Preparation method and application of near-infrared carbonized polymer dot aggregate

Abstract

The invention discloses a preparation method and application of a near-infrared carbonized polymer dot aggregate, and relates to the technical field of composite material preparation. Comprising the following steps: assembling carbonized polymer dots (CPDs) in a hydrogen bond acceptor solvent to obtain a CPDs aggregate; the CPDs are prepared from citric acid and benzoylurea. The specific implementation method of the application in the preparation of the photo-thermoelectric conversion equipment comprises the following steps: blending the CPDs aggregate with a polymer to carry out hybridization reaction to obtain a photo-thermal conversion module; the photo-thermal conversion module is loaded on a semiconductor device to form photo-thermoelectric conversion equipment. The preparation method of the CPDs aggregate is simple and efficient, the construction controllability of the aggregate is improved, and the CPDs aggregate has an efficient photo-thermal conversion effect and has a good application prospect in the aspect of photo-thermoelectric continuous energy transfer devices or photo-thermoelectric generators.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon nanomaterials, and particularly to a preparation method and application of near-infrared carbonized polymer dot aggregates. Background Art

[0002] As a new member of the quantum dot family, Carbonized Polymer Dots (CPDs) have attracted the attention of many researchers due to their low toxicity, simple synthesis, and easy assembly. Hydrogen Bond (H-Bond) is a special supramolecular force, and its strength depends on the types and strengths of the proton donor (D) and acceptor (A). The shell structure of CPDs contains abundant proton donors, which provides an opportunity to construct and stabilize CPD aggregates using strong proton acceptors. However, the current method of constructing CPD aggregates using hydrogen bonds has strong randomness and insufficient repeatability. Therefore, there is an urgent need for some simple and effective strategies to improve the controllability of CPD aggregate construction.

[0003] In addition, as one of the most basic processes in nature, photothermal conversion widely exists in physical, chemical, and biological reactions. Some photons in sunlight can be absorbed by substances and effectively convert light energy into heat energy to achieve the full utilization of renewable solar energy. The construction of CPD aggregates using hydrogen bonds and polymer shells can greatly expand the π-conjugated plane, promote the generation of synergy between particles, and make the aggregates have broader and stronger absorption peaks, which provides an opportunity for efficient photothermal conversion.

[0004] Currently, the depletion of traditional fossil fuels and the large emissions of greenhouse gases can no longer meet the increasing living standards of humans and the urgent needs of modern industrial development. In recent years, the energy conversion method of directly converting heat energy into electrical energy (based on the Seebeck effect) has attracted the attention of scientific researchers because of its advantages of continuous supply, maintenance-free, and pollution-free. However, combining thermoelectric conversion and photothermal conversion to achieve continuous energy transfer of light, heat, and electricity is still a major challenge in the development of new energy. Summary of the Invention

[0005] The purpose of the present invention is to provide a preparation method and application of near-infrared carbonized polymer dot aggregates. By assembling CPDs in a hydrogen bond acceptor solvent, CPD aggregates can be quickly and massively constructed. The constructed CPD aggregates have excellent photothermal conversion effects. Hybridizing the CPD aggregates with polymer materials to prepare a photothermal conversion module, and the photothermal conversion module can be applied to the preparation of photothermal conversion devices, such as photothermal-electric continuous energy transfer devices or photothermal-electric generators, etc., which have good application prospects.

[0006] To solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0007] A preparation method of near-infrared carbonized polymer dot aggregates, comprising the following steps: CPDs are assembled in a hydrogen bond acceptor solvent to obtain CPDs aggregates;

[0008] The CPDs are prepared from citric acid and benzoylurea.

[0009] The CPDs are added to the hydrogen bond acceptor solvent, and the proton donors in the CPDs shell interact with the hydrogen bond acceptor solvent molecules, thereby constructing CPDs aggregates.

[0010] The CPDs used in the present invention are prepared from citric acid and benzoylurea. The specific preparation method includes the following steps: citric acid and benzoylurea are mixed in a mass ratio of 0.5 - 3:1 - 6, 1 - 10 mL of solvent N,N-dimethylformamide is added, 0.01 - 0.2 g of ammonium fluoride is added as a fluorine source additive, and solvothermal preparation is carried out at 120 - 280 °C for 0.5 - 24 h to obtain a reaction product; the obtained reaction product is cooled to room temperature, and then filtered, centrifuged, and washed to obtain a CPDs precipitate; the obtained CPDs are subjected to dialysis treatment, the dialysis cut-off molecular weight is 100 - 14000, the dialysis time is 24 - 120 h, and after freeze-drying, the CPDs based on citric acid and benzoylurea are obtained.

