Sandwich-structure pressure color-changing film based on bicyclic aromatic alkene as well as preparation method and application of sandwich-structure pressure color-changing film

Abstract

The invention belongs to the technical field of piezochromic films, and particularly relates to a sandwich-structure pressure color-changing film based on bicyclic aromatic alkene as well as a preparation method and application of the sandwich-structure pressure color-changing film. The invention discloses a novel dicyclic aromatic alkene derivative, and a pressure color-changing film with a sandwich structure is prepared by using dicyclic aromatic alkene derivative organic small molecules as a color-changing material and packaging the dicyclic aromatic alkene derivative organic small molecules by using a transparent polymer film. After pressure is applied to the film, configuration transformation occurs to the dicyclic aromatic alkene derivative organic small molecules, different molecular configurations have different visible light absorption wavebands, color change is macroscopically shown, the number of the molecules subjected to configuration transformation is positively correlated with the pressure, and quantitative detection of the pressure can be achieved. According to the preparation method of the pressure detection film, the problem that in the prior art, pressure magnitude and distribution are difficult to detect visually is solved, and ultra-thin preparation of the pressure detection film can be achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of piezochromic films, and in particular relates to a sandwich structured piezochromic film based on ditricyclic aromatic olefins, and a preparation method and application thereof. Background Art

[0002] Detecting the pressure distribution on the interface of components is crucial for the precision assembly of high-end manufacturing. However, the shortage of related pressure-sensing film products is considered to be a major bottleneck restricting the high-end manufacturing industry. Because the existing commercial pressure-sensitive films mainly detect pressure distribution based on the color change mechanism of chemical reactions caused by the rupture of microcapsules under pressure, their minimum thickness can only be 100μm, and their lack of flexibility makes it difficult to detect the pressure distribution between complex surfaces. The few pressure-sensitive films based on electrical signals are also difficult to directly visualize and cannot be used alone in complex situations. Therefore, in order to further reduce the thickness of the pressure-sensitive film to improve its flexibility and portability, it is necessary to develop a new type of pressure-sensitive film.

[0003] In recent years, some new pressure-sensitive films have gradually emerged. For example, China's invention patent CN117106340A discloses a high-sensitivity and wide-response pressure-sensitive carbon nano-slurry. The pressure-sensitive film made from it has the advantages of sensitive pressure-resistance response, high pressure sensitivity coefficient, wide range, high precision, etc. It can be used to manufacture flexible pressure sensors and realize large-scale batch manufacturing of flexible pressure sensors. However, the pressure sensor can no longer respond after the pressure is withdrawn. China's invention patent CN205373927U discloses a soft pressure-sensitive film, which can detect information such as pressure size, distribution and pressure area, and can be bent and folded at will. It is soft enough and has a good tactile response. The thickness of the rubber film or polyurethane film used can reach 0.1mm, so that the overall thickness of the sensing film is within 0.3mm. However, the production process of the pressure-sensitive film is complicated, and it can no longer respond after the pressure is withdrawn. At the same time, the above two pressure-sensitive films are based on electrical signal response, and cannot be used alone in complex situations, and cannot be directly visualized. Judgment, which is not conducive to the portability of pressure detection. Therefore, it is necessary to further develop more advanced pressure-sensitive films to solve the problems of existing pressure-sensitive films being difficult to detect without electrical signals, being unable to be directly visualized, and being difficult to make ultra-thin. Summary of the invention

[0004] In order to overcome the shortcomings of the above-mentioned prior art, the present invention provides a sandwich structure flexible pressure-chromic film with adjustable pressure response range, ultra-thinness, and conformability to complex curved surfaces. The response coating of the film is based on a new organic small molecule of a di-tricyclic aromatic olefin derivative, which belongs to a pressure-chromic film based on organic small molecule pressure-induced color change, which not only reduces the pressure response threshold, but also can visualize the distribution of pressure.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] The first aspect of the present invention provides a sandwich structure pressure-chromic film based on bis-tricyclic aromatic olefins, wherein the sandwich structure pressure-chromic film comprises two layers of transparent encapsulation films and a bis-tricyclic aromatic olefin derivative organic small molecule coating in the middle; under specific external stimuli, the bis-tricyclic aromatic olefin derivative organic small molecule can undergo a spatial configuration change, wherein the spatial configuration comprises a folded configuration and a twisted configuration;

[0007] The bicyclic aromatic olefin derivative organic small molecule includes 9-(11-hydrogen-benzo[a]fluorenyl-11-enylene)-10-(4-R-phenyl)-9,10-dihydroacridine as shown in formula (I) and 9-(11-hydrogen-benzo[b]fluorenyl-11-enylene)-10-(4-R-phenyl)-9,10-dihydroacridine as shown in formula (II):

[0008]

[0009] Wherein, R is selected from one of F, Br, CH3, OCH3, H, Ph, and NO2.

[0010] Specifically, the bicyclic aromatic olefin derivative organic small molecules include 9-(11 hydrogen-benzo[a]fluorenyl-11-alkenyl)-10-(4-fluorophenyl)-9,10-dihydroacridine, 9-(11 hydrogen-benzo[a]fluorenyl-11-alkenyl)-10-(4-bromophenyl)-9,10-dihydroacridine, 9-(11 hydrogen-benzo[a]fluorenyl-11-alkenyl)-10-(4-methylphenyl)-9,10-dihydroacridine , 9-(11hydro-benzo[a]fluorenyl-11-ylidene)-10-(4-methoxyphenyl)-9,10-dihydroacridine, 9-(11hydro-benzo[a]fluorenyl-11-ylidene)-10-phenyl-9,10-dihydroacridine, 9-(11hydro-benzo[a]fluorenyl-11-ylidene)-10-biphenyl-9,10-dihydroacridine, 9-(11hydro-benzo[a]fluorenyl-11-ylidene)-10-(4-nitrophenyl)- 9,10-dihydroacridine, 9-(11hydro-benzo[b]fluorenyl-11-enylene)-10-(4-fluorophenyl)-9,10-dihydroacridine, 9-(11hydro-benzo[b]fluorenyl-11-enylene)-10-(4-bromophenyl)-9,10-dihydroacridine, 9-(11hydro-benzo[b]fluorenyl-11-enylene)-10-(4-methylphenyl)-9,10-dihydroacridine, 9-(11hydro-benzo[b]fluorenyl-11-enylene)-10-(4-methylphenyl)-9,10-dihydroacridine, one of 9-(11-hydro-benzo[b]fluorenyl-11-ylidene)-10-(4-methoxyphenyl)-9,10-dihydroacridine, 9-(11-hydro-benzo[b]fluorenyl-11-ylidene)-10-phenyl-9,10-dihydroacridine, 9-(11-hydro-benzo[b]fluorenyl-11-ylidene)-10-biphenyl-9,10-dihydroacridine and 9-(11-hydro-benzo[b]fluorenyl-11-ylidene)-10-(4-nitrophenyl)-9,10-dihydroacridine;

