Design method of liquid-like surface mist collection active synergistic device based on pyroelectric effect

Abstract

The invention discloses a design method of a liquid-like surface mist collection active synergistic device based on a pyroelectric effect. The method comprises the following steps: step 1, pretreating a pyroelectric wafer material; step 2, performing liquid phase modification on the pyroelectric wafer; step 3, covering a PDMS micro-pattern and pasting a film; step 4, performing hydrophilic patterning on the pyroelectric wafer; and step 5, combining fog collecting devices. The fog collection active synergistic device designed by the method can realize active collection of fog on the surface by virtue of the pyroelectric effect of the pyroelectric material, the fog is accelerated to be condensed into small water drops on the surface, the small water drops are converged into large water drops under the low-viscosity effect of the liquid-like surface, and the liquid drops quickly slide off to be exposed out of the smooth surface after being converged to a certain degree, so that the fog collection effect is improved. Water mist condensed small water drops are collected again on the surface under the pyroelectric action, and efficient mist collection is achieved in cycles. The active synergistic device for fog collection is simple in preparation process, small in finished product, free of a large external device, easy to carry and capable of being carried and used.

Description

Technical Field

[0001] This invention belongs to the field of atmospheric water resource development and utilization technology, and relates to an active enhancement device for collecting mist from liquid-like surfaces, specifically a design method for an active enhancement device for collecting mist from liquid-like surfaces based on pyroelectric effects. Background Technology

[0002] Freshwater scarcity, linked to food security, climate change, environmental quality, and poverty, has long been considered one of the world's greatest challenges. Over the past few decades, researchers have focused on various technologies to explore and develop potential freshwater resources, including but not limited to seawater desalination, rainwater harvesting, and wastewater treatment. However, the geographical and climatic conditions of remote or inland areas, as well as issues such as cost, energy consumption, and secondary pollution, limit the development of these technologies. Therefore, there is an urgent need to develop a promising technology to address the situation in remote areas or regions where economic conditions do not support centralized treatment and distribution networks.

[0003] Fog, formed by the condensation of water vapor in the air, contains abundant freshwater resources that can be effectively utilized through fog collection. The Namib desert beetle was once considered nature's best fog collector. Inspired by this attractive strategy, scientists have successfully synthesized efficient water collection methods based on photolithography, composites of materials with different wettability, inkjet printing, and other techniques. However, current fog collection surfaces are mainly superhydrophobic and oil-lubricated surfaces. These liquid-repellent surfaces suffer from poor stability and the ease with which low-surface-tension liquids spread, limiting further development of fog collection. Liquid-like surfaces, due to their good stability and wide range of liquid repellency, have become a new choice for fog collection. Nevertheless, passive water collection via wettable surfaces still suffers from low water accumulation efficiency. In recent years, methods for actively controlling droplets using electric, magnetic, or other fields have attracted widespread attention, and the mechanism of active droplet control using external fields has been successfully applied to fog trapping technology. Scientists have designed and fabricated various electrostatic fog collectors by generating a radial electric field between two electrodes, which apply electricity to the fog droplets and guide them to the collection point. However, this technology often requires high voltage to generate a strong electric field, resulting in a bulky and power-consuming system, limiting its application in outdoor or off-grid environments (such as deserts or plateaus). Furthermore, high-voltage circuits pose safety hazards and are susceptible to breakdown due to humidity. Pyroelectric materials, on the other hand, are a class of materials that can induce non-uniform polarization of internal dipoles through temperature differences, thereby generating charges on their upper and lower surfaces. They hold promise as a next-generation material for fog collection based on electric fields. Summary of the Invention

[0004] To address the problems of poor stability, limited collectable species, and bulky, high-power consumption that make conventional electrostatic water collection systems impractical for current mist collection platforms primarily based on superhydrophobic and oil-lubricated surfaces, this invention provides a design method for an active enhanced mist collection device based on pyroelectric effects on a liquid-like surface. The device designed in this method utilizes the pyroelectric effect of pyroelectric materials to achieve active collection of mist from the surface, accelerating the condensation of mist into small water droplets. Under the low viscosity effect of the liquid-like surface, these small droplets coalesce into larger droplets. Once the droplets have coalesced to a certain extent, they quickly slide off, exposing the smooth surface. The surface then collects the water mist again, condensing it into smaller droplets under the pyroelectric effect, thus achieving efficient mist collection in a continuous cycle.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] A design method for an active enhancement device for collecting mist from liquid-like surfaces based on pyroelectric effects includes the following two technical solutions:

[0007] Technical Solution 1:

[0008] Step 1: Pretreatment of pyroelectric wafer material: The pyroelectric wafer is sequentially placed in acetone, ultrapure water, and isopropanol for ultrasonic cleaning for 5-10 minutes each to thoroughly remove surface stains. Then, it is removed and dried with nitrogen gas, and placed in a plasma cleaner for oxygen plasma treatment. The pyroelectric wafer is one of lithium niobate (LiNbO3) or lithium tantalate (LiTaO3), with a size of 10-100mm × 10-100mm × 0.5-2mm.

[0009] Step 2: Liquid-phase modification of pyroelectric wafers: Take 10-2000 μL of monomolecular silane, dissolve it in 5-40g of solvent, stir evenly, then add 0.5-5μL of ultrapure water and stir thoroughly for 1-3 min. Let it stand at room temperature for 2-15 min, then place the treated pyroelectric wafers in the prepared monomolecular silane solution and immerse them for 15-100 min. After immersion, place them in the solvent and ultrasonically clean for 3-15 min. The monomolecular silane is one of methyldichlorosilane, dimethyldichlorosilane, or 1,2-dichlorotetramethyldisilane; the solvent is toluene or isopropanol.

[0010] Step 3: Assemble the mist collection device: Attach a heating film to the back of the pyroelectric crystal wafer modified in Step 2, set the temperature of the heating film to 40~100℃, fix it on the support, and place a petri dish directly below it to collect and receive the condensate droplets sliding off the sample surface. The mist collection device is now assembled.

[0011] Technical Solution Two:

[0012] Step 1: Pretreatment of pyroelectric wafer material: The pyroelectric wafer is sequentially placed in acetone, ultrapure water, and isopropanol for ultrasonic cleaning for 5-10 minutes each to thoroughly remove surface stains. Then, it is removed and dried with nitrogen gas, and placed in a plasma cleaner for oxygen plasma treatment. The pyroelectric wafer is one of lithium niobate (LiNbO3) or lithium tantalate (LiTaO3), with a size of 10-100mm × 10-100mm × 0.5-2mm.

[0013] Step 2: Liquid-phase modification of pyroelectric wafers: Take 10-2000 μL of monomolecular silane, dissolve it in 5-40g of solvent, stir evenly, then add 0.5-5μL of ultrapure water and stir thoroughly for 1-3 min. Let it stand at room temperature for 2-15 min, then place the treated pyroelectric wafers in the prepared monomolecular silane solution and immerse them for 15-100 min. After immersion, place them in the solvent and ultrasonically clean for 3-15 min. The monomolecular silane is one of methyldichlorosilane, dimethyldichlorosilane, or 1,2-dichlorotetramethyldisilane; the solvent is toluene or isopropanol.

[0014] Step 3: PDMS micro-patterned masking film: First, use a 3D printing device to print an ordered pattern template. The template pattern is one or two of the following: circles (diameter 1mm~5mm, spacing 1mm~5mm) and equilateral triangles (side length 1mm~6mm, spacing 1mm~5mm). Then, mix polydimethylsiloxane resin and curing agent thoroughly at a mass ratio of 10:0.1~2, pour into the template, remove air bubbles, and place in an oven at 60~80℃ for 0.5~3 hours to cure.

[0015] Step 4: Hydrophilic patterning of pyroelectric wafers: Cover the surface of the pyroelectric wafer modified in step 2 with a PDMS patterned masking film. After bonding, place the wafer in a plasma cleaner again to perform oxygen plasma treatment on the surface of the pyroelectric wafer. After treatment, remove the PDMS micro-patterned masking film, rinse the surface with anhydrous ethanol and dry it with nitrogen gas to obtain the hydrophilic patterned pyroelectric wafer.

