Cerium oxide superhydrophilic / superhydrophobic array fog-collecting thin film and its preparation method

Abstract

The application discloses a cerium oxide super-hydrophilic / super-hydrophobic array mist collecting film and a preparation method thereof, and specifically comprises the following steps: step 1, a cerium oxide film is prepared on a silicon substrate by using a sol-gel method; step 2, nanospheres are fixed on the surface of the cerium oxide film by using a hydrothermal synthesis method to obtain a cerium oxide nanosphere film; step 3, the cerium oxide film with the nanosphere structure on the surface is modified by using a molecular self-assembly technology to obtain a super-hydrophobic cerium oxide nanosphere film; and step 4, different specifications of mask plates are covered on the surface of the super-hydrophobic cerium oxide nanosphere film, and deep ultraviolet irradiation is used to obtain the cerium oxide super-hydrophilic / super-hydrophobic array mist collecting film. The mist collecting film can realize efficient mist capturing and mist collecting circulation.

Description

Technical Field

[0001] This invention belongs to the field of fog collection film technology, specifically relating to a method for preparing a cerium oxide superhydrophilic / superhydrophobic array fog collection film, and also relating to a cerium oxide superhydrophilic / superhydrophobic array fog collection film. Background Technology

[0002] Collecting water from fog is a sustainable solution to address water shortages in some regions. Among existing fog-collecting devices and materials, fog-collecting films have become a research hotspot due to their large contact area with fog and wide applicability. Most existing fog-collecting films are superhydrophobic films. However, the growth rate of droplets condensing on the surface of superhydrophobic films is slow, and once they cover the substrate surface, they hinder subsequent droplet condensation, resulting in low fog capture efficiency. Summary of the Invention

[0003] The purpose of this invention is to provide a method for preparing a cerium oxide superhydrophilic / superhydrophobic array fog-collecting film, which solves the problem of low fog capture efficiency of existing fog-collecting films.

[0004] Another objective of this invention is to provide a cerium oxide superhydrophilic / superhydrophobic array fog-collecting film.

[0005] The technical solution adopted in this invention is a method for preparing a cerium oxide superhydrophilic / superhydrophobic array fog-collecting film, which is implemented according to the following steps:

[0006] Step 1: Prepare cerium oxide thin films on silicon substrates using the sol-gel method;

[0007] Step 2: Nanospheres are immobilized on the surface of a cerium oxide film using a hydrothermal synthesis method to obtain a cerium oxide nanosphere film;

[0008] Step 3: Use molecular self-assembly technology to modify the cerium oxide film with nanosphere structure on the surface to a low surface energy, so as to obtain a superhydrophobic cerium oxide nanosphere film.

[0009] Step 4: Cover the surface of the superhydrophobic cerium oxide nanosphere film with photomasks of different specifications, and use deep ultraviolet irradiation to obtain a cerium oxide superhydrophilic / superhydrophobic array fog-collecting film.

[0010] The invention is further characterized in that,

[0011] The specific process of step 1 is as follows:

[0012] Step 1.1: Cerium acetate (III) hydrate is dissolved in anhydrous methanol, then propionic acid is added as a catalyst, the mixture is sealed, stirred, and allowed to stand for aging to obtain cerium oxide sol;

[0013] Step 1.2: Immerse the clean silicon wafer in the cerium oxide sol obtained in Step 1.1, and use the dip-coating method to prepare a smooth and flat sol-gel film on the silicon wafer;

[0014] Step 1.3: Place the sol-gel film obtained in step 1.2 into a muffle furnace for heat treatment, and cool it with the furnace to obtain a cerium oxide film.

[0015] In step 1.1, the concentration of cerium oxide sol is 0.10 mol / L to 0.80 mol / L, and the molar ratio of cerium(III) acetate hydrate to propionic acid is 1:3.

[0016] In step 1.2, the lifting speed of the dip-lift method is 0.5 mm / s to 4 mm / s;

[0017] In step 1.3, the heat treatment process is as follows: first, hold at 200℃ for 10 minutes, then heat from 200℃ to 800℃ and hold for 15 minutes. Repeat the above process 3 times, and hold at 800℃ for 2 hours in the third time.

[0018] The specific process of step 2 is as follows:

[0019] Step 2.1: Using cerium nitrate hexahydrate as the cerium source and urea as the alkali source, dissolve it fully in deionized water. After the solution is completely clear, a hydrothermal reaction solution of cerium oxide is obtained.

[0020] Step 2.2: Place the cerium oxide film obtained in Step 1 at a 45° angle with the film surface facing down into the polytetrafluoroethylene (PTFE) liner, and pour the cerium oxide hydrothermal reaction solution obtained in Step 2.1 into the PTFE liner. Place the PTFE liner into the hydrothermal reactor for reaction, and cool it to room temperature with the furnace. After the reaction is complete, take out the sample.

[0021] Step 2.3: Wash the excess cerium oxide nanoparticles adhering to the sample surface alternately with deionized water and anhydrous ethanol. Dry and anneal the washed sample to obtain a cerium oxide nanosphere film.

