A perylene polyarylether-based super-hydrophobic radiation cooling film with layered structure and preparation method thereof

Abstract

A perylene polyarylether-based super-hydrophobic radiation cooling film with a layered structure and a preparation method thereof, comprising: (1) preparing the perylene polyarylether by polycondensation of bisphenol A, decafluorobiphenyl and DFPP; (2) dissolving the perylene polyarylether in a polar aprotic solvent to prepare a uniform solution. (3) pouring the solution on a glass plate, immersing it in a non-solvent coagulation bath for phase conversion, then immersing it in deionized water to remove the residual solvent, and finally drying it at room temperature to obtain a perylene polyarylether film with a layered structure. The obtained radiation cooling film has the advantages of high reflectivity, high transmittance, good radiation cooling effect, etc., and also has a self-cleaning property similar to that of a lotus leaf to ensure durability for outdoor use. The radiation cooling film is simple to prepare, suitable for industrial production, and has broad application prospects.

Description

Technical Field

[0001] The invention belongs to the field of polymer film materials and relates to a perylene polyarylether-based super-hydrophobic radiation cooling film with a layered structure and a preparation method thereof. Background Art

[0002] Due to the global warming in recent years, the urban heat island effect has been aggravated, which has led to the need to consume a lot of energy every year on air conditioners and other refrigeration equipment. The near-infrared range (700-2500nm) accounts for 52% of the energy from solar thermal radiation, so the development of materials with high near-infrared reflectivity can effectively avoid the accumulation of heat from the sun and reduce the power consumption of air conditioners and other equipment. Studies have found that in summer, families with near-infrared reflective materials installed on the roof of buildings save about 25%-43% of the cooling costs compared to families without installation, so the development of near-infrared reflective materials can effectively reduce environmental pollution, reduce energy consumption, and slow down global warming.

[0003] The structural designs of common radiation cooling materials can be divided into three categories: multilayer films, metamaterials and porous materials. The preparation method of porous materials is simple, the production cost is low, and it is easy to prepare large-size products, so they have great application potential. However, existing porous radiation cooling materials are polluted by dust and rainwater, which leads to a decrease in cooling performance. The lack of weather resistance and fire resistance is also a reason that restricts their large-scale use. Most of the existing radiation cooling materials have a white or silver appearance. If these light-colored materials are used in large quantities, the glare generated will damage the human eye and cause light pollution. These shortcomings limit their use in reality. Summary of the invention

[0004] The purpose of the present invention is to solve the problems of existing radiation cooling materials being easily contaminated during use and light pollution caused by light-colored appearance, and to provide a perylene polyarylether-based super-hydrophobic radiation cooling film with a layered structure and a preparation method thereof. The prepared film has the advantages of super-hydrophobicity and good radiation cooling effect, and presents a deep red appearance.

[0005] The present invention utilizes the polycondensation reaction of bisphenol A compounds, p-fluorobiphenyl compounds and DFPP to obtain perylene-containing polyarylether, which is then dissolved in a polar non-protonic solvent to obtain a perylene-containing polyarylether-based super-hydrophobic radiation cooling film through a non-solvent phase conversion method.

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

[0007] A perylene polyarylether-based super-hydrophobic radiation cooling film with a layered structure. The film consists of a perylene polyarylether-based film, which has a layered porous structure and a thickness of 50 to 300 μm.

[0008] A method for preparing the above-mentioned perylene polyarylether-based super-hydrophobic radiative cooling film with a layered structure, the method comprising the following steps:

[0009] (1) 3,4,9,10-perylenetetracarboxylic dianhydride, 2,3,4,5,6-pentafluoroaniline and anhydrous zinc acetate are added to quinoline, heated and stirred under the protection of nitrogen to react, precipitated with ethanol, filtered, and the red solid was collected. After drying in a vacuum oven at 60° C. for 24 hours, N,N-di(pentafluorophenyl)-3,4,9,10-perylenetetracarboxylic diimide DPFF was obtained;

[0010] The DPFF structural formula is shown in the figure below:

[0011]

[0012] (2) dissolving bisphenol A compounds, para-fluorinated compounds and DPFF in N-methylpyrrolidone to prepare a solution with a mass concentration of 10 to 50%, adding anhydrous potassium carbonate as a catalyst under the protection of argon, heating and magnetic stirring for reaction for 10 to 20 hours, then pouring into deionized water to precipitate, collecting the precipitate and dissolving it in dichloromethane to prepare a solution with a mass concentration of 1 to 10%, then pouring into methanol to precipitate, filtering and collecting the precipitate, and drying in a vacuum oven at 60° C. for 24 hours to obtain a perylene-containing polyarylether;

[0013] When the fluorine compound is decafluorobiphenyl, the chemical structure of the obtained perylene-containing polyarylether is shown in the figure below:

[0014]

[0015] Wherein, n, m = 10 to 500; the changes of n, m are mainly related to the addition ratio of DPFF and decafluorobiphenyl;

[0016] (3) The perylene-containing polyarylether is dissolved in a polar aprotic solvent to prepare a uniform solution, which is poured onto a glass plate, immersed in a non-solvent coagulation bath for phase conversion, and then immersed in deionized water to remove the residual solvent. Finally, the solution is dried at room temperature for 24 hours to obtain a perylene-containing polyarylether-based superhydrophobic radiation cooling film with a layered structure.

