Preparation method of triple bionic fog-collecting surface

Abstract

The present invention discloses a method for preparing a triple bionic fog-collecting surface, belonging to the technical field of wetting modification of metallic copper foam surfaces. The method comprises pretreating the surface of the copper foam; performing a first laser processing on a first preset position on the first surface of the pretreated copper foam to obtain a first striped structure; performing a second laser processing on a second preset position on the first surface of the copper foam to obtain a second striped structure; the first striped structure and the second striped structure form a plurality of intersections, and the plurality of intersections form a plurality of square super-hydrophilic sites on the second surface of the copper foam; the first surface and the second surface are the upper surface and the lower surface of the copper foam, respectively; and thus, a triple bionic fog-collecting surface is obtained. The triple bionic fog-collecting surface prepared by the present invention has excellent fog collection capabilities.

Description

Technical Field

[0001] The invention relates to the technical field of surface wetting modification of metallic copper foam, and in particular to a method for preparing a triple bionic fog-collecting surface. Background Art

[0002] Freshwater shortages have become a major constraint on global socioeconomic development and even pose a threat to human survival. Mist, composed of a large number of tiny water droplets suspended in the atmosphere, accounts for nearly 10% of all fresh water on Earth. Therefore, collecting mist water from the air may be a promising, low-cost, and environmentally friendly alternative to address freshwater shortages.

[0003] Numerous biological surfaces in nature have evolved over millions of years to form unique superwetting surfaces, such as those on lotus leaves, desert beetles, and rice. Inspired by these unique wetting phenomena, the creation of superwetting functional surfaces that surpass natural performance has gradually replaced traditional fog collection methods and become an irreversible trend in current scientific research. However, research on biomimetic surfaces coupled with diverse biological processes is currently limited, and common preparation methods utilize harmful organic solvents, which do not meet the urgent needs of green development and environmental friendliness.

[0004] Therefore, it is of great significance to propose a preparation method for a new type of fog collection surface with simple preparation process, low cost, and green environmental protection. Summary of the Invention

[0005] The purpose of the present invention is to provide a preparation method of a triple bionic fog-collecting surface. The prepared triple bionic fog-collecting surface has excellent fog collection ability. The preparation method is green and environmentally friendly, does not require chemical modification, and is environmentally friendly. With the help of laser processing, the surface structure can be precisely controlled, and large-area preparation is easy to achieve.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A method for preparing a triple bionic fog-collecting surface, comprising:

[0008] Pre-treating the surface of the copper foam: sequentially cleaning the surface of the copper foam with acetone, anhydrous ethanol, and deionized water;

[0009] Preparation of a bionic surface: performing a first laser processing on a first preset position on the first surface of the pretreated copper foam to obtain a first stripe structure; performing a second laser processing on a second preset position on the first surface of the copper foam to obtain a second stripe structure; the first stripe structure and the second stripe structure form a plurality of intersections, and the plurality of intersections form a plurality of square superhydrophilic sites on the second surface of the copper foam; the first surface and the second surface are the upper surface and the lower surface of the copper foam, respectively.

[0010] Further improvements to the technical solution of the present invention are that: the first preset position is a plurality of rectangles of the same size arranged at equal intervals in the horizontal direction; the second preset position is a plurality of rectangles of the same size arranged at equal intervals in the vertical direction; the plurality of rectangles in the first preset position are the same size as the plurality of rectangles in the second preset position; the first preset position and the second preset position are perpendicular to each other.

[0011] A further improvement of the technical solution of the present invention is that the width of the rectangle is 0.50-2.00 mm, the length of the rectangle is the same as the length of the copper foam, and the spacing between adjacent rectangles is 2.00 mm.

[0012] A further improvement of the technical solution of the present invention is that the width of the rectangle is 1.65 mm.

[0013] A further improvement of the technical solution of the present invention is that the side length of the square super-hydrophilic sites is 0.50-2.00 mm, and the distance between adjacent square super-hydrophilic sites is 2.00 mm.

[0014] A further improvement of the technical solution of the present invention is that the side length of the square super-hydrophilic site is 1.65 mm.

[0015] A further improvement of the technical solution of the present invention is that the laser processing parameters of the first laser processing and the second laser processing are the same.

[0016] A further improvement of the technical solution of the present invention is that the line filling spacing of the laser processing parameters is 0.001-0.1 mm, the laser intensity is 12 W, the scanning speed is 500-3000 mm / s, the laser frequency is 20 kHz, and the number of scans is 1-5 times.