[0022] In step 2.1, the concentration of the cerium oxide hydrothermal reaction solution is 0.010 mol / L to 0.080 mol / L;

[0023] In step 2.2, the reaction temperature in the hydrothermal reactor is 100℃, and the reaction time is 24h;

[0024] In step 2.3, the drying temperature is 60℃~80℃ and the drying time is 10min~20min; the annealing process is as follows: the temperature is raised to 450℃ in a muffle furnace at a heating rate of 3℃ / min~5℃ / min and held for 2h.

[0025] The specific process of step 3 is as follows: the cerium oxide nanosphere film obtained in step 2 is immersed in a low surface energy modifier solution for modification, and after being taken out, it is washed with anhydrous ethanol to remove the residual modifier on the surface. After drying, a superhydrophobic cerium oxide nanosphere film is obtained.

[0026] The concentration of the low surface energy modifier solution is 15 g / L to 60 g / L. The low surface energy modifier is one of octadecyltrimethyloxysilane, 1H,1H,2H,2H-perfluorodecyltrimethoxysilane, hexadecyltrimethyloxysilane, and vinyltrimethoxysilane. The solvent is anhydrous ethanol. The immersion modification time is 10 min to 50 min. The drying temperature is 25℃ to 80℃ and the time is 10 min to 30 min.

[0027] The specific process of step 4 is as follows: cover the surface of the superhydrophobic cerium oxide nanosphere film obtained in step 3 with a mask template with a specific pattern, and then irradiate the unmasked area with deep ultraviolet light at room temperature to obtain a cerium oxide superhydrophilic / superhydrophobic array fog collecting film.

[0028] The ultraviolet light wavelength is 180nm~280nm, and the irradiation time is 3h~8h.

[0029] Another technical solution adopted in this invention is a cerium oxide superhydrophilic / superhydrophobic array fog-collecting film, which is obtained by the above preparation method.

[0030] The beneficial effects of this invention are as follows: The preparation method of the cerium oxide superhydrophilic / superhydrophobic array fog-collecting film of this invention firstly uses a combination of sol-gel method and hydrothermal synthesis method to prepare a dense cerium oxide nanosphere film. Then, it is modified with low surface energy using molecular self-assembly technology. Next, it is constructed using deep ultraviolet irradiation-assisted masking technology to construct an array of regularly alternating superhydrophilic and superhydrophobic regions. The superhydrophilic region of the film significantly improves the fog droplet nucleation and capture efficiency, while the superhydrophobic region controls the size of fog droplets adhering to the fog-collecting surface, allowing them to grow to a certain size and roll off the fog-collecting surface, so that the superhydrophilic region can re-contact and capture the fog droplets, thereby achieving efficient fog capture and fog collection cycle. Attached Figure Description

[0031] Figure 1 These are XRD patterns of the cerium oxide thin film prepared by the method of this invention before and after hydrothermal treatment;

[0032] Figure 2 These are contact angle images of the superhydrophobic cerium oxide nanosphere film prepared by the method of this invention;

[0033] Figure 3 These are images showing the roll-off angle of the superhydrophobic cerium oxide nanosphere film prepared by the method of this invention.

[0034] Figure 4This is a SEM image of the cerium oxide superhydrophilic / superhydrophobic array fog-collecting film prepared by the method of this invention;

[0035] Figure 5 This is an EDS electronic layering image of the cerium oxide superhydrophilic / superhydrophobic array fog collecting film prepared by the method of this invention;

[0036] Figure 6 This is the overall EDS surface pattern of the cerium oxide superhydrophilic / superhydrophobic array fog-collecting film prepared by the method of this invention;

[0037] Figure 7 This is a Ce element distribution diagram of the cerium oxide superhydrophilic / superhydrophobic array fog collecting film prepared by the method of this invention;

[0038] Figure 8 This is a diagram showing the O element distribution of the cerium oxide superhydrophilic / superhydrophobic array fog-collecting film prepared by the method of this invention;

[0039] Figure 9 This is a graph showing the F element distribution of the cerium oxide superhydrophilic / superhydrophobic array fog-collecting film prepared by the method of this invention.

[0040] Figure 10 This is a C element distribution diagram of the cerium oxide superhydrophilic / superhydrophobic array fog-collecting film prepared by the method of this invention. Detailed Implementation

[0041] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0042] The method for preparing the cerium oxide superhydrophilic / superhydrophobic array fog-collecting film of the present invention is specifically implemented according to the following steps:

[0043] Step 1: Prepare cerium oxide thin films on silicon substrates using the sol-gel method;

[0044] The specific process is as follows:

[0045] Step 1.1: Cerium acetate (III) hydrate is dissolved in anhydrous methanol, then propionic acid is added as a catalyst, the mixture is sealed and stirred for 2-10 hours, and then allowed to stand for aging for 24 hours to obtain cerium oxide sol.

[0046] The concentration of cerium oxide sol was 0.10 mol / L to 0.80 mol / L, and the molar ratio of cerium(III) acetate hydrate to propionic acid was 1:3.

[0047] Step 1.2: Immerse the clean silicon wafer in the cerium oxide sol obtained in Step 1.1, and use the dip-coating method to prepare a smooth and flat sol-gel film on the silicon wafer;

[0048] The lifting speed is 0.5mm / s to 4mm / s;

[0049] Step 1.3: Place the sol-gel film obtained in step 1.2 into a muffle furnace for heat treatment, and cool it with the furnace to obtain a cerium oxide film;

[0050] The heat treatment process is as follows: first, hold at 200℃ for 10 minutes, then heat from 200℃ to 800℃ and hold for 15 minutes. Repeat the above process 3 times, and hold at 800℃ for 2 hours in the third time.