[0016] Step 5: Assemble the mist collection device: Attach a heating film to the back of the hydrophilic patterned pyroelectric wafer obtained in Step 4, set the temperature of the heating film to 40~100℃, fix it on the support, and place a petri dish directly below it to collect and receive the condensate droplets sliding off the sample surface. The mist collection device is now assembled.

[0017] Compared with the prior art, the present invention has the following advantages:

[0018] (1) The active enhancement device for fog collection designed in this invention combines a liquid-like surface with pyroelectric materials to successfully achieve a passive and active capture method for fog, which greatly improves the water collection efficiency.

[0019] (2) The fog collection active enhancement device designed in this invention has a simple preparation process, the finished product is small and does not require large external devices, it is easy to carry and can be used with you.

[0020] (3) The fog collection active enhancement device designed in this invention has excellent high and low temperature resistance and damp heat resistance on its surface, and can be used for a long time.

[0021] (4) The mist collection active enhancement device designed in this invention can not only collect water mist, but also collect and recycle various organic gases, and has strong multi-environment application capabilities.

[0022] (5) The fog collection active enhancement device designed in this invention uses the hydrolysis and self-polymerization reaction of mono-molecule chlorosilane to in-situ graft polydimethylsiloxane (PDMS) molecular chains on the surface of the pyroelectric wafer to construct a liquid double hydrophobic coating with low viscosity characteristics. It utilizes the pyroelectric effect of the pyroelectric material itself and the low surface energy characteristics of PDMS to achieve efficient fog droplet capture and rapid removal, thereby improving water collection capacity. Attached Figure Description

[0023] Figure 1 A schematic diagram of a fog collection active enhancement device;

[0024] Figure 2 A schematic diagram of the pyroelectric response mechanism of pyroelectric materials:

[0025] Figure 3 A schematic diagram of the active fog collection mechanism of the active fog collection enhancement device;

[0026] Figure 4 The graph shows the change in sliding angle of droplets with different surface tensions and different volumes after pyroelectric crystals are used to modify the surface of liquids.

[0027] Figure 5 To improve the environmental humidity resistance of liquid surfaces modified with pyroelectric crystals;

[0028] Figure 6 The temperature resistance response test results of liquid surfaces modified with pyroelectric crystals are shown in the figures: (a) wetting stability test at 80℃, and (b) wetting stability test under thermal cycling conditions from 0℃ to 80℃.

[0029] Figure 7 Photographs of different surfaces collected at different times for fogging: (a) ordinary lithium niobate, (b) modified lithium niobate, (c) modified and heated glass surface, (d) modified and heated lithium niobate surface.

[0030] Figure 8 Photographs showing the regional distribution of droplets on the surface of a patterned LiTaO3 mist collection active enhancement device. Detailed Implementation

[0031] The technical solution of the present invention will be further described below with reference to the embodiments, but it is not limited thereto. Any modifications or equivalent substitutions to the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention should be covered within the protection scope of the present invention.

[0032] Example 1:

[0033] Take a 20mm piece 40mm A 1 mm thick lithium niobate (LiNbO3) wafer was immersed in acetone solution and sonicated for 5 min. After removal, it was placed in ultrapure water and sonicated for another 5 min, then removed and placed in isopropanol solution for another 5 min. The surface was then removed with tweezers and dried with nitrogen. Next, the surface was treated with oxygen plasma (75 W, 3 min) in an oxygen plasma cleaner. Subsequently, 600 μL of dimethyldichlorosilane was dissolved in 10 g of toluene and stirred until homogeneous. Then, 2 μL of ultrapure water was added and stirred thoroughly for 1 min, followed by standing at room temperature for 5 min. The treated lithium niobate wafer was then immersed in a prepolymerized solution for 60 min, followed by sonication in isopropanol for 5 min, and then dried with nitrogen. The lithium niobate wafer was fixed to a vertical support using an iron stand, with a heating film attached to its back and the film temperature set at 80 °C to achieve precise temperature control of the sample substrate. A standard petri dish was placed directly below the sample to collect and catch any condensation droplets sliding from the sample surface.