[0017] Due to the adoption of the above technical solution, the technical advancements achieved by the present invention are:

[0018] 1. The triple bionic fog-collecting surface prepared by the present invention couples three bionic structures of lotus leaves, rice leaves and desert beetles, but is not limited to the single structure of traditional biological surfaces. Based on a large number of experimental verifications, it creatively proposes "hydrophobic background / super-hydrophilic stripes", "hydrophobic background / super-hydrophilic sites" staggered wetting and "hydrophobic-super-hydrophilic stripes" asymmetric wetting composite triple bionic fog-collecting surfaces; based on the special wetting behavior of the surface, the hydrophilic sites effectively improve the droplet penetration ability, and the stripe structure effectively improves the droplet transport ability, realizing efficient fog collection function, and has broad application prospects.

[0019] 2. The preparation method of the triple bionic fog-collecting surface proposed in the present invention is green and environmentally friendly, does not require chemical modification, and is environmentally friendly; with the help of laser processing, the surface structure can be precisely controlled and large-area preparation can be easily achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. Those skilled in the art can derive other drawings based on these drawings without inventive effort.

[0021] Figure 1 This is a flowchart of a method for preparing a triple bionic fog-collecting surface according to an embodiment of the present application;

[0022] Figure 2 Schematic diagram of a preparation method of a triple bionic fog-collecting surface according to an embodiment of the present application;

[0023] Figure 3 is a schematic diagram of the surface morphology and wettability of a triple bionic mist-collecting surface according to an embodiment of the present application;

[0024] Figure 4 This is a schematic diagram of the fog collection process of a triple bionic fog-collecting surface according to an embodiment of the present application;

[0025] Figure 5 This is a comparison chart of the mist collection amount and mist collection efficiency of the first surface, the second surface, the third surface, and the fourth surface of an embodiment of the present application;

[0026] Figure 6 This is a comparison chart of the mist collection amount and mist collection efficiency of the fifth surface, the sixth surface, the seventh surface, and the third surface of an embodiment of the present application;

[0027] Figure 7 is a diagram of the droplet penetration process of the seventh surface, the eighth surface, the ninth surface, the tenth surface, and the eleventh surface of an embodiment of the present application;

[0028] Figure 8 This is a comparison chart of the mist collection amount and mist collection efficiency of the seventh surface, twelfth surface, thirteenth surface, fourteenth surface, and fifteenth surface of an embodiment of the present application. DETAILED DESCRIPTION

[0029] It should be noted that the terms "including" and "having" and any variations thereof in the specification and claims of the present invention and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or are inherent to these processes, methods, products or apparatuses.

[0030] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments:

[0031] like Figure 1 As shown, a method for preparing a triple bionic fog-collecting surface comprises:

[0032] The surface of the copper foam is pretreated: the surface of the copper foam is cleaned with acetone, anhydrous ethanol and deionized water in sequence;

[0033] Preparation of a bionic surface structure: performing a first laser processing on a first preset position on the first surface of the pretreated copper foam to obtain a first stripe structure; performing a second laser processing on a second preset position on the first surface of the copper foam to obtain a second stripe structure; the first stripe structure and the second stripe structure form a plurality of intersections, and the plurality of intersections form a plurality of square super-hydrophilic sites on the second surface of the copper foam; the first surface and the second surface are the upper surface and the lower surface of the copper foam, respectively.

[0034] Specifically, such as Figure 2 As shown, a schematic diagram of the preparation method of a triple bionic fog-collecting surface according to an embodiment of the present application is schematically shown. The original copper foam 201 is pretreated, and a first laser processing is performed on a first preset position of the first surface (upper surface) of the original copper foam 201 to obtain a copper foam 202 having a first transverse stripe structure. A second laser processing is performed on a second preset position on the upper surface of the copper foam 202 having the first transverse stripe structure to obtain a second longitudinal stripe structure. The first stripe structure and the second stripe structure form a copper foam 203 with a transverse and longitudinal staggered stripe structure. The first stripe structure and the second stripe structure form a plurality of intersections, and the plurality of intersections form a plurality of square super-hydrophilic sites on the second surface (lower surface) of the copper foam 203 with the transverse and longitudinal staggered stripe structure. The unprocessed surface 204 of the original copper foam 201 (the lower surface of the original copper foam 201) shows a hydrophobic background and super-hydrophilic sites, and the processed surface 205 of the original copper foam 201 (the upper surface of the original copper foam 201) shows a hydrophobic background and super-hydrophilic stripes.