[0051] Step 2: Nanospheres are immobilized on the surface of a cerium oxide film using a hydrothermal synthesis method to obtain a cerium oxide nanosphere film;

[0052] The specific process is as follows:

[0053] Step 2.1: Using cerium nitrate hexahydrate as the cerium source and urea as the alkali source, dissolve it fully in deionized water. After the solution is completely clear, a hydrothermal reaction solution of cerium oxide is obtained.

[0054] The concentration of the cerium oxide hydrothermal reaction solution is 0.010 mol / L to 0.080 mol / L;

[0055] Step 2.2: Place the cerium oxide film obtained in Step 1 at a 45° angle with the film surface facing down into a 50 mL polytetrafluoroethylene (PTFE) liner. Pour the cerium oxide hydrothermal reaction solution obtained in Step 2.1 into the PTFE liner. During this process, the volume of the reaction solution should not exceed 2 / 3 of the volume of the PTFE liner. Place the PTFE liner into a hydrothermal reactor and react at 100°C for 24 h. Cool the reactor to room temperature. After the reaction is complete, remove the sample.

[0056] Step 2.3: Wash the excess cerium oxide nanoparticles adhering to the sample surface alternately with deionized water and anhydrous ethanol, and then dry and anneal the washed sample to obtain a cerium oxide nanosphere film.

[0057] The drying temperature is 60℃~80℃, and the drying time is 10min~20min; the annealing process is as follows: the temperature is raised to 450℃ in a muffle furnace at a heating rate of 3℃ / min~5℃ / min and held for 2h.

[0058] Step 3: Use molecular self-assembly technology to modify the cerium oxide film with nanosphere structure on the surface with low surface energy to obtain a superhydrophobic cerium oxide nanosphere film;

[0059] The specific process is as follows:

[0060] The cerium oxide nanosphere film obtained in step 2 was immersed in a low surface energy modifier solution for 10 min to 50 min. After being removed, it was washed with anhydrous ethanol to remove the residual modifier on the surface. After drying, a superhydrophobic cerium oxide nanosphere film was obtained.

[0061] The concentration of the low surface energy modifier solution is 15 g / L to 60 g / L. The low surface energy modifier is one of octadecyltrimethyloxysilane, 1H,1H,2H,2H-perfluorodecyltrimethoxysilane, hexadecyltrimethyloxysilane, and vinyltrimethoxysilane. The solvent is anhydrous ethanol.

[0062] The drying temperature is 25℃~80℃, and the time is 10min~30min;

[0063] Step 4: Cover the surface of the superhydrophobic cerium oxide nanosphere film with masks of different specifications, and use deep ultraviolet irradiation to obtain a cerium oxide superhydrophilic / superhydrophobic array fog-collecting film;

[0064] The specific process is as follows:

[0065] A mask with a specific pattern is covered on the surface of the superhydrophobic cerium oxide nanosphere film obtained in step 3, and the unmasked area is then irradiated with deep ultraviolet light at room temperature to obtain a cerium oxide superhydrophilic / superhydrophobic array fog-collecting film.

[0066] The ultraviolet light wavelength is 180nm~280nm, and the irradiation time is 3h~8h.

[0067] The cerium oxide superhydrophilic / superhydrophobic array fog-collecting film obtained in this invention has a superhydrophilic region with a large adhesion force to fog droplets, which can quickly capture fog droplets in the air and cause them to aggregate and form larger droplets. The superhydrophobic region has a low surface free energy and a high contact angle, and has a very weak adhesion force to fog droplets, which can make the fog droplets roll off the sample surface quickly. The regular alternation of superhydrophilic and superhydrophobic regions can not only accelerate the aggregation and growth of fog droplets and significantly improve the fog droplet nucleation and capture efficiency, but also, when the fog droplets reach the critical size, they can quickly roll off the surface of the array fog-collecting film under the action of low adhesion force or gravity in the superhydrophobic region, allowing the superhydrophilic region to re-contact and capture the fog droplets, and so on, thereby achieving efficient fog capture and fog collection cycle.

[0068] Example 1

[0069] Step 1: Prepare cerium oxide thin films on silicon substrates using the sol-gel method;

[0070] The specific process is as follows:

[0071] Step 1.1: Dissolve 0.6345g of cerium(III) acetate hydrate in 20mL of anhydrous methanol, then add 0.4445g of propionic acid catalyst, seal, stir at room temperature for 3h on a magnetic stirrer, and let stand for 24h to obtain a yellowish-brown transparent cerium oxide sol with a concentration of 0.10mol / L.

[0072] Step 1.2: Immerse the clean silicon wafer in the cerium oxide sol obtained in Step 1.1, and use the dip-coating method to prepare a smooth and flat sol-gel film on the silicon wafer at a coating speed of 0.5 mm / s.

