Poly (p-phenylene benzobisoxazole) nanofiber composite film, preparation method thereof and application of poly (p-phenylene benzobisoxazole) nanofiber composite film in solar interface water evaporation
PBO nanofiber/carbon nanomaterial composite film was prepared by sol-gel-freeze-drying method, which solved the problem of combining PBO fiber and carbon materials in extreme environments, and achieved high-efficiency solar interface water evaporation and thermal flame retardant performance, which was suitable for solar-powered water evaporation devices in extreme environments.
Patent Information
- Application Number
- CN202510414531.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-03
- Publication Date
- 2025-07-11
AI Technical Summary
The prior art is difficult to effectively combine PBO fibers with carbon materials in extreme environments to prepare high-performance composite film materials to achieve efficient solar interface water evaporation, and the existing photothermal materials are insufficient tolerate in extreme environments.
PBO nanofiber/carbon nanomaterial composite film was prepared by sol-gel-freeze-drying method. The mass ratio of carbon nanomaterial to PBO fiber is 1:10-3:2. Carbon nanomaterials such as carboxylated carbon nanotubes, carbon nanotubes, graphene oxide, etc. were used to form a stable composite film.
It realizes the high mechanical strength, heat-resistant flame retardant properties and excellent environmental resistance of the composite film, improves the interfacial water evaporation performance and photothermal conversion efficiency, and is suitable for solar-driven water evaporation devices in extreme environments.
Smart Images
Figure CN120289987A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a preparation method and application of a high-performance polymer nanofiber composite material, and specifically relates to a poly(p-phenylene benzobisoxazole) (abbreviation: PBO) nanofiber composite film, a preparation method thereof, and an application in solar interfacial water evaporation. Background Art
[0002] PBO fibers exhibit many excellent properties, such as high strength, light weight, corrosion resistance, and thermal stability, and have great application potential in many fields such as aerospace, automotive industry, and military industry. Due to the micron scale of PBO fibers and limited surface functional groups, it faces great challenges to achieve a tight combination of PBO and carbon materials and prepare high-performance composite film materials. PBO nanofibers (PBONF) prepared based on PBO fibers show great advantages in the preparation of multifunctional composite materials due to their nano-scale size and more abundant functional groups.
[0003] Solar interfacial water evaporation technology is a technology that uses solar energy to promote the phase change of water vapor on the surface of a photothermal material. By localizing the generated heat on the material surface for evaporation, it greatly reduces the heat loss of the material to the outside of the system. Therefore, it can efficiently promote the transformation of liquid water into gaseous water, and can be used for sewage purification and seawater desalination, and is expected to solve the problem of shortage of fresh water resources in the future. With the development of new photothermal materials, interfacial engineering, and system design, the photothermal conversion efficiency and water evaporation rate have been greatly improved. However, previous work has mainly been carried out in the laboratory. Compared with the relatively stable experimental conditions, the actual application scenarios are complex and changeable, and even face some specific extreme environments, which puts certain requirements on the environmental tolerance of solar evaporators. PBO nanofibers inherit the excellent environmental tolerance of PBO fibers, providing the possibility for the development of solar-driven interfacial water evaporation devices for extreme environments. Summary of the Invention
[0004] In order to solve the above problems existing in the prior art, the present invention provides a poly(p-phenylene benzobisoxazole) nanofiber composite film, a preparation method thereof, and an application thereof in solar interfacial water evaporation. This method prepares a PBO nanofiber / carbon nanomaterial composite film by a sol-gel-freeze drying method. The composite film can be used as a photothermal conversion component in a solar-driven interfacial water evaporation device, and has good interfacial water evaporation performance, mechanical strength, heat-resistant flame-retardant performance, and environmental tolerance. The present invention realizes a PBO nanofiber composite material in the form of a film, which can be used to construct a high-performance solar-driven interfacial water evaporation device for extreme environments.
[0005] The object of the present invention is achieved by the following technical solutions:
[0006] A poly(p-phenylene benzobisoxazole) nanofiber composite film is prepared from carbon nanomaterials and PBO fibers, where:
[0007] The mass ratio of the carbon nanomaterials to the PBO fibers is 1:10 to 3:2;
[0008] The carbon nanomaterials are one of carboxylated carbon nanotubes, carbon nanotubes, graphene oxide, reduced graphene oxide, etc.
