A super-slip structure for the inner wall of a narrow metal channel, and its preparation method and application

Abstract

The present invention discloses an ultra-slip structure for the inner wall of a narrow metal channel, a preparation method, and an application thereof, and relates to the technical field of material surface processing. The ultra-slip structure includes a hierarchical micro-nano rough structure formed on the inner wall of a narrow metal channel by high-pressure infiltration reaction etching, and a reactive silicone oil grafted onto the hierarchical micro-nano rough structure by a modified intermediate. The rough structures of different pore sizes formed by high-pressure infiltration reaction etching significantly improve the uniformity of the rough structure, and the silicone oil can better reside in the rough structure, and the stability and wear resistance of the rough structure are significantly enhanced. At the same time, by grafting the silicone oil onto the rough structure through the modified intermediate, the silicone oil can form a more stable flow lubrication layer, and the wear resistance is further improved. The ultra-slip structure can significantly reduce the flow resistance in the channel while having excellent wear resistance and stability, and is suitable for large-scale promotion and application in the treatment of reducing the flow resistance of narrow channels.

Description

Technical Field

[0001] The present invention relates to the technical field of material surface processing, in particular to super-slip surface technology, and in particular to a super-slip structure of the inner wall of a narrow metal channel, a preparation method thereof, and an application thereof. Background Art

[0002] In many applications involving highly viscous fluids, effectively reducing flow resistance within narrow channels is a key challenge. Microchannel devices require smooth fluid flow within confined spaces to ensure efficient operation and precise control. However, highly viscous fluids often encounter significant flow resistance within these narrow channels, resulting in reduced flow, increased pressure, and potentially causing flow instability and blockage. This not only impacts device performance but can also lead to reduced operating efficiency and shortened service life.

[0003] For example, in the field of direct-write 3D printing, the glue extrusion process often involves using air pressure or a rotating screw to provide shear force, forcing a viscous polymer fluid through a tiny nozzle (typically with an inner diameter of 50-400 μm) to form a linear fluid. A computer controls the needle's trajectory to create the desired shape and structure. However, the highly thixotropic glue used in this process is filled with fillers and has a very high viscosity, typically exceeding 400 Pa·s. This creates high extrusion resistance and low flow rate in the narrow microchannels of the needle tube, often leading to uneven thread thickness, broken threads, and even needle clogging. Therefore, solutions such as increasing the shear rate, adding lubricants, or selecting nozzles with larger inner diameters have been proposed in 3D printing technology. However, these methods often have their limitations. For example, although increasing the shear rate can reduce the viscosity of the fluid to a certain extent, it will also bring about significant thermal effects, which may cause the polymer fluid to cross-link and solidify prematurely, thus affecting the final use effect; in addition, excessively high shear rates will accelerate the wear of the equipment and shorten its service life; adding lubricants (talc, paraffin, fatty acids, fatty acid esters, etc.) to the polymer body will migrate from the inside of the polymer to the tube wall during the extrusion process to form a lubricating layer, increase the degree of wall slip, and reduce the friction resistance of the polymer flow, but the addition of lubricants will reduce the mechanical properties of the polymer body, thereby affecting product performance; although choosing a channel with a larger inner diameter can reduce flow resistance, it will also affect the fine control of the fluid, limiting precision applications.

[0004] In addition, in order to solve the problem of flow resistance of highly viscous fluids in narrow channels, people have also proposed solutions to set up super-slip structures on the inner wall of the channel, such as the patents: CN113819341A A corrosion-resistant super-slip capillary aluminum tube and its preparation method and device; CN112033198A A capillary copper tube for high-speed flow of gallium-based liquid metal containing an oxide layer and its preparation method; WO2021080705A1 Structure and liquid for liquid injection surface structure; CN106865487A Liquid injection type super-slip surface and its laser precision micromachining method; CN115928006A A preparation method for quickly constructing lubrication pipelines, etc. Although the super-slippery structure disclosed in the above patent can effectively solve the problem of flow resistance in narrow channels, during the preparation process of the super-slippery structure in narrow channels, due to the interaction between the channel diameter and the surface tension of the etching liquid, there are problems of uneven etching and difficult to control the etching effect when etching the super-slippery structure, which makes the obtained super-slippery structure have the defect of poor pore uniformity. As a result, the existing super-slippery structure in narrow channels often has problems of poor wear resistance and stability during application, which seriously affects the large-scale promotion and application of super-slippery structures in narrow channels. Summary of the Invention

[0005] The purpose of the present invention is to overcome the problems of poor wear resistance and stability of existing super-slip structures, and proposes a super-slip structure for the inner wall of a narrow metal channel, a preparation method and an application thereof.

[0006] To achieve the above-mentioned object of the invention, the present invention provides an ultra-slip structure on the inner wall of a narrow metal channel, comprising a hierarchical micro-nano rough structure formed on the inner wall of the narrow metal channel by high-pressure infiltration reactive etching, and a reactive silicone oil grafted onto the hierarchical micro-nano rough structure via a modified intermediate;

[0007] Wherein, the narrow metal channel is a metal channel with an inner diameter not greater than 400 μm;

[0008] The chemical reaction pressure of the high-pressure osmosis reaction is not less than 1 MPa;

[0009] The hierarchical micro-nano rough structure includes a micron-scale rough structure with a pore size of 1-10 μm and a nano-scale rough structure with a pore size of 10-100 nm;

[0010] The modified intermediate includes at least one of siloxane, isocyanate, self-polymer and aminosilane;

[0011] The reactive silicone oil is at least one of amino silicone oil, hydroxy silicone oil, epoxy silicone oil, and hydroxyfluoroether silicone oil.

[0012] The present invention provides a super-slip structure on the inner wall of a narrow metal channel. The rough structures of different pore sizes formed by etching on the inner wall of the channel through a high-pressure infiltration reaction not only form an effective synergistic effect and increase the contact surface, so that the silicone oil can better reside in the rough structure; and under the action of the high-pressure etching reaction, the uniformity of the rough structure is significantly improved, the etching effect is controllable, and the stability and wear resistance of the rough structure in the super-slip structure are significantly enhanced; at the same time, the silicone oil is grafted onto the rough structure through a modified intermediate, which not only makes the silicone oil less likely to be lost during the lubrication process, thereby forming a stable flow lubrication layer on the surface of the rough structure, but also can improve the grafting effect of the silicone oil and the wear resistance of the lubrication layer through the action of the modified intermediate and the silicone oil, thereby further improving the stability and wear resistance of the super-slip structure. The super-slip structure can significantly reduce the flow resistance in the channel while having excellent wear resistance and stability, and is suitable for large-scale promotion and application in the treatment of reducing the flow resistance of narrow channels.