[0073] Step 1.3: Place the sol-gel film obtained in step 1.2 into a muffle furnace for heat treatment, and cool it with the furnace to obtain a cerium oxide film;

[0074] The heat treatment process is as follows: first, hold at 200℃ for 10 minutes, then heat from 200℃ to 800℃ and hold for 15 minutes. Repeat the above process 3 times. In the third heat treatment, hold at 800℃ for 2 hours. During this heat treatment process, the polymer will gradually decompose to form cerium oxide, and a cerium oxide film will be obtained as the substrate for the hydrothermal method.

[0075] Step 2: Nanospheres are immobilized on the surface of a cerium oxide film using a hydrothermal synthesis method to obtain a cerium oxide nanosphere film;

[0076] The specific process is as follows:

[0077] Step 2.1: Using 0.1303g of cerium nitrate hexahydrate as the cerium source and 0.0540g of urea as the alkali source, dissolve them completely in 30mL of deionized water. After the solution is completely clear, a hydrothermal reaction solution of cerium oxide with a concentration of 0.010mol / L is obtained.

[0078] Step 2.2: Place the cerium oxide film obtained in Step 1 at a 45° angle with the film surface facing down into a 50 mL polytetrafluoroethylene (PTFE) liner. Pour the cerium oxide hydrothermal reaction solution obtained in Step 2.1 into the PTFE liner. During this process, the volume of the reaction solution should not exceed 2 / 3 of the volume of the PTFE liner. Place the PTFE liner into a hydrothermal reactor and react at 100°C for 24 h. Cool the reactor to room temperature. After the reaction is complete, remove the sample.

[0079] Step 2.3: Wash the excess cerium oxide nanoparticles adhering to the sample surface alternately with deionized water and anhydrous ethanol, and then dry and anneal the washed sample to obtain a cerium oxide nanosphere film.

[0080] The drying temperature is 80℃ and the drying time is 10 min to 20 min; the annealing process is as follows: the temperature is raised to 450℃ in a muffle furnace at a heating rate of 3℃ / min and held for 2 hours.

[0081] Step 3: Use molecular self-assembly technology to modify the cerium oxide film with nanosphere structure on the surface with low surface energy to obtain a superhydrophobic cerium oxide nanosphere film;

[0082] The specific process is as follows:

[0083] The cerium oxide nanosphere film obtained in step 2 was immersed in an anhydrous ethanol solution of 15 g / L octadecyltrimethyloxysilane for 15 min for modification. After removal, it was washed with anhydrous ethanol to remove the residual modifier on the surface. After drying at 80 °C for 10 min to 30 min, a layer of perfluorosilane was self-assembled on the cerium oxide surface to obtain a superhydrophobic cerium oxide nanosphere film.

[0084] Step 4: Cover the surface of the superhydrophobic cerium oxide nanosphere film with masks of different specifications, and use deep ultraviolet irradiation to obtain a cerium oxide superhydrophilic / superhydrophobic array fog-collecting film;

[0085] The specific process is as follows:

[0086] A mask with a stripe size of 1 mm × 5 cm was used to cover the surface of the superhydrophobic cerium oxide nanosphere film obtained in step 3. The unmasked area was then irradiated with ultraviolet light with a wavelength of 180 nm to 280 nm for 3 hours at room temperature to obtain a cerium oxide superhydrophilic / superhydrophobic array fog-collecting film.

[0087] like Figure 1 As shown in the figure, where a is the curve before hydrothermal treatment and b is the curve after hydrothermal treatment, it can be seen that the diffraction intensity of the cerium oxide film is significantly improved after hydrothermal treatment.

[0088] Example 2

[0089] Step 1: Prepare cerium oxide thin films on silicon substrates using the sol-gel method;

[0090] The specific process is as follows:

[0091] Step 1.1: Dissolve 0.95g of cerium acetate (III) hydrate in 20mL of anhydrous methanol, then add 0.67g of propionic acid catalyst, seal the mixture, stir at room temperature for 4h on a magnetic stirrer, and let it stand for aging for 24h to obtain a yellowish-brown transparent cerium oxide sol with a concentration of 0.30mol / L.

[0092] Step 1.2: Immerse the clean silicon wafer in the cerium oxide sol obtained in Step 1.1, and use the dip-coating method to prepare a smooth and flat sol-gel film on the silicon wafer at a coating speed of 1.5 mm / s.

[0093] Step 1.3: Place the sol-gel film obtained in step 1.2 into a muffle furnace for heat treatment, and cool it with the furnace to obtain a cerium oxide film;

[0094] The heat treatment process is as follows: first, hold at 200℃ for 10 minutes, then heat from 200℃ to 800℃ and hold for 15 minutes. Repeat the above process 3 times. In the third heat treatment, hold at 800℃ for 2 hours. During this heat treatment process, the polymer will gradually decompose to form cerium oxide, and a cerium oxide film will be obtained as the substrate for the hydrothermal method.

[0095] Step 2: Nanospheres are immobilized on the surface of a cerium oxide film using a hydrothermal synthesis method to obtain a cerium oxide nanosphere film;

[0096] The specific process is as follows:

[0097] Step 2.1: Using 0.3908g of cerium nitrate hexahydrate as the cerium source and 0.2700g of urea as the alkali source, dissolve them completely in 30mL of deionized water. After the solution is completely clear, a hydrothermal reaction solution of cerium oxide with a concentration of 0.030mol / L is obtained.