[0009] A preparation method of the above poly(p-phenylene benzobisoxazole) nanofiber composite film comprises the following steps:
[0010] Step S1: Add the carbon nanomaterials into a mixed acid of trifluoroacetic acid (TFA) and methanesulfonic acid (MSA), and perform magnetic stirring in cooperation with ultrasonic-assisted dispersion to obtain a carbon nanomaterial mixed acid dispersion liquid, where: the magnetic stirring time is 3 to 6 hours, the ultrasonic time is 1 to 2 hours, and the volume ratio of trifluoroacetic acid to methanesulfonic acid is 1:9 to 9:1;
[0011] Step S2: Add the PBO fibers into the mixed acid dispersion liquid of step S1, and perform mechanical stirring and ultrasonic-assisted dispersion to obtain a PBO nanofiber / carbon nanomaterial mixed acid dispersion liquid, where: the content of the PBO fibers in the PBO nanofiber / carbon nanomaterial mixed acid dispersion liquid does not exceed 0.8 wt%, the mechanical stirring time is 12 to 24 hours, and the ultrasonic time is 0.5 to 2 hours;
[0012] Step S3: Add anhydrous sodium sulfate (Na2SO4) into the dispersion liquid of step S2, and perform mechanical stirring until the anhydrous sodium sulfate is completely dissolved, where: the mass ratio of anhydrous sodium sulfate to the PBO nanofibers is 6 to 10:1, and the mechanical stirring time is 3 to 6 hours;
[0013] Step S4: Pour the PBO nanofiber composite sol into a plastic petri dish, perform freeze aging, and then place it in deionized water for solvent exchange until the pH of the PBO nanofiber composite gel is 7 to obtain a composite hydrogel film, where: the aging time is 12 to 24 hours;
[0014] Step S5: Perform pre-freezing treatment on the composite hydrogel film, and then obtain the PBO nanofiber composite film by freeze drying, where: the pre-freezing treatment method is pre-freezing in a -20°C refrigerator for 12 to 24 hours, pre-freezing in an -80°C refrigerator for 12 to 24 hours, or liquid nitrogen freezing for 10 to 20 minutes.
[0015] The above PBO nanofiber composite film material can be used in a solar-driven interfacial water evaporation device, as a photothermal conversion component in the solar-driven interfacial water evaporation device, and has excellent interfacial water evaporation performance and good mechanical strength and tolerance.
[0016] Compared with the prior art, the present invention has the following advantages:
[0017] 1. The present invention prepares a lightweight, heat-resistant and flame-retardant PBO nanofiber composite film through a simple sol-gel-freeze drying method, successfully composites carbon nanomaterials with PBO nanofibers, and improves the photothermal conversion performance of the film.
[0018] 2. The PBO nanofiber composite film prepared by the present invention takes into account excellent interfacial water evaporation performance and good environmental tolerance, and can meet the application requirements of some specific extreme environments. Description of the Drawings
[0019] Figure 1 is a physical picture of the PBO nanofiber / CCNT composite film;
[0020] Figure 2 is a scanning electron microscope picture of the PBO nanofiber / CCNT composite film;
[0021] Figure 3 is a thermogravimetric curve graph of the PBO nanofiber / CCNT composite film;
[0022] Figure 4 is a combustion test picture of the PBO nanofiber / CCNT composite film;
[0023] Figure 5 is the water mass loss during the vapor generation experiment of the PBO nanofiber / CCNT composite film under 1 sun illumination;
[0024] Figure 6 is the evaporation rate graph of the PBO nanofiber / CCNT composite film after being heated in a tubular furnace under 1 sun illumination. Detailed Embodiments
[0025] The technical solutions of the present invention will be further described below in conjunction with the embodiments, but are not limited thereto. Any modification or equivalent replacement of the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention shall be covered within the protection scope of the present invention.
