Laser preparation method of oleophobic anti-adhesion surface

Abstract

The invention relates to the technical field of coating material preparation, and discloses a laser preparation method of an oleophobic anti-adhesion surface, which comprises the following steps: providing a liquid precursor containing a crosslinkable organosilicon compound, a liquid lubricant and a lubricant microcapsule, and synchronously realizing a micro-nano structure on the surface of a substrate by adopting pulse laser one-time scanning irradiation to obtain the oleophobic anti-adhesion surface. The covalent bonding of the organic silicon framework and the physical locking of the liquid lubricant and the microcapsule are constructed, the covalent bonding is formed between the substrate and the coating, so that the stripping failure caused by physical interface separation of a traditional coating is avoided, and the liquid storage framework and the microcapsule storage structure which are integrally constructed have the advantages that the stability is high; a dynamic anti-adhesion and after-damage lubricant supplementing mechanism is provided for the surface, and the service durability and the function reliability of the surface under the severe working condition are improved.

Description

Technical Field

[0001] This invention relates to a laser preparation method for an oleophobic and anti-adhesion surface, belonging to the field of coating material preparation technology. Background Technology

[0002] Currently, in the field of functional surface construction, to improve the specific properties of the substrate material such as oleophobicity and anti-adhesion, the common approach is to apply a coating to its surface. Early technical practices, such as spraying or physical vapor deposition, covered the substrate with functional coating compositions, which mainly relied on the physical adsorption force or mechanical force between the coating and the substrate to achieve bonding.

[0003] As application requirements increase, subsequent improvements have focused on strengthening this physical bond, such as increasing surface roughness by grinding or sandblasting the substrate to achieve a stronger mechanical bonding effect. However, this approach still has limitations when dealing with long-term thermal cyclic stress. The difference in thermal expansion coefficients between the substrate and coating materials causes continuous small relative displacements at the interface. These displacements gradually destroy the mechanical bonding points, induce microscopic peeling, and create conditions for subsequent intrusion of moisture and oil, ultimately leading to the failure of the coating integrity.

[0004] Therefore, following the path of enhancing physical bonding has not solved the inherent problem of the lack of stable chemical bonds between the coating and the substrate. Specifically, existing technologies mainly suffer from the following shortcomings: 1. Insufficient stability of interfacial bonding, making it difficult for physical forces to withstand periodic composite stresses over time; 2. High risk of coating failure, with the accumulation of microscopic damage easily leading to overall delamination, affecting the long-term operation of the equipment; 3. Limited applicability of the process, making it difficult to guarantee uniform and firm bonding for substrates with complex structures or specific materials. Therefore, how to develop a new coating preparation method that can directly promote chemical bonding between the coating and substrate atoms during the coating process, achieving integrated fusion of the interface, has become the technical problem to be solved by this invention. Summary of the Invention

[0005] This invention provides a laser preparation method for oleophobic and anti-adhesion surfaces. Its main purpose is to solve the problem that existing coating preparation methods rely on physical bonding, which leads to insufficient interface stability and easy peeling failure under thermal cycling conditions.

[0006] To achieve the above objectives, the present invention provides a laser preparation method for an oleophobic and anti-adhesion surface, comprising the following steps: Step a, providing a liquid precursor, the liquid precursor being a suspension containing a crosslinkable organosilicon compound as a network backbone source, a liquid lubricant that does not chemically react with the crosslinkable organosilicon compound, and a plurality of microcapsules uniformly dispersed and encapsulated with the liquid lubricant. Step b: Coat the liquid precursor onto the substrate surface to form a uniform liquid film; Step c involves scanning and irradiating the substrate surface coated with a liquid film using a pulsed laser. During the scanning irradiation process, the energy of a single laser pulse induces a localized rapid melting and resolidification process in the substrate material, resulting in the self-organized formation of micro- and nano-structures on the substrate surface. Furthermore, the high temperature and plasma environment generated by the laser pulse at the interface between the substrate and the liquid film simultaneously drive the crosslinkable organosilicon compound to undergo in-situ pyrolysis and form covalent bonds with the activated substrate surface atoms, constructing a porous solid framework that is metallurgically bonded to the substrate. The formation process of the porous solid framework involves locking the liquid lubricant in its pore network through capillary forces and physical confinement effects, and physically embedding multiple microcapsules.

[0007] Preferably, the crosslinkable organosilicon compound is a mixture of polydimethylsiloxane and fluoroalkylsilane, the liquid lubricant is perfluoropolyether, and the shell material of the multiple microcapsules is selected from the group consisting of melamine resin and silica.