[0017] Furthermore, in step (1), the molar ratio of the 3,4,9,10-perylenetetracarboxylic dianhydride, 2,3,4,5,6-pentafluoroaniline, anhydrous zinc acetate and quinoline is 1:2-10:0.5-5:15-30.

[0018] Furthermore, in step (1), the heating temperature of the synthesis reaction is 160-220° C., nitrogen protection is used, and the rotation speed is 300-600 r / min.

[0019] Furthermore, in step (2), the bisphenol A compound is one or more of bisphenol A and bisphenol AF; and the para-fluorine compound is one or more of 4,4-difluorobenzophenone and decafluorobiphenyl.

[0020] Furthermore, in step (2), the molar ratio of the fluorine compound to DPFF is 1:0.01-0.1; and the molar ratio of the monomer (the molar ratio of the fluorine compound to the bisphenol A compound is 1:1) to anhydrous potassium carbonate is 1:0.5-5.

[0021] Furthermore, in step (2), the heating temperature of the synthesis reaction is 70-100° C., nitrogen protection is used, and the rotation speed is 300-600 r / min.

[0022] Furthermore, in step (3), the mass ratio of the perylene-containing polyarylether to the polar aprotic solvent is 1:5-50.

[0023] Furthermore, in step (3), the phase transformation time of the perylene-containing polyarylether solution in the non-solvent coagulation bath is 1 to 30 minutes.

[0024] Furthermore, in step (3), the polar aprotic solvent is one or more of N-methylpyrrolidone, acetone, dimethyl sulfoxide, and N,N-dimethylacetamide; and the non-solvent coagulation bath is one or more of water, methanol, ethanol, and isopropanol.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] (1) The perylene polyarylether-based super-hydrophobic radiative cooling film of the present invention has a layered porous structure, which enhances its scattering of sunlight. The film has a high reflectivity and a good radiative cooling effect.

[0027] (2) The perylene polyarylether-based super-hydrophobic radiative cooling film of the present invention has a micro-nano rough structure, can provide a good super-hydrophobic effect, has a self-cleaning property, and can effectively prevent the film from being contaminated and causing performance degradation during outdoor use.

[0028] (3) The perylene-containing polyarylether-based super-hydrophobic radiation cooling film of the present invention introduces perylene-containing structural units, and the film has a deep red appearance, thereby avoiding the generation of light pollution.

[0029] (4) The radiative cooling film has the advantages of high reflectivity, high transmittance, good radiative cooling effect, etc. It also has a self-cleaning property similar to lotus leaves to ensure durability for outdoor use. The radiative cooling film is easy to prepare, suitable for industrial production, and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1This is the hydrogen nuclear magnetic resonance spectrum of the perylene-containing polyarylether prepared in Example 1.

[0031] Figure 2 This is the infrared spectrum of the perylene-containing polyarylether prepared in Example 1.

[0032] Figure 3 Schematic diagram of the water contact angle of the 5# film in Example 2.

[0033] Figure 4 This is a scanning electron microscope (SEM) image of the surface of the 5# film in Example 2.

[0034] Figure 5 This is the reflectivity diagram of 5# in Example 2 in the wavelength range of 0.2 to 2.5 μm.

[0035] Figure 6 This is the reflectivity diagram of 5# in Example 2 in the wavelength range of 6 to 18 μm.

[0036] Figure 7 This is a graph showing the change in water contact angle of sample 9# in Example 3 during the UV durability test.

[0037] Figure 8 This is the reflectivity graph of 9# in Example 3 in the wavelength range of 0.2 to 2.5 μm after 120 days of UV durability test. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and advantages of the present invention more clear, the present invention is further described in detail below in conjunction with specific implementation methods. It should be understood that the specific implementation methods described here are only used to explain the present invention and do not limit the scope of protection of the present invention.

[0039] Embodiment 1:

[0040] Perylene-containing polyarylether based on decafluorobiphenyl, hexafluorobisphenol A and DFPP

[0041] Step 1: 0.98 g of 3,4,9,10-perylenetetracarboxylic dianhydride, 1.98 g of 2,3,4,5,6-pentafluoroaniline and 0.5 g of anhydrous zinc acetate are added to 15 mL of quinoline, heated to 200° C. under the protection of nitrogen, stirred for reaction, precipitated with ethanol, filtered, and the red solid was collected, and dried in an oven at 60° C. for 24 h to obtain N,N-di(pentafluorophenyl)-3,4,9,10-perylenetetracarboxylic diimide (DPFF).

