Splicing preparation method of stepped temperature-sensitive hydrogel based on organic long afterglow material

Abstract

The splicing preparation method of the stepped temperature-sensitive hydrogel based on the organic long afterglow material specifically comprises the following steps: cutting and splicing a plurality of groups of composite hydrogel with different temperature stimulation responses, and freezing at low temperature for 12-18 hours to obtain the stepped temperature-sensitive hydrogel, the composite hydrogel with different temperature stimulus responses is prepared by respectively adding water and a long-afterglow luminescent material into PEG and PVA according to a weight ratio of 30-40%, heating, stirring and circularly freezing and thawing, the concentration of PVA in water is 7-10%, and the percentage of the long-afterglow luminescent material in water is 2-5%. Based on the self-healing characteristic of hydrogel, the prepared flexible hydrogel with temperature stimulation response is cut and spliced, the hydrogel with stepped temperature sensing is prepared, the hydrogel can be recycled and has excellent flexibility and stability, and intelligent application of the LPL material is greatly improved.

Description

Technical Field

[0002] The invention belongs to the technical field of application of organic long afterglow materials, and in particular relates to a method for splicing and preparing a stepped temperature-sensitive hydrogel based on organic long afterglow materials. Background Art

[0003] In recent years, long persistent luminescence (LPL) materials have attracted widespread attention due to their unique optical properties, especially their potential applications in bioimaging, anti-counterfeiting, information storage and other fields. Stimulus-responsive LPL materials respond to external stimuli (such as temperature, pressure, humidity, etc.) and show great application potential. Among them, temperature-responsive LPL materials are particularly eye-catching because they can exhibit controllable long persistent luminescence characteristics under specific temperature conditions, making them suitable for practical application scenarios such as temperature sensing and intelligent response.

[0004] In the development of temperature-responsive LPL materials, the host-guest doping strategy has been widely used due to its advantages of low cost, structural diversity, and easy scalable preparation. However, the development of temperature-responsive LPL materials currently faces challenges of poor flexibility and processability, which limits their flexibility and diversity in practical applications. To overcome these limitations, we proposed a strategy to combine LPL-doped materials with hydrogels. Hydrogels are ideal carrier materials due to their light weight, easy processing, good flexibility, and self-healing properties. Summary of the invention

[0005] In order to overcome the above shortcomings, the present invention provides a method for splicing and preparing a stepped temperature-sensitive hydrogel based on an organic long afterglow material. By combining LPL material with hydrogel, we prepared a composite hydrogel that not only has temperature response characteristics, but also can achieve flexible multi-step temperature response through self-healing and splicing. This innovative strategy not only enhances the flexibility of the material, but also expands the application potential of LPL materials in temperature detection and intelligent response systems. In order to achieve the above purpose, the technical solution adopted by the present invention is: A method for preparing a step-type temperature-sensitive hydrogel based on organic long afterglow materials by splicing is as follows: cutting and splicing multiple groups of composite hydrogels with different temperature stimulus responses and then freezing them at low temperatures for 12-18 hours to obtain a step-type temperature-sensitive hydrogel; The composite hydrogel with different temperature stimulus responses is obtained by adding PEG and PVA in a weight ratio of 30%-40% to water and a long afterglow luminescent material, respectively, wherein the concentration of PVA in water is 7-10%, and the percentage of the long afterglow luminescent material in water is 2-5%.

[0006] After further optimization, the specific preparation method of the composite hydrogel is as follows: organic long afterglow luminescent material, PVA and PEG are added to deionized water and heated and stirred to obtain a white emulsion which is then poured into a mold, and a composite hydrogel with temperature stimulus response is obtained through freeze-thaw cycles.

[0007] Further optimization, the heating temperature is 90-100° C., and the stirring time is 3-5 h.

[0008] Further optimization, the freeze-thaw time is 12-18 hours, and the number of freeze-thaw cycles is 3-5 times.