[0008] Preferably, the pulsed laser is a nanosecond laser with a wavelength of 1,064 nanometers and an energy density of 0.5 joules per square centimeter to 2.0 joules per square centimeter applied to the substrate surface.

[0009] Preferably, the covalent bond is a metal-oxygen-silicon bond formed between the metal atoms of the substrate and the silicon atoms of the product after the pyrolysis of the crosslinkable organosilicon compound.

[0010] Preferably, the crosslinkable organosilicon compound and the liquid lubricant in the liquid precursor are selected such that the refractive index of the porous solid framework formed by the pyrolysis of the crosslinkable organosilicon compound and the refractive index of the liquid lubricant satisfy the following conditions: ,in, The refractive index of the porous solid framework, is the refractive index of the liquid lubricant.

[0011] Preferably, the shells of the multiple microcapsules are made of a solid lubricant material.

[0012] Preferably, the solid lubricant material is selected from the group consisting of molybdenum disulfide, graphite, and hexagonal boron nitride.

[0013] Preferably, the particle size of the multiple microcapsules is between one micrometer and ten micrometers.

[0014] Preferably, after scanning irradiation, a rinsing step using an ethanol solvent is included to remove unreacted liquid precursors.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention achieves in-situ pyrolysis of organosilicon compounds in the precursor of self-organized micro / nano structures on the substrate surface through a single pulsed laser scanning irradiation step, as well as covalent bonding between the pyrolysis products and substrate atoms. This process avoids the separation of substrate treatment and coating deposition phases in traditional coating preparation. The metal-oxygen-silicon chemical bonds formed replace physical adsorption or mechanical locking, making the coating a natural extension of the substrate rather than an attachment. As a result, when the surface operates under harsh conditions such as thermal cycling, the initiation cause of interfacial failure, namely micro-peeling caused by thermal expansion mismatch, is effectively suppressed. The overall structural durability of the surface is no longer limited by the strength of the interfacial bonding, but depends on the cohesive force of the material itself. Its failure mode also changes from sheet peeling to the slow wear of homogeneous materials.

[0016] 2. The liquid precursor used in this invention contains, in its formulation, a crosslinkable organosilicon compound with chemically stable liquid lubricant and microcapsules encapsulating the same lubricant. During the laser-induced integrated construction process, not only is a porous solid framework firmly bonded to the substrate formed, but also the pore network generated during the formation of this framework is used to lock the liquid lubricant and microcapsules simultaneously within the framework structure through capillary forces and physical confinement effects. This method results in a surface that is not a static oleophobic layer, but a dynamic anti-adhesion system containing both initial lubrication and reserve lubrication mechanisms. The initially locked lubricant enhances the surface's slip properties, while the pre-embedded microcapsules provide a passively triggered in-situ replenishment path for the surface to recover its function after the lubricant dissipates due to long-term service, thus extending the surface's working life in practical applications.

[0017] 3. This invention further expands the surface protection mechanism by selecting the shell material of the microcapsule in the precursor. When a solid lubricant material is used as the shell of the microcapsule, the single component of the microcapsule simultaneously carries two different functions. Under normal working conditions, the intact microcapsule exists as a storage container for the liquid lubricant. However, under extreme working conditions such as high-pressure friction, the liquid lubricant film may be ruptured. The microcapsule rupture event at this time not only releases the internal liquid lubricant for replenishment, but the shell fragments after rupture can also be ground and spread on the friction interface under the action of external force to form a solid lubricant transfer film. Thus, the surface gains an ability to adaptively adjust the lubrication mode according to the nature of the stress. When facing the challenges of different types of adhesion and wear, it exhibits the working condition adaptability and reliability of a single lubrication mechanism. Attached Figure Description