[0011] The di-tricyclic aromatic olefin derivative organic small molecule has a tricyclic structure and a tetracyclic structure, and the two large conjugated ring structures are connected by a double bond; the di-tricyclic aromatic olefin derivative organic small molecule has two large conjugated ring structures with steric hindrance, resulting in large steric hindrance and inability to keep all atoms in the same plane. The di-tricyclic aromatic olefin derivative organic small molecule has two reversible configurations, including folded and twisted spatial configurations, with different colors in the visible light region, and configuration changes and color changes after multiple stimuli. The twisted configuration energy is lower in the case of a single molecule state (such as in a solution or vapor state), and the folded configuration energy is lower in an aggregated state (such as a crystalline state or powder state); when the di-tricyclic aromatic olefin derivative organic small molecule changes from a single molecule state to an aggregated state, the color of the twisted configuration changes to a folded configuration color, and when the aggregated state changes to a single molecule state, the color of the folded configuration changes to a twisted configuration color. The bending directions of the four rings and three rings in the folded configuration are different, one is an out-of-plane structure and the other is an in-plane structure, and the folded configuration has a structure in which two large conjugated rings cross-fold.

[0012] Preferably, the external stimulus includes pressure, acid-base stimulation, solvent fumigation, heating or light.

[0013] Preferably, the thickness of the di-tricyclic aromatic olefin derivative organic small molecule coating is controlled to be between 3-100 μm, the thickness of the transparent encapsulation film is controlled to be between 0.5-100 μm, and the total thickness of the sandwich structure pressure-chromic film is 5-300 μm.

[0014] Preferably, the dicyclic aromatic olefin derivative organic small molecule is synthesized by using a diazo compound and a thione compound as raw materials through a Keddon-Balogh reaction; the diazo compound includes 11-diazo-11H-benzo[a]fluorene or 11-diazo-11H-benzo[b]fluorene; the thione compound includes but is not limited to 10-(4-fluorophenyl)acridine-9(10H)-thione, 10-(4-bromophenyl)acridine-9(10H)-thione, )acridine-9(10H)-thione, 10-(p-methylphenyl)acridine-9(10H)-thione, 10-(4-methoxyphenyl)acridine-9(10H)-thione, 10-phenylacridine-9(10H)-thione, 10-([1,1'-biphenyl]-4-yl)acridine-9(10H)-thione, and 10-(4-nitrophenyl)acridine-9(10H)-thione.

[0015] The synthesis method of the di-tricyclic aromatic olefin derivative organic small molecule is based on the Keton-Balog coupling reaction, which is a coupling reaction between a diazo compound and a thioketone compound, and an olefin is obtained through a diazo compound intermediate. Among them, the diazo compound can be obtained by oxidizing the hydrazone produced by the condensation of ketone and hydrazine, and the oxidant that can be used includes but is not limited to silver oxide and manganese dioxide; the thioketone compound can be prepared by the reaction of ketone with Lawesson reagent or phosphorus pentasulfide, and the desulfurization of the reaction intermediate ethylene sulfide can be completed by many phosphines (such as triphenylphosphine), and copper powder can also be used for desulfurization.

[0016] The second aspect of the present invention also provides a method for preparing the sandwich structure pressure-chromic film based on bis-tricyclic aromatic olefins described in the first aspect, specifically: the bis-tricyclic aromatic olefin derivative organic small molecules are uniformly coated on a transparent packaging film to form a coating, and then packaged with a second layer of transparent packaging film to obtain a sandwich structure pressure-chromic film.

[0017] Preferably, the coating method of the bicyclic aromatic olefin derivative organic small molecule includes at least one of drop coating, spray coating, spin coating, blade coating or chemical vapor deposition.

[0018] More preferably, the chemical vapor deposition uses a single bi-tricyclic aromatic olefin derivative organic small molecule solid raw material as a precursor.

[0019] More preferably, the precursor solution is composed of a solid organic small molecule raw material of a dicyclic aromatic olefin derivative and a soluble low-boiling point organic solvent or a soluble high-boiling point organic solvent by drip coating, spray coating or spin coating; the soluble low-boiling point organic solvent includes at least one of acetonitrile, dioxane, tetrahydrofuran, acetone, butanone, ethyl acetate, dichloromethane, and diethyl ether, and the soluble high-boiling point organic solvent includes at least one of N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, and ethylene glycol dimethyl ether.

[0020] More preferably, the coating uses a precursor emulsion composed of a di-tricyclic aromatic olefin derivative organic small molecule solid raw material, a sparingly soluble low boiling point solvent and a non-ionic surfactant; the sparingly soluble low boiling point solvent includes at least one of water, methanol, ethanol, cyclohexane, n-hexane and petroleum ether, and the non-ionic surfactant includes at least one of a polyoxyethylene type, a polyol type and a polyether type.

[0021] The third aspect of the present invention further provides the application of the sandwich structure pressure-chromic film based on bis-tricyclic aromatic olefins described in the first aspect in the field of pressure detection.