[0009] Further optimization, the long afterglow luminescent material includes a host material and a guest material, the host material is diphenylamine, phenyl benzoate and triphenylphosphine, the guest material is N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine, N,N'-diphenylbenzidine and N,N'-diphenyl-N,N'-bis(4-methylphenyl)-4,4'-biphenyl diamine, and the following three doping are performed: diphenylamine and N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine, phenyl benzoate and N,N'-diphenyl-N,N'-bis(4-methylphenyl)-4,4'-biphenyl diamine, triphenylphosphine and N,N'-diphenylbenzidine.

[0010] According to further optimization, the number of the multiple groups of composite hydrogels having different temperature stimulation responses is three groups.

[0011] The beneficial effects of the present invention are: 1. By selecting an organic long-lasting luminescent material with a suitable melting point and combining it with a composite hydrogel, a flexible hydrogel with temperature stimulus response is prepared; 2. Based on the self-healing property of hydrogels, the present invention cuts and splices multiple groups of flexible hydrogels with temperature stimulus response to prepare hydrogels with stepped temperature sensation; 3. The temperature detection system of the present invention can be flexibly spliced ​​according to needs; 4. The stepped temperature-sensitive hydrogel of the present invention can be recycled, which greatly improves its practical application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the temperature stimulus response mechanism of the stepped temperature-sensitive long afterglow in the present invention; Figure 2 This is a performance display diagram of the stepped temperature-sensitive long afterglow prepared in the present invention; Figure 3 Schematic diagram of preparation of stepped temperature-sensitive hydrogel in the present invention; Figure 4This is a performance display diagram of the stepped temperature-sensitive hydrogel 1 prepared in Example 4 of the present invention; Figure 5 This is a performance display diagram of the stepped temperature-sensitive hydrogel 2 prepared in Example 5 of the present invention; Figure 6 This is a performance display diagram of the stepped temperature-sensitive hydrogel 3 prepared in Example 6 of the present invention; Figure 7 is a scanning electron microscope image of the stepped temperature-sensitive hydrogel 3 prepared in Example 6 of the present invention; Figure 8 This is a graph showing the cyclic performance of the stepped temperature-sensitive hydrogel 3 prepared in Example 6 of the present invention; Fig. 9 This is a graph showing the water stability and tensile properties of the stepped temperature-sensitive hydrogel 3 prepared in Example 6 of the present invention. DETAILED DESCRIPTION

[0013] In order to more clearly understand the above-mentioned purposes, features and advantages of the present invention, the present invention is described in detail below in conjunction with specific embodiments. The following embodiments are implemented based on the technical solutions of the present invention, and detailed implementation methods and specific operating procedures are given. However, the present invention can also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the following embodiments.

[0014] In the present invention, N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine (NPD) and N,N'-diphenylbenzidine (NDPB) were purchased from San Chemical Technology Co., Ltd. (purity: 98%-99%); triphenylphosphine (TPP), phenyl benzoate (BP) and polyvinyl alcohol (PVA, MW105000) were purchased from Anhui Zesheng Technology Co., Ltd. N,N'-diphenyl-N,N'-bis(4-methylphenyl)-4,4'-biphenyl diamine (p-TPD) and polyethylene glycol (PEG 4000) were purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0015] The instruments and models involved in the tests in the following embodiments are: Ocean Optics multi-band spectrometer, FlexSEM 1000 scanning electron microscope, F-7000 fluorescence spectrometer; Room temperature: 20~25 ℃.

[0016] The power of the UV lamp in the following examples is 20 W (365 nm).

[0017] A method for preparing a stepped temperature-sensitive hydrogel based on organic long afterglow materials by splicing is provided, wherein PEG and PVA are added to water and a long afterglow luminescent material in a weight ratio of 30%-40%, respectively, wherein the concentration of PVA in water is 7-10%, and the percentage of the long afterglow luminescent material in water is 2-5%, to prepare a plurality of groups of composite hydrogels with different temperature stimulus responses, and the plurality of groups of composite hydrogels with different temperature stimulus responses are cut and spliced ​​and then cryogenically frozen for 12-18 hours to obtain a stepped temperature-sensitive hydrogel.