[0042] Step 2: 0.84 g of hexafluorobisphenol A, 0.78 g of decafluorobiphenyl and 0.11 g of DPFF are dissolved in 4 g of N-methylpyrrolidone, 0.41 g of anhydrous potassium carbonate is added as a catalyst under the protection of argon, heated to 85° C. and magnetically stirred for 20 hours under the protection of nitrogen, then poured into deionized water to precipitate, the precipitate is collected and dissolved in dichloromethane to prepare a solution with a mass concentration of 10%, then poured into methanol to precipitate, the precipitate is filtered and collected, and dried in a vacuum oven at 60° C. for 24 hours to obtain a perylene-containing polyarylether. The H NMR data of the compound are: 1H NMR (400 MHz, Chloroform-d) δ8.80 (dd, J=16.6, 7.0 Hz, 1H), 7.42 (d, J=8.4 Hz, 2H), 7.14–6.95 (m, 2H), 6.84 (d, J=8.3 Hz, 1H. The infrared spectrum data are: FT-IR (cm -1 )υ3410, 1712, 1680, 1611, 1486, 1234, 1183, 1070, 980, 930, 721.

[0043] Step 3: Preparation of super-hydrophobic radiation cooling film containing perylene polyarylether: Take 0.5g of perylene polyarylether and dissolve it in 2.625g of N-methylpyrrolidone to make a uniform solution, pour it on a glass plate, immerse it in an ethanol coagulation bath for 1min, 5min, 10min, 15min, 20min for phase conversion, and finally dry it at room temperature for 24 hours. The prepared samples are marked as 1#, 2#, 3#, 4#, and 5#, respectively. The near-infrared reflectivities of the five dried samples were measured by a UV-visible near-infrared spectrophotometer to be 63%, 69%, 86%, 89%, and 93%, respectively. The water contact angles measured using a contact angle tester were 109°, 121°, 139°, 145°, and 160° ( Figure 3 ). Using SEM to characterize the film morphology, it was found that a large number of microspherical layered structures were formed on the surface of the 5# film. These layered structures can effectively scatter sunlight, thereby enhancing the reflectivity and emissivity of the film. Figure 4 and Figure 5 As shown in the results, it can be seen that the reflectivity is the highest and the water contact angle is the highest when immersed in the ethanol coagulation bath for 20 minutes.

[0044] Embodiment 2:

[0045] Perylene-containing polyarylether based on decafluorobiphenyl, hexafluorobisphenol A and DFPP

[0046] Step 1: 0.98 g of 3,4,9,10-perylenetetracarboxylic dianhydride, 1.98 g of 2,3,4,5,6-pentafluoroaniline and 0.5 g of anhydrous zinc acetate are added to 15 mL of quinoline, heated to 200° C. under the protection of nitrogen, stirred for reaction, precipitated with ethanol, filtered, and the red solid was collected, and dried in an oven at 60° C. for 24 h to obtain N,N-di(pentafluorophenyl)-3,4,9,10-perylenetetracarboxylic diimide (DPFF).

[0047] Step 2: 0.84 g of hexafluorobisphenol A, 0.78 g of decafluorobiphenyl and 0.11 g of DPFF are dissolved in 4 g of N-methylpyrrolidone, 0.41 g of anhydrous potassium carbonate is added as a catalyst under the protection of argon, heated to 85° C. and magnetically stirred for 20 hours under the protection of nitrogen, then poured into deionized water to precipitate, the precipitate is collected and dissolved in dichloromethane to prepare a solution with a mass concentration of 10%, then poured into methanol to precipitate, the precipitate is filtered and collected, and dried in a vacuum oven at 60° C. for 24 hours to obtain a perylene-containing polyarylether. The H NMR data of the compound are: 1H NMR (400 MHz, Chloroform-d) δ8.80 (dd, J=16.6, 7.0 Hz, 1H), 7.42 (d, J=8.4 Hz, 2H), 7.14–6.95 (m, 2H), 6.84 (d, J=8.3 Hz, 1H. The infrared spectrum data are: FT-IR (cm -1 )υ3410, 1712, 1680, 1611, 1486, 1234, 1183, 1070, 980, 930, 721.

