Preparation method of super-slippery surface based on modified composite particles

Abstract

The present invention belongs to the technical field of polymer composite materials, and specifically relates to a method for preparing a super-slippery surface based on modified composite particles, comprising the following steps: spraying an organic-inorganic hybrid adhesive on the surface of a substrate and curing it, spraying a modified composite particle dispersion on the surface of the organic-inorganic hybrid adhesive and curing it, obtaining a substrate loaded with modified composite particles, and finally immersing the substrate loaded with modified composite particles in a lubricating oil added with a photoinitiator, and irradiating it under ultraviolet light to obtain a super-slippery surface based on modified composite particles. The super-slippery surface based on modified composite particles prepared by the present invention has excellent performance and can enhance the wear resistance and mechanical strength of the super-slippery surface.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer composite materials, and in particular relates to a method for preparing an ultra-slippery surface based on modified composite particles. Background Art

[0002] As an excellent lubricating material, fluorinated polymers are widely used in high-performance self-lubricating components in the aerospace, aviation and automotive manufacturing industries, and as additives for various polymer matrices and lubricating greases due to their unique chemical structure and molecular chain characteristics. However, they have defects such as poor dispersibility, poor wear resistance, insufficient load-bearing capacity, poor compatibility with other materials, poor creep resistance, and poor dispersion in the polymer matrix due to surface hydrophobicity. In addition, traditional modification methods such as physical mixing, high-energy irradiation and chemical corrosion have gradually exposed obvious drawbacks and cannot meet the application requirements of current technological development.

[0003] At present, mechanical mixing technology is usually used to physically mix fluoropolymers with other polymers or modified particles. This method limits the full play of the lubrication performance of fluoropolymers and is difficult to meet the modern industry's demand for low friction coefficient and high wear resistance. Therefore, it is necessary to develop and use more valuable surface treatment agents and coupling agents through serialization to enhance the interface compatibility between the fluoropolymer matrix and the reinforcement.

[0004] In addition, due to the extremely strong non-polarity of fluorinated polymers, their adhesion is poor, making it difficult to achieve a true "connection" with other materials. The currently used filled / blended inorganic non-metallic materials, metal materials and high molecular polymer materials are difficult to solve the problem of two-phase interface bonding. Although the performance of composite materials can be improved to a certain extent, the performance improvement is very limited.

[0005] Chinese patent CN106811075A discloses a method for preparing a modified silica sol and polyurethane emulsion compounded strippable protective coating, comprising the following steps: 1) adding toluene diisocyanate and the like to a first reactor at room temperature to obtain a primary product; 2) adding dimethylol propionic acid and then triethylamine to the primary product to obtain an aromatic waterborne polyurethane emulsion; 3) obtaining a modified silica sol; 4) adding the modified silica sol and the aromatic waterborne polyurethane emulsion to a third reactor at room temperature to obtain a mixed emulsion for standby use; 5) adding an appropriate amount of potassium salt of acrylic acid copolymer and the like to a fourth reactor containing distilled water to obtain a mixed base liquid; 6) adding the mixed emulsion to the mixed base liquid to obtain a modified silica sol and polyurethane emulsion compounded strippable protective coating. The strippable protective coating prepared by the patent has a strong surface strength and poor toughness, and has a poor protective effect on the coated surface when used.

[0006] Compared with the traditional physical compounding method, the chemical compounding method obviously has more obvious advantages, because the firmness of chemical compounding can make the soft and hard particles obtain a more stable connection, which will not only greatly improve the interfacial bonding force and dispersibility of the fluoropolymer, but also greatly improve the adhesion between the transfer film and the substrate, thereby promoting the homogeneous transfer and continuous film formation of the transfer film. Therefore, using chemical compounding to connect soft and hard phase particles to form a complex with a stable structure and easy to evenly disperse, in order to prepare a high-performance lubricating additive that combines low friction, high wear resistance and high load-bearing capacity, will become an important technical means to improve the tribological properties of polymers.

[0007] However, the existing composite particles cannot simultaneously meet the performance requirements of low friction, high wear resistance and high load-bearing capacity, and the wear resistance of fluoropolymers cannot be enhanced. The chemical modification technology of their interface bonding strength and compatibility with other materials needs to be improved. Summary of the invention

[0008] In view of the deficiencies in the prior art, the object of the present invention is to provide a method for preparing a super-slippery surface based on modified composite particles. The prepared super-slippery surface based on modified composite particles has excellent performance and can enhance the wear resistance and mechanical strength of the super-slippery surface.