[0098] Step 2.2: Place the cerium oxide film obtained in Step 1 at a 45° angle with the film surface facing down into a 50 mL polytetrafluoroethylene (PTFE) liner. Pour the cerium oxide hydrothermal reaction solution obtained in Step 2.1 into the PTFE liner. During this process, the volume of the reaction solution should not exceed 2 / 3 of the volume of the PTFE liner. Place the PTFE liner into a hydrothermal reactor and react at 100°C for 24 h. Cool the reactor to room temperature. After the reaction is complete, remove the sample.

[0099] Step 2.3: Wash the excess cerium oxide nanoparticles adhering to the sample surface alternately with deionized water and anhydrous ethanol, and then dry and anneal the washed sample to obtain a cerium oxide nanosphere film.

[0100] The drying temperature is 80℃ and the drying time is 10 min to 20 min; the annealing process is as follows: the temperature is raised to 450℃ in a muffle furnace at a heating rate of 5℃ / min and held for 2 hours.

[0101] Step 3: Use molecular self-assembly technology to modify the cerium oxide film with nanosphere structure on the surface with low surface energy to obtain a superhydrophobic cerium oxide nanosphere film;

[0102] The specific process is as follows:

[0103] The cerium oxide nanosphere film obtained in step 2 was immersed in an anhydrous ethanol solution of 1H,1H,2H,2H-perfluorodecyltrimethoxysilane with a concentration of 50 g / L for 10 min for modification. After removal, it was washed with anhydrous ethanol to remove the residual modifier on the surface. After drying at 80 °C for 10 min to 30 min, a layer of perfluorosilane was self-assembled on the cerium oxide surface to obtain a superhydrophobic cerium oxide nanosphere film.

[0104] Step 4: Cover the surface of the superhydrophobic cerium oxide nanosphere film with masks of different specifications, and use deep ultraviolet irradiation to obtain a cerium oxide superhydrophilic / superhydrophobic array fog-collecting film;

[0105] The specific process is as follows:

[0106] A mask with a grid size of 50μm×50μm was used to cover the surface of the superhydrophobic cerium oxide nanosphere film obtained in step 3. The unmasked area was then irradiated with ultraviolet light with a wavelength of 180nm~280nm for 4 hours at room temperature to obtain a cerium oxide superhydrophilic / superhydrophobic array fog-collecting film.

[0107] like Figure 2 and Figure 3 As shown, the contact angle is 167.2° and the roll-off angle is 1.8°. ， This indicates that the cerium oxide nanosphere film prepared at this concentration has extremely low adhesion and excellent surface hydrophobicity, allowing the captured droplets to quickly roll off the sample surface upon contact.

[0108] Example 3

[0109] Step 1: Prepare cerium oxide thin films on silicon substrates using the sol-gel method;

[0110] The specific process is as follows:

[0111] Step 1.1: Dissolve 3.1725g of cerium acetate (III) hydrate in 20mL of anhydrous methanol, then add 2.2224g of propionic acid catalyst, seal, stir at room temperature for 6h on a magnetic stirrer, and let stand for aging for 24h to obtain a yellowish-brown transparent cerium oxide sol with a concentration of 0.50mol / L.

[0112] Step 1.2: Immerse the clean silicon wafer in the cerium oxide sol obtained in Step 1.1, and use the dip-coating method to prepare a smooth and flat sol-gel film on the silicon wafer at a coating speed of 2 mm / s.

[0113] Step 1.3: Place the sol-gel film obtained in step 1.2 into a muffle furnace for heat treatment, and cool it with the furnace to obtain a cerium oxide film;

[0114] The heat treatment process is as follows: first, hold at 200℃ for 10 minutes, then heat from 200℃ to 800℃ and hold for 15 minutes. Repeat the above process 3 times. In the third heat treatment, hold at 800℃ for 2 hours. During this heat treatment process, the polymer will gradually decompose to form cerium oxide, and a cerium oxide film will be obtained as the substrate for the hydrothermal method.

[0115] Step 2: Nanospheres are immobilized on the surface of a cerium oxide film using a hydrothermal synthesis method to obtain a cerium oxide nanosphere film;

[0116] The specific process is as follows:

[0117] Step 2.1: Using 0.6513g of cerium nitrate hexahydrate as the cerium source and 0.2703g of urea as the alkali source, dissolve them completely in 30mL of deionized water. After the solution is completely clear, a hydrothermal reaction solution of cerium oxide with a concentration of 0.050mol / L is obtained.

[0118] Step 2.2: Place the cerium oxide film obtained in Step 1 at a 45° angle with the film surface facing down into a 50 mL polytetrafluoroethylene (PTFE) liner. Pour the cerium oxide hydrothermal reaction solution obtained in Step 2.1 into the PTFE liner. During this process, the volume of the reaction solution should not exceed 2 / 3 of the volume of the PTFE liner. Place the PTFE liner into a hydrothermal reactor and react at 100°C for 24 h. Cool the reactor to room temperature. After the reaction is complete, remove the sample.

[0119] Step 2.3: Wash the excess cerium oxide nanoparticles adhering to the sample surface alternately with deionized water and anhydrous ethanol, and then dry and anneal the washed sample to obtain a cerium oxide nanosphere film.