[0035] Figure 3 The surface morphology and wettability of the triple bionic fog collecting surface of one embodiment of the present application are schematically shown as follows: Figure 3 As shown:

[0036] This application utilizes a method that couples three biomimetic structures. The staggered wetting properties of the striped structure enable the rapid, directional transport of water droplets on the resulting structured surface. At the intersections of the striped structures, square superhydrophilic sites are introduced into the corresponding areas of the copper foam's second (lower) surface, enabling rapid penetration of water droplets and forming structural and functional crosslinks. The staggered wetting properties of "hydrophobic background / superhydrophilic stripes," "hydrophobic background / superhydrophilic sites," and the asymmetric wetting properties of "hydrophobic-superhydrophilic stripes" combine to create a structured surface with excellent fog collection capabilities.

[0037] In some embodiments of the present application, a fully structured surface with a rectangular width and square super-hydrophilic sites of 1.65mm side length is preferred. Microscopic surface observation and actual experimental verification have shown that, under the premise that the rectangular width and square super-hydrophilic site spacing parameters are consistent, a fully structured surface with a rectangular width and square super-hydrophilic sites of 1.65mm side length exhibits relatively excellent fog collection properties. Fog collection experiments have also demonstrated good results.

[0038] In some embodiments of the present application, the rectangular stripe structure is composed of several equally sized rectangles arranged at equal intervals, and the superhydrophilic sites are composed of several equally sized squares arranged at equal intervals. The construction of a consistent structure makes the resulting microscopic morphology more aesthetically pleasing and easier to implement in practical operations. By constructing a structure of equally spaced rectangular stripes to mimic the micromorphology of natural rice leaves, a prerequisite for the construction of anisotropic properties of droplets on the surface of copper foam is provided. By constructing a "hydrophobic background / superhydrophilic stripes" and "hydrophobic background / superhydrophilic sites" structure to mimic the microstructure of desert beetles, a prerequisite for the construction of staggered wetting properties of copper foam is provided. By constructing a "hydrophobic-superhydrophilic stripe" Janus surface to mimic the asymmetric wettability of natural lotus leaves, a prerequisite for the construction of asymmetric wettability of droplets on the surface of copper foam is provided.

[0039] In some embodiments of the present application, the width of the rectangle is 0.50-2.00 mm, the length of the rectangle is the same as the length of the copper foam, and the spacing between adjacent rectangles is 2.00 mm.

[0040] In some embodiments of the present application, the side length of the square super-hydrophilic site is 0.50-2.00 mm, and the distance between adjacent square super-hydrophilic sites is 2.00 mm.

[0041] In some embodiments of the present application, the width of the rectangles is preferably 1.65 mm, with a spacing of 2.00 mm between adjacent rectangles. The side length of the square superhydrophilic sites is preferably 1.65 mm, with a spacing of 2.00 mm between adjacent square superhydrophilic sites. Both the width of the rectangles and the side length of the superhydrophilic sites vary within a certain range. Different structured surfaces are constructed using different variable parameters to ensure optimal surface parameter selection.

[0042] In some embodiments of the present application, the laser processing parameters of the first laser processing and the second laser processing are the same.

[0043] In some embodiments of the present application, the laser processing parameters are: line filling spacing of 0.001-0.1mm, laser intensity of 12W, scanning speed of 500-3000 mm / s, laser frequency of 20kHz, and number of scans of 1-5 times. Laser processing adopts a contactless processing method with a high degree of automation, precise and controllable experimental parameters, high processing accuracy, and easy preparation of fine microstructures. Under different line filling spacings, laser intensities, scanning speeds and number of scans, the processed surface structures are inconsistent. The four factors work together to construct the surface morphology, ensuring the diversity of the structural parameters of the prepared surface.

[0044] In some embodiments of the present application, the biomimetic surface comprises a hydrophobic background / superhydrophilic stripes, a hydrophobic background / superhydrophilic sites, and a superhydrophilic stripes-hydrophobic Janus surface composite structure. The resulting triple biomimetic fog-collecting surface, featuring alternating wetting between "hydrophobic background / superhydrophilic stripes," "hydrophobic background / superhydrophilic sites," and asymmetric wetting between "hydrophobic-superhydrophilic stripes," transcends the functional limitations of a single biomimetic prototype and achieves exceptionally efficient fog collection performance.

[0045] Inspired by the surface structures of natural lotus leaves, desert beetles and rice leaves, this application constructs a triple bionic structure coupled morphology on the surface of metal copper foam through a precise and controllable laser processing method, achieving structural synergy and functional optimization. Breaking through the single structural and functional limitations of the bionic prototype, based on a large number of experimental verifications, the structural parameters are rationally coupled and effectively optimized, and a creative triple bionic fog-collecting surface of "hydrophobic background / super-hydrophilic stripes", "hydrophobic background / super-hydrophilic sites" staggered wetting and "hydrophobic-super-hydrophilic stripes" asymmetric wetting composite is proposed. Through reasonable surface treatment, the surface has the required wetting ability, unique interface behavior, and maintains excellent fog collection capabilities.

