps are repeated 4 times with methanol respectively to replace and dissolve impurities in the pore channels. And (3) drying the solid at 80 ℃ overnight, and then drying the solid in a vacuum drying oven at 100 ℃ for 8 hours to remove solvent molecules in the pore channels. 2.192g of a white solid powder was finally obtained.

(4) Integration: 100mg of the porous material A and a magnetic stirrer were weighed into a 10mL Hirak reaction tube and sealed with a rubber cap. After activation for 8 hours at 100 ℃ under static vacuum, it was cooled to room temperature. DASA-1 molecules were dissolved in dichloromethane solvent at a concentration of 2mg/mL, and 3mL of the solution was pipetted into a Hirak reaction tube from above the rubber cap with a puncture using a 5mL syringe while turning on the stirring switch and vigorously stirring for 12 hours. The whole embedding and integration process is carried out under the condition of keeping out light. After the completion of the integration, the solid fraction was separated by a centrifuge at 10000 rpm and washed 3 times with 40mL of dichloromethane by sonication for washing the externally attached molecules for 10 minutes each. And finally, separating out solid powder by using the centrifugation speed of 10000 rpm, and putting the solid powder in a vacuum drying oven at 40 ℃ for vacuum drying overnight to obtain the product.

Example 2

The preferred embodiment of the invention provides a preparation method of a solid powder color-changing material with non-contact induced quick response, which comprises the following specific steps:

(1) Preparation of DASAs molecular intermediates: and mixing the cyclopropane-isopropyl (methylene) malonate and the furfural, and stirring at 35 ℃ for about 4 hours to obtain a yellow intermediate product. And then washing and filtering the obtained yellow product to remove water in the yellow product. And then, extracting the intermediate product by using saturated sodium bisulfite and saturated sodium chloride aqueous solution in sequence to remove impurities in the intermediate product, further removing water in the intermediate product by using anhydrous magnesium sulfate or anhydrous sodium sulfate, and removing the anhydrous magnesium sulfate by suction filtration. Finally, the intermediate is finally purified by column chromatography, eluting with Dichloromethane (DCM). And finally, removing the solvent from the purified intermediate by rotary evaporation to obtain a yellow solid for later use.

(2) Preparation of DASA-1 molecule: taking the intermediate obtained in the last step as an acceptor part to react with Dipropylamine (Dipropylamine) as a donor part, firstly dissolving 5mmol of yellow intermediate in 10ml of anhydrous Tetrahydrofuran (THF) solvent, then adding 5mmol of Dipropylamine, and stirring and reacting for 1.5h in an oil bath kettle at constant temperature of 35 ℃. After the reaction is finished, purifying the product by a column chromatography method, wherein an eluent adopts DCM: EA is 1:3, a proportioning mode. And removing the solvent by rotary evaporation to obtain the purified DASA-1 molecule for later use.

(3) Preparation of the porous material B: 4g of chromium nitrate nonahydrate, 1.65g of terephthalic acid, 0.4mL of hydrofluoric acid were dissolved in 48mL of deionized water. The mixture was stirred at room temperature for 30 minutes and transferred to a 100mL Teflon lined stainless steel hydrothermal kettle. And transferring the hydrothermal kettle to an oven at 220 ℃, heating for 18 hours, and after the kettle body is cooled to room temperature, separating out green solids through suction filtration. Subsequently, the porous material obtained is subjected to a solvent substitution treatment, in particular operating: the green solid powder was washed twice with 50mL of DMF, stirred for 3 hours at 60 ℃ each time and isolated by means of a suction filtration apparatus. The same procedure was repeated 2 times for each of ethanol and water to displace impurities in the pores. After drying the solid at 80 ℃ overnight, putting the solid into a vacuum drying oven to be dried at 150 ℃ overnight in vacuum to remove solvent molecules in the pore channels. Finally, 3.82g of a green solid powder was obtained.

(4) Integration: 100mg of the porous material B and a magnetic stirrer were weighed into a 10mL Hirak reaction tube and sealed with a rubber cap. After activation for 8 hours at 150 ℃ under static vacuum, it was cooled to room temperature. DASA-1 molecules were dissolved in dichloromethane solvent at a concentration of 2mg/mL, and 3mL of the solution was pipetted into a Hirak reaction tube from above the rubber cap with a puncture using a 5mL syringe while turning on the stirring switch and vigorously stirring for 12 hours. The whole embedding and integrating process is carried out under the condition of keeping out light. After the completion of the integration, the solid fraction was separated by a centrifuge at 10000 rpm and washed 3 times with 40mL of dichloromethane by sonication for washing the externally attached molecules for 10 minutes each. And finally, separating out solid powder by using the centrifugation speed of 10000 rpm, and putting the solid powder in a vacuum drying oven at 40 ℃ for vacuum drying overnight to obtain the product.