[0018] Figure 1 This is a technical logic flowchart of a laser preparation method for an oleophobic and anti-adhesion surface according to the present invention; Figure 2 This is a schematic diagram illustrating the state transition of the self-replenishing mechanism of the oleophobic and anti-adhesion surface of the present invention. Figure 3 This is a schematic diagram of the process flow for a laser preparation method of an oleophobic and anti-adhesion surface according to the present invention. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] The present invention discloses a laser preparation method for an oleophobic and anti-adhesion surface, the process of which is constructed as a series of interconnected stages. It begins with the provision of a liquid precursor, followed by coating the liquid precursor into a uniform liquid film on the target substrate surface. Subsequently, a pulsed laser is used to scan and irradiate the liquid film and the substrate. Finally, an optional cleaning step removes unreacted residues to obtain the target functional surface. The preparation method begins with the design of a liquid precursor, which serves as a functional composite suspension. Its formulation addresses the performance degradation of traditional coatings due to lubricant dissipation. To address this issue, the liquid precursor was configured to contain three functional components: a crosslinkable organosilicon compound as the network framework source, a liquid lubricant that does not chemically react with the crosslinkable organosilicon compound, and multiple microcapsules uniformly dispersed and encapsulating the liquid lubricant. This ternary composite formulation system allows the liquid precursor to function as a film-forming material while also possessing initial and reserve lubrication mechanisms, providing a long-lasting self-replenishing foundation for the surface constructed in subsequent laser steps. The specific component selection of the liquid precursor aims to achieve both flexibility and low surface energy. The solid framework of the coating uses a mixture of polydimethylsiloxane and fluoroalkylsilane as the crosslinkable organosilicon compound. The polydimethylsiloxane forms a flexible silicon-oxygen framework after pyrolysis and crosslinking, while the fluoroalkylsilane, through the introduction of its fluorinated groups, gives the final coating surface a low surface energy, thus achieving an oleophobic effect. To enable the surface to possess dynamic slip properties and cope with extreme temperature environments, a chemically stable and low-freezing-point perfluoropolyether is selected as the liquid lubricant. For the microcapsules carrying the reserve lubrication function, the shell material is selected from a combination of melamine resin and silica. Both materials possess a certain degree of mechanical strength and brittleness, enabling them to rupture and release internal lubricant under stress triggering. The particle size of multiple microcapsules was calibrated, with the procedure aimed at balancing the monomeric load of the lubricant with its structural compatibility within the coating. Calibration showed that when the particle size was less than one micrometer, the amount of lubricant encapsulated in a single microcapsule was too small, resulting in insignificant replenishment after rupture. Conversely, when the particle size was greater than ten micrometers, it easily became a structural defect in the coating, affecting its overall mechanical properties. Therefore, through screening experiments, the particle size of multiple microcapsules was determined to be between one and ten micrometers. to Within a certain range, the lubricant reserves and the structural stability of the coating are balanced.

[0021] To ensure batch consistency and long-term storage stability of the liquid precursor in industrial applications, its standard preparation procedure is solidified into a series of quantitative steps. It starts with premixing a crosslinkable organosilicon compound and a liquid lubricant at 25°C under a shear condition of 500 revolutions per minute for 15 minutes, then adding microcapsule powder through a powder metering feeder at a rate not exceeding 10 grams per minute, followed by homogenization at a high shear rate of 10,000 revolutions per minute for 30 minutes, and finally conducting quality acceptance by measuring the sedimentation stability index after 24 hours of standing. This index is determined by the following formula: , where and represent the concentrations of microcapsules in the top 10% and bottom 10% volumes of the suspension respectively. Only when the value of is not less than 0.98 can this batch of precursor be judged as qualified; the homogeneity of laser scanning and the effect of its core chemical bonding are jointly confirmed by the scanning line overlap rate and interface chemical state analysis. The overlap rate is defined as , is the laser spot diameter, is the center distance between adjacent scanning lines. Its optimal value is determined by preparing a series of samples with a gradient change in overlap rate from 15% to 60% at the energy density determined by Example 4 and calculating the height standard deviation of the three-dimensional surface profile data of each sample to obtain the overlap rate setting corresponding to the minimum value; for the samples prepared according to this procedure, depth profiling is carried out using X-ray photoelectron spectroscopy (XPS). The Si2p characteristic peak at approximately 101.5 eV, which belongs to the metal-oxygen-silicon bond and is detected in the interface region, is direct evidence of the formation of interface covalent bonding.