[0046] The above describes the process of the method for preparing the triple bionic fog-collecting surface proposed in this application through multiple embodiments. The following specific examples verify the technical advantages of the method for preparing the triple bionic fog-collecting surface proposed in this application.

[0047] For all the following structured surfaces with rectangular stripe structures and square structures of superhydrophilic sites, the laser-processed side of the copper foam is defined as the B-side, and the unprocessed side of the copper foam is defined as the A-side. Figure 4 The schematic diagram of the mist collection of the triple bionic mist collection surface of an embodiment of the present application is shown schematically. Figure 4 As shown, the copper foam A side faces the direction of the mist.

[0048] To verify the differences in fog collection capabilities of structured surfaces formed by varying the size parameters of the stripe structure and the corresponding superhydrophilic sites, four types of surfaces were prepared on a 2 cm × 2 cm copper foam surface with a spacing of 2.00 mm between adjacent stripe structures and adjacent superhydrophilic sites, using the method proposed in this application to prepare a triple bionic fog-collecting surface.

[0049] Example 1

[0050] The fully structured surface having rectangular stripes with a width of 0.50 mm and square super-hydrophilic sites with a side length of 0.50 mm is named a first surface. The preparation method of the first surface comprises the following steps:

[0051] The copper foam was pretreated by washing it with anhydrous ethanol and deionized water in sequence;

[0052] Preparation of bionic surface structure: a first laser processing is performed on several rectangles of the same size arranged at equal intervals in the horizontal direction on the B surface of the pretreated copper foam to obtain a first stripe structure; a second laser processing is performed on several rectangles of the same size arranged at equal intervals in the longitudinal direction on the B surface of the copper foam to obtain a second stripe structure; the laser processing parameters of the first laser processing and the second laser processing are: line filling spacing of 0.01mm, laser intensity of 12W, scanning speed of 3000mm / s, laser frequency of 20kHz, and number of scans of 1, and an equidistant horizontal and vertical staggered rectangular stripe structure is obtained on the B surface of the copper foam, the rectangle width is 0.50mm, and the spacing between adjacent horizontal and vertical rectangles is 2.00mm; a plurality of square superhydrophilic sites are obtained on the A surface of the copper foam (located at the corresponding positions of the plurality of intersections formed by the first stripe structure and the second stripe structure), the side length of the square superhydrophilic site is 0.50mm, and the spacing between adjacent square superhydrophilic sites is 2.00mm.

[0053] Example 2

[0054] The fully structured surface having rectangular stripes with a width of 1.00 mm and square super-hydrophilic sites with a side length of 1.00 mm is named the second surface. The preparation method of the second surface comprises the following steps:

[0055] The copper foam was pretreated by washing it with anhydrous ethanol and deionized water in sequence;

[0056] Preparation of bionic surface structure: a first laser processing is performed on several rectangles of the same size arranged at equal intervals in the horizontal direction on the B surface of the pretreated copper foam to obtain a first stripe structure; a second laser processing is performed on several rectangles of the same size arranged at equal intervals in the longitudinal direction on the B surface of the copper foam to obtain a second stripe structure; the laser processing parameters of the first laser processing and the second laser processing are: line filling spacing of 0.01mm, laser intensity of 12W, scanning speed of 3000mm / s, laser frequency of 20kHz, and number of scans of 1, and an equidistant horizontal and vertical staggered rectangular stripe structure is obtained on the B surface of the copper foam, the rectangle width is 1.00mm, and the spacing between adjacent horizontal and vertical rectangles is 2.00mm; a plurality of square superhydrophilic sites are obtained on the A surface of the copper foam (located at the corresponding positions of the plurality of intersections formed by the first stripe structure and the second stripe structure), the side length of the square superhydrophilic site is 1.00mm, and the spacing between adjacent square superhydrophilic sites is 2.00mm.

[0057] Example 3

[0058] The fully structured surface having rectangular stripes with a width of 1.65 mm and square super-hydrophilic sites with a side length of 1.65 mm is named the third surface. The preparation method of the third surface comprises the following steps:

[0059] The copper foam was pretreated by washing it with anhydrous ethanol and deionized water in sequence;

[0060] Preparation of bionic surface structure: a first laser processing is performed on several rectangles of the same size arranged at equal intervals in the horizontal direction on the B surface of the pretreated copper foam to obtain a first stripe structure; a second laser processing is performed on several rectangles of the same size arranged at equal intervals in the longitudinal direction on the B surface of the copper foam to obtain a second stripe structure; the laser processing parameters of the first laser processing and the second laser processing are: line filling spacing of 0.01mm, laser intensity of 12W, scanning speed of 3000mm / s, laser frequency of 20kHz, and number of scans of 1, and an equidistant horizontal and vertical staggered rectangular stripe structure is obtained on the B surface of the copper foam, the rectangle width is 1.65mm, and the spacing between adjacent horizontal and vertical rectangles is 2.00mm; a plurality of square superhydrophilic sites are obtained on the A surface of the copper foam (located at the corresponding positions of the plurality of intersections formed by the first stripe structure and the second stripe structure), the side length of the square superhydrophilic site is 1.65mm, and the spacing between adjacent square superhydrophilic sites is 2.00mm.