[0013] Among them, preferably, the metal is one of aluminum and its alloys, iron and its alloys, copper and its alloys.

[0014] Preferably, the high-pressure osmosis reaction is a combination of one or more of high-pressure injection, vacuum infiltration, immersion pressurization, and temperature gradient assistance. More preferably, the chemical reaction pressure of the high-pressure osmosis reaction is 1-10 MPa.

[0015] Among them, preferably, the pore size of the micron-scale rough structure is 4-8 μm; the preferred pore size can more effectively capture silicone oil and form a stable liquid film, thereby improving the lubrication performance, which is beneficial to improving the wear resistance and stability of the super-slip structure.

[0016] Among them, preferably, the pore size of the nano-scale rough structure is 30-70 nm; the preferred pore size can better improve the stability of the surface lubricating layer, reduce the evaporation and loss of silicone oil, and thus help improve the wear resistance and stability of the super-slip structure.

[0017] Among them, preferably, the porosity of the hierarchical micro-nano rough structure formed by etching the inner wall of the channel is not more than 35%; the larger the porosity, the better the lubricity of the super-slip structure, but the worse the wear resistance and stability of the super-slip structure; more preferably, the porosity is 25-35%; the preferred porosity can provide sufficient silicone oil storage space while maintaining the mechanical strength and wear resistance of the hierarchical micro-nano rough structure, which is conducive to improving the lubricity, wear resistance and stability of the super-slip structure.

[0018] Among them, preferably, the pore depth of the hierarchical micro-nano rough structure is 10-15 μm; the preferred pore depth helps to improve the storage capacity of silicone oil, while avoiding increased structural brittleness and wear due to excessively deep pores, thereby helping to improve the wear resistance and stability of the super-slip structure.

[0019] Among them, preferably, the viscosity of the reactive silicone oil is 10-100 mPa•s; the preferred silicone oil viscosity can provide better lubrication performance, is not easy to lose, and can maintain the lubrication effect of the surface for a long time.

[0020] Preferably, the siloxane is at least one of hexamethyldisiloxane, octamethylcyclotetrasiloxane, and polydimethylsiloxane. Siloxane can form a dense organic silicone base layer on the metal surface. This base layer is fixed to the metal surface via covalent bonds, imparting hydrophobicity and chemical stability to the surface, effectively enhancing the adsorption and retention of silicone oil. Furthermore, it has good lipophilicity, helping to maintain uniform adhesion of silicone oil to the surface, thereby forming a stable lubricating layer.

[0021] Among them, preferably, the isocyanate and the self-polymer are at least one of toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, cyclohexamethylene diisocyanate, phenyl diisocyanate, tetrafluorophenyl isocyanate, isophorone diisocyanate, adipic acid diisocyanate trimer, isophorone diisocyanate trimer and toluene diisocyanate trimer; the isocyanate group can undergo cross-linking and grafting reaction with reactive silicone oil, which can not only provide more active sites and better reduce the loss of silicone oil, but also has good wear resistance itself, and can significantly increase the wear resistance of the lubricating layer. Therefore, the introduction of isocyanate groups has a significant effect on improving the stability and wear resistance of the super-slip structure.

[0022] Among them, preferably, the aminosilane is at least one of aminopropyltriethoxysilane and aminoethylaminoethyltriethoxysilane; aminosilane can increase chemical bonding ability, improve cross-linking reactivity, and enhance interaction with reactive silicone oil.

[0023] Among them, preferably, the modified intermediate is a cross-linked product of siloxane, isocyanate trimer and aminosilane; the preferred modified intermediate has a better effect on enhancing the stability and wear resistance of the super-slip structure.

[0024] In order to achieve the above-mentioned object of the invention, the present invention further provides a method for preparing a super-slip structure on the inner wall of a narrow metal channel, comprising the following steps:

[0025] (1) performing a first etching treatment on the inner wall of the narrow metal channel by using a high-pressure infiltration reaction, thereby constructing a micron-scale rough structure on the inner wall of the narrow metal channel; continuing to perform a second etching treatment on the micron-scale rough structure constructed on the inner wall of the narrow metal channel by using a high-pressure infiltration reaction, thereby etching a nanoscale rough structure in the micron-scale rough structure, thereby forming a hierarchical micro-nano rough structure;

[0026] (2) After the hierarchical micro-nano rough structure is subjected to hydroxylation treatment, a modified intermediate is grafted to obtain a modified hierarchical micro-nano rough structure;

[0027] (3) The modified hierarchical micro-nano rough structure is immersed in reactive silicone oil, and after infiltration and grafting reaction, an ultra-smooth structure on the inner wall of the narrow metal channel is obtained.

[0028] In step (1), the type of etching solution and etching conditions for the first etching treatment and the second etching treatment are selected and adjusted according to the material of the inner wall of the narrow metal channel; for example, when the inner wall of the metal channel is a stainless steel channel inner wall, the etching solution for the first etching treatment can be a mixed aqueous solution of ferric chloride, phosphoric acid and hydrogen peroxide; the mass fraction of ferric chloride is 10-20%, the volume fraction of phosphoric acid is 5-15%, and the volume fraction of hydrogen peroxide is 5-15%; the etching temperature is 35-55°C, and the etching time is 30-60 minutes. The etching solution for the second etching treatment is a hydrochloric acid solution with a concentration of 0.8-1.2 mol / L, the etching temperature is 35-55°C, and the etching time is 1-2 hours.

[0029] When the metal channel is an aluminum alloy channel, the first etching process uses a mixed aqueous solution of copper chloride and hydrochloric acid, with a copper chloride mass fraction of 5-10 wt% and a hydrochloric acid mass fraction of 1-5 wt%. The etching temperature is 60-80°C, and the etching time is 50-80 minutes. The second etching process uses an oxalic acid solution, an aminosulfonic acid solution, or an ammonium persulfate solution, with an oxalic acid solution mass fraction of 1-5%, an aminosulfonic acid solution mass fraction of 1-5%, and an ammonium sulfate solution mass fraction of 5-2%. The etching temperature is 30-50°C, and the etching time is 1-1.5 hours.

[0030] When the metal channel is a copper alloy channel, the etching solution for the first etching treatment is a mixed solution of ammonia and hydrogen peroxide, wherein the concentration of ammonia is 1-10 wt%, the concentration of hydrogen peroxide is 3-10 wt%, the etching temperature is 50-70°C, and the etching time is 40-60 minutes. The etching solution for the second etching treatment is a mixed solution of ammonium fluoride and sulfuric acid, wherein the concentration of ammonium fluoride is 1-5 wt%, the concentration of sulfuric acid is 10-30 wt%, the etching temperature is 20-50°C, and the etching time is 1-2 hours.