[0022] The second stage of the preparation method is coating, that is, coating the liquid precursor into a uniform liquid film on the substrate surface. This step can be carried out at normal temperature and pressure using industrial techniques such as spraying, dip coating or spin coating. The material of the substrate can be stainless steel or aluminum alloy. The formation of the liquid film provides a homogeneous reaction environment for the subsequent interaction between the laser and the material; the step that determines the final surface structure and performance in the preparation method is to scan and irradiate the substrate surface coated with the liquid film using pulsed laser. This process solves the problem of insufficient bonding force due to physical interface separation between the substrate and the coating in traditional coating techniques; to achieve the construction of substrate micro-nano structures and chemical bonding between the coatings, the energy parameters of the pulsed laser need to be calibrated. For this purpose, this method uses a nanosecond laser with a wavelength of one thousand and sixty-four nanometers ( ), and an operating procedure for determining its energy density is established: through gradient experiments, it is found that when the energy density acting on the substrate surface is lower than zero point five joules per square centimeter ( When the laser energy is insufficient to induce effective melting of the substrate or complete pyrolysis of the precursor, the structure is incomplete and chemical bonding cannot be established; however, when the energy density exceeds 2.0 joules per square centimeter (…), the laser energy is insufficient to induce effective melting of the substrate or complete pyrolysis of the precursor, resulting in incomplete structure formation and failure to establish chemical bonds. When the laser energy density is applied to the substrate, it will cause excessive ablation of the substrate and completely vaporize the liquid precursor instead of thermally cross-linking it, thus failing to form an effective coating. Therefore, the energy density of the laser applied to the substrate surface is determined to be between 0.5 joules per square centimeter and 2.0 joules per square centimeter. to Within the energy window, a single laser pulse has enough energy to instantaneously trigger a series of pre-set physicochemical processes.

[0023] During the scanning irradiation process, three effects are activated simultaneously: First, the micro-nano structuring of the substrate: the laser pulse induces rapid local melting and resolidification of the substrate material surface, and under the influence of surface tension and hydrodynamic effects, micro-nano structures are formed self-organically. Second, the in-situ pyrolysis of the precursor: the high temperature and plasma environment generated by the laser pulse at the interface between the substrate and the liquid film drive the in-situ pyrolysis of the crosslinkable organosilicon compound adjacent to the interface, generating highly active silicon-containing free radical fragments. Third, the formation of interfacial covalent bonds: the laser-activated metal atoms on the substrate surface react with the silicon-containing free radical fragments to form stable chemical bonds, constructing a porous solid framework that is metallurgically bonded to the substrate. The covalent bonds are metal-oxygen-silicon bonds formed between the metal atoms of the substrate and the silicon atoms of the crosslinkable organosilicon compound pyrolysis products. During the rapid formation of the porous solid framework, its pore network locks the free liquid lubricant and multiple complete microcapsules inside the framework simultaneously through capillary forces and physical confinement effects. Thus, a composite functional surface containing micro-nano structures, covalently bonded interfaces, liquid lubricating layers and microcapsule storage structures is constructed in an integrated manner.

[0024] In applications requiring high optical performance, the porous structure constructed by the aforementioned method suffers from reduced transparency due to light scattering. To address this issue, this invention further discloses a configuration method for achieving optical transparency. The core of this method lies in designing a refractive index matching scheme for the precursor components. The operating procedure is as follows: First, accurately measure the refractive index of the selected liquid lubricant, denoted as... Subsequently, the refractive index of the porous solid framework formed after pyrolysis was controlled by adjusting the chemical composition of the crosslinkable organosilicon compound. Specifically, this can be achieved by changing the molar ratio of high-refractive-index groups, such as benzene rings, to low-refractive-index groups, such as fluorocarbon chains, in the formulation; and by establishing the relationship between the component molar ratio and the final skeleton refractive index through a series of calibration experiments. The corresponding relationship is used to select a specific formulation so that the refractive index of the final porous solid framework and the refractive index of the liquid lubricant satisfy the following conditions: When this condition is met, light scattering is suppressed when passing through the interface between the solid skeleton and the liquid lubricant, allowing the entire composite coating to maintain its slip function while exhibiting optical transparency. Furthermore, to address boundary friction caused by the potential extrusion of the liquid lubricant film under high-pressure friction conditions, this invention also provides a configuration for constructing a dual-modal adaptive lubrication surface. This configuration involves functionalizing the shell material of multiple microcapsules, specifically by using a material that is itself a solid lubricant for the shells of the multiple microcapsules. The solid lubricant material is selected from the group consisting of molybdenum disulfide, graphite, and hexagonal boron nitride. Under this configuration, when the microcapsules experience high stress... Upon rupture, it not only releases the internal liquid lubricant, but the fragments of the ruptured shell are also ground and spread on the friction interface under external force, forming a solid lubricant transfer film. As a result, the surface gains the ability to adjust the lubrication mode according to the nature of the stress it is subjected to in order to cope with different types of adhesion and wear challenges. After scanning irradiation, the entire preparation process also includes a final purification step, namely rinsing with ethanol solvent. This step removes the excess liquid precursors on the surface that have not participated in the reaction, leaving only the functional coating that is firmly bonded to the substrate, thereby obtaining a clean and fully functional oleophobic and anti-adhesion surface.