[0120] The drying temperature is 80℃ and the drying time is 10 min to 20 min; the annealing process is as follows: the temperature is raised to 450℃ in a muffle furnace at a heating rate of 5℃ / min and held for 2 hours.

[0121] Step 3: Use molecular self-assembly technology to modify the cerium oxide film with nanosphere structure on the surface with low surface energy to obtain a superhydrophobic cerium oxide nanosphere film;

[0122] The specific process is as follows:

[0123] The cerium oxide nanosphere film obtained in step 2 was immersed in an anhydrous ethanol solution of hexadecyltrimethyloxysilane with a concentration of 40 g / L for 15 min for modification. After being removed, it was washed with anhydrous ethanol to remove the residual modifier on the surface. After drying at 80 °C for 10 min to 30 min, a layer of perfluorosilane was self-assembled on the cerium oxide surface to obtain a superhydrophobic cerium oxide nanosphere film.

[0124] Step 4: Cover the surface of the superhydrophobic cerium oxide nanosphere film with masks of different specifications, and use deep ultraviolet irradiation to obtain a cerium oxide superhydrophilic / superhydrophobic array fog-collecting film;

[0125] The specific process is as follows:

[0126] A mask with an aperture size of r = 50 mm was used to cover the surface of the superhydrophobic cerium oxide nanosphere film obtained in step 3. The unmasked area was then irradiated with ultraviolet light with a wavelength of 180 nm to 280 nm for 4 h at room temperature to obtain a cerium oxide superhydrophilic / superhydrophobic array fog collecting film.

[0127] like Figure 4 As shown in the SEM image, the microstructure of the cerium oxide superhydrophilic / superhydrophobic array fog collecting film prepared by the method of the present invention is a nanosphere morphology.

[0128] Example 4

[0129] Step 1: Prepare cerium oxide thin films on silicon substrates using the sol-gel method;

[0130] The specific process is as follows:

[0131] Step 1.1: Dissolve 5.0760g of cerium acetate (III) hydrate in 20mL of anhydrous methanol, then add 3.5558g of propionic acid catalyst. After sealing, stir at room temperature for 10h on a magnetic stirrer and let stand for 24h to obtain a yellowish-brown transparent cerium oxide sol with a concentration of 0.80mol / L.

[0132] Step 1.2: Immerse the clean silicon wafer in the cerium oxide sol obtained in Step 1.1, and use the dip-coating method to prepare a smooth and flat sol-gel film on the silicon wafer at a coating speed of 3.5 mm / s.

[0133] Step 1.3: Place the sol-gel film obtained in step 1.2 into a muffle furnace for heat treatment, and cool it with the furnace to obtain a cerium oxide film;

[0134] The heat treatment process is as follows: first, hold at 200℃ for 10 minutes, then heat from 200℃ to 800℃ and hold for 15 minutes. Repeat the above process 3 times. In the third heat treatment, hold at 800℃ for 2 hours. During this heat treatment process, the polymer will gradually decompose to form cerium oxide, and a cerium oxide film will be obtained as the substrate for the hydrothermal method.

[0135] Step 2: Nanospheres are immobilized on the surface of a cerium oxide film using a hydrothermal synthesis method to obtain a cerium oxide nanosphere film;

[0136] The specific process is as follows:

[0137] Step 2.1: Using 1.0421g of cerium nitrate hexahydrate as the cerium source and 0.4324g of urea as the alkali source, dissolve them completely in 30mL of deionized water. After the solution is completely clear, a cerium oxide hydrothermal reaction solution with a concentration of 0.08mol / L is obtained.

[0138] Step 2.2: Place the cerium oxide film obtained in Step 1 at a 45° angle with the film surface facing down into a 50 mL polytetrafluoroethylene (PTFE) liner. Pour the cerium oxide hydrothermal reaction solution obtained in Step 2.1 into the PTFE liner. During this process, the volume of the reaction solution should not exceed 2 / 3 of the volume of the PTFE liner. Place the PTFE liner into a hydrothermal reactor and react at 100°C for 24 h. Cool the reactor to room temperature. After the reaction is complete, remove the sample.

[0139] Step 2.3: Wash the excess cerium oxide nanoparticles adhering to the sample surface alternately with deionized water and anhydrous ethanol, and then dry and anneal the washed sample to obtain a cerium oxide nanosphere film.

[0140] The drying temperature is 80℃ and the drying time is 10 min to 20 min; the annealing process is as follows: the temperature is raised to 450℃ in a muffle furnace at a heating rate of 5℃ / min and held for 2 hours.

[0141] Step 3: Use molecular self-assembly technology to modify the cerium oxide film with nanosphere structure on the surface with low surface energy to obtain a superhydrophobic cerium oxide nanosphere film;

[0142] The specific process is as follows:

[0143] The cerium oxide nanosphere film obtained in step 2 was immersed in an anhydrous ethanol solution of vinyltrimethoxysilane with a concentration of 45 g / L for 10 min for modification. After being removed, it was washed with anhydrous ethanol to remove the residual modifier on the surface. After drying at 80 °C for 10 min to 30 min, a layer of perfluorosilane was self-assembled on the cerium oxide surface to obtain a superhydrophobic cerium oxide nanosphere film.

