CN110340536B - Method and device for preparing anti-fouling drag-reducing material by laser treatment - Google Patents

Abstract

The invention belongs to the technical field of laser processing, and discloses a method and a device for preparing an antifouling and anti-drag material by laser processing, wherein the device mainly comprises a picosecond laser emission component, a femtosecond laser emission component and a scanning and focusing component, wherein the femtosecond laser emission component is used for emitting femtosecond laser, so that a micro-nano mixed structure with super-hydrophobic performance is formed on the surface of a material to be processed; the picosecond laser emission component is used for emitting picosecond laser so as to enable the surface of the material to be processed to form a super-hydrophilic area. The invention improves the structure and the arrangement mode of each component in the device, the corresponding treatment method and the like, utilizes the comprehensive action of picosecond laser and femtosecond laser to form the surface morphology of the super-hydrophilic-super-hydrophobic (or hydrophilic-super-hydrophobic and hydrophobic-super-hydrophobic) material, realizes the composite wettability, can reduce the resistance of the material to be treated in water, plays an antifouling role, and can effectively solve the problems of the micro-nano structure and the large environmental pollution and the like which cannot realize the composite wettability in the traditional electrochemical corrosion method.

Description

Method and device for preparing anti-fouling drag-reducing material by laser treatment

Technical Field

The invention belongs to the technical field of laser processing, and particularly relates to a method and a device for preparing an antifouling and anti-drag material by laser treatment, which can realize the preparation of the antifouling and anti-drag material on the surface.

Background

With the increasing demands on the performance of underwater vehicles and the importance on environmental protection, pollution and friction loss in the underwater navigation of the vehicles are increasingly emphasized by people, and how to prevent pollution and reduce drag is becoming a popular item. The aim of the anti-fouling drag reduction research is to reduce the pollution and friction resistance of the aircraft when moving in water, reduce the energy consumption, improve the navigational speed of the aircraft and prolong the service life. At present, various anti-fouling drag reduction theories and methods are continuously developed, and materials with special wettability are particularly interesting to be used as anti-fouling drag reduction materials. The material with special wettability mainly refers to super-hydrophobic and super-hydrophilic materials, and the two functional materials have respective advantages and defects in the aspects of antifouling and drag reduction. The super-hydrophobic material is characterized in that a large amount of gas is filled between the solid-liquid contact surfaces by utilizing the self hydrophobic characteristic of the super-hydrophobic material, the solid-liquid contact surfaces are reduced, and friction resistance is reduced by utilizing the characteristic that gas-liquid friction is far smaller than solid-liquid friction, so that the purposes of antifouling and drag reduction are achieved. On the other hand, however, the water repellent action of superhydrophobic materials also causes premature separation of liquids, resulting in shock waves, increased differential pressure resistance, and even in certain conditions, increased total resistance. While for super-hydrophilic materials, although the adsorption effect of the super-hydrophilic materials on water can increase the friction resistance and the adsorption stain of objects, the super-hydrophilic materials can well stabilize the flow field, thereby being beneficial to the reduction effect of the total resistance under special conditions. Because the pure super-hydrophilic or super-hydrophobic materials have respective advantages and limitations, how to exert the respective advantages of the two functional materials and inhibit the respective disadvantages, and organically combine the advantages of the two functional materials to form a micro-nano structure which can ensure that the contact area of water and a structure is reduced, the stability of a flow field is maintained, and the hydrophilic and hydrophobic composite infiltration performance of the water and the structure can not be completely separated is realized, so that the effects of preventing pollution and reducing resistance are achieved, and the micro-nano structure is a technical bottleneck for solving the problem.

The structure for realizing the special wettability on the surface of the material is usually prepared by a micro/nano mixed structure, and the conventional method for preparing the special wettability material is mainly by an electrochemical corrosion mode. The electrochemical corrosion method has poor preparation precision and low resolution, so that only single wettability treatment can be carried out on the surface of the material, and the micro-nano structure with the required hydrophilic and hydrophobic composite wettability cannot be produced. In addition, the electrochemical corrosion method can generate a large amount of chemical waste, and the discharge can pollute the environment. Therefore, how to prepare the micro-nano structure with hydrophilic-hydrophobic composite infiltration performance is another technical bottleneck for solving the problem.

Disclosure of Invention

Aiming at the defects or improvement demands of the prior art, the invention aims to provide a method and a device for preparing an anti-fouling and anti-drag material by laser treatment, and the problems that the micro-nano structure with super-hydrophilic-super-hydrophobic composite wettability, large environmental pollution and the like cannot be realized by the traditional electrochemical corrosion method can be effectively solved compared with the prior art by improving the structure of each component in the device and the arrangement mode thereof, the whole process design of the treatment method and the like, and forming the surface morphology (namely super-hydrophilic-super-hydrophobic surface morphology) of the super-hydrophobic and super-hydrophilic phase by utilizing the combined action of picosecond laser and femtosecond laser. By utilizing the device and the method, the super-hydrophobic performance structure and the super-hydrophilic performance structure can be prepared on the surface of the same material in a certain arrangement and combination mode, so that the composite-wettability anti-fouling and drag-reducing functional material is formed, the water repellent characteristic of the super-hydrophobic material is reserved, the anti-fouling and good friction drag-reducing capacity is maintained, the hydrophilic characteristic of the super-hydrophilic material can be utilized, the flow field is stabilized, and the high-efficiency and stable anti-fouling and drag-reducing surface function is finally realized.

In order to achieve the above object, according to one aspect of the present invention, there is provided an apparatus for preparing an anti-fouling drag reducing material by laser processing, which is characterized by comprising a picosecond laser emitting assembly, a femtosecond laser emitting assembly, a scanning focusing assembly, and a carrying table, wherein the carrying table is used for placing a material (10) to be processed for anti-fouling drag reducing processing;

the femtosecond laser emission component comprises a femtosecond laser (1) and a first beam expansion collimating lens (3) which is matched with the femtosecond laser (1), wherein the femtosecond laser (1) is used for emitting a femtosecond laser beam, the femtosecond laser beam is incident to the scanning focusing component through the first beam expansion collimating lens (3) and the light guide lenses (5 and 6) and focused to the material (10) to be processed through the scanning focusing component, and the femtosecond laser emission component is used for carrying out femtosecond laser scanning etching processing on the material (10) to be processed to enable the surface of the material (10) to be processed to form a micro-nano mixed structure (20) meeting the requirement of super-hydrophobic performance;

the picosecond laser emission component comprises a picosecond laser (2) and a second beam expansion collimating lens (4) which is matched with the picosecond laser (2), wherein the picosecond laser (2) is used for emitting picosecond laser beams, the picosecond laser beams are incident to the scanning focusing component through the second beam expansion collimating lens (4) and the light guide lenses (5 and 6) and focused on the material (10) to be processed through the scanning focusing component, and the picosecond laser emission component is used for carrying out picosecond laser scanning processing modification treatment on the material (10) to be processed so as to enable the surface of the material (10) to be processed to form a hydrophobic area or a hydrophilic area or a super-hydrophilic area;

The single treatment of the material (10) to be treated by the femtosecond laser beam or the picosecond laser beam or the comprehensive treatment of the material (10) to be treated by the femtosecond laser beam and the picosecond laser beam can lead the surface of the material (10) to be treated to form a hydrophobic-superhydrophobic morphology with the alternate hydrophobicity and superhydrophobic morphology, or form a hydrophilic-superhydrophobic morphology with the alternate hydrophilicity and superhydrophobic morphology, or form a superhydrophilic-superhydrophobic morphology with the alternate superhydrophobic morphology, thereby reducing the resistance of the material (10) to be treated in water and playing an antifouling role.