[0011] The CPDs aggregates prepared by the present invention have at least one of the following characteristics:

[0012] Characteristic 1: The CPDs aggregates have a larger size compared to their preparation raw materials;

[0013] Characteristic 2: The CPDs aggregates have a broad absorption band in the ultraviolet-visible-near-infrared wavelength range;

[0014] Characteristic 3: The CPDs aggregates have an emission peak in the near-infrared wavelength range;

[0015] Characteristic 4: The CPDs aggregates can generate a large amount of heat under the irradiation of near-infrared light;

[0016] Characteristic 5: The CPDs aggregates can generate a large amount of heat under the irradiation of a xenon lamp;

[0017] Characteristic 6: The CPDs aggregates can generate a large amount of heat under the irradiation of sunlight.

[0018] The CPDs aggregates of the present invention greatly expand the π-conjugated plane, promote the generation of synergistic effects between particles, so that they have a wide and strong light absorption ability, and can convert light energy into heat energy in a short time.

[0019] Furthermore, the hydrogen bond acceptor solvent is selected from one or more of N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, N-methylpyrrolidone, hexamethylphosphoric triamide, and pyridine;

[0020] Furthermore, the hydrogen bond acceptor solvent is dimethyl sulfoxide.

[0021] Furthermore, the mass ratio of the CPDs to the hydrogen bond acceptor solvent is 1:0.1 - 10;

[0022] Furthermore, the mass ratio is 1:2 - 8;

[0023] Even further, the mass ratio is 1:2 - 5.

[0024] Furthermore, the interaction time of the CPDs and the hydrogen bond acceptor solvent is 1 - 3600 s;

[0025] Furthermore, the interaction time is 30 - 1000 s;

[0026] Even further, the interaction time is 120 s - 600 s.

[0027] Furthermore, the drying method of the CPDs aggregate is vacuum drying or freeze drying, and the drying time is 6 h - 96 h;

[0028] Furthermore, the drying method is freeze drying, and the drying time is 24 h - 48 h.

[0029] Application of the CPDs aggregate, the application of the CPDs aggregate in the preparation of a photothermal-electric conversion device.

[0030] Furthermore, the application of the CPDs aggregate in the preparation of a photothermal-electric continuous energy transfer device or a photothermal-electric generator.

[0031] The specific implementation method for application in the preparation of a photothermal-electric conversion device includes the following content:

[0032] (1) The CPDs aggregate is blended with a polymer for a hybridization reaction to obtain a photothermal conversion module;

[0033] (2) The photothermal conversion module is loaded on a semiconductor device to construct a photothermal-electric conversion device.

[0034] Since the structural form of the CPDs aggregate cannot be directly connected to circuit components, to realize the photothermal conversion performance of the carbonized polymer dots (CPDs) aggregate, in the present invention, the CPDs aggregate is blended with a polymer for a hybridization reaction, making the polymer the carrier of the CPDs aggregate to obtain a hybrid material - a photothermal conversion module, and then the photothermal conversion module is loaded on a semiconductor device to construct a photothermal-electric conversion device.

[0035] Further, the polymer is selected from one or more of polyacrylic acid, polyacrylamide, polyacrylate, cellulose, epoxy resin, polyurethane, polyvinyl alcohol, polypyrrole, and polyethylene oxide.

[0036] Further, the mass ratio of the CPDs aggregates to the polymer is 1:1 to 100.

[0037] The beneficial effects of the present invention are as follows:

[0038] The preparation method of the CPDs aggregates of the present invention is simple and efficient, improving the controllability of the construction of the aggregates. The prepared CPDs aggregates have a wide and strong absorption band in the ultraviolet-visible-near infrared region, which endows the aggregates with stronger photon absorption ability. At the same time, the extended π-conjugated plane of the CPDs aggregates promotes the generation of synergy between the CPDs, and finally an efficient photothermal conversion effect is obtained. In addition, the CPDs aggregates have good application prospects in photothermal-electric continuous energy transfer devices or photothermal-electric generators. Description of the Drawings

[0039] Figure 1 Low (a) / high (b) resolution transmission electron microscope images of the CPDs aggregates prepared according to the present invention;

[0040] Figure 2 Absorption spectrum of the CPDs aggregates prepared according to the present invention;

[0041] Figure 3 Emission spectrum of the CPDs aggregates prepared according to the present invention;

[0042] Figure 4 Graph showing the change of photothermal conversion temperature increase (ΔT) with time for CPDs aggregates with different concentrations under the same excitation power;

[0043] Figure 5 Graph showing the change of photothermal conversion temperature increase (ΔT) with time for CPDs aggregates with the same concentration under different excitation powers;

[0044] Figure 6 Thermal imaging diagrams of the CPDs aggregates prepared according to the present invention at different concentrations and excitation powers;

[0045] Figure 7 Thermal imaging diagram of the temperature increase of the photothermal conversion module constructed using the CPDs aggregates prepared according to the present invention;

[0046] Figure 8 Graph showing the change trend of voltage and current with time for the photothermal-electric continuous energy transfer device or photothermal-electric generator constructed using the CPDs aggregates prepared according to the present invention;

[0047] Figure 9 Digital photo of a photothermal power generator constructed with CPDs aggregates prepared using the present invention for charging a smartphone. Detailed implementation mode

[0048] The technical solution of the present invention is described clearly and completely below. Obviously, the embodiments described herein are only a part of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the protection scope of the present invention.