[0026] Raw materials and reagents: PBO fibers (AS, 500D / 330f) are from Zhongke Jinqi New Materials Technology Co., Ltd. Carbon nanomaterials are purchased from Jiangsu Xianfeng Nanomaterials Co., Ltd. Trifluoroacetic acid (TFA, 99.5%) and methanesulfonic acid (MSA, 99%) are purchased from Beijing Innochem Technology Co., Ltd. Anhydrous sodium sulfate is purchased from Tianjin Tianli Chemical Reagent Co., Ltd.
[0027] Example 1
[0028] 0.96 g of carboxylated carbon nanotubes (CCNT) was added to 160 g of a mixed acid solution (V TFA :V MSA = 1:1), and magnetically stirred for 3 hours and ultrasonically treated for 2 hours to fully disperse the CCNT. 0.4 wt% of PBO fibers was added to the above acid solution, and mechanically stirred for 12 hours. Subsequently, 5 g of anhydrous sodium sulfate was added thereto, and stirring was continued for 6 hours and ultrasonically treated for 30 min to obtain a PBONF / CCNT acid sol. The obtained sol was poured into a petri dish and allowed to stand at 5 °C for 12 hours to obtain an acid gel. The acid gel was immersed in water for solvent exchange for 3 days (changing the pure water every 6 hours) to remove the residual mixed acid solvent as much as possible. When the solution was measured to be neutral with a pH test paper, a PBONF / CCNT hydrogel film was prepared. The obtained hydrogel was frozen in liquid nitrogen for 15 minutes and then dried in a freeze dryer for 12 hours to obtain a PBONF / CCNT composite film ( Figure 1 ).
[0029] Example 2
[0030] 0.48 g of CCNT was added to 160 g of a mixed acid solution (V TFA :V MSA = 1:1), and magnetically stirred for 3 hours and ultrasonically treated for 1 hour to fully disperse the CCNT. 0.5 wt% of PBO fibers was added to the above acid solution, and mechanically stirred for 24 hours. Subsequently, 5 g of anhydrous sodium sulfate was added thereto, and stirring was continued for 6 hours and ultrasonically treated for 30 min to obtain a PBONF / CCNT acid sol. The obtained sol was poured into a petri dish and allowed to stand at 5 °C for 12 hours to obtain an acid gel. The acid gel was immersed in water for solvent exchange for 3 days (changing the pure water every 6 hours) to remove the residual mixed acid solvent as much as possible. When the solution was measured to be neutral with a pH test paper, a PBONF / CCNT hydrogel film was prepared. The obtained hydrogel was frozen in liquid nitrogen for 10 minutes and then dried in a freeze dryer for 12 hours to obtain a PBONF / CCNT composite film.
[0031] Example 3
[0032] 0.96 g of CCNT was added to 160 g of a mixed acid solution (V TFA :V MSA= 1:1), stir magnetically for 3 hours and sonicate for 1 hour to fully disperse CCNT. Add 0.6 wt% PBO fibers into the above acid solution, stir mechanically for 24 hours, then add 8 g of anhydrous sodium sulfate thereto, continue stirring for 6 hours and sonicate for 1 hour to obtain PBONF / CCNT acid sol. Pour the obtained sol into a petri dish and let it stand at 5 °C for 12 hours to obtain an acid gel. Immerse the acid gel in water for solvent exchange for 3 days (change the pure water every 6 hours) to remove the residual mixed acid solvent as much as possible. When the solution is measured to be neutral with pH test paper, a PBONF / CCNT hydrogel film is prepared. Freeze the obtained hydrogel in liquid nitrogen for 20 minutes, and then dry it in a freeze dryer for 12 hours to obtain a PBONF / CCNT composite film.
[0033] Example 4
[0034] Add 0.64 g of carbon nanotubes (CNT) into 160 g of mixed acid solution (V TFA :V MSA = 1:1), stir magnetically for 2 hours and sonicate for 1 hour to fully disperse CNT. Add 0.4 wt% PBO fibers into the above acid solution, stir mechanically for 12 hours, then add 5 g of anhydrous sodium sulfate thereto, continue stirring for 6 hours and sonicate for 1 hour to obtain PBONF / CNT acid sol. Pour the obtained sol into a petri dish and let it stand at 5 °C for 12 hours to obtain an acid gel. Immerse the acid gel in water for solvent exchange for 3 days (change the pure water every 6 hours) to remove the residual mixed acid solvent as much as possible. When the solution is measured to be neutral with pH test paper, a PBONF / CNT hydrogel film is prepared. Freeze the obtained hydrogel in liquid nitrogen for 15 minutes, and then dry it in a freeze dryer for 12 hours to obtain a PBONF / CNT composite film.