[0144] Step 4: Cover the surface of the superhydrophobic cerium oxide nanosphere film with masks of different specifications, and use deep ultraviolet irradiation to obtain a cerium oxide superhydrophilic / superhydrophobic array fog-collecting film;

[0145] The specific process is as follows:

[0146] A mask with a mesh size of 50μm×50μm was used to cover the surface of the superhydrophobic cerium oxide nanosphere film obtained in step 3. The unmasked area was then irradiated with ultraviolet light with a wavelength of 180nm~280nm for 5 hours at room temperature to obtain a cerium oxide superhydrophilic / superhydrophobic array fog-collecting film.

[0147] like Figures 5-10 The figure shows the surface morphology and elemental distribution of the cerium oxide superhydrophilic / superhydrophobic array fog-collecting film prepared by the method of this invention. It can be seen that the Ce, O, and C elements are relatively densely and uniformly distributed, indicating that a dense cerium oxide nanosphere superhydrophilic / superhydrophobic array fog-collecting film has been prepared. Some F elements show lattice vacancies, corresponding to the superhydrophilic regions obtained by deep ultraviolet light irradiation, while the remaining parts are superhydrophobic regions.

[0148] Example 5

[0149] Step 1: Prepare cerium oxide thin films on silicon substrates using the sol-gel method;

[0150] The specific process is as follows:

[0151] Step 1.1: Dissolve 5.0760g of cerium acetate (III) hydrate in 20mL of anhydrous methanol, then add 3.5558g of propionic acid catalyst. After sealing, stir at room temperature for 2h on a magnetic stirrer and let stand for 24h to obtain a yellowish-brown transparent cerium oxide sol with a concentration of 0.80mol / L.

[0152] Step 1.2: Immerse the clean silicon wafer in the cerium oxide sol obtained in Step 1.1, and use the dip-coating method to prepare a smooth and flat sol-gel film on the silicon wafer at a coating speed of 4 mm / s.

[0153] Step 1.3: Place the sol-gel film obtained in step 1.2 into a muffle furnace for heat treatment, and cool it with the furnace to obtain a cerium oxide film;

[0154] The heat treatment process is as follows: first, hold at 200℃ for 10 minutes, then heat from 200℃ to 800℃ and hold for 15 minutes. Repeat the above process 3 times. In the third heat treatment, hold at 800℃ for 2 hours. During this heat treatment process, the polymer will gradually decompose to form cerium oxide, and a cerium oxide film will be obtained as the substrate for the hydrothermal method.

[0155] Step 2: Nanospheres are immobilized on the surface of a cerium oxide film using a hydrothermal synthesis method to obtain a cerium oxide nanosphere film;

[0156] The specific process is as follows:

[0157] Step 2.1: Using 1.0421g of cerium nitrate hexahydrate as the cerium source and 0.4324g of urea as the alkali source, dissolve them completely in 30mL of deionized water. After the solution is completely clear, a cerium oxide hydrothermal reaction solution with a concentration of 0.08mol / L is obtained.

[0158] Step 2.2: Place the cerium oxide film obtained in Step 1 at a 45° angle with the film surface facing down into a 50 mL polytetrafluoroethylene (PTFE) liner. Pour the cerium oxide hydrothermal reaction solution obtained in Step 2.1 into the PTFE liner. During this process, the volume of the reaction solution should not exceed 2 / 3 of the volume of the PTFE liner. Place the PTFE liner into a hydrothermal reactor and react at 100°C for 24 h. Cool the reactor to room temperature. After the reaction is complete, remove the sample.

[0159] Step 2.3: Wash the excess cerium oxide nanoparticles adhering to the sample surface alternately with deionized water and anhydrous ethanol, and then dry and anneal the washed sample to obtain a cerium oxide nanosphere film.

[0160] The drying temperature is 60℃ and the drying time is 10 min to 20 min; the annealing process is as follows: the temperature is raised to 450℃ in a muffle furnace at a heating rate of 4℃ / min and held for 2 hours.

[0161] Step 3: Use molecular self-assembly technology to modify the cerium oxide film with nanosphere structure on the surface with low surface energy to obtain a superhydrophobic cerium oxide nanosphere film;

[0162] The specific process is as follows:

[0163] The cerium oxide nanosphere film obtained in step 2 was immersed in an anhydrous ethanol solution of vinyltrimethoxysilane with a concentration of 60 g / L for 50 min for modification. After being removed, it was washed with anhydrous ethanol to remove the residual modifier on the surface. After drying at 25 °C for 10 min to 30 min, a layer of perfluorosilane was self-assembled on the cerium oxide surface to obtain a superhydrophobic cerium oxide nanosphere film.

[0164] Step 4: Cover the surface of the superhydrophobic cerium oxide nanosphere film with masks of different specifications, and use deep ultraviolet irradiation to obtain a cerium oxide superhydrophilic / superhydrophobic array fog-collecting film;

[0165] The specific process is as follows:

[0166] A mask with a mesh size of 50μm×50μm was used to cover the surface of the superhydrophobic cerium oxide nanosphere film obtained in step 3. The unmasked area was then irradiated with ultraviolet light with a wavelength of 180nm~280nm for 8 hours at room temperature to obtain a cerium oxide superhydrophilic / superhydrophobic array fog-collecting film.