[0031] Wherein, in step (2), preferably, the hydroxylation treatment method comprises: immersing the hierarchical micro-nano rough structure in a piranha solution; the piranha solution comprises hydrogen peroxide and concentrated sulfuric acid in a volume ratio of 1:1; the mass fraction of the concentrated sulfuric acid is not less than 70%; the immersion temperature is 50-80°C, and the immersion time is 30-60 minutes.

[0032] Preferably, the grafting method of the modified intermediate comprises: soaking the hierarchical micro-nano rough structure after hydroxylation treatment in a siloxane modification solution, an aminosilane modification solution and / or an isocyanate modification solution.

[0033] Preferably, the siloxane-modified solution comprises a first solvent, siloxane, and concentrated sulfuric acid in a mass ratio of 50-150:5-15:1; the first solvent is at least one of ethanol, isopropanol, toluene, p-xylene, tetrahydrofuran, chloroform, and n-hexane; and the mass fraction of the concentrated sulfuric acid is not less than 70%.

[0034] Preferably, the immersion temperature of the silicone modified solution is 25-45° C., and the soaking time is 2-4 hours.

[0035] Preferably, the volume fraction of the aminosilane modified solution is 0.5-5%; and the solvent is at least one of water, methanol, and ethanol.

[0036] Preferably, the immersion temperature of the aminosilane modified solution is 40-70° C. and the soaking time is 2-4 hours.

[0037] Preferably, the mass fraction of the isocyanate-modified solution is 0.5-2%; and the solvent is at least one of methanol, ethanol, toluene, dichloromethane, n-hexane, cyclohexane, and tetrahydrofuran.

[0038] Preferably, the isocyanate modified solution is immersed in a temperature of 25-45° C. for 2-4 hours.

[0039] Among them, in step (3), preferably, the temperature of the infiltration and grafting reaction is 25-60°C, the vacuum degree is lower than 300Pa, and the time is not less than 10 hours; the preferred infiltration and grafting reaction conditions make the infiltration and grafting cross-linking reaction more thorough, and the lubricity and wear resistance of the super-slip structure are better.

[0040] In order to achieve the above-mentioned purpose of the invention, the present invention further provides an application of an ultra-slip structure of the inner wall of a metal channel in a 3D printer; preferably, the ultra-slip structure is applied to a 3D printer nozzle; using the ultra-slip structure of the present invention for the nozzle of a 3D printer can significantly reduce the friction between the fluid and the channel wall, thereby reducing flow resistance, improving fluid delivery efficiency, and improving 3D printing accuracy; at the same time, the excellent wear resistance and stability of the ultra-slip structure of the present invention can enable the nozzle to maintain lubricity for a long time, avoiding rapid wear of the ultra-slip structure of the nozzle during high-intensity use, ensuring the stability of the quality of 3D printed products, reducing the maintenance frequency and replacement cost of the equipment, and improving the overall economic benefits.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] 1. The ultra-slip structure of the present invention is a rough structure with different pore sizes etched on the inner wall of the channel through high-pressure infiltration reaction, which not only forms an effective synergistic effect and increases the contact surface, so that the silicone oil can better reside in the rough structure; but also under the action of the high-pressure etching reaction, the uniformity of the rough structure is significantly improved, the etching effect is controllable, and the stability and wear resistance of the rough structure in the ultra-slip structure are significantly enhanced.

[0043] 2. The ultra-lubricant structure of the present invention grafts silicone oil onto the rough structure through a modified intermediate, which not only prevents the silicone oil from being lost during the lubrication process, thereby enabling a stable flowing lubrication layer to be formed on the surface of the rough structure, but also enhances the grafting effect of the silicone oil and the wear resistance of the lubricating layer through the action of the modified intermediate and the silicone oil, thereby further enhancing the stability and wear resistance of the ultra-lubricant structure.

[0044] 3. The ultra-slip structure of the present invention can significantly reduce the flow resistance in the channel while having excellent wear resistance and stability, and is suitable for large-scale application in the process of reducing the flow resistance in the channel.

[0045] 4. The preparation method of the super-slippery structure of the present invention has simple process, controllable performance, good stability, and is suitable for large-scale production of super-slippery structures.

[0046] 5. The present invention uses a super-slip structure for the nozzle of a 3D printer, which can significantly reduce the friction between the fluid and the channel wall, thereby reducing flow resistance, improving fluid delivery efficiency, and improving 3D printing accuracy. It is suitable for large-scale application in 3D printers. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 This is a schematic diagram of the structure of the ultra-slip structure of the inner wall of a narrow metal channel of the present invention;

[0048] Figure 2 The diameters of the rubber filaments extruded from the stainless steel nozzle with an inner diameter of 0.15 mm in Example 1 and Blank Example 1 of the present invention at different printing speeds (a is Blank Example 1, b is Example 1).

[0049] Figure numerals: 1-metal tube wall; 2-micrometer-scale roughness structure; 3-nanometer-scale roughness structure; 4-modified intermediate; 5-reactive silicone oil. DETAILED DESCRIPTION

[0050] The present invention will be further described in detail below in conjunction with test examples and specific embodiments. However, this should not be understood as limiting the scope of the present invention to the following embodiments, and all technologies implemented based on the present invention fall within the scope of the present invention.

[0051] Example 1

[0052] A super-slip structure of the inner wall of a metal channel (a stainless steel 3D printer nozzle with an inner diameter of 0.15 mm) (e.g. Figure 1 including a hierarchical micro-nano rough structure formed on the inner wall of a narrow metal channel by high-pressure infiltration reaction etching, and a reactive silicone oil (hydroxy silicone oil with a viscosity of 50 mPa·s) grafted onto the hierarchical micro-nano rough structure via a modified intermediate;

[0053] Modified intermediates include hexamethyldisiloxane, adipic acid diisocyanate trimer, and aminopropyltriethoxysilane;

[0054] The hierarchical micro-nano rough structure includes a micron-scale rough structure with a pore size range of 5-8 μm and a nano-scale rough structure with a pore size range of 40-50 nm. The hierarchical micro-nano rough structure has been modified by siloxane grafting. The porosity of the hierarchical micro-nano rough structure is 30% and the pore depth is 12 μm.