As a further preferred aspect of the present invention, the femto-second laser emission module and the pico-second laser emission module share a pair of light guides (5, 6), and the pair of light guides (5, 6) are respectively a first light guide (5) and a second light guide (6), and the laser beam is incident to the scanning focusing module through the first light guide (5) and the second light guide (6) in sequence, and by adjusting the first light guide (5), the switching of whether the scanning focusing module is connected to the femto-second laser beam path or the pico-second laser beam path can be realized;

preferably, the scanning focusing assembly comprises a scanning galvanometer, a scanning field lens and a Z-axis moving mechanism (9), wherein the scanning galvanometer and the scanning field lens are matched to carry out scanning focusing on a laser beam, and the Z-axis moving mechanism (9) is used for driving the scanning galvanometer and the scanning field lens to integrally move along the Z-axis direction so as to control the position of a focusing point of the laser beam in the Z-axis direction;

Preferably, the Z-axis moving mechanism (9) is further used for driving the second light guide mirror (6) to synchronously move along the Z-axis direction.

As a further preferred aspect of the present invention, the laser light emission ports of both the femtosecond laser (1) and the picosecond laser (2) are disposed opposite to each other;

the carrying workbench is specifically a three-dimensional workbench and is used for placing and driving the material (10) to be processed to move and adjusting the spatial position of the material (10) to be processed;

the dust collection pipeline (12) and the protection air tap (13) are further arranged above the carrying workbench, wherein the dust collection pipeline (12) is used for removing waste generated in the laser treatment process of the material (10) to be treated, and the protection air tap (13) is used for conveying protection gas to the surface of the material (10) to be treated.

According to another aspect of the invention, the invention provides a method for preparing an antifouling drag reduction material by laser treatment, which is characterized in that the method takes a non-hydrophilic non-lyophobic material which is non-hydrophobic and non-hydrophilic as an object to be treated, and specifically comprises the following steps:

(1) And (3) femtosecond laser scanning etching treatment: performing femtosecond laser scanning etching processing treatment on the object to be processed by using femtosecond laser, so that a micro-nano mixed structure meeting the requirement of super-hydrophobic performance is formed on the surface of the object to be processed;

(2) Formation of superhydrophobic surfaces: depositing a low-surface-energy material on the micro-nano mixed structure surface of the object to be treated after the treatment in the step (1), so that the surface of the object to be treated forms a super-hydrophobic performance surface; wherein the low surface energy material has a surface free energy lower than that of water;

(3) Picosecond laser scanning modification treatment: and carrying out picosecond laser scanning processing modification treatment on the super-hydrophobic performance surface of the object to be treated by utilizing picosecond laser to form a hydrophobic region or a hydrophilic region or a super-hydrophilic region on the surface of the object to be treated, so that the surface of the object to be treated finally forms a hydrophobic-super-hydrophobic morphology with alternate hydrophobic and super-hydrophobic, a hydrophilic-super-hydrophobic morphology with alternate hydrophilic and super-hydrophobic, or a super-hydrophilic-super-hydrophobic morphology with alternate super-hydrophilic and super-hydrophobic, further reducing the resistance of the object to be treated in water, bringing an antifouling effect and preparing the antifouling drag-reducing material.

According to a further aspect of the present invention, there is provided a method for preparing an anti-fouling drag reducing material by laser treatment, characterized in that the method uses a hydrophobic material as an object to be treated, and specifically comprises the following steps:

(1) And (3) femtosecond laser scanning etching treatment: performing femtosecond laser scanning etching processing treatment on the object to be processed by using femtosecond laser to form a micro-nano mixed structure with super-hydrophobic performance on the surface of the object to be processed, wherein the micro-nano mixed structure with super-hydrophobic performance is the super-hydrophobic performance surface;

(2) Picosecond laser scanning modification treatment: and carrying out picosecond laser scanning processing modification treatment on the super-hydrophobic performance surface of the object to be treated by utilizing picosecond laser to form a hydrophobic region or a hydrophilic region or a super-hydrophilic region on the surface of the object to be treated, so that the surface of the object to be treated finally forms a hydrophobic-super-hydrophobic morphology with alternate hydrophobic and super-hydrophobic, a hydrophilic-super-hydrophobic morphology with alternate hydrophilic and super-hydrophobic, or a super-hydrophilic-super-hydrophobic morphology with alternate super-hydrophilic and super-hydrophobic, further reducing the resistance of the object to be treated in water, bringing an antifouling effect and preparing the antifouling drag-reducing material.

According to still another aspect of the present invention, there is provided a method for preparing an anti-fouling drag reducing material by laser treatment, characterized in that the method uses a hydrophilic material as an object to be treated, specifically comprising the steps of:

(1) And (3) femtosecond laser scanning etching treatment: performing femtosecond laser scanning etching processing treatment on the object to be processed by using femtosecond laser, so that a micro-nano mixed structure meeting the requirement of super-hydrophobic performance is formed on the surface of the object to be processed;

(2) Formation of superhydrophobic surfaces: depositing a low-surface-energy material on the micro-nano mixed structure surface of the object to be treated after the treatment in the step (1), so that the surface of the object to be treated forms a super-hydrophobic performance surface; wherein the low surface energy material has a surface free energy lower than that of water;

(3) Picosecond laser scanning modification treatment: and carrying out picosecond laser scanning processing modification treatment on the super-hydrophobic performance surface of the object to be treated by utilizing picosecond laser to form a hydrophobic region or a hydrophilic region or a super-hydrophilic region on the surface of the object to be treated, so that the surface of the object to be treated finally forms a hydrophobic-super-hydrophobic morphology with alternate hydrophobic and super-hydrophobic, a hydrophilic-super-hydrophobic morphology with alternate hydrophilic and super-hydrophobic, or a super-hydrophilic-super-hydrophobic morphology with alternate super-hydrophilic and super-hydrophobic, further reducing the resistance of the object to be treated in water, bringing an antifouling effect and preparing the antifouling drag-reducing material.

As a further preferred aspect of the invention, the hydrophobic region is in particular a hydrophobic dot, hydrophobic line or hydrophobic surface; the hydrophilic area is specifically a hydrophilic point, a hydrophilic line or a hydrophilic surface; the super-hydrophilic region is specifically a super-hydrophilic point, a super-hydrophilic line or a super-hydrophilic surface.