[0025] Example 1: In a continuously operating food processing production line, the surface of its stainless steel conveyor belt assembly is subjected to repeated washing with high-temperature, high-pressure steam daily to remove grease and protein residues. When an oleophobic coating is applied to the surface of the assembly using a physical spraying method, after several thermal cycles, due to the mismatch in the thermal expansion coefficients of the stainless steel substrate and the oleophobic coating, periodic shear stress is generated at the physical interface between the two, leading to micro-peeling. Subsequently, high-temperature steam penetrates these micro-peeling areas through capillary action, creating pressure at the interface, causing... This causes the coating to bubble and peel off in sheets, resulting in the failure of its anti-adhesion function. To address this issue, stainless steel conveyor belt assemblies of the same specifications are surface-prepared using the method disclosed above. A layer of liquid precursor is coated on the surface of the assembly, comprising a mixture of polydimethylsiloxane and fluoroalkylsilane as the network skeleton, a perfluoropolyether as a liquid lubricant, and melamine resin microcapsules encapsulating the same perfluoropolyether with a particle size between one micrometer and ten micrometers. Subsequently, a nanosecond pulsed laser with a wavelength of 1064 nanometers is used at a rate of 1.5 joules per square centimeter (…). The energy density of the laser pulse is used to scan and irradiate the surface of the component coated with the liquid film. At the instant of the laser pulse, the substrate surface is melted and then solidified to form a micro-nano structure. At the same time, polydimethylsiloxane and fluoroalkylsilane at the interface undergo in-situ pyrolysis, and the products form metal-oxygen-silicon bonds with the activated substrate metal atoms. The formation of this chemical bond makes the coating part of the substrate surface, and the original physical interface is replaced by a gradient transition zone.

[0026] In this single laser irradiation step, the two technical objectives of adhesion durability and surface lubricity are achieved synergistically. Their interrelationship lies in the fact that the high-energy environment provided by the laser pulse is a necessary condition for the formation of high-strength metal-oxygen-silicon bonds at the interface. It is precisely under this high-energy input that the melting and resolidification of the substrate and the in-situ pyrolysis and cross-linking of the organosilicon occur simultaneously, thereby constructing a porous solid framework with liquid storage capacity. In this process, the formation of high-strength chemical bonds and the construction of the porous liquid storage structure are two inseparable aspects of the same physicochemical event. The former provides a stable structural carrier for the lubrication system, while the latter locks the liquid lubricant and microcapsules within the structure, thus enhancing the lubrication system. The presence of this material also reduces the mechanical and chemical erosion of the surface during operation, maintaining the integrity of the skeletal structure. Components prepared by this method are reintroduced into the aforementioned food processing production line and run for the same period. After undergoing the same frequency of cleaning procedures including high-temperature and high-pressure steam rinsing, no blistering or peeling is observed on the component surface, and its oleophobic and anti-adhesion properties are maintained. Its failure mode changes from interfacial peeling to surface-to-surface wear of a homogeneous material. When micro-wear occurs on the surface, the microcapsules embedded inside can rupture under external stress, releasing lubricant to replenish the worn area and maintain its functional stability, thus extending the service life of the component.

[0027] Example 2: To objectively verify the effectiveness of the preparation method disclosed in this invention in improving the interfacial bonding stability and long-term service durability of the coating, this experiment was conducted. By simulating thermal cycling and mechanical wear conditions, the performance of surfaces prepared using the method of this invention was compared with that prepared using physical coating. The preparation process of the test samples is as follows: multiple pieces of material with dimensions of… A portion of the 304 stainless steel sheets, used as a control sample, were coated with a layer of fluorosilane polymer coating using a spraying method. Heat curing Another part, as a sample of the present invention, employs the method disclosed above to coat its surface with a layer comprising a mixture of polydimethylsiloxane and fluoroalkylsilane, a perfluoropolyether liquid lubricant, and melamine resin microcapsules encapsulated with the same perfluoropolyether, and uses a nanosecond laser with a wavelength of 1064 nanometers to... The energy density was scanned and irradiated, and finally washed with ethanol and dried.

[0028] In the interface bonding stability test, two sets of samples were placed in a high and low temperature alternating test chamber and subjected to 100 cycles of accelerated aging test. The temperature range for each cycle was set to [temperature range missing]. to This parameter setting accumulates and amplifies the stress generated at the interface due to the mismatch in thermal expansion coefficients over a wide temperature range; after the aging test, based on... The standard uses a cross-cut adhesion test to rate the coating adhesion. The coating in the comparison sample showed extensive peeling at the edges of the cross-cut areas, and its adhesion level was rated as [insert rating here]. In contrast, the sample of this invention showed no coating peeling at the edges of the gridded areas, and the cuts were smooth; its adhesion level was rated as [insert level here]. This result indicates that the metal-oxygen-silicon bonds formed in situ by laser technology create a more robust chemical bond between the substrate and the coating than physical adsorption, which can suppress interfacial failure under thermal cycling stress.