[0055] The specific preparation method is as follows:

[0056] (1) The inner wall of the printer nozzle is subjected to a first etching treatment (the etching solution can be a mixed aqueous solution of ferric chloride, phosphoric acid and hydrogen peroxide; the mass fraction of ferric chloride is 15%, the volume fraction of phosphoric acid is 10%, and the volume fraction of hydrogen peroxide is 10%; the etching reaction pressure is 5 MPa, the temperature is 45 ° C, and the time is 50 min). A micron-level rough structure is constructed on the inner wall of the printer nozzle. After the etching is completed, it is ultrasonically cleaned with deionized water, isopropyl alcohol, and deionized water in sequence, and dried;

[0057] (2) The micron-scale rough structure constructed on the inner wall of the printer nozzle is subjected to a second etching treatment (the etching solution is a hydrochloric acid solution with a concentration of 1 mol / L, the etching reaction pressure is 5 MPa, the temperature is 45 ° C, and the etching time is 1.5 h). A nano-scale rough structure is etched in the micron-scale rough structure to obtain a hierarchical micro-nano rough structure. After the etching is completed, it is ultrasonically cleaned with deionized water, isopropyl alcohol, and deionized water in sequence, and then dried;

[0058] (3) The hierarchical micro-nano rough structure was first hydroxylated using a piranha solution (hydrogen peroxide and concentrated sulfuric acid in a volume ratio of 1:1; the mass fraction of concentrated sulfuric acid was 98%) (temperature 60 °C, time 40 min); then the hydroxylated hierarchical micro-nano rough structure was immersed in a siloxane modification solution (isopropyl alcohol, hexamethyldisiloxane and concentrated sulfuric acid in a mass ratio of 100:10:1; the mass fraction of concentrated sulfuric acid was 98%) for reaction (350 Pa vacuum environment, temperature 35 °C, time 10 h), an aminosilane modification solution (methanol solution of aminopropyltriethoxysilane with a volume fraction of 2%) for reaction (temperature 50 °C, time 3 h), and an isocyanate modification solution (methanol solution of adipic acid diisocyanate trimer with a mass fraction of 1%) for reaction (temperature 35 °C, time 3 h) to obtain the modified hierarchical micro-nano rough structure;

[0059] (4) The modified hierarchical micro-nano rough structure was infiltrated and grafted with reactive silicone oil (temperature 40 °C, vacuum 350 Pa, infiltration time 12 h) to obtain a super-smooth structure on the inner wall of the metal channel.

[0060] Example 2

[0061] An ultra-slip structure on the inner wall of a metal channel (a stainless steel 3D printer nozzle with an inner diameter of 0.15 mm) includes a hierarchical micro-nano rough structure formed on the inner wall of the narrow metal channel by high-pressure infiltration reactive etching, and a reactive silicone oil (hydroxyl silicone oil with a viscosity of 50 mPa·s) grafted onto the hierarchical micro-nano rough structure via a modified intermediate.

[0062] Modified intermediates include adipic acid diisocyanate trimer;

[0063] The hierarchical micro-nano rough structure includes a micron-scale rough structure with a pore size range of 5-8 μm and a nano-scale rough structure with a pore size range of 40-50 nm. The hierarchical micro-nano rough structure has a porosity of 30% and a pore depth of 12 μm.

[0064] The specific preparation method is as follows:

[0065] (1) The inner wall of the printer nozzle is subjected to a first etching treatment (the etching solution can be a mixed aqueous solution of ferric chloride, phosphoric acid and hydrogen peroxide; the mass fraction of ferric chloride is 15%, the volume fraction of phosphoric acid is 10%, and the volume fraction of hydrogen peroxide is 10%; the etching reaction pressure is 5 MPa, the temperature is 45 ° C, and the time is 50 min). A micron-level rough structure is constructed on the inner wall of the printer nozzle. After the etching is completed, it is ultrasonically cleaned with deionized water, isopropyl alcohol, and deionized water in sequence, and dried;

[0066] (2) The micron-scale rough structure constructed on the inner wall of the printer nozzle is subjected to a second etching treatment (the etching solution is a hydrochloric acid solution with a concentration of 1 mol / L, the etching reaction pressure is 5 MPa, the temperature is 45 ° C, and the etching time is 1.5 h). A nano-scale rough structure is etched in the micron-scale rough structure to obtain a hierarchical micro-nano rough structure. After the etching is completed, it is ultrasonically cleaned with deionized water, isopropyl alcohol, and deionized water in sequence, and then dried;

[0067] (3) The hierarchical micro-nano rough structure was first hydroxylated using a piranha solution (hydrogen peroxide and concentrated sulfuric acid with a volume ratio of 1:1; the mass fraction of concentrated sulfuric acid was 98%) (temperature 60 ° C, time 40 min); then the hydroxylated hierarchical micro-nano rough structure was immersed in an isocyanate modification solution (methanol solution of adipic acid diisocyanate trimer with a mass fraction of 1%) for reaction (temperature 35 ° C, time 3 h) to obtain a modified hierarchical micro-nano rough structure;

[0068] (4) The modified hierarchical micro-nano rough structure was infiltrated and grafted with reactive silicone oil (temperature 40 °C, vacuum 350 Pa, infiltration time 12 h) to obtain a super-smooth structure on the inner wall of the metal channel.

[0069] Example 3

[0070] An ultra-slip structure on the inner wall of a metal channel (a stainless steel 3D printer nozzle with an inner diameter of 0.15 mm) includes a hierarchical micro-nano rough structure formed on the inner wall of the narrow metal channel by high-pressure infiltration reactive etching, and a reactive silicone oil (epoxy silicone oil with a viscosity of 100 mPa·s) grafted onto the hierarchical micro-nano rough structure via a modified intermediate.

[0071] Modified intermediates include octamethylcyclotetrasiloxane, toluene diisocyanate, and aminoethylaminoethyltriethoxysilane;

[0072] The hierarchical micro-nano rough structure includes a micron-scale rough structure with a pore size range of 1-3 μm and a nano-scale rough structure with a pore size range of 10-30 nm. The hierarchical micro-nano rough structure has been modified by siloxane grafting. The porosity of the hierarchical micro-nano rough structure is 25%, and the pore depth is 10 μm.