According to a further aspect of the present invention, there is provided a method for preparing an anti-fouling drag reducing material by laser treatment, characterized in that the method uses a hydrophobic material as an object to be treated, and specifically comprises the following steps:

and (3) femtosecond laser scanning etching treatment: performing femtosecond laser scanning etching processing treatment on the object to be processed by using femtosecond laser to form a micro-nano mixed structure with super-hydrophobic performance on the surface of the object to be processed, wherein the micro-nano mixed structure with super-hydrophobic performance is the super-hydrophobic performance surface;

while the unprocessed surface still appears hydrophobic; the components and arrangement modes of the hydrophobic surface and the superhydrophobic surface are designed to obtain hydrophobic and superhydrophobic patterns which meet expected settings, or a certain distribution of hydrophobic areas are reserved in the superhydrophobic areas of the processing area, so that the surface of the object to be processed finally forms a superhydrophobic and hydrophobic interphase morphology, the resistance of the object to be processed in water is further reduced, and meanwhile, an antifouling effect is brought, so that the antifouling drag-reducing material is prepared.

According to a further aspect of the present invention, there is provided a method for preparing an anti-fouling drag reducing material by laser treatment, characterized in that the method uses hydrophilic or non-hydrophilic non-hydrophobic material as an object to be treated, specifically comprising the steps of:

and (3) femtosecond laser scanning etching treatment: performing femtosecond laser scanning etching processing treatment on the object to be treated by using femtosecond laser, forming a micro-nano structure on a preselected area of the surface of the material, and then integrally treating the surface of the material by using a low surface energy reagent to form a micro-nano mixed structure with super-hydrophobic performance on the surface of the object to be treated, wherein the micro-nano mixed structure with super-hydrophobic performance is the super-hydrophobic performance surface; wherein the low surface energy material has a surface free energy lower than that of water;

whereas the surface area not subjected to femtosecond laser processing appears hydrophobic due to the action of the low surface energy agent; the components and arrangement modes of the hydrophobic surface and the superhydrophobic surface are designed to obtain hydrophobic and superhydrophobic patterns which meet expected settings, or a certain distribution of hydrophobic areas are reserved in the superhydrophobic areas of the processing area, so that the surface of the object to be processed finally forms a superhydrophobic and hydrophobic interphase morphology, the resistance of the object to be processed in water is further reduced, and meanwhile, an antifouling effect is brought, so that the antifouling drag-reducing material is prepared.

As a further preferred aspect of the invention, the hydrophobic region is in particular a hydrophobic dot, a hydrophobic line or a hydrophobic surface.

Compared with the prior art, the technical scheme of the invention provides a new thought for preparing the special composite wettability anti-pollution drag reduction functional material, the corresponding method and device utilize ultra-fast laser (picosecond laser and femtosecond laser) processing to have the characteristics of high efficiency, high precision, high resolution, high flexibility, non-contact, strong material adaptability, cleanness, no pollution and the like, and the composite wettability micro-nano structure is formed by adopting a scanning focusing assembly (such as a three-dimensional high-speed scanning galvanometer) and a carrying workbench (such as a three-dimensional workbench) as a laser source to prepare the material surface, so that the hydrophilic and hydrophobic subsection proportion, morphology, period and arrangement mode of a processed area can be precisely controlled on the material surface, particularly orderly arranged super-hydrophilic structure and super-hydrophobic structure (namely super-hydrophilic-super-hydrophobic structure; possibly hydrophilic-super-hydrophobic structure) can be formed, and the composite wettability micro-nano structure can be formed, the contact surface of the material with water can be reduced under water, stable interface can be obtained, anti-pollution liquid flow can be guided, and the anti-pollution liquid can be applied to underwater navigation surface treatment of an underwater vehicle.

The processing device comprises a femtosecond laser emission component and a picosecond laser emission component, wherein the femtosecond laser emission component is used for emitting femtosecond laser, and the femtosecond laser is utilized for carrying out femtosecond laser scanning etching processing on a material to be processed, so that a micro-nano mixed structure with super-hydrophobic performance can be formed on the surface of the material; the picosecond laser emission component is used for emitting picosecond laser, and can form a super-hydrophilic area on the surface of the material by utilizing picosecond laser scanning direct writing modification treatment; therefore, the comprehensive treatment of the material to be treated by the femtosecond laser beam and the picosecond laser beam can lead the surface of the material to be treated to form a super-hydrophobic and super-hydrophilic alternate morphology (of course, the single treatment of the material to be treated by the femtosecond laser beam or the picosecond laser beam can also be utilized to form a hydrophilic-super-hydrophobic structure and a hydrophobic-super-hydrophobic structure), thereby reducing the resistance of the material to be treated in water and playing an antifouling role. The invention further provides a specific treatment method for the materials to be treated with different hydrophobicity and hydrophilicity, and the surface of the materials to be treated is ensured to be efficiently provided with the morphology between superhydrophobic and superhydrophilic, the morphology between hydrophilic and superhydrophobic, or the morphology between hydrophobic and superhydrophobic.

Compared with the characteristics of the super-hydrophobic material, the composite wettability material prepared by the method and the device has the following advantages:

1. clean, environment-friendly and pollution-free: aiming at the preparation of the super-hydrophobic material by the traditional chemical method, the method uses the ultra-fast laser to scan the surface of the material in a specific mode, does not have any chemical corrosion process, and the low surface energy reagent used in the process is ready for use, so that no chemical waste is generated in the preparation process, the preparation environment is clean and environment-friendly, and the energy is utilized efficiently;

2. high-efficiency drag reduction capacity: due to the water repellency of the traditional super-hydrophobic material, although the solid-liquid friction force can be reduced in theory, the liquid and the solid are separated in advance, so that the pressure difference resistance is improved, and the total resistance is possibly increased to a certain extent. The composite wettability material prepared by the design of the invention can play a role in preventing the premature release of fluid by utilizing a micro-nano mixed structure of hydrophilic points, lines or surfaces on the micrometer scale, and can optimize the hydrodynamic characteristics of the material on the micrometer scale by utilizing a special distribution form so as to obtain a better and more stable antifouling and drag-reducing effect;

3. flexible and adjustable: because of the characteristics of high precision and resolution of ultrafast laser processing, and the characteristics of high intellectualization of the ultrafast laser processing, the preparation method and equipment related in the invention can be correspondingly adjusted according to different requirements of materials, namely, materials meeting different special performance requirements can be obtained by accurately controlling the period, the scale, the distribution form and the like of the micro-nano structure.

4. Is not limited by the material: due to the excellent characteristics of the ultrafast laser, micro-nano processing treatment (metal, nonmetal, organic material and the like) can be performed on different materials only by reasonably regulating and controlling laser processing parameters. If the material is a hydrophobic material, the composite wettability material can be prepared by only two steps of forming a micro-nano mixed structure through laser scanning and etching and forming a super-hydrophilic area through laser scanning direct writing modification; if the material itself is hydrophilic, the composite wettability material can be finally obtained through low surface energy treatment of forming a low surface energy deposition layer by a low surface energy chemical reagent and high-speed ultrafast laser scanning direct writing modification according to a certain proportion, morphology, period and arrangement mode. The laser processing parameterization is only required to be regulated and controlled aiming at different materials, so that the 'one machine is multipurpose'.