[0022] The sandwich structure pressure-chromic film provided by the present invention changes the color of the ditricyclic aromatic olefin from a folded configuration to a twisted configuration when subjected to pressure. The colors of the two configurations are different in the visible light region, and the number of molecules that undergo configuration change is positively correlated with the pressure. The pressure can be quantitatively detected, thereby effectively solving the technical problem of the lack of a pressure-chromic film for detecting the pressure size and distribution in the prior art.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The present invention discloses a new organic small molecule of a bis-tricyclic aromatic olefin derivative, and uses the organic small molecule of a bis-tricyclic aromatic olefin derivative as a color-changing material, and uses a transparent polymer film to encapsulate it to form a sandwich structure pressure-changing film that can visualize the pressure distribution. After pressure is applied to the film, the organic small molecule of the bis-tricyclic aromatic olefin derivative undergoes a configurational change, and different molecular configurations have different visible light absorption bands, which show color changes on a macroscopic level. The number of molecules that undergo configurational changes is positively correlated with the pressure, and quantitative detection of the pressure can be achieved. The preparation method of the pressure detection film provided by the present invention solves the problem that it is difficult to visualize the pressure size and distribution in the prior art, and can achieve ultra-thin preparation of the pressure detection film. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the structure of a new bi-tricyclic aromatic olefin derivative;

[0026] Figure 2 It is a schematic diagram of the structure of the sandwich structure pressure-chromic film;

[0027] Figure 2 In the invention, 1-transparent encapsulation film layer, 2-new bi-tricyclic aromatic olefin derivative coating layer.

[0028] Figure 3 This is a real picture of the sandwich structure pressure-chromic film before pressure is applied;

[0029] Figure 4 Schematic diagram of the color development of the sandwich structure pressure-chromic film after pressure is applied;

[0030] Figure 5 Schematic diagram of the color development of the sandwich structure pressure-chromic film as the pressure increases;

[0031] Figure 6 This is the standard curve of the average Lab color difference ΔE and pressure of the sandwich structure pressure-chromic film. DETAILED DESCRIPTION

[0032] The specific embodiments of the present invention are further described below. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in each embodiment of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0033] The experimental methods in the following examples are conventional methods unless otherwise specified, and the experimental materials used in the following examples are commercially available unless otherwise specified.

[0034] In view of the fact that current piezochromic films mainly detect pressure distribution based on the mechanism of color change due to microcapsule rupture under pressure, the present application provides a piezochromic film based on organic small molecule piezochromism, which uses a new di-tricyclic aromatic olefin organic small molecule as a color-changing coating. When the compressed configuration of the molecule changes, the color of the molecule can change in the visible light region, and the degree of change of its finger configuration is positively correlated with the pressure, and the color change rate is positively correlated with the pressure. Based on this principle, the detection of pressure size and distribution is achieved.

[0035] The sandwich structure pressure-chromic film provided by the present invention comprises a di-tricyclic aromatic olefin derivative organic small molecule coating and a transparent encapsulation film, wherein the molecular formula of the pressure-chromic material coating is as follows: Figure 1 As shown, the structure of the piezochromic film is as follows Figure 2 As shown in the figure (in the figure, 1 is a transparent encapsulation film, and 2 is a di-tricyclic aromatic olefin piezochromic coating). When no pressure is applied, the sandwich piezochromic film shows the color of the folded configuration, and when pressure is applied, the pressed area shows the color of the twisted configuration, thereby realizing pressure detection. At the same time, even if the pressure returns to normal pressure, the color change can continue, thereby realizing real-time detection in the visible light region, and its total thickness can be controlled between 5-300μm, which can realize pressure measurement of complex curved surfaces and reduce the influence of the film on the pressure surface.

[0036] Preferably, the present application further defines the type of pressure-responsive coating; the di-tricyclic aromatic olefin derivative organic small molecule is selected from 9-(11-hydrogen-benzo[a]fluorenyl-11-enyl)-10-(4-fluorophenyl)-9,10-dihydroacridine, 9-(11-hydrogen-benzo[a]fluorenyl-11-enyl)-10-(4-bromophenyl)-9,10-dihydroacridine, 9-(11-hydrogen-benzo[a]fluorenyl-11-enyl)-10-(4-bromophenyl)-9,10-dihydroacridine, benzo[a]fluorenyl-11-ylidene)-10-(4-methoxyphenyl)-9,10-dihydroacridine, 9-(11hydro-benzo[a]fluorenyl-11-ylidene)-10-phenyl-9,10-dihydroacridine, 9-(11hydro-benzo[a]fluorenyl-11-ylidene)-10-biphenyl-9,10-dihydroacridine, 9-(11hydro-benzo[a]fluorenyl-11-ylidene)-10- (4-nitrophenyl)-9,10-dihydroacridine, 9-(11hydro-benzo[b]fluorenyl-11-enylene)-10-(4-fluorophenyl)-9,10-dihydroacridine, 9-(11hydro-benzo[b]fluorenyl-11-enylene)-10-(4-bromophenyl)-9,10-dihydroacridine, 9-(11hydro-benzo[b]fluorenyl-11-enylene)-10-(4-methoxyphenyl)- One of 9-(11-hydro-benzo[b]fluorenyl-11-ylidene)-10-phenyl-9,10-dihydroacridine, 9-(11-hydro-benzo[b]fluorenyl-11-ylidene)-10-biphenyl-9,10-dihydroacridine and 9-(11-hydro-benzo[b]fluorenyl-11-ylidene)-10-(4-nitrophenyl)-9,10-dihydroacridine.

[0037] The raw materials used for the transparent packaging film include but are not limited to at least one of polyethylene terephthalate packaging film, polyethylene packaging film, polyvinyl chloride packaging film, polyvinyl alcohol packaging film, polyparaxylene packaging film, polystyrene packaging film, polypropylene packaging film, polycaprolactone packaging film, polymethyl methacrylate packaging film, and polydimethylsiloxane packaging film.

[0038] In addition, the present invention also provides a method for preparing the above-mentioned sandwich structure pressure-induced chromic film, comprising first preparing a transparent encapsulation film by chemical vapor deposition and a thermal process; then coating the inner surface of the transparent encapsulation film with a di-tricyclic aromatic olefin derivative organic small molecule by one of the processes such as drop coating, spray coating, scraping, spin coating or chemical vapor deposition, and heating to volatilize the solvent in the coating precursor to obtain a pressure-responsive coating, and then encapsulating a layer of transparent film by chemical vapor deposition to obtain a sandwich structure pressure-induced chromic film, and finally converting the twisted configuration into a folded configuration by oven heating or solvent fumigation.