[0073] The specific preparation method is as follows:

[0074] (1) The inner wall of the printer nozzle is subjected to a first etching treatment (the etching solution can be a mixed aqueous solution of ferric chloride, phosphoric acid and hydrogen peroxide; the mass fraction of ferric chloride is 20%, the volume fraction of phosphoric acid is 15%, and the volume fraction of hydrogen peroxide is 15%; the etching reaction pressure is 1 MPa, the temperature is 35°C, and the time is 30 min), and a micron-scale rough structure is constructed on the inner wall of the metal channel. After the etching is completed, it is ultrasonically cleaned with deionized water, isopropyl alcohol, and deionized water in sequence, and then dried;

[0075] (2) The micron-scale rough structure constructed on the inner wall of the printer nozzle is subjected to a second etching treatment (the etching solution is a hydrochloric acid solution with a concentration of 0.8 mol / L, the etching reaction pressure is 1 MPa, the temperature is 55 ° C, and the etching time is 1 h). A nano-scale rough structure is etched in the micron-scale rough structure to obtain a hierarchical micro-nano rough structure. After the etching is completed, it is ultrasonically cleaned with deionized water, isopropyl alcohol, and deionized water in sequence, and then dried;

[0076] (3) The hierarchical micro-nano rough structure was first hydroxylated using a piranha solution (hydrogen peroxide and concentrated sulfuric acid in a volume ratio of 1:1; the mass fraction of concentrated sulfuric acid was 70%) (temperature 50°C, time 30 min); the hydroxylated hierarchical micro-nano rough structure was then immersed in a siloxane modification solution (ethanol, octamethylcyclotetrasiloxane and concentrated sulfuric acid in a mass ratio of 50:15:1; the mass fraction of concentrated sulfuric acid was 70%) for grafting reaction (temperature 45°C, time 12 h), an aminosilane modification solution (methanol solution of aminoethylaminoethyltriethoxysilane with a volume fraction of 1%) for reaction (temperature 70°C, time 2 h), and an isocyanate modification solution (aqueous solution of toluene diisocyanate with a mass fraction of 2%) for reaction (temperature 25°C, time 4 h) to obtain the modified hierarchical micro-nano rough structure;

[0077] (4) The modified hierarchical micro-nano rough structure was infiltrated and grafted with reactive silicone oil (temperature 30 °C, vacuum 400 Pa, infiltration time 11 h) to obtain a super-smooth structure on the inner wall of the metal channel.

[0078] Example 4

[0079] An ultra-slip structure on the inner wall of a metal channel (a stainless steel 3D printer nozzle with an inner diameter of 0.15 mm) includes a hierarchical micro-nano rough structure formed on the inner wall of the narrow metal channel by high-pressure infiltration reactive etching, and a reactive silicone oil (amino silicone oil with a viscosity of 10 mPa·s) grafted onto the hierarchical micro-nano rough structure via a modified intermediate.

[0080] Modified intermediates include toluene diisocyanate trimer and aminoethylaminoethyltriethoxysilane;

[0081] The hierarchical micro-nano rough structure includes a micron-scale rough structure with a pore size range of 7-10 μm and a nano-scale rough structure with a pore size range of 60-100 nm. The hierarchical micro-nano rough structure has been modified by siloxane grafting. The porosity of the hierarchical micro-nano rough structure is 35%, and the pore depth is 15 μm.

[0082] The specific preparation method is as follows:

[0083] (1) The inner wall of the printer nozzle is subjected to a first etching treatment (the etching solution can be a mixed aqueous solution of ferric chloride, phosphoric acid and hydrogen peroxide; the mass fraction of ferric chloride is 20%, the volume fraction of phosphoric acid is 15%, and the volume fraction of hydrogen peroxide is 15%; the etching reaction pressure is 10 MPa, the temperature is 55°C, and the time is 60 min), and a micron-scale rough structure is constructed on the inner wall of the metal channel. After the etching is completed, it is ultrasonically cleaned with deionized water, isopropyl alcohol, and deionized water in sequence, and then dried;

[0084] (2) The micron-scale rough structure constructed on the inner wall of the printer nozzle is subjected to a second etching treatment (the etching solution is a hydrochloric acid solution with a concentration of 1.2 mol / L, the etching reaction pressure is 10 MPa, the temperature is 35 ° C, and the etching time is 2 h). A nano-scale rough structure is etched in the micron-scale rough structure to obtain a hierarchical micro-nano rough structure. After the etching is completed, it is ultrasonically cleaned with deionized water, isopropyl alcohol, and deionized water in sequence, and then dried;

[0085] (3) First, the hierarchical micro-nano rough structure was hydroxylated using a piranha solution (hydrogen peroxide and concentrated sulfuric acid in a volume ratio of 1:1; the mass fraction of concentrated sulfuric acid was 85%) (temperature 50 ° C, time 60 min); then, the hydroxylated hierarchical micro-nano rough structure was reacted with an aminosilane modification solution (methanol solution of aminoethylaminoethyltriethoxysilane with a volume fraction of 3%) (temperature 35 ° C, time 4 h) and an isocyanate modification solution (aqueous solution of toluene diisocyanate trimer with a mass fraction of 0.5%) (temperature 45 ° C, time 2 h) to obtain the modified hierarchical micro-nano rough structure;

[0086] (4) The modified hierarchical micro-nano rough structure was infiltrated and grafted with reactive silicone oil (temperature 60 °C, vacuum 300 Pa, infiltration time 10 h) to obtain a super-smooth structure on the inner wall of the metal channel.

[0087] Example 5

[0088] An ultra-slip structure on the inner wall of a metal channel (an aluminum alloy 3D printer nozzle with an inner diameter of 0.15 mm) includes a hierarchical micro-nano rough structure formed on the inner wall of the narrow metal channel by high-pressure infiltration reactive etching, and a reactive silicone oil (hydroxyl silicone oil with a viscosity of 50 mPa·s) grafted onto the hierarchical micro-nano rough structure via a modified intermediate.

[0089] Modified intermediates include hexamethyldisiloxane, adipic acid diisocyanate trimer, and aminopropyltriethoxysilane;

[0090] The hierarchical micro-nano rough structure includes a micron-scale rough structure with a pore size range of 5-8 μm and a nano-scale rough structure with a pore size range of 40-50 nm. The hierarchical micro-nano rough structure has been modified by siloxane grafting. The porosity of the hierarchical micro-nano rough structure is 30% and the pore depth is 12 μm.