[0034] The following tests were performed on the materials obtained in this embodiment:

[0035] (1) such as Figure 4 As shown, seven types of droplets with low to high surface tension all exhibit very low sliding angles on the surface of the modified liquid pyroelectric crystal, and the sliding angle decreases as the droplet volume increases.

[0036] (2) such as Figure 5 As shown, in the long-term environmental stability test (25℃, 30% RH), after the surface was exposed to the atmosphere for 10 days, the offset of the critical sliding angle of the water droplets ΔSA<2° did not decrease. Even when placed in an environment with relative humidity of 99% for 24 hours, no observable hydration swelling effect (ΔSA<2°) was observed on the surface. This shows that the fog collection active enhancement device designed in this invention has good environmental humidity stability.

[0037] (3) such as Figure 6As shown, after aging at 80℃ for 24 hours, the surface wettability did not change significantly. Even after 20 cycles of high and low temperature testing from 0℃ to 80℃, the surface wettability did not change significantly. This indicates that the active fog collection enhancement device designed in this invention has excellent environmental temperature stability.

[0038] (4) such as Figure 7 As shown, the surface droplets of the active fog collection enhancement device designed in this invention condense significantly faster and slide off more quickly and thoroughly.

[0039] Example 2:

[0040] Take a 25mm piece 25mm A 1 mm thick lithium tantalate (LiTaO3) wafer was immersed in acetone solution and sonicated for 5 min. After removal, it was placed in ultrapure water solution and sonicated for 5 min, then removed and placed in isopropanol solution for another 5 min of sonication. The wafer was then removed with tweezers and dried with nitrogen. Next, the surface was treated with oxygen plasma (75 W, 3 min) in an oxygen plasma cleaner. Subsequently, 1200 μL of 1,2-dichlorotetramethyldisilane was dissolved in 20 g of toluene and stirred until homogeneous. Then, 4 μL of ultrapure water was added and stirred thoroughly for 2 min, followed by standing at room temperature for 10 min. The treated lithium tantalate wafer was then immersed in a prepolymerized solution for 80 min, followed by sonication in isopropanol for 5 min, and finally dried with nitrogen. Mix 50 g of polydimethylsiloxane resin and 5 g of curing agent thoroughly, then pour the mixture into a micro-pattern mold with a circular pattern (2 mm in diameter and 2 mm in spacing). Place the mold in a vacuum oven at 80°C for 2 hours to cure. Remove the mold and attach it to the surface of a modified lithium tantalate wafer. Perform oxygen plasma treatment on the surface using an oxygen plasma cleaner (75 W, 3 min). Remove the PDMS micro-pattern masking film, rinse repeatedly with anhydrous ethanol, and dry with nitrogen. This yields a micro-patterned, liquid-like surface lithium tantalate wafer. Fix the wafer on a vertical support, attach a heating film to its back, and set the film temperature to 60°C to precisely control the sample substrate temperature. Place a standard petri dish directly below the sample to collect and catch any condensed droplets sliding from the sample surface.

[0041] The following tests were performed on the materials obtained in this embodiment:

[0042] like Figure 8 As shown, the droplets in the micropatterned LiTaO3 mist collection active enhancement device have obvious regional distribution, which will further improve the mist collection efficiency and water collection capacity.

Claims

1. A design method of a pyroelectricity-based liquid-like surface mist collection active intensifier device, characterized by The method comprises the following steps: Step one, pyroelectric wafer material pretreatment: pyroelectric wafer is sequentially placed in acetone, ultrapure water, isopropanol, each ultrasonic cleaning for 5-10 min, thoroughly clean the surface stains, then take out and dry the surface with nitrogen, place in the plasma cleaner to treat the wafer surface with oxygen plasma; Step two, pyroelectric wafer liquid modification: take 10-2000 μL of monomolecular silane, dissolve in 5-40 g solvent, stir evenly, then add 0.5-5 μL of ultrapure water, stir thoroughly for 1-3 min, stand at room temperature for 2-15 min, then place the treated pyroelectric wafer in the prepared monomolecular silane solution for 15-100 min, after soaking, place in solvent for ultrasonic cleaning for 3-15 min; Step three, mist collection device combination: in step two, the back of the modified pyroelectric wafer is attached to the heating film, fixed on the support, and a culture dish is placed directly below to collect and receive the condensate droplets falling from the sample surface, and the mist collection device combination is completed.