Claims

1. A method for preparing a cerium oxide superhydrophilic / superhydrophobic array fog-collecting film, characterized by, The method is implemented according to the following steps: Step 1: preparing a cerium oxide film on a silicon substrate by a sol-gel method; The specific process of step 1 is as follows: Step 1.1: dissolving cerium acetate hydrate in anhydrous methanol and then adding a catalyst propionic acid, sealing and stirring and standing to age, to obtain a cerium oxide sol; Step 1.2: immersing a clean silicon wafer in the cerium oxide sol obtained in step 1.1 to prepare a smooth sol-gel film on the silicon wafer by an immersion-drawing method; Step 1.3: placing the sol-gel film obtained in step 1.2 in a muffle furnace for heat treatment, and then cooling to obtain a cerium oxide film; Step 2: immobilizing nanospheres on the surface of the cerium oxide film by a hydrothermal synthesis method to obtain a cerium oxide nanosphere film; The specific process of step 2 is as follows: Step 2.1: dissolving cerium nitrate hexahydrate as a cerium source and urea as an alkali source in deionized water, and then obtaining a cerium oxide hydrothermal reaction solution after the solution is completely clarified; Step 2.2: placing the cerium oxide film obtained in step 1 in a polytetrafluoroethylene liner with the surface downward at an angle of 45°, and then pouring the cerium oxide hydrothermal reaction solution obtained in step 2.1 into the polytetrafluoroethylene liner, and placing the polytetrafluoroethylene liner in a hydrothermal kettle for reaction, and then cooling to room temperature, and then taking out the sample after the reaction is completed; Step 2.3: washing the sample surface with deionized water and anhydrous ethanol alternately to remove the excess cerium oxide nanometer powder attached to the surface, and then drying and annealing the washed sample to obtain a cerium oxide nanosphere film; Step 3: modifying the cerium oxide film with a nanosphere structure on the surface by a molecular self-assembly technology to obtain a super-hydrophobic cerium oxide nanosphere film; The specific process of step 3 is as follows: immersing the cerium oxide nanosphere film obtained in step 2 in a low-surface-energy modifier solution for modification, and then taking out the sample and washing with anhydrous ethanol to remove the residual modifier on the surface, and then drying to obtain a super-hydrophobic cerium oxide nanosphere film; The low-surface-energy modifier is one of octadecyltrimethyl oxysilane, 1H, 1H, 2H, 2H-perfluorodecyltrimethoxysilane, hexadecyltrimethyl oxysilane and vinyltrimethoxysilane; Step 4: covering different specifications of mask plates on the surface of the super-hydrophobic cerium oxide nanosphere film, and then irradiating by deep ultraviolet light to obtain a cerium oxide super-hydrophilic / super-hydrophobic array fog collection film; The specific process of step 4 is as follows: covering a mask plate with a specific pattern on the surface of the super-hydrophobic cerium oxide nanosphere film obtained in step 3, and then irradiating the unmasked area at room temperature by deep ultraviolet light to obtain a cerium oxide super-hydrophilic / super-hydrophobic array fog collection film.

2. The method of claim 1, wherein the ceria superhydrophilic / superhydrophobic array fog collection film is prepared by the steps of: In step 1.1, the concentration of the cerium oxide sol is 0.10 mol / L to 0.80 mol / L, and the molar ratio of cerium acetate hydrate to propionic acid is 1:3; In step 1.2, the drawing speed of the immersion-drawing method is 0.5 mm / s to 4 mm / s; In step 1.3, the heat treatment process is as follows: first, heat treatment at 200℃ for 10 min, then heating from 200℃ to 800℃ and holding for 15 min, repeating the above process for 3 times, and holding at 800℃ for 2 h in the third time.

3. The method of claim 1, wherein the ceria superhydrophilic / superhydrophobic array fog collection film is prepared by the steps of: In step 2.1, the concentration of the cerium oxide hydrothermal reaction solution is 0.010 mol / L to 0.080 mol / L; In step 2.2, the temperature of the reaction in the hydrothermal kettle is 100 ℃, and the reaction time is 24 h; In step 2.3, the drying temperature is 60 ℃ to 80 ℃, the drying time is 10 min to 20 min, and the annealing process is as follows: the temperature is raised to 450 ℃ at a rate of 3 ℃ / min to 5 ℃ / min in a muffle furnace and is kept for 2 h.

4. The method of claim 1, wherein the ceria superhydrophilic / superhydrophobic array fog collection film is prepared by the steps of: The concentration of the low surface energy modifier solution is 15 g / L to 60 g / L, the solvent is anhydrous ethanol, the soaking modification time is 10 min to 50 min, the drying temperature is 25 ℃ to 80 ℃, and the time is 10 min to 30 min.

5. The method of claim 1, wherein the ceria superhydrophilic / superhydrophobic array fog collection film is prepared by the steps of: The wavelength of the ultraviolet light is 180 nm to 280 nm, and the irradiation time is 3 h to 8 h.

6. A ceria superhydrophilic / superhydrophobic array fog collection film characterized by, The preparation method is obtained by using any one of claims 1 to 5.

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