[0035] Example 5
[0036] Add 0.16 g of GO into 160 g of mixed acid solution (V TFA :V MSA = 1:1), stir magnetically for 3 hours and sonicate for 1 hour to fully disperse GO. Add 0.4 wt% PBO fibers into the above acid solution, stir mechanically for 12 hours, then add 5 g of anhydrous sodium sulfate thereto, continue stirring for 5 hours and sonicate for 30 min to obtain PBONF / GO acid sol. Pour the obtained sol into a petri dish and let it stand at 5 °C for 12 hours to obtain an acid gel. Immerse the acid gel in water for solvent exchange for 3 days (change the pure water every 6 hours) to remove the residual mixed acid solvent as much as possible. When the solution is measured to be neutral with pH test paper, a PBONF / GO hydrogel film is prepared. Freeze the obtained hydrogel in liquid nitrogen for 10 minutes, and then dry it in a freeze dryer for 12 hours to obtain a PBONF / GO composite film.
[0037] Example 6
[0038] 0.32 g of reduced graphene oxide (rGO) was added to 160 g of a mixed acid solution (V TFA :V MSA = 1:1), magnetically stirred for 3 hours and ultrasonically treated for 1 hour to fully disperse rGO. 0.4 wt% PBO fibers were added to the above acid solution, mechanically stirred for 12 hours, then 5 g of anhydrous sodium sulfate was added thereto, and stirring was continued for 6 hours and ultrasonically treated for 30 min to obtain a PBONF / rGO acid sol. The obtained sol was poured into a petri dish and allowed to stand at 5 °C for 12 hours to obtain an acid gel. The acid gel was immersed in water for solvent exchange for 3 days (pure water was changed every 6 hours) to remove the residual mixed acid solvent as much as possible. When the solution was measured to be neutral with a pH test paper, a PBONF / rGO hydrogel film was prepared. The obtained hydrogel was frozen in liquid nitrogen for 20 minutes and then dried in a freeze dryer for 12 hours to obtain a PBONF / rGO composite film.
[0039] Comparative Example 1
[0040] 0.4 wt% PBO fibers were added to 160 g of a mixed acid solution (V TFA :V MSA = 1:1), mechanically stirred for 12 hours, then 5 g of anhydrous sodium sulfate was added thereto, and stirring was continued for 6 hours and ultrasonically treated for 30 min to obtain a PBO nanofiber acid sol. The obtained sol was poured into a petri dish and allowed to stand at 5 °C for 12 hours to obtain an acid gel. The acid gel was immersed in water for solvent exchange for 3 days (pure water was changed every 6 hours) to remove the residual mixed acid solvent as much as possible. When the solution was measured to be neutral with a pH test paper, a PBONF nanofiber hydrogel was prepared. The obtained hydrogel was frozen in liquid nitrogen for 15 minutes and then dried in a freeze dryer for 12 hours to obtain a PBO nanofiber film.
[0041] The beneficial effects of the present invention were verified by using Example 1 and through the following tests:
[0042] Test 1: Morphological characterization of the PBONF / CCNT composite film
[0043] A composite film sample was taken, and after sputtering gold on the sample surface, it was observed and characterized by scanning electron microscopy (SEM). Figure 2 The SEM images showed that the PBONF / CCNT composite film had three-dimensional through pores, providing a super high specific surface area and low density, achieving self-floating and rapid water molecule transport, and at the same time greatly reducing the thermal conductivity of the composite film, which was beneficial for the film to localize energy in the light absorption layer.