Taking super-hydrophobic-super-hydrophilic morphology as an example, due to the characteristic of precise and controllable ultra-fast laser scanning, the composite wettability structure induced on the surface of the super-hydrophobic substrate material has high intelligent controllability, and the trend of the super-hydrophilic micro-nano structure can be precisely controlled on the micrometer scale by reasonably controlling the period, the dimension and the distribution form of the super-hydrophilic waterline or plane, so that the mechanical property in water is microscopically controlled, and the drag reduction effect is achieved; on the other hand, the material is super-hydrophobic in macroscopic sense due to the super-hydrophobic treatment of the whole material, so the material has good antifouling effect. By combining the two characteristics, the material has antifouling and drag-reducing characteristics.

The traditional method for preparing the super-hydrophobic material mainly comprises a chemical method, and the super-hydrophobic microstructure is prepared by the chemical method, so that the structural accuracy is not high, the microstructure can be described only from the statistical angle, and the dimension, morphology, arrangement mode and the like of the structure can not be controlled accurately. Meanwhile, because the whole surface is treated when the surface is processed by a chemical method, the hydrophilic and hydrophobic selective processing cannot be realized. When the ultra-fast laser (picosecond laser and femtosecond laser) is used for preparing the ultra-hydrophilic and hydrophobic material, the characteristics of high precision and high controllability of the ultra-fast laser are fully utilized, the combination of the hydrophilic and hydrophobic structures is realized on the micrometer scale, different patterns are formed through arrangement and combination, the water flow guiding effect can be realized, and the defect that the traditional ultra-hydrophobic material cannot realize the drag reduction effect is overcome.

The invention utilizes ultrafast laser such as picosecond or femtosecond laser, on one hand, provides higher processing precision, and on the other hand, avoids the occurrence of thermal effect; taking the example of forming the super-hydrophilic region by using the picosecond laser, the picosecond laser has higher processing precision, can avoid thermal effect, and can also avoid the influence on the non-hydrophilic region in the processing process. The invention utilizes femtosecond laser to form a micro-nano mixed structure (micro-nano mixed structure, namely, a primary structure with a characteristic dimension of several micrometers to tens of micrometers and a secondary structure with a characteristic dimension of several tens to hundreds of nanometers) which meets the requirement of super-hydrophobic performance; when the material to be treated has hydrophobicity, the material can directly show superhydrophobicity after being processed (namely, the micro-nano mixed structure with superhydrophobicity is obtained); if the material does not have hydrophobicity, the material can be matched with low surface energy treatment to form a micro-nano mixed structure with super-hydrophobic property on the surface of the material to be treated. The low surface energy material in the invention refers to a material with theoretical upper surface free energy lower than the surface free energy of water (72 mN/m), and the lower the surface energy is, the better the effect is; of course, the film layer cannot destroy the original micro-nano structure.

Drawings

FIG. 1 is a schematic diagram of a micro-nano mixed structure device for preparing super-hydrophobic performance on the whole surface of a material.

Fig. 2 is a schematic diagram of a micro-nano mixed structure of the super-hydrophobic performance of the whole surface laser preparation of the material.

FIG. 3 is a schematic diagram of spraying a layer of low surface energy chemical reagent film on a micro-nano mixed structure for preparing super-hydrophobic properties.

FIG. 4 is a schematic diagram of a micro-nano mixed structure device for preparing super-hydrophilic performance on the whole surface of a material.

FIG. 5 shows one of the composite wetting micro-nano mixed structures.

FIG. 6 is a second form of composite wetting micro-nano hybrid structure.

FIG. 7 is a third aspect of the composite wetting micro-nano hybrid structure.

The meaning of the reference numerals in the figures is as follows: the laser device comprises a femtosecond laser device 1, a picosecond laser device 2, beam expansion collimating lenses 3 and 4 (wherein 3 is a first beam expansion collimating lens and is matched with the femtosecond laser device, 4 is a second beam expansion collimating lens and is matched with the picosecond laser device), 5 and 6 are light guide lenses, 7 is a three-dimensional high-speed scanning vibrating lens, 8 is a telecentric scanning field lens, 9 is a Z-axis moving mechanism, 10 is a material to be prepared (i.e. a material to be processed), 11 is a three-dimensional workbench, 12 is a dust collection pipeline, 13 is a protection air tap, 20 is a micro-nano mixed structure, 21 is a super-hydrophobic performance surface, and 22, 23 and 24 are super-hydrophilic points, super-hydrophilic lines and super-hydrophilic surfaces (hydrophobic and hydrophilic points, lines and surfaces can be hydrophobic and hydrophilic according to different processing modes).

Detailed Description

The present invention will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention. In addition, the technical features of the embodiments of the present invention described below may be combined with each other as long as they do not collide with each other.

Based on the invention, the method for preparing the composite wettability micro-nano structure on the surface of the material without super-hydrophobic performance generally comprises the following steps:

1. carrying out scanning etching processing on the surface of the material by utilizing ultra-fast laser and a three-dimensional high-speed scanning galvanometer, and preparing a micro-nano mixed structure with ultra-hydrophobic performance on the whole surface of the material;

2. carrying out special low surface energy treatment (such as spraying, PVD, CVD and the like) on the micro-nano mixed structure on the surface of the material by using a low surface energy chemical reagent, so that a low surface energy deposition layer is formed on the surface of the material, and a substrate material with super-hydrophobic performance is obtained;

3. and then, carrying out selective scanning and direct writing modification on the surface of the super-hydrophobic substrate material by using ultra-fast laser according to a certain proportion, morphology, period and arrangement mode, and re-inducing to form super-hydrophilic points, lines or surfaces on the super-hydrophobic surface, thereby obtaining a micro-nano mixed structure with specific distribution of super-hydrophilic and hydrophobic phases, forming a composite wettability micro-nano mixed structure, and preparing the super-hydrophobic and hydrophobic phase or the super-hydrophobic and hydrophilic phase according with wettability micro-nano mixed structure in the same way.

In the method for preparing the composite wettability micro-nano structure of the substrate material with the hydrophobic property, the substrate material is hydrophobic, so that only the first step and the third step are needed, and the second step can be omitted: namely: carrying out scanning etching processing on the surface of a hydrophobic substrate material by utilizing ultra-fast laser and a three-dimensional high-speed scanning galvanometer, and preparing a micro-nano mixed structure with ultra-hydrophobic performance on the whole surface of the material; and then selectively scanning and directly writing on the superhydrophobic performance surface by using ultrafast laser according to a certain proportion, morphology, period and arrangement mode to modify at a high speed, and re-inducing to form superhydrophilic points, lines or surfaces on the superhydrophobic surface, so as to obtain a superfine nano mixed structure with superfine particles distributed in a specific manner, and form a composite wettability micro nano mixed structure.

The method for preparing the composite wettability micro-nano structure on the substrate material with hydrophilic performance comprises the following steps: the composite wettability material is obtained directly through the low surface energy treatment of the second step and the high-speed ultrafast laser scanning direct writing modification of the third step according to a certain proportion, morphology, period and arrangement mode without the treatment of the first step.