[0039] In order to further clearly demonstrate the present invention, the following is a detailed description in the form of Examples 1-9 and experimental examples:

[0040] Embodiment 1:

[0041] This embodiment provides an embodiment of a sandwich structure pressure-chromic film with a total thickness of less than 100 μm, including the steps of preparing a transparent packaging film and preparing a di-tricyclic aromatic olefin derivative organic small molecule coating.

[0042] The preparation of the bicyclic aromatic olefin organic small molecule is as follows:

[0043] Weigh 1.2 g of 11-diazo-11H-benzo[b] (CAS No. 96615-37-1), 0.5 g of 10-(4-fluorophenyl)acridine-9(10H)-thione (CAS No. 2356110-22-8) and 0.9 g of triphenylphosphine (CAS No. 603-35-0), add them together into 10 mL of mixed xylene (CAS No. 1330-20-7), reflux at 140° C. for 1 h, and generate 0.3 g of 9-(11-hydro-benzo[b]fluorenyl-11-enyl)-10-(4-fluorophenyl)-9,10-dihydroacridine (structural formula as shown in FIG. 1 ). Figure 1 As shown in formula (II), R=F).

[0044] Wherein, the preparation of transparent encapsulation film is as follows:

[0045] Weigh 1.0g of the molecular weight is 277.19g·mol -1 Polyparaxylene (CAS No. 28804-46-8) is added to a stainless steel container, which is then placed in a tubular furnace connected to another low-temperature stainless steel cavity (whose temperature is controlled at 25-100°C). The tubular furnace is then heated to raise its temperature to 620-680°C and kept warm for 3-4 hours until the polyparaxylene is completely cracked. After stopping heating and cooling to room temperature, a transparent encapsulation film can be obtained on the inner wall of the low-temperature stainless steel with a thickness controlled within 30μm. Another layer of transparent encapsulation film is prepared using the same method.

[0046] The preparation of the organic small molecule coating of the bicyclic aromatic olefin derivative is as follows:

[0047] Weigh 0.1 g of 9-(11hydro-benzo[b]fluorenyl-11-enyl)-10-(4-fluorophenyl)-9,10-dihydroacridine powder and add it to 2 mL of ethyl acetate. After the powder is completely dissolved, spray the solution on a transparent packaging film, place it on a heating plate at 50-60°C to allow the solvent to completely evaporate to form a film, and the thickness can be controlled within 30 μm. Then, make a second layer of transparent packaging film on the transparent packaging film sprayed with the organic small molecule coating (the two layers of transparent packaging films are prepared by the same method), and finally place it in a 110°C oven and heat it for 4 hours to process the twisted configuration coating into a folded configuration coating, thereby obtaining an ultra-thin sandwich structure pressure-chromic film.

[0048] Embodiment 2:

[0049] This embodiment provides an embodiment of a sandwich structure pressure-chromic film with a total thickness of less than 100 μm, including the steps of preparing a transparent packaging film and preparing a di-tricyclic aromatic olefin derivative organic small molecule coating.

[0050] The preparation of the bicyclic aromatic olefin organic small molecule is as follows:

[0051] Weigh 1.0 g of 11-diazo-11H-benzo[b] (CAS No. 96615-37-1), 0.5 g of 10-(4-bromophenyl)acridine-9(10H)-thione (CAS No. 1609624-50-1) and 0.8 g of triphenylphosphine (CAS No. 603-35-0), add them together in 10 mL of mixed xylene (CAS No. 1330-20-7) and reflux at 140° C. for 1 h to generate 0.3 g of 9-(11-hydro-benzo[b]fluorenyl-11-enyl)-10-(4-bromophenyl)-9,10-dihydroacridine (structural formula as shown in FIG. 1). Figure 1 As shown in formula (II), R = Br).

[0052] Wherein, the preparation of transparent encapsulation film is as follows:

[0053] Weigh 1.0 g of 1799 type polyvinyl alcohol (cas number 9002-89-5) and add it to 40 mL of water, place it in an environment of 80-90°C and heat it until the polyvinyl alcohol is completely dissolved, then take 1-2 mL of the solution and spin coat it on a glass substrate at a speed of 4000-6000 rpm, and the spin coating time is controlled within 30 s. After spin coating, place it on a 90-100°C heating plate to completely evaporate the solvent to obtain a transparent transparent encapsulation film with a thickness controlled within 30 μm. Another layer of transparent encapsulation film is prepared by the same method.

[0054] The preparation of the organic small molecule coating of the bicyclic aromatic olefin derivative is as follows:

[0055] Weigh 0.1 g of 9-(11 hydrogen-benzo[b]fluorenyl-11-ene)-10-(4-bromophenyl)-9,10-dihydroacridine powder and add it to 2 mL of ethyl acetate. After the powder is completely dissolved, spray the solution on a transparent packaging film, place it on a 50-60°C heating plate to allow the solvent to completely evaporate to form a film with a thickness of less than 30 μm, and then make a second layer of transparent packaging film on the transparent packaging film sprayed with the organic small molecule coating (the two layers of transparent packaging films are prepared using the same method), and finally put it in a 110°C oven and heat it for 4 hours to process the twisted configuration coating into a folded configuration coating, thereby obtaining an ultra-thin sandwich structure pressure-chromic film.

[0056] Embodiment 3:

[0057] This embodiment provides an embodiment of a sandwich structure pressure-chromic film with a total thickness of less than 100 μm, including the steps of preparing a transparent packaging film and preparing a di-tricyclic aromatic olefin derivative organic small molecule coating.

[0058] The preparation of the bicyclic aromatic olefin organic small molecule is as follows:

[0059] Weigh 1.1 g of 11-diazo-11H-benzo[b] (CAS No. 96615-37-1), 0.5 g of 10-(4-methoxyphenyl)acridine-9(10H)-thione (CAS No. 2356110-17-1) and 0.8 g of triphenylphosphine (CAS No. 603-35-0), add them together into 10 mL of mixed xylene (CAS No. 1330-20-7) and reflux at 140°C for 1 h to generate 0.3 g of 9-(11-hydro-benzo[b]fluorenyl-11-enyl)-10-(4-methylphenyl)-9,10-dihydroacridine (structural formula: Figure 1 As shown in formula (II), R=OCH3).

