Fluorinated transparent aramid fiber aerogel material as well as preparation method and application thereof

Abstract

The invention discloses a fluorinated transparent aramid fiber aerogel material as well as a preparation method and application thereof. The fluorinated transparent aramid fiber aerogel material is prepared through reaction of an aramid framework element, a spatial configuration element and a chroma inhibition element, the spatial configuration element has the function of adjusting the pore structure and the light transmittance of aerogel, and the chroma inhibition element has a fluorinated group. The function of inhibiting the formation of electron transfer complexes in the polymerization process is realized. According to the fluorinated transparent aramid fiber aerogel material, the aramid fiber aerogel material with high transparency and strong mechanical performance can be prepared by adjusting the proportion of an aramid framework element, a spatial configuration element and a chroma inhibition element, and the aramid fiber aerogel material has good transmittance in a visible light region and high transparency in an infrared region; the material also has the advantages of simple preparation, adjustable light transmittance, extreme environment resistance, good mechanical properties and the like, and is expected to be applied to the fields of passive heating, aerogel intelligent windows, thermal insulation building materials and the like.

Description

Technical Field

[0001] The present invention relates to an aramid fiber aerogel material, and particularly to a fluorinated transparent aramid fiber aerogel material, its preparation method and application, belonging to the technical field of polymer aerogel materials. Background Art

[0002] Aerogel smart windows can regulate heat conduction, heat convection and thermal radiation, thereby controlling the energy exchange between indoors and outdoors, greatly reducing the use of unnecessary energy such as air conditioners or heaters in buildings, and reducing building energy consumption. In recent years, in order to realize the application of aerogels in smart windows, researchers have done a lot of work in improving the transparency, mechanical strength and temperature resistance and heat insulation performance of aerogels. For example, Keramati et al. prepared silica aerogels with high light transmittance and filled the aerogels into the gaps of a double-glass system to obtain aerogel smart windows with excellent heat insulation performance. However, the mechanical properties of this inorganic silica aerogel are poor and it needs to be fixed with a glass sandwich to be used. Smalyukh et al. developed highly transparent silanized cellulose aerogels for improving the energy efficiency of building glass, but these natural polymer aerogels cannot be used in extreme environments and cannot meet the requirements of building fire prevention and flame retardancy. Mettry et al. prepared polyimide aerogels with strong mechanical properties and high transparency using melamine and acetic anhydride as raw materials, but their high density results in poor heat insulation performance. Therefore, developing aerogel smart windows with high transparency, strong mechanical properties, good heat insulation performance and the ability to withstand various extreme environments remains a huge challenge. Summary of the Invention

[0003] The main object of the present invention is to provide a fluorinated transparent aramid fiber aerogel material and its preparation method to overcome the deficiencies in the prior art.

[0004] Another object of the present invention is also to provide the application of the fluorinated transparent aramid fiber aerogel material.

[0005] To achieve the foregoing invention objects, the technical solutions adopted by the present invention include:

[0006] An embodiment of the present invention provides a fluorinated transparent aramid fiber aerogel material, which is prepared by reacting at least any one of a spatial configuration element and a chromaticity suppression element with an aramid backbone element. The spatial configuration element can regulate the pore structure of the aerogel and improve the light transmittance of the aerogel. The chromaticity suppression element has a fluorinated group and has the function of inhibiting the formation of electron transfer complexes during the polymerization process and improving transparency.

[0007] In some embodiments, the spatial configuration element includes any one or a combination of a linear spatial configuration element, a zigzag spatial configuration element, and a planar spatial configuration element.

[0008] In some embodiments, the chromaticity suppression element includes a fluorinated monomer.

[0009] The embodiments of the present invention also provide a method for preparing a fluorinated transparent aramid fiber aerogel material, which includes:

[0010] In a protective atmosphere, a polymerization reaction is carried out on a mixed reaction system containing an aramid skeleton element, a spatial configuration element, a chromaticity suppression element, and an organic solvent to obtain a gel-like polymer;

[0011] The gel-like polymer is subjected to film-forming treatment and sol-gel transformation to obtain a gel film;

[0012] The gel film is subjected to drying treatment to obtain a fluorinated transparent aramid fiber aerogel material.

[0013] The embodiments of the present invention also provide the application of the aforementioned fluorinated transparent aramid fiber aerogel material in the fields of passive heating, smart windows, or energy-saving building materials.