[0061] Example 4

[0062] The fully structured surface having rectangular stripes with a width of 2.00 mm and square super-hydrophilic sites with a side length of 2.00 mm is named the fourth surface. The preparation method of the fourth surface includes the following steps:

[0063] The copper foam was pretreated by washing it with anhydrous ethanol and deionized water in sequence;

[0064] Preparation of bionic surface structure: a first laser processing is performed on several rectangles of the same size arranged at equal intervals in the horizontal direction on the B surface of the pretreated copper foam to obtain a first stripe structure; a second laser processing is performed on several rectangles of the same size arranged at equal intervals in the longitudinal direction on the B surface of the copper foam to obtain a second stripe structure; the laser processing parameters of the first laser processing and the second laser processing are: line filling spacing of 0.01 mm, laser intensity of 12 W, scanning speed of 3000 mm / s, laser frequency of 20 kHz, and number of scans of 1, and an equidistant horizontal and vertical staggered rectangular stripe structure is obtained on the B surface of the copper foam, the rectangle width is 2.00 mm, and the spacing between adjacent horizontal and vertical rectangles is 2.00 mm; a plurality of square superhydrophilic sites are obtained on the A surface of the copper foam (located at the corresponding positions of the plurality of intersections formed by the first stripe structure and the second stripe structure), the side length of the square superhydrophilic site is 2.00 mm, and the spacing between adjacent square superhydrophilic sites is 2.00 mm.

[0065] like Figure 5 As shown in the diagrams of the fog collection amount and fog collection efficiency of the first surface, the second surface, the third surface and the fourth surface, it was found that under the premise that the spacing parameters of the rectangular horizontal and vertical stripes and the square super-hydrophilic sites are consistent, the third surface exhibits the best fog collection characteristics. Therefore, the fully structured surface with a stripe structure width and a square super-hydrophilic site side length of 1.65 mm is selected as the preferred scheme for the subsequent structural form for the discussion of fog collection efficiency.

[0066] In order to verify the difference in fog collection performance between the structured surfaces formed by the rectangular stripe structure and the square super-hydrophilic site structure, the third surface of the preferred embodiment 3 was selected. Three surfaces as controls were prepared on a 2 cm × 2 cm copper foam surface using the same laser processing parameters as the method for preparing a triple bionic fog collection surface proposed in this application:

[0067] Comparative Example 1

[0068] As a control, the unprocessed copper foam surface was named the fifth surface.

[0069] Comparative Example 2

[0070] As a comparison, a fully structured surface in which both sides of the copper foam are super-hydrophilic is named the sixth surface. The preparation method of the sixth surface includes the following steps:

[0071] The copper foam was pretreated by washing it with anhydrous ethanol and deionized water in sequence;

[0072] Preparation of bionic surface structure: The pretreated copper foam B surface was subjected to the first laser processing for full structuring in the horizontal direction (full plane scanning, without setting the stripe structure), and then the B surface was subjected to the second laser processing for full structuring in the vertical direction (full plane scanning, without setting the stripe structure). The direction of the second laser processing was perpendicular to the direction of the first laser processing. The laser processing parameters for the first and second laser processing were: line filling spacing of 0.01 mm, laser intensity of 12 W, scanning speed of 3000 mm / s, laser frequency of 20 kHz, and number of scans of 1 time; a full plane structure after horizontal and vertical scanning was obtained on the copper foam B surface, and a full plane super hydrophilic surface was obtained on the copper foam A surface.

[0073] Comparative Example 3

[0074] As a comparison, a fully structured surface with Janus on both sides of the copper foam is named the seventh surface. The preparation method of the seventh surface includes the following steps:

[0075] The copper foam was pretreated by washing it with anhydrous ethanol and deionized water in sequence;

[0076] Preparation of bionic surface structure: The pretreated copper foam B surface was subjected to transverse (or longitudinal) full-structured laser processing (full-plane scanning, no stripe structure was set). The laser processing parameters were: line filling spacing of 0.01 mm, laser intensity of 12 W, scanning speed of 3000 mm / s, laser frequency of 20 kHz, and number of scans of 1. A full-plane structure of unidirectional scanning was obtained on the copper foam B surface. No secondary laser processing was performed, and the copper foam A surface maintained a hydrophobic surface.