[0060] Wherein, the preparation of transparent encapsulation film is as follows:

[0061] Weigh 1.0 g of polyethylene particles with a molecular weight of 600w (CAS number is 9002-88-4) and add them to a glass beaker, heat to 100-130°C until the polyvinyl chloride particles are completely melted, then preheat the glass substrate to 70-80°C, pour the molten polyvinyl chloride liquid on the glass substrate, and then prepare a stainless steel scraper plate, fix the glass substrate and control the distance between the scraper plate and the glass substrate to adjust the film thickness, then move the stainless steel scraper plate horizontally until the molten polyethylene liquid is completely scraped, and then cool to room temperature to obtain a transparent transparent encapsulation film with a thickness controlled within 30μm. Another layer of transparent encapsulation film is prepared by the same method.

[0062] The preparation of the organic small molecule coating of the bicyclic aromatic olefin derivative is as follows:

[0063] Weigh 0.1 g of 9-(11 hydrogen-benzo[b]fluorenyl-11-eneyl)-10-(4-methoxyphenyl)-9,10-dihydroacridine powder and add it to 2 mL of N,N-dimethylformamide. After the powder is completely dissolved, the solution is scraped on a transparent packaging film. After the scraping is completed, it is placed on a 100°C heating plate to allow the solvent to completely evaporate to form a film with a thickness controlled within 30 μm. Then, a second layer of transparent packaging film is made on the transparent packaging film sprayed with an organic small molecule coating (the two layers of transparent packaging films are prepared using the same method). Finally, it is placed in a 110°C oven and heated for 4 hours to process the twisted configuration coating into a folded configuration coating, thereby obtaining an ultra-thin sandwich structure pressure-chromic film.

[0064] Embodiment 4:

[0065] This embodiment provides an embodiment of a sandwich structure pressure-chromic film with a total thickness of less than 100 μm, including the steps of preparing a transparent packaging film and preparing a di-tricyclic aromatic olefin derivative organic small molecule coating.

[0066] The preparation of the bicyclic aromatic olefin organic small molecule is as follows:

[0067] Weigh 1.1 g of 11-diazo-11H-benzo[b] (CAS No. 96615-37-1), 0.5 g of 10-(4-methoxyphenyl)acridine-9(10H)-thione (CAS No. 2356110-17-1) and 0.8 g of triphenylphosphine (CAS No. 603-35-0), add them together in 10 mL of mixed xylene (CAS No. 1330-20-7) and reflux at 140° C. for 1 h to generate 0.3 g of 9-(11-hydro-benzo[b]fluorenyl-11-enyl)-10-(4-methoxyphenyl)-9,10-dihydroacridine (structural formula: Figure 1 As shown in formula (II), R=OCH3).

[0068] Wherein, the preparation of transparent encapsulation film is as follows:

[0069] Weigh 1.0 g of polyvinyl chloride particles (cas number 9002-86-2K68-65) and add them to a glass beaker, heat to 80-100°C until the polyvinyl chloride particles are completely melted, then preheat the glass substrate to 75-100°C, pour the molten polyvinyl chloride liquid on the glass substrate, and then prepare a stainless steel scraper plate, fix the glass substrate and control the distance between the scraper plate and the glass substrate to adjust the thickness of the film, then move the stainless steel scraper plate horizontally until the molten polyvinyl chloride liquid is completely scraped, and then cool to room temperature to obtain a transparent transparent encapsulation film with a thickness controlled within 30 μm. Another layer of transparent encapsulation film is prepared by the same method.

[0070] The preparation of the organic small molecule coating of the bicyclic aromatic olefin derivative is as follows:

[0071] Weigh 0.1 g of 9-(11 hydrogen-benzo[b]fluorenyl-11-enyl)-10-(4-methoxyphenyl)-9,10-dihydroacridine powder and add it to 2 mL of N,N-dimethylformamide. After the powder is completely dissolved, the solution is scraped on a transparent packaging film. After the scraping is completed, it is placed on a 100°C heating plate to allow the solvent to completely evaporate to form a film with a thickness controlled within 30 μm. Finally, it is fumigated at room temperature in an ethyl acetate atmosphere for 2 h to flip the configuration. Then, a second layer of transparent packaging film is made on the transparent packaging film sprayed with an organic small molecule coating (the two layers of transparent packaging films are prepared using the same method), thereby obtaining an ultra-thin sandwich structure pressure-chromic film.

[0072] Embodiment 5:

[0073] This embodiment provides an embodiment of a sandwich structure pressure-chromic film with a total thickness of less than 100 μm, including the steps of preparing a transparent packaging film and preparing a di-tricyclic aromatic olefin derivative organic small molecule coating.

[0074] The preparation of the bicyclic aromatic olefin organic small molecule is as follows:

[0075] Weigh 1.3 g of 11-diazo-11H-benzo[b] (CAS No. 96615-37-1), 0.5 g of 10-(4-phenyl)acridine-9(10H)-thione (CAS No. 17435-20-0) and 0.9 g of triphenylphosphine (CAS No. 603-35-0), add them together in 10 mL of mixed xylene (CAS No. 1330-20-7) and reflux at 140° C. for 1 h to generate 0.3 g of 9-(11-hydro-benzo[b]fluorenyl-11-enyl)-10-(4-phenyl)-9,10-dihydroacridine (structural formula as shown in FIG. 1 ). Figure 1 As shown in formula (II), R=H).

[0076] Wherein, the preparation of transparent encapsulation film is as follows:

[0077] Weigh 1.0 g of polymethyl methacrylate (CAS No. 9011-14-7) with an average molecular weight of 35,000 and add it to 20 mL of acetone. Place it on a mixer to dissolve and mix it. Then take 1 to 2 mL of the solution and spin coat it on a glass substrate at a speed of 4000 to 6000 rpm. The spin coating time is controlled within 30 seconds. After the spin coating is completed, place it on a 50 to 60° C. heating plate to completely evaporate the solvent to form a film, and obtain a transparent transparent encapsulation film with a thickness controlled within 30 μm. Another layer of transparent encapsulation film is prepared by the same method.