[0044] Test 2: Thermal stability performance analysis of the PBONF / CCNT composite film
[0045] As Figure 3 shown, the thermogravimetric analysis (TGA) results indicate that PBONF and the composite film have high thermal stability. The decomposition temperature of the PBONF film is as high as about 583 °C. After adding CCNT, the thermal decomposition temperature of the composite film decreases, but it is still higher than 350 °C and starts to decompose at 350 - 400 °C. In the steady state of a normal interfacial water evaporation system, the temperature of the interfacial material is not very high. However, in the actual application environment, there is a high possibility of local high temperature or the need to be used in some extremely high-temperature environments. If the thermal stability of the material is not good, it is very likely to cause the decomposition or even failure of the photothermal material. The PBONF / CCNT composite film can better meet the thermal stability requirements of the interfacial water evaporation material.
[0046] Experiment 3: Flame Retardant and Fireproof Performance of PBONF / CCNT Composite Film
[0047] Due to its chemical composition, high thermal stability and ordered structure, the PBONF / CCNT composite film has good flame retardant and fireproof performance. The flame retardant performance of the prepared PBONF / CCNT composite film was tested by combustion experiments. Figure 4 In [the experiment], a 10 mm × 12 mm film was placed on the high-temperature flame of an alcohol lamp. During the combustion process, it was observed that a dense carbonized barrier quickly formed at the combustion interface. After removing the heat source, the flame on the film could be extinguished immediately, and the geometric morphology of the sample after combustion hardly changed and there was no phenomenon of melting and dripping. This self-limiting combustion behavior indicates that the composite film has significant flame retardant and fireproof performance.
[0048] Experiment 4: Test on the Solar Interfacial Water Evaporation Performance of PBONF / CCNT Composite Film
[0049] A film sample with a diameter of 4 cm was placed on the water surface, and a simulated sunlight was used to irradiate the system (room temperature was about 25 °C). The mass change of the evaporator system with the illumination time was carefully recorded by an electronic balance to study the solar interfacial water evaporation performance of the composite film, as Figure 5 shown. The mass loss of the water evaporation system of the PBONF / CCNT composite film reached 1.50 g. In contrast, the evaporation amount of pure water was only 0.25 g. After incorporating CCNT into the PBONF film, the water evaporation rate of the film increased significantly, and the evaporation rate of the composite film reached 1.45 kg·m -2 ·h -1, about 6 times that of pure water, indicating that CCNTs as a light absorber greatly promotes the light absorption ability and photothermal conversion ability of the film. To further study the solar - water vapor conversion performance, the evaporation efficiency (η) was calculated. Through calculation, the evaporation efficiency of the composite film was 91.0%. The outstanding efficiency of the composite film in this system is derived from the high - efficiency wide - wavelength light absorption rate, excellent heat insulation performance, and high porosity beneficial to water transportation and water vapor release.
[0050] Experiment 5: Water evaporation rate of PBONF / CCNTs composite film under extreme conditions
[0051] To simulate the influence of extreme temperature on the water evaporation rate of the composite film, 4 composite films were placed in a tube furnace and heated for 30 min. The set temperatures were room temperature, 100 °C, 200 °C, and 300 °C respectively. Then, a simulated sunlight was used to irradiate the system, and the mass loss of the evaporator system was carefully recorded by an electronic balance to calculate the water evaporation rate at the steady state of each sample. As can be seen from Figure 6 , after being burned at 300 °C for 30 min, the composite film still had an evaporation rate of 1.36 kg·m -2 ·h -1 , which was not much different from the evaporation rate of 1.45 kg·m -2 ·h -1 of the sample without heat treatment, indicating that the prepared composite film has excellent high - temperature resistance.
[0052] The present invention prepares a PBO nanofiber / carbon nanomaterial composite film by the sol-gel-freeze drying method. The PBO nanofibers and the carbon nanomaterials can be combined together through physical and chemical interactions to form a stable structure. This interaction can enhance the interfacial bonding force of the composite material, prevent the agglomeration and shedding of carbon nanomaterials such as carbon nanotubes, and improve the stability and service life of the material. The carbon nanomaterials have high strength, and after being combined with the PBO nanofibers, they can enhance each other, further improving the mechanical properties of the composite material. In practical applications, this composite material can withstand certain external forces and pressures, maintain the stability of the structure, and ensure the smooth progress of the interfacial water evaporation process. The carbon nanomaterials have excellent light absorption properties and have good absorption ability in the entire solar spectrum range, and can effectively convert solar energy into heat energy. After combining the carbon nanomaterials with the PBO nanofibers, the carbon nanomaterials can be evenly distributed on the surface and inside of the PBO nanofibers, increasing the light absorption area and absorption intensity of the composite material for sunlight, thereby improving the photothermal conversion efficiency. At the same time, the composite film inherits the excellent heat resistance, high flame retardancy and dimensional stability of the PBO fiber, enabling it to meet the application requirements of some specific extreme environments. This solar-driven interfacial water evaporation device based on the PBO NF / carbon nanomaterial composite film can be used in application scenarios such as seawater desalination, sewage treatment, and solar-driven water evaporation power generation.