[0014] Compared with the prior art, the beneficial effects of the present invention at least include:

[0015] 1) The fluorinated transparent aramid fiber aerogel material provided by the present invention can be prepared into an aramid fiber aerogel material with high transparency and strong mechanical properties by adjusting the proportions of the aramid skeleton element, the spatial configuration element, and the chromaticity suppression element. The spatial configuration element can effectively adjust the spatial structure of the aerogel to achieve the adjustment of the light transmittance, and the chromaticity suppression element can inhibit the formation of electron transfer complexes during the polymerization process and reduce the chromaticity of the aerogel;

[0016] 2) The fluorinated transparent aramid fiber aerogel material provided by the present invention has ultra-high mechanical strength, good transmittance in the visible light region, and high transparency in the infrared region;

[0017] 3) The fluorinated transparent aramid fiber aerogel material provided by the present invention has the advantages of simple preparation, adjustable light transmittance, resistance to extreme environments, and good mechanical properties, and is expected to be applied in the fields of passive heating, aerogel smart windows, energy-saving thermal insulation building materials, etc. Description of the Drawings

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative efforts.

[0019] Figure 1Flow chart for the preparation of a fluorinated transparent aramid fiber aerogel material in a typical embodiment of the present invention;

[0020] Figure 2 Schematic diagram of the elementary unit and chemical structural formula of a fluorinated transparent aramid fiber aerogel material in a typical embodiment of the present invention;

[0021] Figure 3 Schematic diagram for the regulation of the spatial structure of a fluorinated transparent aramid fiber aerogel material in a typical embodiment of the present invention;

[0022] Figure 4 Physical picture of the fluorinated transparent aramid fiber aerogel material prepared in Example 1 of the present invention;

[0023] Figure 5 High infrared transmittance picture of the fluorinated transparent aramid fiber aerogel material prepared in Example 1 of the present invention. Detailed implementation manners

[0024] In view of the problem that the aerogel thermal management technology cannot achieve efficient energy conservation and emission reduction, the present invention proposes a fluorinated highly transparent aramid fiber aerogel metamaterial for the thermal management of smart windows. So far, there is no report or patent on fluorinated transparent aramid fiber aerogels. Therefore, the novel smart aerogel material developed by the present invention lays a new foundation for opening up a new passive thermal management technology for carbon emission reduction, and has very important scientific significance and application value.

[0025] The technical solution, its implementation process, principle, etc. will be further explained below. However, it should be understood that within the scope of the present invention, all the above technical features of the present invention and the technical features specifically described in the following (examples) can be combined with each other to form new or preferred technical solutions. Due to space limitations, they will not be repeated one by one here.

[0026] As an aspect of the technical solution of the present invention, a fluorinated transparent aramid fiber aerogel material involved therein is prepared by reacting at least any one of a spatial configuration elementary unit and a chromaticity suppression elementary unit with an aramid backbone elementary unit.

[0027] Furthermore, the spatial configuration elementary unit and the chromaticity suppression elementary unit can be added separately or simultaneously.

[0028] Specifically, the spatial configuration elementary unit adopted in the present invention has the function of regulating the pore structure and light transmittance of the aerogel.

[0029] In some specific embodiments, the spatial configuration units include any one or a combination of more than one of linear spatial configuration units, zigzag spatial configuration units, planar spatial configuration units, etc. Preferably, it is a combination of zigzag spatial configuration units and planar spatial configuration units. In the present invention, zigzag spatial configuration units with a certain bending angle and planar spatial configuration units are introduced into the aramid skeleton units to change the spatial configuration of the aerogel, which can increase the pore radius of the gel and improve the light transmittance of the aerogel.

[0030] In some more preferred embodiments, the linear spatial configuration units may include any one or a combination of two of p-phenylenediamine (PPD) and 3,3'-dimethylbenzidine (DBD), etc., but are not limited thereto.

[0031] In some more preferred embodiments, the zigzag spatial configuration units may include any one or a combination of two of 5-amino-2-(4-aminophenyl)benzimidazole (APBIA) and 4,4'-diaminodiphenyl ether (ODA), etc., but are not limited thereto.

[0032] In some more preferred embodiments, the planar spatial configuration units may include any one or a combination of two of melamine (MA) and 3,3'-diaminobenzidine (DAB), etc., but are not limited thereto.