Example 3

(2) Preparation of DASA-2 molecule: dissolving 3mmol of the yellow intermediate prepared in the step (1) in 10ml of solvent anhydrous Dichloromethane (DCM), adding 3mmol of N-propylaniline, stirring and reacting for 2h in an oil bath kettle at constant temperature of 35 ℃, purifying the product by a column chromatography method after the reaction is finished, and eluting by using DCM: EA is 10:1 in the formula (I). Care was taken to avoid light during reaction and purification. And finally, removing the solvent by rotary evaporation to obtain the purified DASA-2 molecule.

(3) Preparation of porous material A: first, 3.34g of aluminum chloride hexahydrate and 3.28g of terephthalic acid were dissolved in 50mL of DMF solvent, respectively, which took about 30 minutes. After the two parts are completely dissolved, the two solutions are mixed in a 500mL round-bottom flask, a magnetic stirring rotor is placed in the round-bottom flask, a condensation reflux device is connected, and the round-bottom flask is stabilized on a heating stirring table. The heating table was set at 135 ℃ and heating was continued with stirring for 18 hours. And after the reaction is cooled to room temperature, separating white solid powder by a suction filtration device. Subsequently, the obtained porous material is subjected to a solvent substitution treatment, specifically operated as follows: the white solid powder was washed three times with 50mL of DMF, stirred for 3 hours each time, and isolated by suction filtration. The same operation steps are repeated 4 times with methanol respectively to replace and dissolve impurities in the pore channels. And (3) drying the solid at 80 ℃ overnight, and then drying the solid in a vacuum drying oven at 100 ℃ for 8 hours to remove solvent molecules in the pore channels. 2.192g of a white solid powder was finally obtained.

(4) Integration: 100mg of the porous material A and a magnetic stirrer were weighed into a 10mL Hirak reaction tube and sealed with a rubber cap. After activation for 8 hours at 100 ℃ under static vacuum, it was cooled to room temperature. DASA-2 molecules were dissolved in dichloromethane solvent at a concentration of 2mg/mL, and 3mL of the solution was pipetted into a Hirak reaction tube from above the rubber cap with a puncture using a 5mL syringe while turning on the stirring switch and vigorously stirring for 12 hours. The whole embedding and integrating process is carried out under the condition of keeping out light. After the completion of the integration, the solid fraction was separated by a centrifuge at 10000 rpm and washed 3 times with 40mL of dichloromethane by sonication for washing the externally attached molecules for 10 minutes each. And finally, separating out solid powder by using the centrifugation speed of 10000 rpm, and putting the solid powder in a vacuum drying oven at 40 ℃ for vacuum drying overnight to obtain the product.

Example 4

(1) Preparation of DASAs molecular intermediates: mixing the cyclopropane-isopropyl (methylene) ester and the furfural, and stirring at 35 ℃ for about 4 hours to obtain a yellow intermediate product. And then washing and filtering the obtained yellow product to remove water in the yellow product. And then, extracting the intermediate product by using saturated sodium bisulfite and saturated sodium chloride aqueous solution in sequence to remove impurities in the intermediate product, further removing water in the intermediate product by using anhydrous magnesium sulfate or anhydrous sodium sulfate, and removing the anhydrous magnesium sulfate by suction filtration. Finally, the intermediate is finally purified by column chromatography, eluting with Dichloromethane (DCM). And finally, removing the solvent from the purified intermediate by rotary evaporation to obtain a yellow solid for later use.

(3) Preparation of the porous material B: 4g of chromium nitrate nonahydrate, 1.65g of terephthalic acid, 0.4mL of hydrofluoric acid were dissolved in 48mL of deionized water. The mixture was stirred at room temperature for 30 minutes and transferred to a 100mL Teflon lined stainless steel hydrothermal kettle. And transferring the hydrothermal kettle to an oven at 220 ℃, heating for 18 hours, and after the kettle body is cooled to room temperature, separating out green solids through suction filtration. Subsequently, the obtained porous material is subjected to a solvent substitution treatment, specifically operated as follows: the green solid powder was washed twice with 50mL of DMF, stirred for 3 hours at 60 ℃ each time and isolated by means of a suction filtration apparatus. The same procedure was repeated 2 times for each of ethanol and water to displace impurities in the pores. The solid is dried at 80 ℃ overnight and then put into a vacuum drying oven to be dried at 150 ℃ overnight in vacuum to remove solvent molecules in the pore channels. Finally, 3.82g of a green solid powder was obtained.