Claims
1. A poly(p-phenylene benzobisoxazole) nanofiber composite film, characterized in that The composite film is prepared from carbon nanomaterials and PBO fibers, wherein: the mass ratio of the carbon nanomaterials to the PBO fibers is 1:10 to 3:
2.
2. The poly(p-phenylene benzobisoxazole) nanofiber composite film according to claim 1, wherein The carbon nanomaterials are one of carboxylated carbon nanotubes, carbon nanotubes, graphene oxide, and reduced graphene oxide.
3. A method for preparing the poly(p-phenylene benzobisoxazole) nanofiber composite film according to any one of claims 1-2, characterized in that The method comprises the following steps: Step S1: Add the carbon nanomaterials into a mixed acid of trifluoroacetic acid and methanesulfonic acid, and perform magnetic stirring in cooperation with ultrasonic-assisted dispersion to obtain a carbon nanomaterial mixed acid dispersion liquid; Step S2: Add the PBO fibers into the mixed acid dispersion liquid obtained in Step S1, and perform mechanical stirring and ultrasonic-assisted dispersion to obtain a PBO nanofiber / carbon nanomaterial mixed acid dispersion liquid, wherein: the content of the PBO fibers in the PBO nanofiber / carbon nanomaterial mixed acid dispersion liquid does not exceed 0.8 wt%; Step S3: Add anhydrous sodium sulfate into the dispersion liquid obtained in Step S2, and perform mechanical stirring until the anhydrous sodium sulfate is completely dissolved, wherein: the mass ratio of the anhydrous sodium sulfate to the PBO nanofibers is 6 to 10:1; Step S4: Pour the PBO nanofiber composite sol into a plastic petri dish, perform freeze aging, and then place it in deionized water for solvent exchange until the pH of the PBO nanofiber composite gel is 7 to obtain a composite hydrogel film; Step S5: Perform pre-freezing treatment on the composite hydrogel film, and then obtain a PBO nanofiber composite film through freeze drying.
4. The preparation method of the poly(p-phenylene benzobisoxazole) nanofiber composite film according to claim 3, characterized in that In the said Step S1, the magnetic stirring time is 3 to 6 hours, and the ultrasonic time is 1 to 2 hours.
5. The preparation method of the poly(p-phenylene benzobisoxazole) nanofiber composite film according to claim 3, characterized in that The volume ratio of the trifluoroacetic acid to the methanesulfonic acid is 1:9 to 9:
1.
6. The preparation method of the poly(p-phenylene benzobisoxazole) nanofiber composite film according to claim 1, characterized in that In the said Step S2, the mechanical stirring time is 12 to 24 hours, and the ultrasonic time is 0.5 to 2 hours.
7. The preparation method of the poly(p-phenylene benzobisoxazole) nanofiber composite film according to claim 1, characterized in that In the said Step S3, the mechanical stirring time is 3 to 6 hours.
8. The preparation method of the poly(p-phenylene benzobisoxazole) nanofiber composite film according to claim 1, characterized in that In the said Step S4, the aging time is 12 to 24 hours.
9. The preparation method of the poly(p-phenylene benzobisoxazole) nanofiber composite film according to claim 1, characterized in that In the said Step S5, the pre-freezing treatment method is pre-freezing in a -20°C refrigerator for 12 to 24 hours, pre-freezing in an -80°C refrigerator for 12 to 24 hours, or liquid nitrogen freezing for 10 to 20 minutes.
10. Application of the poly(p-phenylene benzobisoxazole) nanofiber composite film according to any one of claims 1-2 in a photothermal conversion component of a solar interface water evaporation device.