A freeze history indicator and use thereof

Abstract

The application provides a freezing history indicator, which comprises a diaryl viologen and a guanidine macrocycle, the diaryl viologen has a structure as shown in the figure, R is a methanethiol group, a methoxy group, a nitrogen-nitrogen dimethyl group or other electron-donating groups, and the guanidine macrocycle has a structure as shown in the figure; the freezing history indicator has low cost, can indicate the sample alone after being packaged, and has obvious fluorescence color contrast before and after freezing; the fluorescence color remains unchanged after the indicator is recovered to normal from freezing, and the indicator does not recover to the normal state before freezing, so that the display effect is good, and whether the substance has experienced the freezing process can be clearly indicated; the technology is based on materials with low cost, small dosage, easy preparation and portable labels, and can be used for following the product to detect the freezing history of the whole logistics process.

Description

Technical Field

[0001] This invention relates to the field of monitoring indicators, to a freezing history indicator and its application, specifically to compositions, devices comprising the compositions, and methods for using them to monitor historical information on whether food, pharmaceuticals, etc., have been frozen. Background Technology

[0002] In daily life, due to the complexity of environmental factors, food, medicine, and other items may undergo a freezing and thawing process, returning to a non-frozen state. The ice crystals produced during this process can damage cell or protein structures, leading to accelerated food spoilage and drug inactivation. For observers, this historical information about the freezing process is missing, making it difficult to determine from appearance whether a substance has undergone freezing. While precise temperature recording devices such as digital thermometers can be used in actual production and transportation to record whether batches of items have undergone freezing, they are insufficiently accurate for individual objects, resulting in unclear display effects and failing to solve the problem of visual judgment. Currently, there is a lack of low-cost and convenient freezing indication technology; therefore, the application of low-cost and simple indicators to monitor this historical process has become both a need and a challenge.

[0003] The freezing history indicator described in this invention is low-cost and can be individually used to indicate samples after encapsulation. This indicator exhibits a clear contrast in fluorescence color before and after freezing, and the fluorescence color remains unchanged after the sample returns to its pre-freezing state, providing good visibility and clearly indicating whether a substance has undergone a freezing process. This technology is based on low-cost materials, requires small quantities, and is easy to manufacture into portable tags, which can be used to track the freezing history of products throughout their entire logistics process. Summary of the Invention

[0004] The purpose of this invention is to address the problem that food or medicine may lack freezing history information during transportation and storage by proposing a simple indicator for monitoring freezing history and its application, thereby solving the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A frozen history indicator comprising diaryl viologen and a guanidine macrocycle:

[0007] The structure of the diaryl viologen is as follows:

[0008]

[0009] R is an electron-donating group;

[0010] The macrocyclic structure of the guanidine is as follows:

[0011]

[0012] Furthermore, the electron-donating group is methylthio, methoxy, or aziridinedimethyl. Furthermore, the n=8 in the guanidine macrocyclic structure.

[0013] Furthermore, the molar ratio of the diaryl viologen to the guanidine macrocycle is 1:0.5 to 2.

[0014] Furthermore, it also includes a solvent, which is pure water.

[0015] Furthermore, the preparation method of the diaryl viologen is as follows: 1,1'-bis(2,4-dinitrophenyl)-4,4'-bipyridinium dichloride and aniline with an electron-donating group at the para position are heated under reflux in an ethanol solution. After the reactants are cooled to room temperature, the ethanol is removed by rotary evaporation under reduced pressure. A small amount of methanol is added to the obtained solid to dissolve it, and the solid is then precipitated by adding a large amount of diethyl ether. The above methanol solution-diethyl ether precipitation is repeated several times, and the product is obtained by vacuum drying.

[0016]

[0017] Furthermore, it is obtained by condensing glycosuria and paraformaldehyde under acidic conditions and then recrystallizing them in multiple stages.

[0018]

[0019] Another objective of this invention is to provide a freezing history indicator device, which involves bonding a grooved sheet to the interface of a storage container using a UV-sensitive adhesive. During bonding, an injection port is left at the bonding point beforehand. A mixture of diaryl viologen and guanidine macrocyclic compounds prepared at room temperature is injected into the mixture while ensuring no air bubbles remain. Finally, the injection port is sealed with an adhesive to obtain the freezing history indicator device.

[0020] The sheet will deform or melt when heated to 80°C.

[0021] The materials used for storing the items include glass and plastic.

[0022] Another object of the present invention is to provide an application of a freezing history indicator in monitoring freezing history.