(4) Integration: 100mg of the porous material B and a magnetic stirrer were weighed into a 10mL Hirak reaction tube and sealed with a rubber cap. After activation for 8 hours at 150 ℃ under static vacuum, it was cooled to room temperature. DASA-2 molecules were dissolved in dichloromethane solvent at a concentration of 2mg/mL, and 3mL of the solution was pipetted into a Hirak reaction tube from above the rubber cap with a puncture using a 5mL syringe while turning on the stirring switch and vigorously stirring for 12 hours. The whole embedding and integrating process is carried out under the condition of keeping out light. After the completion of the integration, the solid fraction was separated by a centrifuge at 10000 rpm and washed 3 times with 40mL of dichloromethane by sonication for washing the externally attached molecules for 10 minutes each. And finally, separating out solid powder by using the centrifugation speed of 10000 rpm, and putting the solid powder in a vacuum drying oven at 40 ℃ for vacuum drying overnight to obtain the product.

Experimental example 1

The material from example 2 was placed on A4 paper and compacted to prevent the powder from blowing off, as shown in figure 2. Using 40mW/cm ² The brown powder rapidly changed to green after being irradiated with a green light source for 10 seconds (fig. 3 and 4). The powder-attached area was heated again with a heat gun for 10 seconds, and the powder returned to brown as shown in FIG. 5. The reflectivity span of the material of the invention is over 50% as determined by uv-vis spectroscopy.

As shown in fig. 6, different porous materials and different DASA molecules can be matched to achieve different color of the powder. The material obtained in example 1 was bright red powder, the material obtained in example 3 was purple powder, the material obtained in example 2 was brown powder and the material obtained in example 4 was reddish brown powder.

Experimental example 2

When the powder is used as a solid block additive, the prepared block with fixed morphology also has visible light and thermal control color change performance. The preparation process comprises the following steps: the powder material prepared in example 2 was added to a polydimethylsiloxane prepolymer and a curing agent in a ratio of 10:1, removing bubbles by a vacuum pump, curing at 60 ℃ for 8 hours to form a block cube with color and appearance, wherein the brown cube is changed into a green cube under the irradiation of green light and is changed into the brown cube after heat treatment as shown in fig. 7.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims

1. A preparation method of a solid powder color-changing material with non-contact induction and quick response is characterized by comprising the following steps:

s1, preparation of DASAs molecular intermediates: stirring the cyclopropyl (methylene) propionate and furfural at the temperature of 30-40 ℃ for 4-5 hours, and then sequentially carrying out water washing, suction filtration, extraction, drying, secondary suction filtration, column chromatography purification and rotary evaporation to obtain an intermediate;

s4, preparing a porous material A: mixing aluminum chloride hexahydrate and terephthalic acid, heating to 120-145 ℃, stirring for reaction for 15-20h, cooling, and performing suction filtration to obtain a porous material A; the mass ratio of the aluminum chloride hexahydrate to the terephthalic acid is 2-5:2-4;

s5, preparing a porous material B: mixing chromium nitrate nonahydrate, terephthalic acid and hydrofluoric acid, stirring at room temperature for 15-45min, heating at 200-240 deg.C for 15-20h, cooling, and vacuum filtering to obtain porous material B; the ratio of the chromium nitrate nonahydrate to the terephthalic acid to the hydrofluoric acid is 3-5g;

2. The method for preparing the solid powder color-changing material with the non-contact induced rapid response of claim 1, wherein the molar ratio of the S1 malonic acid cyclic (isopropylidene) ester to the furfural is 1-3:1.

3. The method for preparing the solid powder discoloring material capable of inducing fast response in a non-contact manner according to claim 1, wherein the molar ratio of the S2 intermediate to dipropylamine is 1-3:1.

4. The method for preparing the solid powder color-changing material for non-contact induction of rapid response according to claim 1, wherein the reaction conditions of S2 are as follows: stirring for 2-3h at normal temperature.

5. The method for preparing the solid powder color-changing material for non-contact induction of rapid response according to claim 1, wherein the reaction conditions of S2 are as follows: stirring for 1.5-2h at 30-35 ℃.

6. The method for preparing the solid powder color-changing material with the non-contact induced rapid response of claim 1, wherein the molar ratio of the S3 intermediate to the N-propylaniline is 1-3:1.

7. The method for preparing solid powder discoloring material capable of inducing fast response in a contactless manner according to claim 1, wherein the concentration of DASA-1 molecules or DASA-2 molecules in S6 is 1-3mg/mL; the mass ratio of the porous material A or the porous material B to the DASA-1 molecules or the DASA-2 molecules is 80-120.

8. A solid powder discoloration material inducing a rapid response without contact, which is prepared by the method of any one of claims 1 to 7.