[0091] The specific preparation method is as follows:

[0092] (1) The inner wall of the printer nozzle (ultrasonic cleaning treatment in ethanol solution and deionized water for 10 minutes respectively, and drying) is subjected to the first etching treatment (the etching solution is a mixed solution of copper chloride and hydrochloric acid, the mass fraction of copper chloride is 10wt%, the mass fraction of hydrochloric acid is 3.5wt%; the etching reaction pressure is 5MPa, the temperature is 70℃, and the etching time is 60min). A micron-level rough structure is constructed on the inner wall of the printer nozzle. After the etching is completed, it is ultrasonically cleaned with deionized water, isopropyl alcohol, and deionized water in sequence, and dried;

[0093] (2) The micron-scale rough structure constructed on the inner wall of the printer nozzle is subjected to a second etching treatment (the etching solution is a 3.5% mass fraction oxalic acid solution; the etching reaction pressure is 5 MPa, the temperature is 40 ° C, and the etching time is 1.2 h). A nano-scale rough structure is etched in the micron-scale rough structure to obtain a hierarchical micro-nano rough structure. After the etching is completed, it is ultrasonically cleaned with deionized water, isopropyl alcohol, and deionized water in sequence, and then dried;

[0094] (3) The hierarchical micro-nano rough structure was first hydroxylated using a piranha solution (hydrogen peroxide and concentrated sulfuric acid in a volume ratio of 1:1; the mass fraction of concentrated sulfuric acid was 98%) (temperature 60 °C, time 40 min); then the hydroxylated hierarchical micro-nano rough structure was immersed in a siloxane modification solution (isopropyl alcohol, hexamethyldisiloxane and concentrated sulfuric acid in a mass ratio of 100:10:1; the mass fraction of concentrated sulfuric acid was 98%) for reaction (350 Pa vacuum environment, temperature 35 °C, time 10 h), an aminosilane modification solution (methanol solution of aminopropyltriethoxysilane with a volume fraction of 2%) for reaction (temperature 50 °C, time 3 h), and an isocyanate modification solution (methanol solution of adipic acid diisocyanate trimer with a mass fraction of 1%) for reaction (temperature 35 °C, time 3 h) to obtain the modified hierarchical micro-nano rough structure;

[0095] (4) The modified hierarchical micro-nano rough structure was infiltrated and grafted with reactive silicone oil (temperature 40 °C, vacuum 350 Pa, infiltration time 12 h) to obtain a super-smooth structure on the inner wall of the metal channel.

[0096] Example 6

[0097] An ultra-slip structure on the inner wall of a metal channel (a copper alloy 3D printer nozzle with an inner diameter of 0.15 mm) includes a hierarchical micro-nano rough structure formed on the inner wall of the narrow metal channel by high-pressure infiltration reactive etching, and a reactive silicone oil (hydroxyl silicone oil with a viscosity of 50 mPa·s) grafted onto the hierarchical micro-nano rough structure via a modified intermediate.

[0098] Modified intermediates include hexamethyldisiloxane, adipic acid diisocyanate trimer, and aminopropyltriethoxysilane;

[0099] The hierarchical micro-nano rough structure includes a micron-scale rough structure with a pore size range of 5-8 μm and a nano-scale rough structure with a pore size range of 40-50 nm. The hierarchical micro-nano rough structure has been modified by siloxane grafting. The porosity of the hierarchical micro-nano rough structure is 30% and the pore depth is 12 μm.

[0100] The specific preparation method is as follows:

[0101] (1) The inner wall of the printer nozzle (ultrasonic cleaning treatment in ethanol solution and deionized water for 10 minutes respectively, and drying) is subjected to the first etching treatment (the etching solution is a mixed solution of ammonia water and hydrogen peroxide, wherein the concentration of ammonia water is 5wt%, the concentration of hydrogen peroxide is 8wt%, the etching reaction pressure is 5MPa, the temperature is 60℃, and the etching time is 50min). A micron-level rough structure is constructed on the inner wall of the printer nozzle. After the etching is completed, it is ultrasonically cleaned with deionized water, isopropyl alcohol, and deionized water in sequence, and dried;

[0102] (2) The micron-scale rough structure constructed on the inner wall of the printer nozzle is subjected to a second etching treatment (the etching solution is a mixed solution of ammonium fluoride and sulfuric acid, the concentration of ammonium fluoride is 3wt%, the concentration of sulfuric acid is 15wt%, the etching reaction pressure is 5MPa, the temperature is 30℃, and the etching time is 1.5h). A nanoscale rough structure is etched in the micron-scale rough structure to obtain a hierarchical micro-nano rough structure. After the etching is completed, the structure is ultrasonically cleaned with deionized water, isopropyl alcohol, and deionized water in sequence, and then dried;

[0103] (3) The hierarchical micro-nano rough structure was first hydroxylated using a piranha solution (hydrogen peroxide and concentrated sulfuric acid in a volume ratio of 1:1; the mass fraction of concentrated sulfuric acid was 98%) (temperature 60 °C, time 40 min); then the hydroxylated hierarchical micro-nano rough structure was immersed in a siloxane modification solution (isopropyl alcohol, hexamethyldisiloxane and concentrated sulfuric acid in a mass ratio of 100:10:1; the mass fraction of concentrated sulfuric acid was 98%) for reaction (350 Pa vacuum environment, temperature 35 °C, time 10 h), an aminosilane modification solution (methanol solution of aminopropyltriethoxysilane with a volume fraction of 2%) for reaction (temperature 50 °C, time 3 h), and an isocyanate modification solution (methanol solution of adipic acid diisocyanate trimer with a mass fraction of 1%) for reaction (temperature 35 °C, time 3 h) to obtain the modified hierarchical micro-nano rough structure;

[0104] (4) The modified hierarchical micro-nano rough structure was infiltrated and grafted with reactive silicone oil (temperature 40 °C, vacuum 350 Pa, infiltration time 12 h) to obtain a super-smooth structure on the inner wall of the metal channel.

[0105] Example 7

[0106] A super-slip structure on the inner wall of a metal channel (a stainless steel 3D printer nozzle with an inner diameter of 0.15 mm) differs from Example 1 only in that the etching temperature and time are adjusted to reduce the porosity of the hierarchical micro-nano roughness to only 15%.

[0107] Example 8

[0108] A super-slip structure of the inner wall of a metal channel (a stainless steel 3D printer nozzle with an inner diameter of 0.15 mm) differs from Example 1 only in that the etching temperature and time are adjusted to make the porosity of the hierarchical micro-nano rough structure reach 40%.

[0109] Example 9

[0110] A super-slip structure of the inner wall of a metal channel (a stainless steel 3D printer nozzle with an inner diameter of 0.15 mm) is obtained, which differs from Example 1 only in that the etching temperature and time are adjusted so that the pore depth of the hierarchical micro-nano rough structure is only 8 μm.

[0111] Example 10

[0112] A super-slip structure of the inner wall of a metal channel (a stainless steel 3D printer nozzle with an inner diameter of 0.15 mm) differs from Example 1 only in that the etching temperature and time are adjusted so that the pore depth of the hierarchical micro-nano rough structure reaches 18 μm.

[0113] Example 11

[0114] A super-slip structure of the inner wall of a metal channel (a stainless steel 3D printer nozzle with an inner diameter of 0.15 mm) is different from Example 1 only in that the infiltration oil is hydroxyl silicone oil with a viscosity of 5 mPa·s.