[0078] The preparation of the organic small molecule coating of the bicyclic aromatic olefin derivative is as follows:

[0079] 0.4 g of 9-(11 hydrogen-benzo[b]fluorenyl-11-ylidene)-10-phenyl-9,10-dihydroacridine powder was weighed and completely evaporated on a transparent packaging film to form a film with a thickness controlled within 30 μm. The film was then reversed under room temperature fumigation with ethyl acetate, and then a second layer of transparent packaging film was made on the transparent packaging film sprayed with an organic small molecule coating (the two layers of transparent packaging films were prepared using the same method), thereby obtaining an ultra-thin sandwich structure pressure-chromic film.

[0080] Embodiment 6:

[0081] This embodiment provides an embodiment of a sandwich structure pressure-chromic film with a total thickness of less than 100 μm, including the steps of preparing a transparent packaging film and preparing a di-tricyclic aromatic olefin derivative organic small molecule coating.

[0082] The preparation of the bicyclic aromatic olefin organic small molecule is as follows:

[0083] Weigh 1.0 g of 11-diazo-11H-benzo[b] (CAS No. 96615-37-1), 0.5 g of 10-(4-biphenyl)acridine-9(10H)-thione (CAS No. 2356110-14-8) and 0.7 g of triphenylphosphine (CAS No. 603-35-0), add them together into 10 mL of mixed xylene (CAS No. 1330-20-7) and reflux at 140°C for 1 hour to generate 0.3 g of 9-(11-hydro-benzo[b]fluorenyl-11-enyl)-10-(4-biphenyl)-9,10-dihydroacridine (structural formula as shown in FIG. 1 ). Figure 1 As shown in formula (II), R=Ph).

[0084] Wherein, the preparation of transparent encapsulation film is as follows:

[0085] Weigh 1.0 g of polyvinyl chloride particles (cas number 9002-86-2K68-65) and add them to 20 mL of N, N-dimethylformamide. Place them on a mixer to dissolve and mix them. Then take 1 to 2 mL of the solution and spin coat it on a glass substrate at a speed of 4000 to 6000 rpm. The spin coating time is controlled at 30 s. After spin coating, place it on a 130 to 150 ° C heating plate to completely evaporate the solvent to form a film, and obtain a transparent transparent encapsulation film with a thickness controlled within 30 μm. Another layer of transparent encapsulation film is prepared by the same method.

[0086] The preparation of the organic small molecule coating of the bicyclic aromatic olefin derivative is as follows:

[0087] Weigh 0.4 g of 9-(11-hydrogen-benzo[b]fluorenyl-11-ylidene)-10-biphenyl-9,10-dihydroacridine powder and completely evaporate it on a transparent packaging film to form a film. The evaporation current is 6 A and the vacuum degree is 1.0×10 -4 Pa, the evaporation takes about 20 minutes from the start to the end, the thickness is controlled within 30μm, and then it is fumigated in ethyl acetate atmosphere at room temperature for 2h to flip its configuration, and then a second layer of transparent encapsulation film is made on the transparent encapsulation film sprayed with an organic small molecule coating (the two layers of transparent encapsulation films are prepared by the same method), thereby obtaining an ultra-thin sandwich structure pressure-chromic film.

[0088] Embodiment 7:

[0089] This embodiment provides an embodiment of a sandwich structure pressure-chromic film with a total thickness of less than 100 μm, including the steps of preparing a transparent packaging film and preparing a di-tricyclic aromatic olefin derivative organic small molecule coating.

[0090] The preparation of the bicyclic aromatic olefin organic small molecule is as follows:

[0091] Weigh 1.1 g of 11-diazo-11H-benzo[b] (CAS No. 96615-37-1), 0.5 g of 10-(4-nitrophenyl)acridine-9(10H)-thione (CAS No. 2356110-20-6) and 0.8 g of triphenylphosphine (CAS No. 603-35-0), add them together in 10 mL of mixed xylene (CAS No. 1330-20-7), reflux at 140° C. for 1 h, and generate 0.3 g of 9-(11-hydro-benzo[b]fluorenyl-11-enyl)-10-(4-nitrophenyl)-9,10-dihydroacridine (structural formula as shown in FIG. 1 ). Figure 1 As shown in formula (II), R = NO2).

[0092] Wherein, the preparation of transparent encapsulation film is as follows:

[0093] Weigh 1.0g of Dow Corning 184 polydimethylsiloxane liquid and add it to 20mL of cyclohexane. Place it on a mixer to dissolve and mix it. Then take 1-2mL of the solution and spin coat it on a glass substrate at a speed of 4000-6000rpm. The spin coating time is controlled within 30s. After spin coating, place it on a 50-60℃ heating plate to completely evaporate the solvent to form a film, and obtain a transparent transparent encapsulation film with a thickness controlled within 30μm. Another layer of transparent encapsulation film is prepared by the same method.

[0094] The preparation of the organic small molecule coating of the bicyclic aromatic olefin derivative is as follows:

[0095] 0.1 g of 9-(11 hydrogen-benzo[b]fluorenyl-11-ylidene)-10-(4-nitrophenyl)-9,10-dihydroacridine powder was weighed and added to methanol. The resulting suspension was subjected to 120 W ultrasonic treatment for 30 min to treat the twisted molecular suspension of the ditricyclic aromatic olefin into a folded molecular suspension. The folded molecular suspension was then centrifuged to remove the folded solid. 1 mL of pure water and 0.1% (volume percentage) of non-ionic surfactant Triton X-100 were added thereto. After dispersion and mixing in a cell disruptor, the solid was sprayed on a transparent packaging film. After spraying, the solid was placed on a 100° C. heating plate to completely evaporate the solvent to form a film, thereby obtaining a transparent packaging film with a thickness of less than 30 μm. A second transparent packaging film was then prepared on the transparent packaging film sprayed with an organic small molecule coating (the two transparent packaging films were prepared using the same method), thereby obtaining an ultra-thin sandwich structure pressure-chromic film.