[0033] In some embodiments, the present invention introduces a fluorinated monomer as a chromaticity suppression unit. By utilizing the high electronegativity, low molar polarization, and high free volume fraction of the fluorinated group, the formation of electron transfer complexes during the polymerization process is inhibited, the chromaticity formed during the polymerization process is reduced, and the transparency of the aerogel is further improved.

[0034] In some specific embodiments, the chromaticity suppression units include fluorinated biphenyl diamine compounds, preferably including any one or a combination of two of 2,2-bis(trifluoromethyl)diaminobiphenyl (TFB), 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane (HFBAPP), etc., but are not limited thereto.

[0035] In some embodiments, the aramid skeleton units include any one or a combination of two of terephthaloyl chloride (TPC) and 4,4'-biphenylacetyl chloride (BPDC), etc., but are not limited thereto.

[0036] Among some more preferred embodiments, a fluorinated transparent aramid fiber aerogel material selects terephthaloyl chloride (TPC) and 4,4'-biphenylacetyl chloride (BPDC) as aramid backbone units, selects p-phenylenediamine (PPD) and 3,3'-dimethylbenzidine (DBD) as linear spatial configuration units, selects 5-amino-2-(4-aminophenyl) benzimidazole (APBIA) and 4,4'-diaminodiphenyl ether (ODA) as zigzag spatial configuration units, selects melamine (MA) and 3,3'-diaminobenzidine (DAB) as planar spatial configuration units, and selects 2,2-bis(trifluoromethyl) benzidine (TFB) as a chromaticity suppression unit.

[0037] The schematic diagram of the spatial structure adjustment of the fluorinated transparent aramid fiber aerogel material is as Figure 3 shown.

[0038] In some embodiments, the pore diameter of the pores contained in the fluorinated transparent aramid fiber aerogel material is 5-100 nm.

[0039] In some embodiments, the fluorinated transparent aramid fiber aerogel material has high transparency, with an average transparency in the visible light region as high as over 50%, an average light transmittance in the infrared region as high as over 80%, and a tensile fracture strength exceeding 0.8 MPa.

[0040] In summary, the present invention uses linear, zigzag, and planar monomers as spatial configuration units to adjust the pore structure of the aerogel, and uses fluorine-containing monomers as chromaticity suppression units to inhibit the formation of electron transfer complexes during the polymerization process, thereby achieving innovation in the material structure.

[0041] As another aspect of the technical solution of the present invention, a preparation method of a fluorinated transparent aramid fiber aerogel material it involves includes:

[0042] In a protective atmosphere, a mixed reaction system containing aramid backbone units, spatial configuration units, chromaticity suppression units, and an organic solvent is subjected to a polymerization reaction to obtain a gel-like polymer;

[0043] The gel-like polymer is subjected to film-forming treatment and sol-gel transformation to obtain a gel film;

[0044] The gel film is subjected to drying treatment to obtain a fluorinated transparent aramid fiber aerogel material.

[0045] In some specific embodiments, the preparation method includes: in a protective atmosphere, the mixed reaction system is slowly raised from 0-5 °C in an ice bath to room temperature for a polymerization reaction, and the reaction rate is controlled by low temperature to avoid uneven structure caused by too fast gel cross-linking. The reaction duration is 4-8 h to prepare a gel-like polymer.

[0046] Further, the protective atmosphere may be a nitrogen atmosphere, but is not limited thereto.

[0047] Further, the organic solvent may be selected as NMP.

[0048] Further, the preparation method further includes: adding a cosolvent for increasing the solubility of the aramid backbone units to the mixed reaction system, and the cosolvent may be calcium chloride, but is not limited thereto.

[0049] In some specific embodiments, the mass ratio of the spatial configuration units, the chromaticity suppression units to the aramid backbone units is 25:0:20 to 0:25:20, preferably 20:5:20 to 15:10:20. The reason for the preference is that: the spatial configuration units, as the main body, improve the pore structure of the gel and enhance the light transmittance of the gel, and only a small amount of the chromaticity suppression units is required to achieve the effect of suppressing chromaticity. If the proportion of the spatial configuration units exceeds the ratio, it will cause excessive adjustment of the spatial structure, resulting in a serious decrease in light transmittance and a significant reduction in mechanical properties.