[0049] Example 1

[0050] A kind of near-infrared CPDs aggregate, and its preparation method includes the following steps:

[0051] (1) Add CPDs based on citric acid and benzoylurea into N,N-dimethylformamide, and utilize the proton donors in the CPDs shell based on citric acid and benzoylurea to interact with N,N-dimethylformamide, thereby constructing CPDs aggregates.

[0052] (2) The mass ratio of CPDs based on citric acid and benzoylurea to N,N-dimethylformamide is 1:1.

[0053] (3) The interaction time of CPDs based on citric acid and benzoylurea with N,N-dimethylformamide is 360 s.

[0054] (4) The prepared CPDs aggregates are selected for vacuum drying for 12 h.

[0055] Figure 1 This is the low (a) / high (b) resolution transmission electron microscope image of the CPDs aggregates obtained in this example. The results show that the obtained CPDs aggregates are in an irregular aggregated state, and their average particle size is 3 - 5 nm.

[0056] Figure 2 This is the absorption spectrum of the CPDs aggregates obtained in this example, showing broad spectral absorption from the ultraviolet light region to the visible light region and then to the near-infrared light region, and strong absorption peaks from the visible light region to the near-infrared light region.

[0057] Figure 3 This is the emission spectrum of the CPDs aggregates obtained in this example, showing emission peaks in the near-infrared light region.

[0058] Example 2

[0059] A kind of near-infrared CPDs aggregate, and its preparation method includes the following steps:

[0060] (1) Add the CPDs based on citric acid and benzoylurea into dimethyl sulfoxide, and utilize the proton donors in the shell of the CPDs based on citric acid and benzoylurea to interact with dimethyl sulfoxide, thereby constructing CPDs aggregates.

[0061] (2) The mass ratio of the CPDs based on citric acid and benzoylurea to dimethyl sulfoxide is 1:2.

[0062] (3) The interaction time of the CPDs based on citric acid and benzoylurea with dimethyl sulfoxide is 3600 s.

[0063] (4) The prepared CPDs aggregates are freeze-dried for 72 h.

[0064] Figure 4 For the CPDs aggregates obtained in this example, the photothermal conversion temperatures at different concentrations are as follows. At the concentration range of 1 μg / mL to 160 μg / mL, the maximum temperature increase can reach 54 °C within 10 min.

[0065] Figure 5 For the CPDs aggregates obtained in this example, the photothermal conversion temperatures under different excitation powers are as follows. Under the excitation power of 0.1 W / cm 2 ~1.4 W / cm 2 , the maximum temperature increase can reach 94 °C within 10 min.

[0066] Example 3

[0067] Use the CPDs aggregates to prepare a photothermal conversion module, and the specific steps are as follows:

[0068] (1) In an EP tube, utilize the interaction between the CPDs based on citric acid and benzamide and hexamethylphosphoric triamide to prepare CPDs aggregates with concentrations of 10 μg / mL, 20 μg / mL, 40 μg / mL, 80 μg / mL, and 160 μg / mL according to the method of Example 1;

[0069] (2) Irradiate the CPDs aggregates with different concentrations using a near-infrared laser with different powers.

[0070] (3) Collect the temperature of the CPDs aggregates within 10 min through an infrared thermal imager.

[0071] The infrared thermal images of the CPDs aggregates prepared by the present invention under different concentrations and excitation powers are as shown in Figure 6 shown.

[0072] As can be seen from Figure 6 it,

[0073] Under the irradiation of near-infrared lasers with the same power, different concentrations of CPDs aggregates will generate different temperatures. As the concentration increases, the temperature shows an upward trend. Under the irradiation of near-infrared lasers with different powers, the same concentration of CPDs aggregates will generate different temperatures. As the power increases, the temperature shows an upward trend.

[0074] Example 4

[0075] A photothermal conversion module, the preparation method of which comprises the following steps:

[0076] (1) Co-hybridize the CPDs aggregates in Example 1 with epoxy resin.

[0077] (2) The mass ratio of the aggregates to the epoxy resin is 1:1.

[0078] (3) The curing time is 24 h.

[0079] (4) Irradiate with a xenon lamp or sunlight for 10 min, and collect data with an infrared thermal imager.