[0018] The long afterglow luminescent material includes a host material and a guest material, wherein the host material is diphenylamine (DPA), phenyl benzoate (PB) and triphenylphosphine (TPP), and the guest material is N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine (NPD), N,N'-diphenylbenzidine (NDPB) and N,N'-diphenyl-N,N'-bis(4-methylphenyl)-4,4'-biphenyl diamine (p-TPD), and the following three dopings are performed: diphenylamine and N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine, phenyl benzoate and N,N'-diphenyl-N,N'-bis(4-methylphenyl)-4,4'-biphenyl diamine, triphenylphosphine and N,N'-diphenylbenzidine.

[0019] Figure 1 It is a schematic diagram of the temperature stimulus response mechanism of the step-type temperature-sensitive long afterglow in the present invention. As can be seen from the figure, when the temperature reaches the melting point of the main material, the main body in the long afterglow luminescent material cannot provide a good rigid environment, resulting in the loss of afterglow performance.

[0020] Figure 2 This is a performance display diagram of the stepped temperature-sensitive long afterglow prepared in the present invention. It can be seen from the figure that the doping materials DPA:NDPB, BP:p-TPD and TPP:NPD have good afterglow performance, and there are color differences between the three doping materials, which is conducive to the identification of the temperature-sensitive hydrogel when measuring temperature.

[0021] Among them, the specific preparation methods of three temperature-sensitive hydrogels doped with materials DPA:NDPB, BP:p-TPD and TPP:NPD are as shown in the following Examples 1-3.

[0022] Example 1 Preparation of 55℃ temperature-sensitive hydrogel: 1.00 g DPA:NDPB organic long afterglow luminescent material, 2.40 g PVA and 0.96 g PEG were added to 30 mL of deionized water, and then stirred at 95℃ for 3 h to obtain a white emulsion. The emulsion was poured into a mold and then freeze-thawed four times to obtain a 55℃ temperature-sensitive hydrogel.

[0023] Example 2 Preparation of 75℃ temperature-sensitive hydrogel: 1.00 g of BP:p-TPD organic long afterglow luminescent material, 2.40 g of PVA and 0.96 g of PEG were added to 30 mL of deionized water, and then stirred at 95℃ for 3 h to obtain a white emulsion. The emulsion was poured into a mold and then freeze-thawed four times to obtain a 75℃ temperature-sensitive hydrogel.

[0024] Example 3 Preparation of 80℃ temperature-sensitive hydrogel: 1.00 g of TPP:NPD organic long afterglow luminescent material, 2.40 g of PVA and 0.96 g of PEG were added to 30 mL of deionized water, and then stirred at 95℃ for 3 h to obtain a white emulsion. The emulsion was poured into a mold and then freeze-thawed four times to obtain an 80℃ temperature-sensitive hydrogel.

[0025] By splicing any two or three of the three groups of temperature-sensitive hydrogels prepared in Examples 1-3, different stepped temperature-sensitive hydrogels can be obtained. The specific preparation method is shown in the following Examples 4-6.

[0026] Example 4 Preparation of 55°C stepped temperature-sensitive hydrogel by splicing: The temperature-sensitive hydrogels prepared in Example 1 and Example 3 were sheared, and frozen for 12-18 hours in a tightly spliced ​​state to obtain a stepped temperature-sensitive hydrogel 1.

[0027] Figure 4 This is a performance display diagram of the stepped temperature-sensitive hydrogel 1 prepared in Example 4 of the present invention. It can be seen from the figure that the temperature-sensitive hydrogel 1 can undergo DPA:NDPB regional quenching at 55°C, achieving clear temperature discrimination.

[0028] Example 5 Preparation of 75°C stepped temperature-sensitive hydrogel by splicing: The temperature-sensitive hydrogels prepared in Example 2 and Example 3 were sheared, and frozen for 12-18 hours in a tightly spliced ​​state to obtain stepped temperature-sensitive hydrogel 2.

[0029] Figure 5 This is a performance display diagram of the stepped temperature-sensitive hydrogel 2 prepared in Example 5 of the present invention. It can be seen from the figure that the temperature-sensitive hydrogel 2 can undergo BP:p-TPD regional quenching at 75°C, achieving clear temperature discrimination.