[0050] In some specific embodiments, the preparation method specifically includes: using a doctor blade coating method to make the gel-like polymer into a film, and then impregnating it into ethanol or acetone for sol-gel transition to obtain a gel film. The present invention combines the doctor blade coating method with sol-gel transition. Compared with conventional freeze-drying or compression molding, this process is more conducive to the uniformity of the film structure, and the film thickness is lower, which is beneficial to light transmission.

[0051] Further, the thickness of the gel film is below 1000 μm.

[0052] In some specific embodiments, the drying treatment includes supercritical drying, preferably carbon dioxide supercritical drying, but is not limited thereto.

[0053] Further, the time of the drying treatment is 24 - 72 h.

[0054] The present invention replaces the solvent by the sol-gel method and obtains a transparent aramid fiber aerogel by supercritical drying. At the same time, the light transmittance performance of the fluorinated transparent aramid fiber aerogel material can be adjusted by adjusting the proportion of the two system components.

[0055] Among them, in some more specific embodiments, taking the aramid backbone unit TPC, the spatial configuration unit APBIA and the chromaticity suppression unit TFB as examples, the preparation method of the fluorinated transparent aramid fiber aerogel material includes the following steps:

[0056] Step 1) Under a nitrogen atmosphere, an organic solvent is added to a reaction kettle. The reaction kettle is placed in an ice-water bath. After APBIA and TFB are dissolved, TPC is added, and a gel-like polymer is obtained through reaction.

[0057] Step 2) The polymer prepared in Step 1 is used to prepare a film by a doctor blade coating method using a doctor blade coater. The film is impregnated into ethanol for sol-gel transformation, and then replaced with absolute ethanol multiple times.

[0058] Step 3) The gel material obtained in Step 2 is dried by supercritical carbon dioxide for 1 - 3 days to obtain a fluorinated transparent aramid fiber aerogel material.

[0059] Further, in Step 1, the polymerization reaction is carried out in an ice bath and then naturally rises to room temperature. By regulating the temperature in the present invention, the molecular polymerization rate can be affected, the molecular chain uniformity can be improved, and thus the transparency can be optimized.

[0060] Further, in Step 2, the thickness of the film needs to be adjusted with a doctor blade, and the solvent replacement needs to be carried out multiple times.

[0061] As another aspect of the technical solution of the present invention, it also relates to the application of the aforementioned fluorinated transparent aramid fiber aerogel material. The fluorinated transparent aramid fiber aerogel material prepared in the present invention has the advantages of high light transmittance, large mechanical strength, and resistance to various extreme environments, and is expected to be applied in fields such as passive heating, smart windows, and energy-saving thermal insulation building materials.

[0062] Further, the smart window includes a transparent aerogel smart window.

[0063] The fluorinated transparent aramid fiber aerogel material prepared in the present invention has ultra-high transparency, excellent heat insulation performance, and strong mechanical properties, and can be used to explore the energy-saving and consumption-reducing effects of aerogels in smart windows. At low temperatures, sunlight can easily pass through the transparent aerogel smart window, raising the indoor temperature, while the good heat insulation performance can prevent heat from escaping, raising the indoor temperature, achieving low-temperature passive heating, and reducing the heating energy consumption of buildings. At high temperatures, the good heat insulation performance of the aerogel can effectively reduce the heat conduction of external high temperatures, greatly reducing the use of air-conditioning energy in buildings and reducing the cooling energy consumption of buildings.

[0064] The thermal management technology based on aerogel smart windows is a new type of sustainable, low-energy-consuming, and low-cost passive thermal management technology, which can effectively reduce energy consumption and carbon emissions. The present invention prepares a highly transparent aramid fiber aerogel material by adjusting the ratios of aramid backbone units, spatial configuration units, and chromaticity suppression units, and uses this material in transparent smart windows to achieve low-temperature passive heating and high-temperature energy-saving and consumption-reducing intelligent thermal management, breaking through the application innovation of solar thermal management.

[0065] The technical solutions of the present invention will be further described in detail below in conjunction with several preferred embodiments and the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. It should be noted that the following embodiments are intended to facilitate the understanding of the present invention, but do not limit it in any way. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative work belong to the scope of protection of the present invention. The aramid backbone unit TPC, the spatial configuration unit APBIA, and the chromaticity suppression unit TFB used in the following embodiments were purchased.