2. The method of designing a pyroelectrically based liquid-like surface mist-collecting active booster device according to claim 1, characterized in that In step one, the pyroelectric wafer is one of lithium niobate and lithium tantalate, with a size of 10-100 mm x 10-100 mm x 0.5-2 mm.

3. The method of designing a pyroelectrically based liquid-like surface mist-collecting active booster device according to claim 1, characterized in that In step two, the monomolecular silane is one of methyldichlorosilane, dimethyldichlorosilane and 1,2-dichlorotetramethyldisilane, and the solvent is toluene or isopropanol.

4. The method of designing a pyroelectrically based liquid-like surface mist-collecting active booster device according to claim 1, characterized in that In step three, the temperature of the heating film is set to 40-100℃.

5. A method of designing a pyroelectrically based liquid-like surface fog collection active booster device, characterized by The method comprises the following steps: Step one, pyroelectric wafer material pretreatment: pyroelectric wafer is sequentially placed in acetone, ultrapure water, isopropanol, each ultrasonic cleaning for 5-10 min, thoroughly clean the surface stains, then take out and dry the surface with nitrogen, place in the plasma cleaner to treat the wafer surface with oxygen plasma; Step two, pyroelectric wafer liquid modification: take 10-2000 μL of monomolecular silane, dissolve in 5-40 g solvent, stir evenly, then add 0.5-5 μL of ultrapure water, stir thoroughly for 1-3 min, stand at room temperature for 2-15 min, then place the treated pyroelectric wafer in the prepared monomolecular silane solution for 15-100 min, after soaking, place in solvent for ultrasonic cleaning for 3-15 min; Step three, PDMS micro-pattern mask film: first, use 3D printing device to print out an ordered pattern template, then mix polydimethylsiloxane resin and curing agent in a mass ratio of 10:0.1-2, pour into the template to remove bubbles, and place in an oven at 60-80℃ for 0.5-3 hours; Step four, pyroelectric wafer hydrophilic patterning: cover the PDMS patterned mask film on the surface of the modified pyroelectric wafer in step two, then place it again in the plasma cleaner to treat the surface of the pyroelectric wafer with oxygen plasma, remove the PDMS micro-pattern mask film after treatment, then rinse the surface with anhydrous ethanol and dry it with nitrogen, to obtain a hydrophilic patterned pyroelectric wafer; Step five, mist collecting device combination: the hydrophilic patterned pyroelectric wafer back surface obtained in step four is attached to a heating film, fixed on a support, and a culture dish is placed directly below to collect and receive the condensate droplets sliding from the sample surface, and the mist collecting device combination is completed.

6. The method of designing a pyroelectrically based liquid-like surface mist-collecting active booster device according to claim 5, characterized in that In step one, the pyroelectric wafer is one of lithium niobate and lithium tantalate, and the size is 10-100 mm x 10-100 mm x 0.5-2 mm.

7. The method of designing a pyroelectrically based liquid-like surface mist-collecting active booster device according to claim 5, characterized in that In step two, the monomolecular silane is one of methyldichlorosilane, dimethyldichlorosilane, and 1,2-dichlorotetramethyldisilane, and the solvent is toluene or isopropyl alcohol.

8. The method of designing a pyroelectrically based liquid-like surface mist-collecting active booster device according to claim 5, characterized in that In step three, the template pattern is one or both of a circle and an equilateral triangle.

9. The method of designing a pyroelectrically based liquid-like surface mist-collecting active booster device according to claim 8, characterized in that The diameter of the circle is 1-5 mm, and the spacing is 1-5 mm, and the side length of the equilateral triangle is 1-6 mm, and the spacing is 1-5 mm.

10. The method of designing a pyroelectrically based liquid-like surface mist-collecting active booster device according to claim 5, characterized in that In step five, the temperature of the heating film is set to 40-100℃.

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