Fig. 1 shows a device for preparing a composite wettability micro-nano structure on the surface of a material, which mainly comprises a femtosecond laser 1, a picosecond laser 2, two beam expansion collimating lenses 3 and 4, two light guide lenses 5 and 6, a three-dimensional high-speed scanning vibrating lens 7, a telecentric scanning field lens 8, a Z-axis moving mechanism 9 and a three-dimensional workbench 11, and a dust collection pipeline 12 and a protection air tap 13 can be preferably arranged. The material to be prepared 10 is fixed on the surface of the three-dimensional table 11. The specific implementation steps for preparing the composite wettability micro-nano structure without super-hydrophobic property on the surface of the material are as follows: the femtosecond laser 1 is started, the output laser beam is amplified and collimated by the beam expanding collimating lens 3, then is input into the three-dimensional high-speed scanning vibrating lens 7 by the light guide lenses 5 and 6, is focused on the surface of a material 10 to be prepared by the telecentric scanning field lens 8 and the Z-axis moving mechanism 9, is matched with a three-dimensional workbench, and is subjected to large-area high-speed scanning etching processing, so that the micro-nano mixed structure 20 with superhydrophobic performance is prepared on the whole surface of the material (see figure 2). Thereby completing the first step of preparing the composite wettability micro-nano structure.

Meanwhile, a dust collection pipeline 12 can be arranged to suck away smoke and dust generated in the processing process of the laser preparation material 10, and a protective gas (such as nitrogen, argon and the like) is further conveyed to the surface of the material 10 through the arrangement of a protective gas nozzle 13, so that the surface of the material is prevented from being polluted in the laser preparation process.

And then spraying a layer of low-surface-energy chemical reagent film (such as PFOTS and PDMS) on the micro-nano mixed structure 20 with super-hydrophobic property prepared by femtosecond laser on the surface of the material 10 to obtain the substrate material with super-hydrophobic property. Finally, turning over the light guide lens 3 in the laser preparation device by 90 degrees (as shown in fig. 4), starting the picosecond laser 2, amplifying and collimating the output laser beam by the beam expanding collimator lens 4, inputting the amplified laser beam to the three-dimensional high-speed scanning vibrating lens 7 by the light guide lenses 5 and 6, focusing the output laser beam on the superhydrophobic performance surface 21 of the material 10 to be prepared by the telecentric scanning field lens 8 and adjusting the Z-axis moving mechanism 9, and matching with the three-dimensional workbench for selectively, scanning and direct writing modification at a high speed according to a certain proportion, morphology, period and arrangement mode, and re-inducing the superhydrophobic surface to form a superhydrophilic point 22 (see fig. 5), a superhydrophilic line 23 (see fig. 6) or a superhydrophilic surface 24 (see fig. 7), or other proportion, morphology, period and arrangement modes, so as to obtain a superfine and alternate micro-nano mixed structure with specific distribution, and a composite wettability.

The method for preparing the composite wettability micro-nano structure by the hydrophobicity of the substrate material comprises the following steps:

since the substrate material itself is hydrophobic, the super-hydrophobic surface 21 shown in fig. 3 can be obtained by adopting a femto-second laser, scanning and etching the surface of the material by a three-dimensional high-speed scanning galvanometer and matching with a three-dimensional workbench, and preparing the substrate material 10 into a micro-nano mixed structure with super-hydrophobic performance. Then, picosecond laser is utilized to carry out selective high-speed scanning direct writing modification on the superhydrophobic performance surface 21 according to a certain proportion, morphology, period and arrangement mode, and superhydrophobic points 22 (fig. 5), superhydrophilic water lines 23 (fig. 6) or superhydrophilic water surfaces 24 (fig. 7) are re-induced on the superhydrophobic surface, so that a superfine nano mixed structure with specific distribution and superhydrophilic and hydrophobic phases is obtained, and a composite wettability micro nano mixed structure is formed.

Since the process involves the combination of superhydrophilic and superhydrophobic structures on the micrometer scale, the following considerations apply during the process: firstly, ensuring geometric dimensions and precision; secondly, the thermal effect needs to be avoided as much as possible in the processing process; the third involves mutation of the hydrophilic and hydrophobic regions. Therefore, the invention selects ultrafast laser as a processing light source. During processing, it is desirable to maintain a low energy density and a high processing rate to avoid thermal effects. In the process of etching the microstructure, higher power density is required to ensure the accuracy and quality of etching processing, while in the process of surface modification, lower energy is required to prevent the processed structure from being damaged by etching again.

In order to enable the femtosecond laser to obtain a desired micro-nano mixed structure with super-hydrophobic performance, the processing parameters can be adjusted according to the material to be processed and the processing requirement, so long as the processing parameters can ensure: 1. high peak power; 2. a small spot diameter; 3. and (3) a low heat affected zone. The formation of superhydrophilic regions using picosecond lasers has mainly 2 causes: 1. removing the low surface energy film on the surface; 2. the laser directly acts on the surface of a specific material, so that the free energy of the surface of the material can be greatly increased, and the surface shows extremely strong hydrophilicity. The super-hydrophilic region is formed by picosecond laser, and the hydrophilic region is mainly formed by modifying the existing micro-nano structure, so that the requirements are that: 1. low energy density; 2. and the low heat affected zone can adjust the processing parameters of the picosecond laser according to the processed material and the actual processing requirement.

Examples:

example 1: preparation of composite wettability structures on copper surfaces

Firstly, a femtosecond laser with the wavelength of 1030nm is adopted, the power is set to be 80W, the frequency is 2MH, the scanning speed is 5000mm/s, the laser is focused on the surface of a copper material, a dust collection pipeline and a protection air tap are started, and the copper surface is subjected to high-speed femtosecond laser etching processing to obtain a micro/nano mixed rough surface; depositing a layer of low surface energy chemical reagent PFOTS (perfluorodecyl trimethylsilane) on the surface of the micro/nano mixed rough surface area, and curing at 300 ℃ in an oven after the deposition to obtain a superhydrophobic surface; and finally, starting a dust collection pipeline and a protection air tap by adopting a picosecond laser with the wavelength of 532nm under the parameters of 5W of power, 1MH of frequency and 1000mm/s of scanning speed, and carrying out selective hydrophilic modification on the superhydrophobic surface of the copper material by adopting a dot pattern with the diameter of 400 microns and the dot spacing of 800 microns and the cycle ratio of 1 to 100, so that superhydrophilic areas which are specially arranged and distributed on the micrometer scale are formed on the original superhydrophobic surface, and a surface with composite wettability is formed. The antifouling resistance-reducing experiment shows that the antifouling effect of the copper surface treated by the composite wettability is improved, and the water resistance is reduced by about 10%.