[0077] Figure 6 Schematic diagrams show the fog collection capacity and efficiency of the fifth, sixth, and seventh surfaces, as well as the third surface, for one embodiment of the present application. It was found that, given consistent rectangular structure spacing, the third surface exhibited the best fog collection properties. Therefore, a fully structured surface with a rectangular width and square super-hydrophilic sites of 1.65 mm side length was selected as the preferred solution.

[0078] To verify the technical advantages of the embodiments of the present application, and to verify the differences in droplet penetration ability of the structured surface formed by the square super-hydrophilic site structure under different parameter conditions, four types of surfaces with a spacing of 2 mm between adjacent square super-hydrophilic sites were prepared on a 2 cm × 2 cm copper foam surface by varying the side lengths of the square super-hydrophilic site structure according to the same laser parameters proposed in this application:

[0079] Example 5

[0080] The fully structured surface with square super-hydrophilic sites having a side length of 0.50 mm is named the eighth surface. The preparation method of the eighth surface comprises the following steps:

[0081] The copper foam was pretreated by washing it with anhydrous ethanol and deionized water in sequence;

[0082] Preparation of a bionic surface structure: The pretreated copper foam B surface is subjected to a first laser processing for full structuring in the horizontal (or vertical) direction (full plane scanning, without setting a stripe structure). The laser processing parameters are: line filling spacing of 0.01 mm, laser intensity of 12 W, scanning speed of 3000 mm / s, laser frequency of 20 kHz, and number of scans of 1, to obtain a full horizontal (or vertical) plane structure on the copper foam B surface. Then, under the same laser processing parameters, a second laser processing is performed on the intersection area of ​​the horizontal and vertical stripes on the B surface (according to the corresponding position of the stripe structure in Example 1). The direction of the second laser processing is perpendicular to the direction of the first laser processing. A plurality of square superhydrophilic sites are obtained on the A surface at the corresponding position of the intersection area of ​​the horizontal and vertical stripes on the B surface. The side length of the square superhydrophilic site is 0.50 mm, and the distance between adjacent square superhydrophilic sites is 2.00 mm.

[0083] Example 6

[0084] The fully structured surface with square super-hydrophilic sites having a side length of 1.00 mm is named the ninth surface. The preparation method of the ninth surface comprises the following steps:

[0085] The copper foam was pretreated by washing it with anhydrous ethanol and deionized water in sequence;

[0086] Preparation of bionic surface structure: The pretreated copper foam B surface is subjected to a first laser processing for full structuring in the horizontal (or vertical) direction (full plane scanning, without setting a stripe structure). The laser processing parameters are: line filling spacing of 0.01 mm, laser intensity of 12 W, scanning speed of 3000 mm / s, laser frequency of 20 kHz, and scanning number of 1. A full horizontal (or vertical) plane structure is obtained on the copper foam B surface. Then, under the same laser processing parameters, a second laser processing is performed on the intersection area of ​​the horizontal and vertical stripes on the B surface (according to the corresponding position of the stripe structure in Example 2). The direction of the second laser processing is perpendicular to the direction of the first laser processing. A plurality of square superhydrophilic sites are obtained on the A surface at the corresponding position of the intersection area of ​​the horizontal and vertical stripes on the B surface. The side length of the square superhydrophilic site is 1.00 mm, and the distance between adjacent square superhydrophilic sites is 2.00 mm.

[0087] Example 7

[0088] The fully structured surface with square super-hydrophilic sites having a side length of 1.65 mm is named the tenth surface. The preparation method of the tenth surface comprises the following steps:

[0089] The copper foam was pretreated by washing it with anhydrous ethanol and deionized water in sequence;

[0090] Preparation of a bionic surface structure: The pretreated copper foam B surface is subjected to a first laser processing for full structuring in the horizontal (or vertical) direction (full plane scanning, without setting a stripe structure). The laser processing parameters are: line filling spacing of 0.01 mm, laser intensity of 12 W, scanning speed of 3000 mm / s, laser frequency of 20 kHz, and number of scans of 1, to obtain a full horizontal (or vertical) plane structure on the copper foam B surface. Then, under the same laser processing parameters, a second laser processing is performed on the intersection area of ​​the horizontal and vertical stripes on the B surface (according to the corresponding position of the stripe structure in Example 3). The direction of the second laser processing is perpendicular to the direction of the first laser processing. A plurality of square superhydrophilic sites are obtained on the A surface at the corresponding position of the intersection area of ​​the horizontal and vertical stripes on the B surface. The side length of the square superhydrophilic site is 1.65 mm, and the distance between adjacent square superhydrophilic sites is 2.00 mm.