[0009] The technical solution adopted by the present invention to solve its technical problem is:

[0010] The method for preparing the ultra-slippery surface based on modified composite particles of the present invention comprises the following steps:

[0011] (1) diluting silica sol or silica sol precursor in deionized water, then adding it to a solvent, and then adding a modifier to obtain an organic silica sol adhesive, and then compounding the organic silica sol adhesive with polyurethane, and crushing it to obtain an organic-inorganic hybrid adhesive;

[0012] (2) reacting the fluorinated polymer latex particles with the mixed solution, washing and drying to obtain a core-shell composite material;

[0013] (3) dispersing the core-shell composite material in ethanol to obtain a core-shell composite material dispersion, adding an amine reagent, a pore-forming agent and water thereto, mixing to obtain a first mixed solution, and mixing a zirconium source and an auxiliary pore-forming agent to obtain a second mixed solution;

[0014] (4) mixing the first mixed solution and the second mixed solution and performing a hydrolysis condensation reaction to obtain a core-shell type mesoporous composite material, and extracting and calcining the core-shell type mesoporous composite material to prepare composite particles with a rattle-shaped structure having a cavity;

[0015] (5) dispersing the rattle-shaped composite particles with cavities and a modifier in a solvent for reaction, and centrifuging, washing, and drying after the reaction to obtain modified composite particles;

[0016] (6) The modified composite particles of step (5) are prepared into a modified composite particle dispersion, and then the organic-inorganic hybrid adhesive of step (1) is sprayed on the surface of the substrate for curing, and then the modified composite particle dispersion is sprayed on the surface of the organic-inorganic hybrid adhesive for curing to obtain a substrate carrying the modified composite particles, and finally the substrate carrying the modified composite particles is immersed in a lubricating oil added with a photoinitiator, and irradiated under ultraviolet light to obtain an ultra-smooth surface based on the modified composite particles.

[0017] in:

[0018] In the step (1), the silica sol is one or more of acidic silica sol, alkaline silica sol or neutral silica sol; the silica sol precursor is one or both of methyl orthosilicate or ethyl orthosilicate; the solvent is anhydrous ethanol; and the modifier is one or more of silane coupling agent KH-550, silane coupling agent KH-560, silane coupling agent KH-570 or methyltriethylsilane.

[0019] In the step (1), the polyurethane is one or more of polyester waterborne polyurethane, polyether waterborne polyurethane or polycarbonate waterborne polyurethane; the mass ratio of silica sol or silica sol precursor to deionized water, solvent and modifier is (2-3.5):(0.5-1.5):(3-5):(3-5); the compounding is uniform mixing, the mass ratio of the organic silica sol binder to the polyurethane is (0.01-9):1, and the pulverization is ultrasonic cell pulverization.

[0020] The fluorinated polymer latex particles in the step (2) are prepared by reacting a fluorinated polymer emulsion with a crosslinking agent and an initiator, wherein the fluorinated polymer emulsion is one of polyvinylidene fluoride emulsion, polyvinyl fluoride emulsion, polytetrafluoroethylene emulsion or polyperfluoroethylene propylene emulsion, the crosslinking agent is glycidyl methacrylate, and the initiator is potassium persulfate; the ratio of the fluorinated polymer emulsion, the crosslinking agent and the initiator is (8-12): (6-10): (0.83-0.12), the fluorinated polymer emulsion and the crosslinking agent are both measured in ml, and the initiator is measured in g.

[0021] In the step (2), the mixed solution is a mixed solution of glycidyl methacrylate, hydroxyethyl methacrylate, γ-methacryloxypropyltrimethoxysilane and an initiator, the initiator is potassium persulfate, and the ratio of potassium persulfate, glycidyl methacrylate, hydroxyethyl methacrylate and γ-methacryloxypropyltrimethoxysilane is (0.0231-0.033): (2-5): (1-3): (0.5-2), potassium persulfate is measured in g, glycidyl methacrylate, hydroxyethyl methacrylate and γ-methacryloxypropyltrimethoxysilane are all measured in ml; the volume ratio of the fluorinated polymer emulsion to the mixed solution is 1:1.45-1.7, the reaction time is 9-11.5h, the reaction temperature is 65-75°C, the washing is 3-5 times of ethanol washing, the drying temperature is 55-65°C, and the drying time is 1.5-2.5h.

[0022] In the step (3), the amine reagent is one of ammonia water, triethanolamine or urea, the pore-forming agent is hexadecyltrimethylammonium bromide or hexadecyltrimethylammonium chloride, the zirconium source is one of zirconium oxychloride, zirconium oxynitrate or zirconium acetate, and the auxiliary pore-forming agent is cyclohexane or ether; the mass ratio of the core-shell composite material to ethanol is 1:45-55, the volume ratio of the core-shell composite material dispersion to water is 1:0.33-1.56, and the mass ratio of the core-shell composite material, the amine reagent, the pore-forming agent, the zirconium source and the auxiliary pore-forming agent is (30-70): (0.2-0.5): (3.5-5): (2.5-7): (12-30).

[0023] In the step (4), the temperature of the hydrolysis condensation reaction is 50-100°C, and the time of the hydrolysis condensation reaction is 10-15h; the extraction is performed by mixing the core-shell mesoporous composite material, ammonium nitrate and ethanol and extracting them under reflux conditions at 50-75°C for 10-15h, and the mass ratio of the core-shell mesoporous composite material, ammonium nitrate and ethanol is 1:1-5:70-79; and the calcination is performed at 300-370°C for 2-5h.

[0024] In the step (5), the mass ratio of the composite particles with a hollow rattle-shaped structure, the modifier and the solvent is 1:(5-14):(35-44), the solvent is ethanol; the modifier is γ-glycidylpropylmethyldimethoxysilane or 3-glycidyloxypropylmethyldimethoxysilane; the reaction time is 2-5h, and the reaction temperature is 35-50°C.