[0066] Example 1

[0067] The specific steps of a preparation method of a fluorinated transparent aramid fiber aerogel material are as follows:

[0068] (1) Under a nitrogen atmosphere, add 200 mL of NMP to a reaction kettle, then add 12 g of anhydrous calcium chloride treated at high temperature, turn on the oil bath to heat to 80 °C, and set the stirring rate to 450 r / min. After heating for about 35 min, wait until the calcium chloride is completely dissolved, place the reaction kettle in an ice-water bath, and continue to cool to room temperature.

[0069] (2) Add 1.12 g of 3,3'-dimethylbenzidine, 2.41 g of p-phenylenediamine, and 0.45 g of 2,2-bis(trifluoromethyl)diaminobiphenyl to the reaction kettle in step (1). After it is completely dissolved, place it in a new ice-water bath again. Then, add 4.122 g of terephthaloyl chloride and stir in the ice-water bath for 4 h. At the same time, gradually increase the stirring rate to 1500 r / min every half hour. When the "climbing rod" phenomenon starts to appear in the polymer in the reaction kettle, stop stirring, remove the reaction kettle, and obtain a gel-like polymer.

[0070] (3) Use a doctor blade coater to prepare a film from the high-viscosity gel-like polymer obtained in step (2) by the doctor blade coating method. The film thickness is controlled by the doctor blade. Subsequently, immerse the film in ethanol for sol-gel transformation, that is, obtain a gel film by phase separation, and then replace it with anhydrous ethanol three times. Finally, perform supercritical drying with carbon dioxide for 2 days, with a supercritical drying pressure of 9 MPa and a drying temperature of 35 °C to obtain a fluorinated transparent aramid fiber aerogel film material.

[0071] Example 2

[0072] The specific steps of a preparation method of a fluorinated transparent aramid fiber aerogel material are as follows:

[0073] (1) Under a nitrogen atmosphere, 200 mL of NMP was added to a reaction kettle, and then 12 g of anhydrous calcium chloride treated at high temperature was added. The oil bath was turned on and heated to 80 °C, and the stirring rate was set at 450 r / min. After heating for about 35 min, when the calcium chloride was completely dissolved, the reaction kettle was placed in an ice-water bath and further cooled to room temperature.

[0074] (2) 3.21 g of 3,3′-dimethylbenzidine and 0.45 g of 2,2-bis(trifluoromethyl)benzidine diamine were added to the reaction kettle in step (1). After they were completely dissolved, it was placed in a new ice-water bath. Then, 4.122 g of terephthaloyl chloride was added, and it was stirred in the ice-water bath for 8 h. At the same time, the stirring rate was gradually increased to 1500 r / min every half hour. When the "climbing rod" phenomenon began to appear in the polymer in the reaction kettle, the stirring was stopped, and the reaction kettle was removed to obtain a gel-like polymer.

[0075] (3) The high-viscosity gel-like polymer obtained in step (2) was used to prepare a film by the doctor blade coating method with a doctor blade coater. The film thickness was controlled by the doctor blade. Subsequently, the film was immersed in ethanol for sol-gel transformation, and then a gel film was obtained by phase separation, and it was replaced with anhydrous ethanol three times. Finally, it was dried by supercritical carbon dioxide for 2 days. The supercritical drying pressure was 9 MPa, and the drying temperature was 35 °C to obtain a fluorinated transparent aramid fiber aerogel film material.

[0076] Example 3

[0077] The specific steps of a preparation method of a fluorinated transparent aramid fiber aerogel material are as follows:

[0078] (1) Under a nitrogen atmosphere, 200 mL of NMP was added to a reaction kettle, and then 12 g of anhydrous calcium chloride treated at high temperature was added. The oil bath was turned on and heated to 80 °C, and the stirring rate was set at 450 r / min. After heating for about 35 min, when the calcium chloride was completely dissolved, the reaction kettle was placed in an ice-water bath and further cooled to room temperature.

[0079] (2) 2.7 g of p-phenylenediamine and 0.45 g of 2,2-bis(trifluoromethyl)benzidine diamine were added to the reaction kettle in step (1). After they were completely dissolved, it was placed in a new ice-water bath. Then, 4.122 g of terephthaloyl chloride was added, and it was stirred in the ice-water bath for 6 h. At the same time, the stirring rate was gradually increased to 1500 r / min every half hour. When the "climbing rod" phenomenon began to appear in the polymer in the reaction kettle, the stirring was stopped, and the reaction kettle was removed to obtain a gel-like polymer.