[0080] Figure 7 The thermal imaging schematic diagram of the photothermal conversion module made of the CPDs aggregates obtained in this example after being irradiated with a xenon lamp or sunlight for 10 min (the picture scale is 2 cm). The right side is the blank control without loading the photothermal module, and the left side is the photothermal conversion module, in which the photothermal conversion module shows 50.7 °C.

[0081] Example 5

[0082] Apply the photothermal conversion module obtained in Example 4 of this example to a photothermal-electric continuous energy transfer device, and the specific steps include the following:

[0083] (1) Load the photothermal conversion module on a semiconductor device to construct a photothermal-electric continuous energy transfer device.

[0084] (2) Irradiate the hybrid material with a xenon lamp or sunlight, and collect the output voltage and current with a multimeter.

[0085] From Figure 8 It can be seen that as the illumination continues, the hybrid material heats up, driving the semiconductor to generate electricity, and the voltage and current are collected through a multimeter. Draw the trend charts of voltage and current versus time.

[0086] Example 6

[0087] A photothermal conversion module, the preparation method of which comprises the following steps:

[0088] (1) Co-hybridize the CPDs aggregates in Example 2 with polyvinyl alcohol.

[0089] (2) The mass ratio of the aggregate to the epoxy resin is 1:100.

[0090] (3) The curing time is 0.5 h.

[0091] (4) Irradiate with a xenon lamp or sunlight for 10 min, and collect data using an infrared thermal imager.

[0092] The photothermal conversion module obtained in Example 6 was applied to a photothermal power generator. The specific steps are as follows:

[0093] (1) Load the photothermal conversion module onto a semiconductor device to construct a photothermal power generator.

[0094] (2) Irradiate the hybrid material with a xenon lamp or sunlight, and use this generator to charge a smartphone.

[0095] Figure 9 Digital photos showing a photothermal power generator constructed with the CPDs aggregates prepared by the present invention charging a smartphone (the picture scale is 5 cm).

[0096] It should be noted that the characterization data of the finally obtained CPDs aggregates have been specifically listed in Example 1, and the specific data of their functions have been listed in Examples 1 and 2. The raw material components and preparation condition parameters in Example 6 are slightly different from those in Examples 1 and 2, but they do not affect the properties of the CPDs aggregates themselves and their ability to be applied to photothermal continuous energy transfer or photothermal power generators. Therefore, for the sake of brevity, the specific test data will not be repeated.

Claims

1. A preparation method of near-infrared carbonized polymer dot aggregates, characterized in that, It includes the following: CPDs are assembled in a hydrogen bond acceptor solvent to obtain CPDs aggregates; The CPDs are prepared from citric acid and benzoylurea.

2. The preparation method according to claim 1, characterized in that, The hydrogen bond acceptor solvent is selected from one or more of N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, N-methylpyrrolidone, hexamethylphosphoric triamide, and pyridine; Furthermore, the hydrogen bond acceptor molecule is dimethyl sulfoxide.

3. The preparation method according to claim 1, characterized in that, The mass ratio of the CPDs to the hydrogen bond acceptor solvent is 1:0.1 - 10; Furthermore, the mass ratio is 1:2 - 8; Even further, the mass ratio is 1:2 - 5.

4. The preparation method according to claim 1, wherein, The interaction time of the CPDs and the hydrogen bond acceptor solvent is 1 - 3600 s; Furthermore, the interaction time is 30 - 1000 s; Even more further, the interaction time is 120 s - 600 s.

5. The preparation method according to claim 1, characterized in that, The drying method of the CPDs aggregates is vacuum drying or freeze drying, and the drying time is 6 h - 96 h; Furthermore, the drying method is freeze drying, and the drying time is 24 h - 48 h.

6. Use of the CPDs aggregate according to any one of claims 1 to 5, characterized in that, The application of the CPDs aggregates in the preparation of photothermal-electric conversion devices.

7. Use of the CPDs aggregates according to any one of claims 6, characterized in that, The application of the CPDs aggregates in the preparation of photothermal-electric continuous energy transfer devices or photothermal-electric generators.

8. Use of the CPDs aggregates according to any one of claims 6, characterized in that, The specific implementation method for application in the preparation of photothermal-electric conversion devices includes the following: (1) The CPDs aggregates are blended with a polymer for a hybridization reaction to obtain a photothermal conversion module; (2) The photothermal conversion module is loaded on a semiconductor device to construct a photothermal-electric conversion device.

9. Use of the carbonized polymer dot aggregates according to any one of claims 8, characterized in that, The polymer is selected from one or more of polyacrylic acid, polyacrylamide, polyacrylate, cellulose, epoxy resin, polyurethane, polyvinyl alcohol, polypyrrole, and polyoxyethylene.

10. Use of the CPDs aggregates according to any one of claims 8, characterized in that, The mass ratio of the CPDs aggregates to the copolymer is 1:1 - 100.

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