[0096] Embodiment 8:

[0097] This embodiment provides an embodiment of a sandwich structure pressure-chromic film with a total thickness of less than 100 μm, including the steps of preparing a transparent packaging film and preparing a di-tricyclic aromatic olefin derivative organic small molecule coating.

[0098] The preparation of the bicyclic aromatic olefin organic small molecule is as follows:

[0099] Weigh 1.1 g of 11-diazo-11H-benzo[b] (CAS No. 96615-37-1), 0.5 g of 10-(4-nitrophenyl)acridine-9(10H)-thione (CAS No. 2356110-20-6) and 0.8 g of triphenylphosphine (CAS No. 603-35-0), add them together in 10 mL of mixed xylene and reflux at 140° C. for 1 h to generate 0.3 g of 9-(11-hydro-benzo[b]fluorenyl-11-enyl)-10-(4-nitrophenyl)-9,10-dihydroacridine (structural formula as shown in FIG. 1 ). Figure 1 As shown in formula (II), R = NO2).

[0100] Wherein, the preparation of transparent encapsulation film is as follows:

[0101] Weigh 1.0 g of polycaprolactone particles with a molecular weight of 80,000 (cas is 24980-41-4) and add them to 20 mL of acetone. Place them on a mixer to dissolve and mix them. Then take 1 to 2 mL of the solution and spin coat it on a glass substrate at a speed of 4000 to 6000 rpm. The spin coating time is controlled within 30 s. After the spin coating is completed, place it on a 50 to 60 ° C heating plate to completely evaporate the solvent to form a film, and obtain a transparent transparent encapsulation film with a thickness controlled within 30 μm. Another layer of transparent encapsulation film is prepared by the same method.

[0102] The preparation of the organic small molecule coating of the bicyclic aromatic olefin derivative is as follows:

[0103] Weigh 0.1 g of 9-(11-hydrogen-benzo[b]fluorenyl-11-ylidene)-10-(4-nitrophenyl)-9,10-dihydroacridine powder and add it to methanol. The resulting suspension is subjected to 120W ultrasonic treatment for 30 minutes to treat the twisted molecular suspension of the tricyclic aromatic olefin into a folded molecular suspension. The folded molecular suspension is then centrifuged, and the folded solid layer is taken out. 1 mL of pure water and 0.1% (volume percentage) of nonionic liquid are added thereto. The type surfactant Triton X-100 is dispersed and mixed in a cell disruptor and then sprayed on a transparent packaging film. After spraying, it is placed on a 100°C heating plate to allow the solvent to completely evaporate to form a film, thereby obtaining a transparent packaging film with a thickness controlled within 30 μm. Then, a second layer of transparent packaging film is made on the transparent packaging film sprayed with an organic small molecule coating (the two layers of transparent packaging films are prepared using the same method), thereby obtaining an ultra-thin sandwich structure pressure-chromic film.

[0104] Embodiment 9:

[0105] This embodiment provides an embodiment of a sandwich structure pressure-chromic film with a total thickness of less than 100 μm, including the steps of preparing a transparent packaging film and preparing a di-tricyclic aromatic olefin derivative organic small molecule coating.

[0106] The preparation of the bicyclic aromatic olefin organic small molecule is as follows:

[0107] Weigh 1.1 g of 11-diazo-11H-benzo[b] (CAS No. 96615-37-1), 0.5 g of 10-(4-nitrophenyl)acridine-9(10H)-thione (CAS No. 2356110-20-6) and 0.8 g of triphenylphosphine (CAS No. 603-35-0), add them together in 10 mL of mixed xylene and reflux at 140° C. for 1 h to generate 0.3 g of 9-(11-hydro-benzo[b]fluorenyl-11-enyl)-10-(4-nitrophenyl)-9,10-dihydroacridine (structural formula as shown in FIG. 1 ). Figure 1 As shown in formula (II), R = NO2).

[0108] Wherein, the preparation of transparent encapsulation film is as follows:

[0109] Weigh 1.0 g of polystyrene particles (cas is 9003-53-6) and add them to 20 mL of ethyl acetate. Place them on a mixer to dissolve and mix them. Then take 1 to 2 mL of the solution and spin coat it on a glass substrate at a speed of 4000 to 6000 rpm. The spin coating time is controlled within 30 s. After spin coating, place it on a 50 to 60 ° C heating plate to completely evaporate the solvent support film to obtain a transparent transparent encapsulation film with a thickness controlled within 30 μm. Another layer of transparent encapsulation film is prepared by the same method.

[0110] The steps of preparing the organic small molecule coating of the bicyclic aromatic olefin derivative include:

[0111] Weigh 0.5 g of 9-(11hydro-benzo[b]fluorenyl-11-ylidene)-10-(4-nitrophenyl)-9,10-dihydroacridine powder and completely evaporate it on a transparent packaging film to form a film with a thickness controlled within 30 μm. Heat it in an oven at 110°C for 4 hours to flip the configuration, and then make a second layer of transparent packaging film on the transparent packaging film sprayed with an organic small molecule coating (the two layers of transparent packaging films are prepared by the same method), thereby obtaining an ultra-thin sandwich structure pressure-chromic film.

[0112] Experimental example:

[0113] Taking the sandwich structure pressure-chromic film based on organic small molecules of bis-tricyclic aromatic olefin derivatives prepared in Example 8 as an example, the performance of the film was tested. The actual sample before the pressure test was as follows: Figure 3 The film is shown in yellow folded configuration. When measuring, the film is cut into a 4mm×4mm square size, and a sandpaper with an area of ​​4mm×4mm and a mesh size of 320 is used as a pressing plate. A pressure of 30MPa is applied by a tablet press at room temperature and pressure. Figure 4As shown, it becomes a yellow-green film, the raised parts of the sandpaper turn green, and the non-raised parts are yellow, which means that the folded configuration of the organic small molecule coating of the dicyclic aromatic olefin derivative is transformed into a twisted configuration, which shows that the pressure-chromic film provided by the present invention realizes pressure detection of uneven surfaces based on the color-changing mechanism of the configuration transformation of the organic small molecule dicyclic aromatic olefin derivative, and can maintain the pressure response characteristics when the pressure is withdrawn, and is a sandwich structure pressure-chromic film with great application potential.