[0080] (3) The high-viscosity gel-like polymer obtained in step (2) is used to prepare a film by the doctor blade coating method with a doctor blade coater, and the film thickness is controlled by the doctor blade. Subsequently, the film is immersed in ethanol for sol-gel transformation, and then a gel film is obtained by phase separation, and it is replaced with absolute ethanol three times. Finally, supercritical drying with carbon dioxide is carried out for 2 days, the supercritical drying pressure is 9 MPa, and the drying temperature is 35 °C to obtain a fluorinated transparent aramid fiber aerogel film material.

[0081] Example 4

[0082] This example is different from Example 1 in that: in step (2), p-phenylenediamine and 3,3'-dimethylbenzidine are replaced with 5-amino-2-(4-aminophenyl)benzimidazole and 4,4'-diaminodiphenyl ether.

[0083] Example 5

[0084] This example is different from Example 1 in that: in step (2), p-phenylenediamine and 3,3'-dimethylbenzidine are replaced with melamine and 3,3'-diaminobenzidine.

[0085] Example 6

[0086] This example is different from Example 1 in that: on the basis of Example 1, 5-amino-2-(4-aminophenyl)benzimidazole and 4,4'-diaminodiphenyl ether are further added in step (2).

[0087] Example 7

[0088] This example is different from Example 4 in that: on the basis of Example 4, melamine and 3,3'-diaminobenzidine are further added in step (2).

[0089] Example 8

[0090] This example is different from Example 1 in that: on the basis of Example 1, 5-amino-2-(4-aminophenyl)benzimidazole, 4,4'-diaminodiphenyl ether, melamine and 3,3'-diaminobenzidine are further added in step (2).

[0091] Example 9

[0092] This example is different from Example 1 in that: in step (2), 2,2-bis(trifluoromethyl)diaminobiphenyl is replaced with 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane (HFBAPP).

[0093] Example 10

[0094] This embodiment is different from Embodiment 1 in that: in step (2), terephthaloyl chloride is replaced with 4,4'-biphenylacetyl chloride.

[0095] Example 11

[0096] This comparative example is basically the same as Embodiment 1, except that: in step (2), 2,2-bis(trifluoromethyl)benzidine is not added.

[0097] Example 12

[0098] This comparative example is basically the same as Embodiment 1, except that: in step (2), p-phenylenediamine and 3,3'-dimethylbenzidine are not added.

[0099] Comparative Example 1

[0100] This comparative example is basically the same as Embodiment 1, except that: in step (2), 3,3'-dimethylbenzidine is replaced with 5-amino-2-(4-aminophenyl)benzimidazole and the mass ratio is greater than 25:5:10.

[0101] Comparative Example 2

[0102] This comparative example is basically the same as Embodiment 1, except that: in step (2), 3,3'-dimethylbenzidine is replaced with 5-amino-2-(4-aminophenyl)benzimidazole and the mass ratio is 10:20:20.

[0103] Comparative Example 3

[0104] This comparative example is basically the same as Example 111, except that: in step (2), the mass ratio of the spatial configuration unit, the chromaticity inhibition unit to the aramid skeleton unit is 30:5:10.

[0105] As Figure 1 shown, it is the preparation flow chart of the aerogel of the fluorinated transparent aramid fiber aerogel material in the above embodiments. The prepared high-viscosity polymer is formed into a thin film by the doctor blade method, and the thin film is subjected to sol-gel transformation, and finally supercritical drying is carried out to obtain it.

[0106] As Figure 2 shown, it is the unit and chemical structural formula of the fluorinated transparent aramid fiber aerogel material in a typical embodiment. TPC and BPDC are selected as the aramid skeleton units, PPD and DBD are selected as the linear spatial configuration units, APBIA and ODA are selected as the zigzag spatial configuration units, MA and DAB are selected as the planar spatial configuration units, and TFB is selected as the chromaticity inhibition unit.

[0107] As Figure 3As shown in the figure, it is a schematic diagram of the spatial structure adjustment of Examples 1, 4, and 5. Different pore-structured fluorinated transparent aramid fiber aerogel materials are obtained by regulating aramid backbone units, spatial configuration units, and chromaticity suppression units.

[0108] As Figure 4 shown in the figure, it is a physical picture of the fluorinated transparent aramid fiber aerogel material prepared in Example 1, showing its visible light transparency.

[0109] As Figure 5 shown in the figure, it is a high infrared transmittance picture of the fluorinated transparent aramid fiber aerogel material prepared in Example 1, showing its ultra-high infrared transmittance.