[0023] After freeze-activation, the electron-donating group R facilitates the formation of a special assembly structure between diaryl viologen and guanidine macrocycles. Once the temperature returns to room temperature, thermal fluctuations are insufficient to reassemble the activated structure. The activated assembly structure is restored to its state before freezing activation, thereby enabling the indication and recording of freeze history.

[0024] Electron-donating groups containing heteroatoms exhibit n-π transitions, resulting in a redshift in both absorption and emission, placing them within the visible light region for easy observation with the naked eye.

[0025] Compared with the prior art, the present invention, employing the above technical solution, has the following technical effects:

[0026] The freezing history indicator described in this invention is low in cost, and the packaged freezing history indicator device can independently indicate the sample. This indicator exhibits a clear contrast in fluorescence color before and after freezing, and the fluorescence color remains unchanged after the substance returns to its pre-freezing state, providing good display effect and clearly indicating whether a substance has undergone a freezing process. This technology is based on low-cost materials, requires small quantities, and is easy to manufacture into portable tags, which can be used to track the freezing history of a product throughout its entire logistics process. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 The experimental group 1 and the control group 2 of this invention are packaged to form an indicator device B;

[0029] Figure 2 The indication state of the indicator device B of the present invention in experimental group 1 and control group 2 at room temperature;

[0030] Figure 3 The indication states of the indicator device B of the present invention are shown in experimental group 1 (which has undergone a freezing process and has not thawed) and control group 2 (which has undergone a cooling process and has not frozen).

[0031] Figure 4 The indication states of the indicator device B of the present invention are shown in experimental group 1 (which has undergone a freezing process and then thawed) and control group 2 (which has undergone a cooling process and has not been frozen). Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] Example 1

[0034] The structure of diaryl viologen is:

[0035] R is a methylthio group;

[0036] 1,1'-bis(2,4-dinitrophenyl)-4,4'-bipyridinium dichloride and aniline with an electron-donating methylthio group at the para position were heated under reflux in an ethanol solution for 6 hours. After the reactants were cooled to room temperature, the ethanol was removed by rotary evaporation under reduced pressure at 50°C. A small amount of methanol was added to dissolve the solid, and the solid was then precipitated by adding a large amount of diethyl ether. The above methanol-diethyl ether precipitation was repeated twice, and the product was dried under vacuum to obtain the product.

[0037] The macrocyclic structure of the guanidine is as follows:

[0038] n = 8.

[0039] It is obtained by condensing glycosuria and paraformaldehyde under acidic conditions and then recrystallizing in multiple stages.

[0040] Indicator A is made by bonding a grooved sheet to the interface of a storage container with a UV photosensitive adhesive. During bonding, an injection port is left at the bonding point in advance. Under the condition of ensuring no air bubbles remain, a mixture of diaryl viologen and guanidine macrocyclic compounds prepared at a molar ratio of 1:0.5 at room temperature is injected into the container. Finally, the injection port is sealed with adhesive to obtain the freezing history indicator A.

[0041] Example 2

[0042] The structure of diaryl viologen is:

[0043] R stands for methoxy group;

[0044] 1,1'-bis(2,4-dinitrophenyl)-4,4'-bipyridinium dichloride and aniline with an electron-donating methoxy group at the para position were heated under reflux in an ethanol solution for 6 hours. After the reactants were cooled to room temperature, the ethanol was removed by rotary evaporation under reduced pressure at 50°C. A small amount of methanol was added to dissolve the solid, and the solid was then precipitated by adding a large amount of diethyl ether. The above methanol-diethyl ether precipitation was repeated twice, and the product was dried under vacuum to obtain the product.

[0045] The macrocyclic structure of the guanidine is as follows:

[0046] n = 8.

[0047] It is obtained by condensing glycosuria and paraformaldehyde under acidic conditions and then recrystallizing in multiple stages.

[0048] Indicator B is made by bonding a grooved sheet to the interface of a storage container with a UV-sensitive adhesive. During bonding, an injection port is left at the bonding point in advance. Under the condition of ensuring no air bubbles remain, a mixture of diaryl viologen and guanidine macrocyclic compounds prepared at a molar ratio of 1:1 at room temperature is injected into the container. Finally, the injection port is sealed with adhesive to obtain the freezing history indicator B.