[0048] Step 3: Preparation of super-hydrophobic radiative cooling film containing perylene polyarylether: dissolve the perylene polyarylether in N-methylpyrrolidone to prepare uniform solutions with solid contents of 5%, 10%, 15%, 20%, and 25%, respectively, pour them on glass plates, immerse them in an ethanol coagulation bath for 20 minutes for phase conversion, and finally dry them at room temperature for 24 hours. The prepared samples were marked as 6#, 7#, 8#, 9#, and 10#, respectively. The near-infrared reflectivities of the five dried samples were measured by a UV-visible near-infrared spectrophotometer to be 48%, 66%, 94%, 95%, and 79%, respectively. The results show that the reflectivity is highest when the solid content of the casting liquid is 20%. Place the 9# sample of Example 3 in a sunlight-exposed position for a UV stability test. The water contact angle of the film is tested every 20 days. Figure 6 It can be seen that even after 120 days of sunlight exposure, the film still has good superhydrophobic properties, and its reflectivity has no obvious change ( Figure 7 ).

Claims

1. A method for preparing a perylene polyarylether-based super-hydrophobic radiation cooling film having a layered structure, characterized in that: The film is composed of a perylene polyarylether film, the film has a layered porous structure, and the thickness is 50 to 300 μm; the method comprises the following steps: (1) 3,4,9,10-perylenetetracarboxylic dianhydride, 2,3,4,5,6-pentafluoroaniline and anhydrous zinc acetate were added to quinoline, heated and stirred under the protection of nitrogen, precipitated with ethanol, filtered, and the red solid was collected. After drying in a vacuum oven at 60 ° C for 24 hours, N,N-di(pentafluorophenyl)-3,4,9,10-perylenetetracarboxylic diimide DPFF was obtained; (2) Dissolving bisphenol A compounds, para-fluorinated compounds and DPFF in N-methylpyrrolidone to prepare a solution with a mass concentration of 10-50%, adding anhydrous potassium carbonate as a catalyst under the protection of argon, heating and magnetic stirring for reaction for 10-20 hours, then pouring into deionized water to precipitate, collecting the precipitate and dissolving it in dichloromethane to prepare a solution with a mass concentration of 1-10%, then pouring into methanol to precipitate, filtering and collecting the precipitate, and vacuum drying at 60°C for 24 hours to obtain a perylene-containing polyarylether; the para-fluorinated compound is one or more of 4,4-difluorobenzophenone and decafluorobiphenyl; (3) The perylene-containing polyarylether was dissolved in a polar aprotic solvent to prepare a uniform solution, which was poured onto a glass plate, immersed in a non-solvent coagulation bath for phase inversion, and then immersed in deionized water to remove the residual solvent. Finally, the solution was dried at room temperature for 24 h to obtain a perylene-containing polyarylether-based superhydrophobic radiative cooling film with a layered structure.

2. The method for preparing a layered super-hydrophobic radiation cooling film containing perylene polyarylether according to claim 1, characterized in that: In step (1), the molar ratio of 3,4,9,10-perylenetetracarboxylic dianhydride, 2,3,4,5,6-pentafluoroaniline, anhydrous zinc acetate and quinoline is 1:2-10:0.5-5:15-30.

3. The method for preparing a layered super-hydrophobic radiation cooling film containing perylene polyarylether according to claim 1, characterized in that: In step (1), the heating temperature of the synthesis reaction is 160-220°C, nitrogen protection is used, and the rotation speed is 300-600r / min.

4. The method for preparing a layered super-hydrophobic radiation cooling film containing perylene polyarylether according to claim 1, characterized in that: In step (2), the bisphenol A compound is one or more of bisphenol A and bisphenol AF.

5. The method for preparing a perylene polyarylether-based super-hydrophobic radiative cooling film having a layered structure according to claim 1, characterized in that: In step (2), the molar ratio of the para-fluorine compound to DPFF is 1:0.01-0.1; the molar ratio of the monomer to anhydrous potassium carbonate is 1:0.5-5, and the monomer is a para-fluorine compound to a bisphenol A compound in a molar ratio of 1:

1.

6. The method for preparing a layered super-hydrophobic radiation cooling film containing perylene polyarylether groups according to claim 1, characterized in that: In step (2), the heating temperature of the synthesis reaction is 70-100 °C, nitrogen protection is used, and the rotation speed is 300-600 r / min.

7. The method for preparing a perylene polyarylether-based super-hydrophobic radiative cooling film having a layered structure according to claim 1, characterized in that: In step (3), the mass ratio of the perylene-containing polyarylether to the polar aprotic solvent is 1:5-50.

8. The method for preparing a layered super-hydrophobic radiation cooling film containing perylene polyarylether groups according to claim 1, characterized in that: In step (3), the phase transformation time of the perylene polyarylether solution in the non-solvent coagulation bath is 1 to 30 minutes.

9. The method for preparing a layered super-hydrophobic radiation cooling film containing perylene polyarylether groups according to claim 1, characterized in that: In step (3), the polar aprotic solvent is one or more of N-methylpyrrolidone, acetone, dimethyl sulfoxide, and N,N-dimethylacetamide; and the non-solvent coagulation bath is one or more of water, methanol, ethanol, and isopropanol.

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