Example 2: preparation of composite wettability structures on polytetrafluoroethylene surfaces

Firstly, a femtosecond laser with the wavelength of 355nm is adopted, the power is set to be 50W, the frequency is 1MH, the scanning speed is 1000mm/s, the laser is focused on the surface of polytetrafluoroethylene, a dust collection pipeline and a protection air tap are opened, and rapid femtosecond laser etching processing is carried out on the surface of polytetrafluoroethylene, so that the micro/nano mixed rough surface is obtained. Because polytetrafluoroethylene has lower surface energy, the polytetrafluoroethylene does not need low surface energy treatment and can be directly subjected to the next treatment. Directly carrying out super-hydrophilic modification on the surface of polytetrafluoroethylene, changing a 1064nm picosecond laser, setting the power to be 30W, setting the frequency to be 2MH, scanning the scanning speed to be 2000mm/s, starting a dust collection pipeline and a protection air tap, carrying out selective hydrophilic modification on the super-hydrophobic surface of polytetrafluoroethylene in a linear pattern with the line width of 30 microns, and obtaining super-hydrophilic areas with specific arrangement and distribution on the micrometer scale according to the periodic ratio of 1 to 150, thereby finally forming the composite wettability surface. The antifouling drag reduction experiment tests show that the antifouling effect of the polytetrafluoroethylene surface treated by the composite wettability is good, the polytetrafluoroethylene surface is placed in seawater for a long time, no stain is adsorbed on the surface, and the water resistance is reduced by about 25%.

Example 3: preparation of composite wettability structures on glass surfaces

Firstly, a femtosecond laser with the wavelength of 355nm is adopted, the power of 10W, the frequency of 500kHz and the scanning speed of 200mm/s are set, the laser is focused on the surface of glass, a dust collection pipeline and a protection air tap are opened, and rapid femtosecond laser etching is carried out on the surface of the glass, so that the micro/nano mixed rough surface is obtained. And then depositing a layer of low surface energy chemical reagent PDMS (polydimethylsiloxane) on the surface of the processing area after the surface of the processing area, and curing at 300 ℃ in an oven after the deposition to obtain the superhydrophobic surface. And finally, adopting a 355nm picosecond laser to carry out selective hydrophilic modification on the glass super-hydrophobic surface in an area pattern with a line width of 400 microns under the parameters of 5W of power, 1MH of frequency and 1000mm/s of scanning rate, and obtaining hydrophilic areas with specific arrangement and distribution on a micrometer scale according to a cycle ratio of 1 to 200, thereby finally forming the composite wettability surface. The anti-fouling drag reduction experiment tests prove that the glass surface treated by the composite wettability has good anti-fouling effect, almost no stain is adsorbed on the surface after being placed in seawater for a long time, and the water resistance is reduced by about 15 percent.

Example 4: preparation of composite wettability structures on aluminium alloy surfaces

Firstly, a femtosecond laser with the wavelength of 355nm is adopted, the power of 5W, the frequency of 200kHz and the scanning speed of 200mm/s are set, the laser is focused on the surface of glass, a dust collection pipeline and a protection air tap are started, and the ultra-fast femtosecond laser selective etching is carried out on the surface of the aluminum alloy by pre-designing specific processing patterns (namely selective etching and reserving a blank of a specific area), so that the micro/nano mixed rough surface distributed in a specific mode is obtained. And then depositing a layer of low surface energy chemical reagent PFOTS (perfluorodecyl trimethyl silane) on the surface of the processing area after the surface of the processing area is processed, curing the surface at 300 ℃ in an oven after the deposition, wherein the processed area is a super-hydrophobic surface, and the reserved blank surface is a hydrophobic surface, so that the composite wettability surface is finally formed. The antifouling drag reduction experiment tests show that the antifouling effect of the composite wettability treated aluminum alloy surface is good, the composite wettability treated aluminum alloy surface is placed in seawater for a long time, almost no stain is adsorbed on the surface, and the water resistance is reduced by about 20%.

Example 5: preparation of composite wettability structures on silicon surfaces

Firstly, a femtosecond laser with the wavelength of 355nm is adopted, the power is set to be 10W, the frequency is 2MH, the scanning speed is 2000mm/s, the laser is focused on the surface of silicon, a dust collection pipeline and a protection air tap are opened, and the surface of the silicon is subjected to rapid femtosecond laser etching processing, so that the micro/nano mixed rough surface is obtained. And depositing a layer of low surface energy chemical reagent PFOTS (perfluorodecyl trimethylsilane) on the surface of the micro/nano mixed rough surface area, and curing at 300 ℃ in an oven after the deposition is finished to obtain the superhydrophobic surface. The hydrophilic modification is carried out on the silicon surface, a 1064nm picosecond laser is used, the power is set to be 15W, the frequency is 200kHz, the scanning speed is 1000mm/s, a dust collection pipeline and a protection air tap are opened, the selective hydrophilic modification is carried out on the silicon super-hydrophobic surface according to a linear pattern with the line width of 15 microns and the periodic ratio of 1 to 100, hydrophilic areas with specific arrangement and distribution are obtained on the micron scale, and finally the composite wettability surface is formed. The antifouling drag reduction experiment tests show that the antifouling effect of the polytetrafluoroethylene surface treated by the composite wettability is good, the polytetrafluoroethylene surface is placed in seawater for a long time, no stain is adsorbed on the surface, and the water resistance is reduced by about 10%.

Example 6: preparation of composite wettability structures on aluminium foil surfaces

Firstly, a femtosecond laser with the wavelength of 1064nm is adopted, the power is set to be 5W, the frequency is 20kH, the scanning speed is 500mm/s, the laser is focused on the surface of an aluminum foil, a dust collection pipeline and a protection air tap are started, and high-speed femtosecond laser etching processing is carried out on the copper surface to obtain a micro/nano mixed rough surface; depositing a layer of low surface energy chemical reagent PFOTS (perfluorodecyl trimethylsilane) on the surface of the micro/nano mixed rough surface area, and curing at 300 ℃ in an oven after the deposition to obtain a superhydrophobic surface; and finally, a picosecond laser with the wavelength of 355nm is adopted to open a dust collection pipeline and a protection air tap under the parameters of 5W of power, 1MH of frequency and 1000mm/s of scanning speed, the copper superhydrophobic surface is selectively hydrophilically modified with a dot pattern with the diameter of 200 microns and the dot spacing of 400 microns and the cycle ratio of 1 to 200, so that hydrophilic areas which are specially arranged and distributed on the micrometer scale are formed on the original superhydrophobic surface, and a composite wettability surface is formed. The antifouling resistance reduction experiment tests prove that the antifouling effect of the surface of the aluminum foil treated by the composite wettability is improved, and the water resistance is reduced by about 20%.

The picosecond laser and the femtosecond laser in the invention specifically refer to the picosecond laser with the pulse width of 10 picoseconds to 200 picoseconds and the femtosecond laser with the pulse width of 100 femtoseconds to 800 femtoseconds. The hydrophobicity, hydrophilicity in the present invention meets the conventional definition in the art, i.e., if the surface tension of the material surface is smaller than water (72 mN/m), it has hydrophobicity; if the surface tension of the material surface is greater than that of water (72 mN/m), it has hydrophilicity; non-hydrophobic, and non-hydrophilic materials in the present invention, including neutral materials, are in the hydrophilic to hydrophobic transition zone without significant propensity. In addition, superhydrophobicity means that the contact angle with water is greater than 150 °, superhydrophilicity means that the contact angle with water is less than 10 °, and the conventional definition is satisfied.