[0091] Example 8

[0092] The fully structured surface with square superhydrophilic sites having a side length of 2.00 mm is named the eleventh surface. The preparation method of the eleventh surface includes the following steps:

[0093] The copper foam was pretreated by washing it with anhydrous ethanol and deionized water in sequence;

[0094] Preparation of a bionic surface structure: The pretreated copper foam B surface is subjected to a first laser processing for full structuring in the horizontal (or vertical) direction (full plane scanning, without setting a stripe structure). The laser processing parameters are: line filling spacing of 0.01 mm, laser intensity of 12 W, scanning speed of 3000 mm / s, laser frequency of 20 kHz, and number of scans of 1, to obtain a full horizontal (or vertical) plane structure on the copper foam B surface. Then, under the same laser processing parameters, a second laser processing is performed on the intersection area of ​​the horizontal and vertical stripes on the B surface (according to the corresponding position of the stripe structure in Example 4). The direction of the second laser processing is perpendicular to the direction of the first laser processing. A plurality of square superhydrophilic sites are obtained on the A surface at the corresponding position of the intersection area of ​​the horizontal and vertical stripes on the B surface. The side length of the square superhydrophilic site is 2.00 mm, and the distance between adjacent square superhydrophilic sites is 2.00 mm.

[0095] Figure 7Schematic diagrams of the droplet penetration process on the seventh, eighth, ninth, tenth, and eleventh surfaces of one embodiment of the present application are shown. It was found that surfaces with superhydrophilic sites had shorter penetration times than the original Janus surface and therefore exhibited better penetration properties. The tenth surface exhibited the most excellent droplet penetration properties. Therefore, a fully structured surface with square superhydrophilic sites with a side length of 1.65 mm was selected as the preferred solution, consistent with the experiments in this experimental example.

[0096] To verify the technical advantages of the embodiments of the present application and to examine the differences in fog collection performance of the structured surface formed by the super-hydrophilic stripe structure under different parameter conditions, four types of surfaces with a rectangular stripe structure spacing of 2 mm were produced on a 2 cm × 2 cm copper foam surface by varying the width of the rectangular stripe structure using the same laser processing parameters proposed in this application:

[0097] Example 9

[0098] The patterned structured surface with a rectangular stripe structure having a width of 0.5 mm is named the twelfth surface. The preparation method of the twelfth surface comprises the following steps:

[0099] The copper foam was pretreated by washing it with anhydrous ethanol and deionized water in sequence;

[0100] Preparation of a biomimetic surface structure: The pretreated copper foam surface B (according to the stripe structure pattern in Example 1) was laser processed. The laser processing parameters were: line filling spacing of 0.01 mm, laser intensity of 12 W, scanning speed of 3000 mm / s, laser frequency of 20 kHz, and number of scans of 1. A horizontally and vertically staggered stripe structure plane was obtained on the copper foam surface B. No secondary processing was performed in the staggered stripe area. The stripe structure was 0.5 mm wide and the same length as the copper foam. The spacing between adjacent stripes was 2 mm.

[0101] Example 10

[0102] The patterned structured surface with a rectangular stripe structure width of 1 mm is named the thirteenth surface. The preparation method of the thirteenth surface includes the following steps:

[0103] The copper foam was pretreated by washing it with anhydrous ethanol and deionized water in sequence;

[0104] Preparation of a biomimetic surface structure: The pretreated copper foam surface B (according to the stripe structure pattern in Example 2) was laser processed. The laser processing parameters were: line filling spacing of 0.01 mm, laser intensity of 12 W, scanning speed of 3000 mm / s, laser frequency of 20 kHz, and number of scans of 1. A horizontally and vertically staggered stripe structure plane was obtained on the copper foam surface B. No secondary processing was performed in the staggered stripe area. The stripe structure was 1 mm wide and the same length as the copper foam. The spacing between adjacent stripes was 2 mm.

[0105] Example 11

[0106] The patterned structured surface having a rectangular stripe structure with a width of 1.65 mm is named the fourteenth surface. The preparation method of the fourteenth surface comprises the following steps:

[0107] The copper foam was pretreated by washing it with anhydrous ethanol and deionized water in sequence;

[0108] Preparation of a biomimetic surface structure: The pretreated copper foam surface B (according to the stripe structure pattern in Example 3) was laser processed. The laser processing parameters were: line filling spacing of 0.01 mm, laser intensity of 12 W, scanning speed of 3000 mm / s, laser frequency of 20 kHz, and number of scans of 1. A horizontal and vertical staggered stripe structure plane was obtained on the copper foam surface B. No secondary processing was performed in the staggered stripe area. The stripe structure was 1.65 mm wide and the same length as the copper foam. The spacing between adjacent stripes was 2 mm.