[0029] In verifying functional durability and self-replenishing capability, a reciprocating friction and wear testing machine was used. A loaded steel wool friction head was used to rub the surfaces of two sets of samples. Repeated wear; before the wear test, the initial water contact angle of the sample group of this invention was... The initial water contact angle of the comparison sample group was ,go through After repeated wear cycles, the contact angle of the control group decreased to and after standing No recovery was observed afterward, and the measured value was [value missing]. This indicates that its hydrophobic structure has undergone irreversible damage; under the same wear conditions, although the contact angle of the sample group of the present invention decreased to However, it remains hydrophobic, and under the same static conditions... Afterwards, its contact angle recovered to The mechanism of this contact angle recovery phenomenon lies in the fact that under the frictional stress caused by wear, the microcapsules embedded in the skeleton rupture, releasing the internally stored perfluoropolyether lubricant, which replenishes the lubrication layer in the worn area in situ, thereby restoring the hydrophobic slip function of the surface. According to the comprehensive test results, the oleophobic and anti-adhesion surface prepared by the method disclosed in this invention has a chemical bonding interface, which has the ability to maintain structural integrity under thermal cycling conditions. At the same time, the liquid lubricant and microcapsule reserve structure contained within it provide a way for the surface to recover its function after mechanical wear. Compared with physical coating methods, its service durability and functional reliability under harsh working conditions are changed.

[0030] Example 3: This example combines Figures 1 to 3 A laser preparation method for an oleophobic and anti-adhesion surface is described, such as... Figure 1 As shown, the figure begins with the preparation of a liquid precursor in step one. This precursor is composed of a crosslinkable organosilicon compound as the network framework source, a liquid lubricant as the initial lubrication source, and lubricant microcapsules as the reserve lubrication source. Subsequently, in step two, the liquid precursor is coated onto the substrate surface to form a uniform liquid film. In step three, a pulsed laser is used for scanning irradiation. This single irradiation step simultaneously achieves three core effects: the effect of laser-induced local rapid melting and resolidification of the substrate material to self-organize and form a porous solid framework; and the effect of micro / nano-structures. The process involves three main steps: 1) pyrolysis of organosilicon driven by high temperature and plasma to form metal-oxygen-silicon covalent bonds with the substrate; 2) in-situ pyrolysis and bonding; and 3) locking of the liquid lubricant and microcapsules through capillary forces and physical confinement effects of the porous framework; and 4) physical locking of the lubricant. An optional step 4, solvent rinsing to remove unreacted residues, yields the final product: an oleophobic, non-adhesive surface covalently bonded to the substrate. This surface, when subjected to surface wear, can trigger the rupture of internal microcapsules, releasing the liquid lubricant and achieving functional self-recovery.

[0031] like Figure 2 As shown, the prepared surface is in an initial intact state, possessing oleophobic slip properties and intact internal microcapsules. When the surface is subjected to a mechanical wear event, it will enter a surface wear state, where its lubricating film is damaged or punctured. In this state, the microcapsule rupture event triggered by stress brings the system into a lubrication replenishment state. At this time, the microcapsules embedded in the skeleton rupture and release the internal lubricant. As the lubricant spreads, the system enters a functional recovery state. The lubricant replenishes the worn area in situ, restoring the surface's hydrophobic slip function. As the system stabilizes, it returns to its initial intact state to cope with the next wear event.

[0032] like Figure 3 As shown, the process begins with the precursor raw material and the substrate material, such as stainless steel or aluminum alloy, used as the substrate to be treated. In the liquid precursor preparation unit, liquid precursors are prepared using a ternary composite formulation. Subsequently In the substrate surface coating unit, the precursor is applied to the substrate to form the coated substrate. ,exist In the integrated laser fabrication unit, pulsed laser energy from a laser energy source acts on the surface to be processed, forming a post-reaction surface. Ultimately, in... In the solvent washing and purification unit, the surface after the reaction is cleaned to remove unreacted residues and obtain a clean final product, namely a functionalized surface, while the waste after cleaning is sent to the waste pool.