[0049] Example 3

[0050] The structure of diaryl viologen is:

[0051] R stands for nitrogen-nitrodimethyl;

[0052] 1,1'-bis(2,4-dinitrophenyl)-4,4'-bipyridinium dichloride and aniline with an electron-donating N-N dimethyl group at the para position were heated under reflux in an ethanol solution for 6 hours. After the reactants were cooled to room temperature, the ethanol was removed by rotary evaporation under reduced pressure at 50°C. A small amount of methanol was added to dissolve the solid, and the solid was then precipitated by adding a large amount of diethyl ether. The above methanol-diethyl ether precipitation was repeated three times, and the product was dried under vacuum to obtain the product.

[0053] The macrocyclic structure of the guanidine is as follows:

[0054] n = 8.

[0055] It is obtained by condensing glycosuria and paraformaldehyde under acidic conditions and then recrystallizing in multiple stages.

[0056] The indicator device C is made by bonding a grooved sheet to the interface of the storage container with a UV photosensitive adhesive. During bonding, an injection port is left at the bonding point in advance. Under the condition of ensuring no air bubbles remain, a mixture of diaryl viologen and guanidine macrocyclic compounds prepared at a molar ratio of 1:2 at room temperature is injected into the container. Finally, the injection port is sealed with adhesive to obtain the freezing history indicator device C.

[0057] Example 4

[0058] Both experimental group 1 and control group 2 consisted entirely of pure water, with a freezing history indicator sealed on the bottle cap to form indicator device 2, see [link to device 2]. Figure 1 Both experimental group 1 and control group 2 showed orange fluorescence in the initial unfrozen state, as indicated. Figure 2 In experimental group 1, after undergoing the freezing process (without thawing), the indicator showed green fluorescence; in control group 2, which only underwent the cooling process (without freezing), the indicator remained orange. Figure 3 After thawing, the indicator in experimental group 1 still showed green fluorescence, while that in control group 2 showed orange fluorescence. Figure 4 This indicates that the sample has undergone a freezing history process.

[0059] This invention has significant application value and broad application potential. It is not limited to monitoring the freezing history of food and pharmaceuticals; this indicator can also be applied to aqueous systems where monitoring is required below 0 degrees Celsius. For example, in temperature-sensitive environments, such as polar or high-altitude research stations, this indicator can be used to monitor environmental changes and provide visual indicators of temperature history.

[0060]

[0061] The fluorescence or solution color of indicator devices A, B, and C in their initial unfrozen state, as well as the changes in apparent fluorescence or solution color and absorption-emission spectra after undergoing freezing and thawing processes at or below 0 degrees Celsius.

[0062] When we heat the indicator to above 80°C, we can wipe away the frozen activated products and achieve reversible recycling.

[0063] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. It should be noted that implementations not illustrated or described in the drawings or the main text of the specification are forms known to those skilled in the art and have not been described in detail.

[0064] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A freeze history indicator device, characterized in that: A freezing history indicator, comprising diaryl viologen and guanidine macrocyclic compounds, is encapsulated. The encapsulation process includes: bonding a grooved sheet to the interface of a storage container using a UV-sensitive adhesive; pre-leaving an injection port at the bonding point during bonding; injecting a room-temperature mixture of diaryl viologen and guanidine macrocyclic compounds into the mixture while ensuring no air bubbles remain; and finally sealing the injection port with adhesive to obtain a freezing history indicator device. The structure of the diaryl viologen is as follows: ， Where R is an electron-donating group; The macrocyclic structure of the guanidine is as follows: ，n=8； The electron-donating group in the diaryl viologen structure is methylthio, methoxy, or nitrogen-nitrodimethyl; the molar ratio of the diaryl viologen to the guanidine macrocycle is 1:0.5~2.

2. The freeze history indicator device according to claim 1, characterized in that: The freezing history indicator also includes a solvent, which is pure water.

3. The freeze history indicator device according to claim 1, characterized in that: The preparation method of the diaryl viologen is as follows: 1,1'-bis(2,4-dinitrophenyl)-4,4'-bipyridinium dichloride and aniline with an electron-donating group at the para position are heated under reflux in an ethanol solution. After the reactants are cooled to room temperature, the ethanol is removed by rotary evaporation under reduced pressure. The obtained solid is dissolved in methanol and then precipitated in diethyl ether. The above process of methanol dissolution-diethyl ether precipitation is repeated and then vacuum dried to obtain the product.

4. The freeze history indicator device according to claim 1, characterized in that: The guanidine macrocycle is prepared by condensing glycoside urea and paraformaldehyde under acidic conditions and then recrystallizing.

5. The application of the freezing history indicator device according to claim 1 in monitoring freezing history.

6. The application in monitoring freezing history according to claim 5, characterized in that: The freeze history indicator can monitor whether the device has experienced a freezing history.

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