[0114] At the same time, the film was cut into a square size of 4 mm × 4 mm, and a stainless steel sheet with an area of ​​4 mm × 4 mm was used as a pressing plate. After gradually applying pressure (0-30 MPa) with a tablet press, Figure 5 As shown in the figure, as the pressure gradually increases, the green color of the distorted configuration becomes darker. The average Lab color difference ΔE of the film is calculated and the standard curve of pressure is as follows: Figure 6 Shown: ΔE=[(ΔL)2+(Δa)2+(Δb)2]0 . 5, L represents black and white, 0 is black, 100 is white; A is red for positive value, green for negative value, 0 is neutral color; B is yellow for positive value, blue for negative value, 0 is neutral color; ΔL, Δa, Δb are the differences of lightness L and chromaticity index a, b between the reference sample and the sample under test. ΔE is positively correlated with pressure change. The greater the pressure, the greater the color difference and the greater the ΔE. Figure 6 This shows that the film can realize quantitative detection of pressure visualization and is a sandwich structure pressure-chromic film with great application potential.

[0115] In addition, the sandwich structure pressure-chromic films prepared in Examples 1-7 and Example 9 have the same pressure-induced chromic properties and are also sandwich structure pressure-chromic films with great application potential.

[0116] The embodiments of the present invention are described in detail above, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions and variations of these embodiments are made without departing from the principles and spirit of the present invention, and still fall within the protection scope of the present invention.

Claims

1. A sandwich structure pressure-chromic film based on bis-tricyclic aromatic olefins, characterized in that: The sandwich structure pressure-chromic film comprises two layers of transparent encapsulation films and a bi-tricyclic aromatic olefin derivative organic small molecule coating in the middle; under specific external stimulation, the bi-tricyclic aromatic olefin derivative organic small molecule can undergo a spatial configuration change, and the spatial configuration includes a folded configuration and a twisted configuration; The bicyclic aromatic olefin derivative organic small molecule includes 9-(11-hydrogen-benzo[a]fluorenyl-11-enylene)-10-(4-R-phenyl)-9,10-dihydroacridine as shown in formula (I) and 9-(11-hydrogen-benzo[b]fluorenyl-11-enylene)-10-(4-R-phenyl)-9,10-dihydroacridine as shown in formula (II): Wherein, R is selected from one of F, Br, CH3, OCH3, H, Ph, and NO2.

2. The sandwich structure pressure-chromic film based on bis-tricyclic aromatic olefins according to claim 1, characterized in that: The external stimulation includes pressure, acid-base stimulation, solvent fumigation, heating or light.

3. The sandwich structure pressure-chromic film based on bis-tricyclic aromatic olefins according to claim 1, characterized in that: The thickness of the di-tricyclic aromatic olefin derivative organic small molecule coating is controlled to be between 3 and 100 μm, the thickness of the transparent encapsulation film is controlled to be between 0.5 and 100 μm, and the total thickness of the sandwich structure pressure-chromic film is 5 to 300 μm.

4. The sandwich structure pressure-chromic film based on bis-tricyclic aromatic olefins according to claim 1, characterized in that: The dicyclic aromatic olefin derivative organic small molecule is synthesized by using a diazo compound and a thione compound as raw materials through a Keddon-Balogh reaction; the diazo compound includes 11-diazo-11H-benzo[a]fluorene or 11-diazo-11H-benzo[b]fluorene; the thione compound includes but is not limited to 10-(4-fluorophenyl)acridine-9(10H)-thione, 10-(4-bromophenyl)acridine-9(10H)-thione, The invention relates to one of acridine-9(10H)-thione, 10-(p-methylphenyl)acridine-9(10H)-thione, 10-(4-methoxyphenyl)acridine-9(10H)-thione, 10-phenylacridine-9(10H)-thione, 10-([1,1'-biphenyl]-4-yl)acridine-9(10H)-thione and 10-(4-nitrophenyl)acridine-9(10H)-thione.

5. The method for preparing the sandwich structure pressure-chromic film based on bis-tricyclic aromatic olefins according to any one of claims 1 to 4, characterized in that: The organic small molecules of the ditricyclic aromatic olefin derivatives are uniformly coated on a transparent packaging film to prepare a coating, and then a second layer of transparent packaging film is used for packaging to obtain a sandwich structure pressure-chromic film.

6. The method for preparing a sandwich structure pressure-chromic film based on bis-tricyclic aromatic olefins according to claim 5, characterized in that: The coating method of the bicyclic aromatic olefin derivative organic small molecule includes at least one of drop coating, spray coating, spin coating, scraping coating or chemical vapor deposition.

7. The method for preparing a sandwich structure pressure-chromic film based on bis-tricyclic aromatic olefins according to claim 6, characterized in that: Chemical vapor deposition uses a single di-tricyclic aromatic olefin derivative organic small molecule solid raw material as a precursor.

8. The method for preparing a sandwich structure pressure-chromic film based on bis-tricyclic aromatic olefins according to claim 6, characterized in that: The precursor solution is formed by drip coating, spray coating or spin coating using organic small molecule solid raw materials of di-tricyclic aromatic olefin derivatives and soluble low-boiling point organic solvents or soluble high-boiling point organic solvents; the soluble low-boiling point organic solvent includes at least one of acetonitrile, dioxane, tetrahydrofuran, acetone, butanone, ethyl acetate, dichloromethane, and diethyl ether; the soluble high-boiling point organic solvent includes at least one of N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, and ethylene glycol dimethyl ether.

9. The method for preparing a sandwich structure pressure-chromic film based on bis-tricyclic aromatic olefins according to claim 6, characterized in that: The scraping uses organic small molecule solid raw materials of di-tricyclic aromatic olefin derivatives, insoluble low boiling point solvents and non-ionic surfactants to form a precursor emulsion; the insoluble low boiling point solvent includes at least one of water, methanol, ethanol, cyclohexane, n-hexane and petroleum ether, and the non-ionic surfactant includes at least one of polyoxyethylene type, polyol type and polyether type.

10. Application of the sandwich structure pressure-chromic film based on bis-tricyclic aromatic olefins as claimed in any one of claims 1 to 4 in the field of pressure detection.

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