[0033] Example 4: In a specific engineering application, an oleophobic and anti-adhesion surface needs to be applied to an aluminum alloy substrate. Given the differences in laser energy absorption and thermal conductivity among different substrate materials, the following procedure is used to systematically determine the laser energy density process window suitable for this material system; take a piece of... The 6061 aluminum alloy plate, after being polished and cleaned, is uniformly coated with a liquid precursor with the same formula as described above using a spin coating method; the fiber nanosecond pulse laser used has the ability to independently adjust the output power, pulse frequency and scanning speed, and is equipped with a field lens to maintain the uniformity of the spot size on the processing plane.

[0034] Plan a design on the surface of the aluminum alloy plate The array consists of one hundred arrays with an area of An independent test area; the laser scanning program is set to scan at a speed from […] along the X-axis of the array. Linear change to Along the Y-axis, the laser pulse frequency changes from... Linear change to This setting can generate a coverage area from a single sample surface. to A gradient-varying energy density matrix is ​​generated, where each test area corresponds to a known energy density value. After laser irradiation and ethanol cleaning, two independent quantitative assessments are performed on each test area in the matrix. The first assessment is the coating adhesion, which involves dividing each area using a cross-cutting method and providing the coating adhesion based on the area of ​​peeling at the cut. to The first evaluation is the adhesion rating; the second is the microstructure assessment, which uses a scanning electron microscope to image the center of each region. Based on the image characteristics, the microstructure is divided into three categories: low-energy regions, high-energy regions, and suitable morphology regions. The results of the two evaluations are mapped to select regions that simultaneously meet the adhesion rating criteria. Furthermore, the microstructure represents all test points within the suitable morphology region; this procedure transforms the selection of process parameters into a systematic process based on a quantitative evaluation of coating adhesion and microstructure, thereby determining the energy density range applicable to a specific material system.

[0035] Example 5: In a precision optical window application, to prevent oil and frost from adhering and affecting its sensing function, an oleophobic and anti-adhesion surface needs to be prepared on its surface. This application requires the coating to have optical transparency, and the technical requirements are that the refractive index of the porous solid framework formed by the pyrolysis of crosslinkable organosilicon compounds is [not specified]. Refractive index of the wetted liquid lubricant Matching, that is, satisfying To this end, the following offline calibration procedure was adopted to determine the chemical composition ratio that can achieve this matching; this procedure is achieved by establishing the chemical composition of the crosslinkable organosilicon compound and its refractive index after pyrolysis of the solid framework. Based on the corresponding relationship, a benzene ring-containing silane monomer with a high refractive index and a fluoroalkyl silane monomer with a low refractive index were selected as basic components to prepare a series of organosilicon precursor solutions with varying molar ratios. In this series of solutions, the total molar concentration of the two silane monomers remained constant, but their molar ratio varied from... Systematic changes to Subsequently, each precursor solution in the series was coated onto a silicon wafer substrate and scanned with the same laser parameters as in the aforementioned embodiments to form a series of samples containing only porous solid frameworks with different chemical compositions; the refractive index of each sample was measured using an ellipsometer at the target optical wavelength. Measurements were performed to obtain a set of values ​​relating the molar ratio of silane monomers to the final framework refractive index. The corresponding experimental data are used to construct a calibration database or fit a calibration curve.

[0036] When preparing a specific optical window, the refractive index of the selected perfluoropolyether liquid lubricant is first measured. Subsequently, based on the calibration data established by the aforementioned procedures, a method to generate a refractive index was identified. With the measured A matching molar ratio of silane monomers is determined; ultimately, a liquid precursor comprising a crosslinkable organosilicon compound, a liquid lubricant, and lubricant microcapsules is formulated based on this molar ratio and applied to the fabrication of optical windows; this procedure enables the fabrication of optical windows with a specific refractive index. A liquid lubricant that can be formulated to produce a corresponding refractive index. The ratio of organosilicon compounds in the framework is adjusted to achieve the preparation of an optically transparent, oleophobic, and non-adhesive surface.

[0037] Example 6: One of the technical challenges in preparing self-healing surfaces for high-wear conditions is determining the concentration of lubricant microcapsules in the liquid precursor to find an operating point that maximizes functional self-healing efficiency while ensuring the mechanical integrity of the coating is not lower than a preset benchmark. To this end, the following procedure was established to systematically determine this concentration parameter. The procedure begins with the preparation of a series of liquid precursor samples in which the type and ratio of crosslinkable organosilicon compounds and liquid lubricants are kept constant, and only the volume percentage of lubricant microcapsules is used as the sole variable, set in gradients of 1%, 5%, 10%, 15%, and 20%. For each precursor in this series, coating samples are prepared on multiple identical 304 stainless steel substrates using the same coating method and calibrated laser process parameters.