[0030] Example 6 Preparation of 55°C and 75°C stepped temperature-sensitive hydrogels by splicing: The temperature-sensitive hydrogels prepared in Example 1, Example 2 and Example 3 were sheared, and frozen for 12-18 hours in a tightly spliced ​​state to obtain a stepped temperature-sensitive hydrogel 3.

[0031] Figure 6 This is a performance display diagram of the step-type temperature-sensitive hydrogel 3 prepared in Example 6 of the present invention. As can be seen from the figure, the temperature-sensitive hydrogel 3 has a dual-step temperature-sensitive performance, and DPA:NDPB regional quenching can occur at 55°C, and BP:p-TPD regional quenching can occur at 75°C. At the same time, due to the different afterglow colors of the long afterglow materials, clear temperature discrimination is achieved. Figure 7 This is a scanning electron microscope image of the stepped temperature-sensitive hydrogel 3 prepared in Example 6 of the present invention. As can be seen from the figure, the large number of holes inside the gel are conducive to the uniform dispersion of the LPL material, so that the temperature-sensitive hydrogel still has uniform luminescence performance under deformation. Figure 8 This is a graph showing the recycling performance of the step-type temperature-sensitive hydrogel 3 prepared in Example 6 of the present invention. As can be seen from the figure, the gel has good recycling performance and can have excellent application potential. Fig. 9 This is a diagram showing the water stability and tensile properties of the stepped temperature-sensitive hydrogel 3 prepared in Example 6 of the present invention. As can be seen from the figure, the presence of the gel protects the LPL material very well, making it have good stability in water, and still has uniform luminescence performance under stretching. These excellent properties show that the stepped temperature-sensitive hydrogel has excellent flexibility and stability, greatly improving the intelligent application of LPL materials.

[0032] The above shows and describes the main features, methods of use, basic principles and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited by the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements according to actual conditions, and these changes and improvements fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for preparing a step-by-step temperature-sensitive hydrogel based on organic long afterglow materials, characterized in that: The specific preparation method is as follows: cutting and splicing multiple groups of composite hydrogels with different temperature stimulus responses and then freezing them at low temperatures for 12-18 hours to obtain a stepped temperature-sensitive hydrogel; The composite hydrogel with different temperature stimulus responses is obtained by adding PEG and PVA in a weight ratio of 30%-40% to water and a long afterglow luminescent material, respectively, wherein the concentration of PVA in water is 7-10%, and the percentage of the long afterglow luminescent material in water is 2-5%.

2. The method for preparing the step-by-step temperature-sensitive hydrogel based on the organic long afterglow material according to claim 1, characterized in that: The specific preparation method of the composite hydrogel is as follows: adding an organic long afterglow luminescent material, PVA and PEG into deionized water, heating and stirring, preparing a white emulsion, and then pouring it into a mold, and obtaining a composite hydrogel with temperature stimulus response through a freeze-thaw cycle.

3. The method for preparing the step-by-step temperature-sensitive hydrogel based on the organic long afterglow material according to claim 2, characterized in that: The heating temperature is 90-100° C. and the stirring time is 3-5 h.

4. The method for preparing the step-by-step temperature-sensitive hydrogel based on the organic long afterglow material according to claim 2, characterized in that: The freeze-thaw time is 12-18 hours, and the number of freeze-thaw cycles is 3-5 times.

5. The method for preparing the step-by-step temperature-sensitive hydrogel based on the organic long afterglow material according to claim 1, characterized in that: The long afterglow luminescent material includes a host material and a guest material, wherein the host material is diphenylamine, phenyl benzoate and triphenylphosphine, and the guest material is N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine, N,N'-diphenylbenzidine and N,N'-diphenyl-N,N'-bis(4-methylphenyl)-4,4'-biphenyl diamine, and the following three dopings are performed: diphenylamine and N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine, phenyl benzoate and N,N'-diphenyl-N,N'-bis(4-methylphenyl)-4,4'-biphenyl diamine, triphenylphosphine and N,N'-diphenylbenzidine.

6. The method for preparing the step-by-step temperature-sensitive hydrogel based on the organic long afterglow material according to claim 1, characterized in that: The number of the multiple groups of composite hydrogels having different temperature stimulus responses includes but is not limited to three groups.

Images