[0115] Example 12

[0116] A super-slip structure of the inner wall of a metal channel (a stainless steel 3D printer nozzle with an inner diameter of 0.15 mm) is provided, which differs from Example 1 only in that the infiltration oil is hydroxyl silicone oil with a viscosity of 110 mPa•s.

[0117] Example 13

[0118] A super-slip structure of the inner wall of a metal channel (a stainless steel 3D printer nozzle), which differs from Example 1 only in that the inner diameter of the stainless steel 3D printer nozzle is 0.4 mm.

[0119] Comparative Example 1

[0120] A super-slip structure of the inner wall of a metal channel (a stainless steel 3D printer nozzle with an inner diameter of 0.15 mm) differs from Example 1 only in that dimethyl silicone oil (viscosity 50 mPa·s) is used instead of reactive silicone oil, so the silicone oil is not grafted onto the rough structure.

[0121] Comparative Example 2

[0122] A super-slip structure of the inner wall of a metal channel (a stainless steel 3D printer nozzle with an inner diameter of 0.15 mm) is different from Example 1 only in that: during the etching process, no high-pressure infiltration reaction is used, and the etching reaction pressure is only 0.5 MPa.

[0123] Comparative Example 3

[0124] A super-slip structure of the inner wall of a metal channel (a stainless steel 3D printer nozzle with an inner diameter of 0.15 mm) differs from Example 1 only in that: no grafting is performed through an intermediate modifier, but instead, after hydroxylation, it is directly immersed in reactive silicone oil.

[0125] Comparative Example 4

[0126] A super-slip structure of the inner wall of a metal channel (a stainless steel 3D printer nozzle), which differs from Example 1 only in that the inner diameter of the stainless steel 3D printer nozzle is 0.5 mm.

[0127] Comparative Example 5

[0128] A super-slip structure of the inner wall of a metal channel is different from Example 1 only in that the inner diameter of the stainless steel 3D printer nozzle is 0.5 mm, and during the etching process, high-pressure infiltration reaction is not used, and the etching reaction pressure is only 0.5 MPa.

[0129] Comparative Example 6

[0130] A super-slip structure of the inner wall of a metal channel is different from Example 1 only in that the inner diameter of the stainless steel 3D printer nozzle is 0.4 mm, and during the etching process, high-pressure infiltration reaction is not used, and the etching reaction pressure is only 0.5 MPa.

[0131] Comparative Example 7

[0132] A super-slip structure of the inner wall of a metal channel (a stainless steel 3D printer nozzle with an inner diameter of 0.15 mm) differs from Example 1 only in that the etching temperature and time are adjusted so that the hierarchical micro-nano rough structure includes a micron-scale rough structure with a pore size range of 5-8 μm and a nanoscale rough structure with a pore size range of 120-150 nm.

[0133] Comparative Example 8

[0134] A super-slip structure of the inner wall of a metal channel (a stainless steel 3D printer nozzle with an inner diameter of 0.15 mm) differs from Example 1 only in that the etching temperature and time are adjusted so that the hierarchical micro-nano rough structure includes a micron-scale rough structure with a pore size range of 12-15 μm and a nanoscale rough structure with a pore size range of 40-50 nm.

[0135] Comparative Example 9

[0136] A super-slip structure of the inner wall of a metal channel (a stainless steel 3D printer nozzle with an inner diameter of 0.15 mm) differs from Example 1 only in that the etching temperature and time are adjusted so that the hierarchical micro-nano rough structure includes a micron-scale rough structure with a pore size range of 0.5-0.8 μm and a nanoscale rough structure with a pore size range of 40-50 nm.

[0137] Comparative Example 10

[0138] A super-slip structure of the inner wall of a metal channel (a stainless steel 3D printer nozzle with an inner diameter of 0.15 mm) differs from Example 1 only in that the etching temperature and time are adjusted so that the hierarchical micro-nano rough structure includes a micron-scale rough structure with a pore size range of 5-8 μm and a nanoscale rough structure with a pore size range of 6-8 nm.

[0139] Blank example 1

[0140] A stainless steel 3D printer nozzle with an inner diameter of 0.15 mm, without any treatment.

[0141] Blank example 2

[0142] Aluminum alloy 3D printer nozzle with an inner diameter of 0.15mm, without any treatment.

[0143] Blank example 3

[0144] Copper alloy 3D printer nozzle with an inner diameter of 0.15 mm, without any treatment.

[0145] Blank example 4

[0146] A stainless steel 3D printer nozzle with an inner diameter of 0.5 mm, without any treatment.

[0147] Experimental example:

[0148] The 3D printer nozzles in Examples 1-13, Comparative Examples 1-10, and Blank Examples 1-4 were subjected to direct-write 3D printing glue extrusion tests (5 tests per group, with the average value taken): at an air pressure of 60 psi and a screw speed of 138 r / min, printing tests were conducted using 1700SE silicone rubber, 1700SE silicone rubber with 5 wt% silica nanoparticles added, and 1700SE silicone rubber with 10 wt% silica nanoparticles added as printing slurries. The glue extrusion flow rate, stable lubrication duration, and nozzle clogging of each 3D printer nozzle were measured. The experimental results are as follows:

[0149]

[0150] The results of the experimental example show that:

[0151] From the analysis of the experimental data of the embodiments, comparative examples and blank examples, it can be seen that the liquid-like super-slippery surface structure of the microporous structure on the inner wall of the channel provided by the present invention can effectively reduce the friction between the inner wall of the needle and the high-viscosity fluid, while significantly improving the wear resistance of the super-slippery surface structure, thereby greatly extending the lubrication duration. Among them, the pore size, pore depth, porosity, silicone oil type, whether the intermediate modifier is grafted and the etching reaction pressure of the rough structure in the super-slippery structure have a relatively significant effect on the lubrication performance and wear resistance of the super-slippery structure. Analysis of the experimental data of Example 1 and Comparative Example 1 shows that the grafting of silicone oil onto the hierarchical micro-nano rough structure can significantly improve the wear resistance of the super-slip structure, and its wear resistance is significantly improved compared with the existing form of directly loading silicone oil (Comparative Example 1); Analysis of the experimental data of Example 1 and Comparative Example 2 shows that when etching to generate the hierarchical micro-nano rough structure, the use of high-pressure infiltration reaction can significantly improve the uniformity of the rough structure, thereby significantly improving its wear resistance; Analysis of the experimental data of Example 1 and Comparative Example 3 shows that grafting the intermediate modifier onto the hierarchical micro-nano rough structure can increase the grafting effect of silicone oil and improve the wear resistance of the super-slip layer, which significantly improves the wear resistance of the super-slip structure; Analysis of the experimental data of Examples 1, 13, Comparative Examples 4-6 and Blank Example 4 shows , the use of high-pressure infiltration reaction can only significantly improve the uniformity of the rough structure of narrow channels (not greater than 0.4μm), while for channels with larger diameters, the improvement in their wear resistance is not obvious; analysis of the data of Example 1 and Example 11-12 shows that the viscosity of the reactive silicone oil also affects the wear resistance of the super-lubricating structure. When the viscosity of the infiltration oil is 10-100mPa.s, the super-lubricating structure has better wear resistance; analysis of the data of Example 1 and Comparative Examples 7-8 shows that in the super-lubricating structure, the pore size of the nano-rough structure and the micron rough structure has a significant effect on the wear resistance of the super-lubricating structure. The smaller micron pore size (1-10μm) can more effectively capture the infiltration oil and form a stable liquid film, thereby improving the lubrication performance; the nano-scale pore size (10-100 The results show that a moderate pore depth (10-15 µm) can further improve the stability of the surface lubricating layer and reduce the evaporation and loss of the impregnating oil. Analysis of the data of Examples 1 and 9-10 shows that a moderate pore depth (10-15 µm) helps to improve the storage capacity of the impregnating oil while avoiding increased structural brittleness and wear due to excessive pore depth. Analysis of the data of Examples 1 and 9-10 shows that a moderate porosity (25%-35%) can provide sufficient storage space for the impregnating oil while maintaining the mechanical strength and wear resistance of the structure.In addition, analysis of the data of Example 1, Examples 5-6 and Blank Examples 1-3 shows that the liquid-like super-slip surface structure of the microporous structure of the inner wall of the channel provided by the present invention effectively reduces the friction between the inner wall of the nozzle and the highly viscous fluid, and the wall-slip drag reduction effect is very significant; under the same printing parameters, the glue extrusion flow rate of the nozzle with the super-slip structure of the present invention is 2-3 times that of the unmodified needle; the maximum printing speed it can adapt to is about 1-2 times that of the unmodified nozzle, and it is also found during the experiment that the glue filament of the nozzle without the super-slip modification breaks on the substrate during high-speed printing, while the nozzle with the super-slip structure of the present invention keeps the filament straight and intact when printing at a higher speed (see. Figure 2 ); In particular, by arranging the super-slip structure of the present invention in the nozzle, it is possible to obtain thinner silk threads when the nozzle moves at high speed, and the printable rubber wire diameter is also much smaller than the rubber wire diameter printed by the nozzle needle. It can be seen that the use of the super-slip structure of the present invention in a 3D printer can significantly reduce the friction between the fluid and the channel wall, thereby reducing the flow resistance, improving the fluid delivery efficiency, and improving the 3D printing accuracy; at the same time, the excellent wear resistance and stability of the super-slip structure of the present invention can enable the nozzle to maintain lubricity for a long time, avoiding the rapid wear of the super-slip structure of the nozzle during high-intensity use, ensuring the stability of the quality of 3D printed products, reducing the maintenance frequency and replacement cost of the equipment, and improving the overall economic benefits.

[0152] Those skilled in the art can make various other corresponding changes and modifications based on the technical solutions and concepts described above, and all of these changes and modifications should fall within the scope of protection of the claims of the present invention.

Claims

1. A super-slip structure on the inner wall of a narrow metal channel, characterized in that: The invention comprises a hierarchical micro-nano rough structure formed on the inner wall of a narrow metal channel by high-pressure infiltration reaction etching, and a reactive silicone oil grafted onto the hierarchical micro-nano rough structure through a modified intermediate; Wherein, the narrow metal channel is a metal channel with an inner diameter not greater than 400 μm; The chemical reaction pressure of the high-pressure osmosis reaction is not less than 1 MPa; The hierarchical micro-nano rough structure includes a micron-scale rough structure with a pore size of 1-10 μm and a nano-scale rough structure with a pore size of 10-100 nm; The modified intermediate includes at least one of siloxane, isocyanate, self-polymer and aminosilane; The reactive silicone oil is at least one of amino silicone oil, hydroxy silicone oil, epoxy silicone oil, and hydroxyfluoroether silicone oil.

2. The super-slip structure according to claim 1, characterized in that: The porosity of the hierarchical micro-nano rough structure formed by etching the inner wall of the channel is no more than 35%.

3. The super-slip structure according to claim 1, characterized in that: The pore depth of the hierarchical micro-nano rough structure is 10-15 μm.

4. The super-slip structure according to claim 1, characterized in that: The chemical reaction pressure of the high-pressure osmosis reaction is 1-10 MPa.

5. The super-slip structure according to claim 1, characterized in that: The reactive silicone oil has a viscosity of 10-100 mPa·s.

6. The super-slip structure according to claim 1, characterized in that: The siloxane is at least one of hexamethyldisiloxane, octamethylcyclotetrasiloxane and polydimethylsiloxane.

7. The super-slip structure according to claim 1, characterized in that: The isocyanate and the self-polymer are at least one of toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, cyclohexamethylene diisocyanate, phenyl diisocyanate, tetrafluorophenyl isocyanate, isophorone diisocyanate, adipic acid diisocyanate trimer, isophorone diisocyanate trimer and toluene diisocyanate trimer.

8. The super-slip structure according to claim 1, characterized in that: The aminosilane is at least one of aminopropyltriethoxysilane and aminoethylaminoethyltriethoxysilane.

9. A method for preparing the super-slip structure according to any one of claims 1 to 8, characterized in that: (1) performing a first etching treatment on the inner wall of the narrow metal channel by using a high-pressure infiltration reaction, thereby constructing a micron-scale rough structure on the inner wall of the narrow metal channel; continuing to perform a second etching treatment on the micron-scale rough structure constructed on the inner wall of the narrow metal channel by using a high-pressure infiltration reaction, thereby etching a nanoscale rough structure in the micron-scale rough structure, thereby forming a hierarchical micro-nano rough structure; (2) After the hierarchical micro-nano rough structure is subjected to hydroxylation treatment, a modified intermediate is grafted to obtain a modified hierarchical micro-nano rough structure; (3) The modified hierarchical micro-nano rough structure is immersed in reactive silicone oil, and after infiltration and grafting reaction, an ultra-smooth structure on the inner wall of the narrow metal channel is obtained.

10. An application of the super-slip structure according to any one of claims 1 to 8, characterized in that: Application in 3D printers.

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