[0038] After sample preparation, two independent performance characterizations were performed on samples at each concentration gradient. The first was an assessment of the coating's mechanical integrity, using a pencil hardness test to determine the coating hardness grade of each sample. The results showed that the pencil hardness of the coating decreased with increasing microcapsule volume percentage, indicating that excessive microcapsules reduce the compactness of the solid skeleton. The second was an assessment of self-healing efficiency. First, the initial water contact angle of each sample was measured. Then, uniform scratches were created on the sample surface using a scratch tester. After standing for 24 hours, the water contact angle of the scratched area was measured again. The healing efficiency was defined as the contact angle recovery rate. The test results showed that the self-healing efficiency increased with the increase of the microcapsule volume percentage, but the increase slowed down after 15%. Based on the test data of the above two properties, a concentration range that balances mechanical stability and self-healing efficiency can be determined. In this application scenario, when the coating hardness is required to be no less than 4H and the self-healing efficiency is no less than 80%, the volume percentage range of lubricant microcapsules can be determined to be between 10% and 15% through data analysis. This procedure, through quantitative evaluation of the coating's mechanical integrity and self-healing efficiency, determines the concentration range of lubricant microcapsules that meets the requirements of specific engineering applications.

[0039] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A laser preparation method for an oleophobic and anti-adhesion surface, characterized in that, Includes the following steps: Step a, providing a liquid precursor, the liquid precursor being a suspension containing a crosslinkable organosilicon compound as a network backbone source, a liquid lubricant that does not chemically react with the crosslinkable organosilicon compound, and a plurality of microcapsules uniformly dispersed and encapsulated with the liquid lubricant. Step b: Coat the liquid precursor onto the substrate surface to form a uniform liquid film; Step c involves scanning and irradiating the substrate surface coated with a liquid film using a pulsed laser. During the scanning irradiation process, the energy of a single laser pulse induces a localized rapid melting and resolidification process in the substrate material, resulting in the self-organized formation of micro- and nano-structures on the substrate surface. Furthermore, the high temperature and plasma environment generated by the laser pulse at the interface between the substrate and the liquid film simultaneously drive the crosslinkable organosilicon compound to undergo in-situ pyrolysis and form covalent bonds with the activated substrate surface atoms, constructing a porous solid framework that is metallurgically bonded to the substrate. The formation process of the porous solid framework involves locking the liquid lubricant in its pore network through capillary forces and physical confinement effects, and physically embedding multiple microcapsules.

2. The laser preparation method for an oleophobic and anti-adhesion surface according to claim 1, characterized in that, The crosslinkable organosilicon compound is a mixture of polydimethylsiloxane and fluoroalkylsilane, the liquid lubricant is perfluoropolyether, and the shell material of the multiple microcapsules is selected from the group consisting of melamine resin and silica.

3. The laser preparation method for an oleophobic and anti-adhesion surface according to claim 1, characterized in that, The pulsed laser is a nanosecond laser with a wavelength of 1,064 nanometers, and its energy density on the substrate surface is 0.5 joules per square centimeter to 2.0 joules per square centimeter.

4. The laser preparation method for an oleophobic and anti-adhesion surface according to claim 1, characterized in that, Covalent bonding is a metal-oxygen-silicon bond formed between the metal atoms of the substrate and the silicon atoms of the product after the pyrolysis of the crosslinkable organosilicon compound.

5. The laser preparation method for an oleophobic and anti-adhesion surface according to claim 1, characterized in that, The crosslinkable organosilicon compound and the liquid lubricant in the liquid precursor are selected such that the refractive index of the porous solid framework formed by the pyrolysis of the crosslinkable organosilicon compound and the refractive index of the liquid lubricant satisfy the following conditions: ,in, The refractive index of the porous solid framework, is the refractive index of the liquid lubricant.

6. The laser preparation method for an oleophobic and anti-adhesion surface according to claim 1, characterized in that, The shells of multiple microcapsules are made of a solid lubricant material.

7. The laser preparation method for an oleophobic and anti-adhesion surface according to claim 6, characterized in that, The solid lubricant material is selected from the group consisting of molybdenum disulfide, graphite, and hexagonal boron nitride.

8. The laser preparation method for an oleophobic and anti-adhesion surface according to claim 1, characterized in that, The particle size of the multiple microcapsules ranges from one micrometer to ten micrometers.

9. The laser preparation method for an oleophobic and anti-adhesion surface according to claim 1, characterized in that, Following scanning irradiation, a rinsing step using ethanol solvent is also included to remove unreacted liquid precursors.

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