[0109] Example 12

[0110] The patterned structured surface with a rectangular stripe structure having a width of 2 mm is named the fifteenth surface. The preparation method of the fifteenth surface comprises the following steps:

[0111] The copper foam was pretreated by washing it with anhydrous ethanol and deionized water in sequence;

[0112] Preparation of a biomimetic surface structure: The pretreated copper foam surface B (according to the stripe structure pattern in Example 4) was laser processed. The laser processing parameters were: line filling spacing of 0.01 mm, laser intensity of 12 W, scanning speed of 3000 mm / s, laser frequency of 20 kHz, and number of scans of 1. A horizontally and vertically staggered stripe structure plane was obtained on the copper foam surface B. No secondary processing was performed in the staggered stripe area. The stripe structure was 2 mm wide and the length was the same as the length of the copper foam. The spacing between adjacent stripes was 2 mm.

[0113] Figure 8A schematic diagram comparing the mist collection volume and efficiency of the seventh, twelfth, thirteenth, fourteenth, and fifteenth surfaces of an embodiment of the present application is shown. It was found that the striped surface exhibited better mist collection than the original Janus surface, with the fourteenth surface exhibiting the most excellent droplet penetration characteristics. Therefore, a fully structured surface with rectangular stripes of 1.65 mm width was selected as the preferred solution, consistent with the experimental results of this experimental embodiment.

[0114] In addition, the value ranges of parameters such as line filling spacing, scanning speed, and scanning times in the present invention are all capable of realizing the present invention and are not listed here one by one.

[0115] In summary, the preparation method of the triple bionic fog-collecting surface proposed in this application is simple and easy, the surface structure can be precisely controlled, and it is easy to achieve large-area preparation. The prepared surface couples three bionic structures of lotus leaves, rice leaves and desert beetles, but is not limited by the single structural function limitations of traditional biological surfaces. Based on a large number of experimental verifications, it creatively proposes a "hydrophobic background-superhydrophilic stripes" staggered wetting and "hydrophobic-superhydrophilic stripes" asymmetric wetting composite triple bionic fog-collecting surface. Compared with traditional bionic structure surfaces, the above-mentioned triple bionic fog-collecting surface has better fog collection ability and broad application prospects, providing an important reference for the study of coupled bionic wetting surfaces and the analysis of special interface behaviors and their mechanisms.

[0116] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a triple bionic fog-collecting surface, characterized in that: include: Pre-treating the surface of the copper foam: sequentially cleaning the surface of the copper foam with acetone, anhydrous ethanol, and deionized water; Preparing a biomimetic surface: performing a first laser processing on a first preset position on the first surface of the pretreated copper foam to obtain a first stripe structure; performing a second laser processing on a second preset position on the first surface of the copper foam to obtain a second stripe structure; the first stripe structure and the second stripe structure form a plurality of intersections, and the plurality of intersections form a plurality of square superhydrophilic sites on the second surface of the copper foam; the first surface and the second surface are the upper surface and the lower surface of the copper foam, respectively; The first preset position is a plurality of rectangles of the same size arranged at equal intervals in the horizontal direction; the second preset position is a plurality of rectangles of the same size arranged at equal intervals in the vertical direction; the plurality of rectangles in the first preset position are the same size as the plurality of rectangles in the second preset position; the first preset position and the second preset position are perpendicular to each other; The laser processing parameters of the first laser processing and the second laser processing are the same; the line filling spacing of the laser processing parameters is 0.001-0.1mm, the laser intensity is 12W, the scanning speed is 500-3000mm / s, the laser frequency is 20kHz, and the number of scans is 1-5 times.

2. The method for preparing a triple bionic fog-collecting surface according to claim 1, characterized in that: The width of the rectangle is 0.50-2.00 mm, the length of the rectangle is the same as the length of the copper foam, and the spacing between adjacent rectangles is 2.00 mm.

3. The method for preparing a triple bionic fog-collecting surface according to claim 1, characterized in that: The width of the rectangle is 1.65 mm.

4. The method for preparing a triple bionic fog-collecting surface according to claim 1, characterized in that: The side length of the square super-hydrophilic sites is 0.50-2.00 mm, and the distance between adjacent square super-hydrophilic sites is 2.00 mm.

5. The method for preparing a triple bionic fog-collecting surface according to claim 1, characterized in that: The side length of the square superhydrophilic site is 1.65 mm.

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