[0110] Specifically, the performance parameters of the fluorinated transparent aramid fiber aerogel materials prepared in the above Examples 1-12 and Comparative Examples 1-3 are shown in Table 1.

[0111] Table 1 Performance parameters of the fluorinated transparent aramid fiber aerogel materials prepared in Examples 1-10 and Comparative Examples 1-3

[0112]

[0113]

[0114] In addition, the inventors of this case also referred to the foregoing examples and conducted tests with other raw materials, process operations, and process conditions described in this specification, and all obtained relatively ideal results.

[0115] It should be understood that the above are only some embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the creative concept of the present invention, other deformations and improvements can be made, and these all belong to the protection scope of the present invention.

Claims

1. A fluorinated transparent aramid fiber aerogel material, characterized in that, The fluorinated transparent aramid fiber aerogel material is prepared by reacting at least any one of a spatial configuration element and a chromaticity suppression element with an aramid backbone element. The spatial configuration element can adjust the pore structure of the aerogel and improve the light transmittance of the aerogel. The chromaticity suppression element has a fluorinated group and has the function of inhibiting the formation of electron transfer complexes during polymerization and improving transparency.

2. The fluorinated transparent aramid fiber aerogel material according to claim 1, wherein: The spatial configuration element includes any one or a combination of a linear spatial configuration element, a zigzag spatial configuration element, and a planar spatial configuration element; preferably, the linear spatial configuration element includes any one or a combination of p-phenylenediamine and 3,3'-dimethylbenzidine; preferably, the zigzag spatial configuration element includes any one or a combination of 5-amino-2-(4-aminophenyl)benzimidazole and 4,4'-diaminodiphenyl ether; preferably, the planar spatial configuration element includes any one or a combination of melamine and 3,3'-diaminobenzidine.

3. The fluorinated transparent aramid fiber aerogel material according to claim 1, wherein: The chromaticity suppression element includes a fluorinated monomer; preferably, the chromaticity suppression element includes a fluorinated biphenyl diamine compound, preferably including any one or a combination of 2,2-bis(trifluoromethyl)diaminobiphenyl and 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane.

4. The fluorinated transparent aramid fiber aerogel material according to claim 1, wherein: The aramid backbone element includes any one or a combination of terephthaloyl chloride and 4,4'-biphenylacetyl chloride.

5. The fluorinated transparent aramid fiber aerogel material according to claim 1, wherein: The pores of the fluorinated transparent aramid fiber aerogel material have a pore diameter of 5-100 nm, an average transparency in the visible light region of more than 50%, an average light transmittance in the infrared region of more than 80%, and a tensile fracture strength exceeding 0.8 MPa.

6. The preparation method of the fluorinated transparent aramid fiber aerogel material according to any one of claims 1-5, characterized in that, Comprising: In a protective atmosphere, a polymerization reaction is carried out on a mixed reaction system containing an aramid backbone element, a spatial configuration element, a chromaticity suppression element, and an organic solvent to obtain a gel-like polymer. The gel-like polymer is subjected to film-forming treatment and sol-gel transformation to obtain a gel film. The gel film is subjected to drying treatment to obtain a fluorinated transparent aramid fiber aerogel material.

7. The preparation method according to claim 6, characterized in that, Comprising: In a protective atmosphere, the mixed reaction system is gradually heated from 0-5 °C in an ice bath to room temperature and subjected to a polymerization reaction for 4-8 h to obtain a gel-like polymer. Preferably, the preparation method further includes adding a co-solvent for increasing the solubility of the aramid backbone element to the mixed reaction system, and the co-solvent includes calcium chloride. Preferably, the organic solvent includes NMP.

8. The preparation method according to claim 6, characterized in that: The mass ratio of the spatial configuration element, the chromaticity suppression element to the aramid backbone element is 25:0:20 to 0:25:

20.

9. The preparation method according to claim 6, wherein Comprising: The gel-like polymer is made into a film by the doctor blade coating method, and then impregnated into ethanol or acetone for sol-gel transformation to obtain a gel film. And / or, the drying treatment is supercritical carbon dioxide drying, and the drying treatment time is 24-72 h.

10. Use of the fluorinated transparent aramid fiber aerogel material according to any one of claims 1-5 in the fields of passive heating, smart windows or energy-saving building materials. Preferably, the smart window includes a transparent aerogel smart window.

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