It will be readily appreciated by those skilled in the art that the foregoing description is merely a preferred embodiment of the invention and is not intended to limit the invention, but any modifications, equivalents, improvements or alternatives falling within the spirit and principles of the invention are intended to be included within the scope of the invention.

Claims (7)

1. A method for preparing an anti-fouling drag reducing material by laser treatment, which is a device for preparing an anti-fouling drag reducing material by using laser treatment, the device comprises a picosecond laser emission component, a femtosecond laser emission component, a scanning focusing component and a carrying workbench, wherein the carrying workbench is used for placing a material (10) to be treated for the anti-fouling drag reducing treatment;

The femtosecond laser emission component comprises a femtosecond laser (1) and a first beam expansion collimating lens (3) which is matched with the femtosecond laser (1), wherein the femtosecond laser (1) is used for emitting a femtosecond laser beam, the femtosecond laser beam is incident to the scanning focusing component through the first beam expansion collimating lens (3) and the light guide lenses (5 and 6) and focused to the material (10) to be processed through the scanning focusing component, and the femtosecond laser emission component is used for carrying out femtosecond laser scanning etching processing on the material (10) to be processed to enable the surface of the material (10) to be processed to form a micro-nano mixed structure (20) meeting the requirement of super-hydrophobic performance;

the picosecond laser emission component comprises a picosecond laser (2) and a second beam expansion collimating lens (4) which is matched with the picosecond laser (2), wherein the picosecond laser (2) is used for emitting picosecond laser beams, the picosecond laser beams are incident to the scanning focusing component through the second beam expansion collimating lens (4) and the light guide lenses (5 and 6) and focused on the material (10) to be processed through the scanning focusing component, and the picosecond laser emission component is used for carrying out picosecond laser scanning processing modification treatment on the material (10) to be processed so as to enable the surface of the material (10) to be processed to form a hydrophobic area or a hydrophilic area or a super-hydrophilic area;

The femtosecond laser beam and the picosecond laser beam are utilized for comprehensively treating the material (10) to be treated, so that the surface of the material (10) to be treated can form a hydrophobic-superhydrophobic morphology with the alternate hydrophobic and superhydrophobic, or a hydrophilic-superhydrophobic morphology with the alternate hydrophilic and superhydrophobic, or a superhydrophilic-superhydrophobic morphology with the alternate superhydrophilic and superhydrophobic is formed, the resistance of the material (10) to be treated in water is further reduced, and an antifouling effect is realized;

the femtosecond laser emission assembly and the picosecond laser emission assembly share a pair of light guide lenses (5, 6), the pair of light guide lenses (5, 6) are respectively a first light guide lens (5) and a second light guide lens (6), laser beams sequentially enter the scanning focusing assembly through the first light guide lens (5) and the second light guide lens (6), and switching of whether the scanning focusing assembly is connected with a femtosecond laser beam path or a picosecond laser beam path can be realized by adjusting the first light guide lens (5);

the method is characterized in that the method takes non-hydrophobic and non-hydrophilic non-hydrophobic material as an object to be treated, and specifically comprises the following steps:

(1) And (3) femtosecond laser scanning etching treatment: performing femtosecond laser scanning etching processing treatment on the object to be processed by using femtosecond laser, so that a micro-nano mixed structure meeting the requirement of super-hydrophobic performance is formed on the surface of the object to be processed;

(2) Formation of superhydrophobic surfaces: depositing a low-surface-energy material on the micro-nano mixed structure surface of the object to be treated after the treatment in the step (1), so that the surface of the object to be treated forms a super-hydrophobic performance surface; wherein the low surface energy material has a surface free energy lower than that of water;

(3) Picosecond laser scanning direct writing finishing treatment: and carrying out picosecond laser scanning direct writing processing modification treatment on the super-hydrophobic performance surface of the object to be treated by utilizing picosecond laser to form a hydrophobic region or a hydrophilic region or a super-hydrophilic region on the surface of the object to be treated, so that the surface of the object to be treated finally forms a hydrophobic-super-hydrophobic morphology with alternate hydrophobic and super-hydrophobic, a hydrophilic-super-hydrophobic morphology with alternate hydrophilic and super-hydrophobic, or a super-hydrophilic-super-hydrophobic morphology with alternate super-hydrophilic and super-hydrophobic, further reducing the resistance of the object to be treated in water, bringing an antifouling effect, and thus preparing the antifouling drag-reducing material.

2. A method for preparing an anti-fouling drag reducing material by laser treatment, which is a device for preparing an anti-fouling drag reducing material by using laser treatment, the device comprises a picosecond laser emission component, a femtosecond laser emission component, a scanning focusing component and a carrying workbench, wherein the carrying workbench is used for placing a material (10) to be treated for the anti-fouling drag reducing treatment;

The femtosecond laser emission component comprises a femtosecond laser (1) and a first beam expansion collimating lens (3) which is matched with the femtosecond laser (1), wherein the femtosecond laser (1) is used for emitting a femtosecond laser beam, the femtosecond laser beam is incident to the scanning focusing component through the first beam expansion collimating lens (3) and the light guide lenses (5 and 6) and focused to the material (10) to be processed through the scanning focusing component, and the femtosecond laser emission component is used for carrying out femtosecond laser scanning etching processing on the material (10) to be processed to enable the surface of the material (10) to be processed to form a micro-nano mixed structure (20) meeting the requirement of super-hydrophobic performance;

the picosecond laser emission component comprises a picosecond laser (2) and a second beam expansion collimating lens (4) which is matched with the picosecond laser (2), wherein the picosecond laser (2) is used for emitting picosecond laser beams, the picosecond laser beams are incident to the scanning focusing component through the second beam expansion collimating lens (4) and the light guide lenses (5 and 6) and focused on the material (10) to be processed through the scanning focusing component, and the picosecond laser emission component is used for carrying out picosecond laser scanning processing modification treatment on the material (10) to be processed so as to enable the surface of the material (10) to be processed to form a hydrophobic area or a hydrophilic area or a super-hydrophilic area;

The femtosecond laser beam and the picosecond laser beam are utilized for comprehensively treating the material (10) to be treated, so that the surface of the material (10) to be treated can form a hydrophobic-superhydrophobic morphology with the alternate hydrophobic and superhydrophobic, or a hydrophilic-superhydrophobic morphology with the alternate hydrophilic and superhydrophobic, or a superhydrophilic-superhydrophobic morphology with the alternate superhydrophilic and superhydrophobic is formed, the resistance of the material (10) to be treated in water is further reduced, and an antifouling effect is realized;

the femtosecond laser emission assembly and the picosecond laser emission assembly share a pair of light guide lenses (5, 6), the pair of light guide lenses (5, 6) are respectively a first light guide lens (5) and a second light guide lens (6), laser beams sequentially enter the scanning focusing assembly through the first light guide lens (5) and the second light guide lens (6), and switching of whether the scanning focusing assembly is connected with a femtosecond laser beam path or a picosecond laser beam path can be realized by adjusting the first light guide lens (5);

the method is characterized in that the method takes a hydrophobic material as an object to be treated and specifically comprises the following steps:

(1) And (3) femtosecond laser scanning etching treatment: performing femtosecond laser scanning etching processing treatment on the object to be processed by using femtosecond laser to form a micro-nano mixed structure with super-hydrophobic performance on the surface of the object to be processed, wherein the micro-nano mixed structure with super-hydrophobic performance is the super-hydrophobic performance surface;

(2) Picosecond laser scanning direct writing finishing treatment: and carrying out picosecond laser scanning direct writing processing modification treatment on the super-hydrophobic performance surface of the object to be treated by utilizing picosecond laser to form a hydrophobic region or a hydrophilic region or a super-hydrophilic region on the surface of the object to be treated, so that the surface of the object to be treated finally forms a hydrophobic-super-hydrophobic morphology with alternate hydrophobic and super-hydrophobic, a hydrophilic-super-hydrophobic morphology with alternate hydrophilic and super-hydrophobic, or a super-hydrophilic-super-hydrophobic morphology with alternate super-hydrophilic and super-hydrophobic, further reducing the resistance of the object to be treated in water, bringing an antifouling effect, and thus preparing the antifouling drag-reducing material.

3. A method for preparing an anti-fouling drag reducing material by laser treatment, which is a device for preparing an anti-fouling drag reducing material by using laser treatment, the device comprises a picosecond laser emission component, a femtosecond laser emission component, a scanning focusing component and a carrying workbench, wherein the carrying workbench is used for placing a material (10) to be treated for the anti-fouling drag reducing treatment;

the femtosecond laser emission component comprises a femtosecond laser (1) and a first beam expansion collimating lens (3) which is matched with the femtosecond laser (1), wherein the femtosecond laser (1) is used for emitting a femtosecond laser beam, the femtosecond laser beam is incident to the scanning focusing component through the first beam expansion collimating lens (3) and the light guide lenses (5 and 6) and focused to the material (10) to be processed through the scanning focusing component, and the femtosecond laser emission component is used for carrying out femtosecond laser scanning etching processing on the material (10) to be processed to enable the surface of the material (10) to be processed to form a micro-nano mixed structure (20) meeting the requirement of super-hydrophobic performance;

The picosecond laser emission component comprises a picosecond laser (2) and a second beam expansion collimating lens (4) which is matched with the picosecond laser (2), wherein the picosecond laser (2) is used for emitting picosecond laser beams, the picosecond laser beams are incident to the scanning focusing component through the second beam expansion collimating lens (4) and the light guide lenses (5 and 6) and focused on the material (10) to be processed through the scanning focusing component, and the picosecond laser emission component is used for carrying out picosecond laser scanning processing modification treatment on the material (10) to be processed so as to enable the surface of the material (10) to be processed to form a hydrophobic area or a hydrophilic area or a super-hydrophilic area;

the femtosecond laser beam and the picosecond laser beam are utilized for comprehensively treating the material (10) to be treated, so that the surface of the material (10) to be treated can form a hydrophobic-superhydrophobic morphology with the alternate hydrophobic and superhydrophobic, or a hydrophilic-superhydrophobic morphology with the alternate hydrophilic and superhydrophobic, or a superhydrophilic-superhydrophobic morphology with the alternate superhydrophilic and superhydrophobic is formed, the resistance of the material (10) to be treated in water is further reduced, and an antifouling effect is realized;

the femtosecond laser emission assembly and the picosecond laser emission assembly share a pair of light guide lenses (5, 6), the pair of light guide lenses (5, 6) are respectively a first light guide lens (5) and a second light guide lens (6), laser beams sequentially enter the scanning focusing assembly through the first light guide lens (5) and the second light guide lens (6), and switching of whether the scanning focusing assembly is connected with a femtosecond laser beam path or a picosecond laser beam path can be realized by adjusting the first light guide lens (5);

The method is characterized in that hydrophilic materials are used as objects to be treated, and the method specifically comprises the following steps:

(1) And (3) femtosecond laser scanning etching treatment: performing femtosecond laser scanning etching processing treatment on the object to be processed by using femtosecond laser, so that a micro-nano mixed structure meeting the requirement of super-hydrophobic performance is formed on the surface of the object to be processed;

(2) Formation of superhydrophobic surfaces: depositing a low-surface-energy material on the micro-nano mixed structure surface of the object to be treated after the treatment in the step (1), so that the surface of the object to be treated forms a super-hydrophobic performance surface; wherein the low surface energy material has a surface free energy lower than that of water;

(3) Picosecond laser scanning direct writing finishing treatment: and carrying out picosecond laser scanning direct writing processing modification treatment on the super-hydrophobic performance surface of the object to be treated by utilizing picosecond laser to form a hydrophobic region or a hydrophilic region or a super-hydrophilic region on the surface of the object to be treated, so that the surface of the object to be treated finally forms a hydrophobic-super-hydrophobic morphology with alternate hydrophobic and super-hydrophobic, a hydrophilic-super-hydrophobic morphology with alternate hydrophilic and super-hydrophobic, or a super-hydrophilic-super-hydrophobic morphology with alternate super-hydrophilic and super-hydrophobic, further reducing the resistance of the object to be treated in water, bringing an antifouling effect, and thus preparing the antifouling drag-reducing material.

4. The method for producing an anti-fouling drag reducing material by laser treatment according to any one of claims 1 to 3, wherein the hydrophobic region is specifically a hydrophobic dot, a hydrophobic line or a hydrophobic surface; the hydrophilic area is specifically a hydrophilic point, a hydrophilic line or a hydrophilic surface; the super-hydrophilic region is specifically a super-hydrophilic point, a super-hydrophilic line or a super-hydrophilic surface.

5. A method of producing an anti-fouling drag reducing material by laser processing according to any one of claims 1 to 3, wherein the scanning focusing assembly comprises a scanning galvanometer, a scanning field lens and a Z-axis moving mechanism (9), wherein the scanning galvanometer and the scanning field lens are matched to carry out scanning focusing on a laser beam, and the Z-axis moving mechanism (9) is used for driving the scanning galvanometer and the scanning field lens to integrally move along the Z-axis direction so as to control the position of a focusing point of the laser beam in the Z-axis direction.

6. The method for producing an anti-fouling drag reducing material by laser processing according to claim 5, wherein the Z-axis moving mechanism (9) is further configured to drive the second light guide mirror (6) to move synchronously along the Z-axis direction.

7. A method of producing an anti-fouling drag reducing material by laser treatment according to any one of claims 1 to 3, characterized in that the laser outlets of both the femtosecond laser (1) and the picosecond laser (2) are arranged opposite;

The carrying workbench is specifically a three-dimensional workbench and is used for placing and driving the material (10) to be processed to move and adjusting the spatial position of the material (10) to be processed;

the dust collection pipeline (12) and the protection air tap (13) are further arranged above the carrying workbench, wherein the dust collection pipeline (12) is used for removing waste generated in the laser treatment process of the material (10) to be treated, and the protection air tap (13) is used for conveying protection gas to the surface of the material (10) to be treated.