[0025] In the step (6), the mass concentration of the modified composite particle dispersion is 1-20%; the substrate is one of glass, carbon steel, stainless steel, copper, magnesium alloy or aluminum alloy; the curing temperature is 50-100°C and the curing time is 1-3h.

[0026] In the step (6), the mass ratio of the photoinitiator to the lubricating oil is 1:(199-999); the lubricating oil is an amino-terminated perfluoropolyether lubricating oil or a mercapto-terminated perfluoropolyether lubricating oil; the photoinitiator is one of benzoin, benzoin ethyl ether or benzoin butyl ether; the irradiation power is 1-10W, and the irradiation time is 30-120min.

[0027] The present invention firstly utilizes an organic silane coupling agent as a bridge to react with the functional groups of inorganic silane and polyurethane at both ends, and finally forms a cross-linked three-dimensional network adhesive by bridging; then a core-shell composite material containing a pore-forming agent is prepared, and then the pore-forming agent is removed by extraction, and the middle layer is removed by calcination to obtain composite particles with a rattle-shaped structure having a cavity, wherein the composite particles with a rattle-shaped structure having a cavity have a fluorine-containing polymer as a core and mesoporous zirconium dioxide as a shell, and then a silane coupling agent with an epoxy group is grafted onto the composite particles with a cavity as a modifier to obtain modified composite particles; the modified composite particles are coated on the surface of the adhesive and then immersed in lubricating oil, and the lubricating oil enters the cavity of the modified composite particles under the capillary action, thereby improving the oil storage capacity thereof, and when irradiated with ultraviolet light, the photoinitiator can promote the reaction between the amino-terminated perfluoropolyether lubricating oil or the thiol-terminated perfluoropolyether lubricating oil and the modified composite particles, thereby improving the stability thereof.

[0028] Since the cavity capacity of the rattle-shaped composite particles with cavities is high, it not only improves the interfacial compatibility and dispersibility, but also promotes the homogeneous transfer and continuous film formation of the internal fluoropolymer during the friction process. In addition, the zirconium oxide layer of the composite particles is a hard layer. During the friction process, it will prevent the destruction of the banded crystal structure of the fluoropolymer and hinder the movement of the fluoropolymer molecular chain, thereby reducing the wear of the fluoropolymer surface. It can also play a role of preferential load bearing, prevent the further generation of subsurface cracks, reduce the size of wear debris, and increase the adhesion of the transfer film. Finally, the friction coefficient of the super-slippery surface is further reduced by grafting lubricating oil, which can effectively reduce the damage to the super-slippery surface. Therefore, the excellent properties of the super-slippery surface based on the modified composite particles, such as the improvement of mechanical strength, the formation of uniform and continuous friction film, the enhancement of transfer film adhesion, the improvement of wear resistance, and the new chemical reaction in the friction process, are not obtained by the addition of a single component or a simple component, but are the synergistic effect of multiple substances combined into a film.

[0029] The beneficial effects of the present invention are as follows:

[0030] When preparing a super-slippery surface based on modified composite particles, the present invention first obtains a super-hydrophobic surface with an organic-inorganic hybrid adhesive as a matrix, composite particles with a hollow rattle-shaped structure having a fluorine-containing polymer as a core and mesoporous zirconium dioxide as a shell as a filler, and then lubricating oil is poured into the super-hydrophobic surface to obtain a super-slippery surface based on the modified composite particles.

[0031] (1) The modified composite particles in the super-slippery surface prepared by the present invention have a fluorine-containing polymer as the core. The fluorine-containing polymer core can stably adsorb the lubricating oil due to the van der Waals force and the same polarity as the lubricating oil. When an object contacts the super-slippery surface and moves relative to it, the lubricating oil can form a continuous lubricating film between the contact surfaces. This lubricating film can reduce the friction between the contact surfaces, allowing them to slide relative to each other more smoothly. The van der Waals force allows the lubricating oil molecules and the fluorine-containing polymer core to be tightly combined. From a microscopic perspective, the lubricating oil molecules are "attracted" and fixed on the surface of the fluorine-containing polymer. This adsorption effect can ensure that the lubricating oil is relatively evenly distributed on the surface and will not fall off easily when subjected to external interference, such as slight vibration and small-amplitude friction. After the lubricating oil is stably adsorbed on the fluorine-containing polymer core, a special lubricating environment is formed on the super-slippery surface. When an object contacts this super-slippery surface, the lubricating oil can quickly diffuse around the contact point, further reducing the friction coefficient. The mesoporous zirconium dioxide shell in the rattle-shaped composite particle with a cavity can vacuum-infuse lubricating oil into it through the capillary action of the mesopores, and a large amount of lubricating oil can be stored in its mesoporous cavity.

[0032] (2) The present invention can effectively prevent the swelling of the substrate by the lubricating oil. The low surface energy polymer shell layer provides a site for the storage and grafting of the lubricating oil. Through the chemical grafting method, the adsorbed and stored lubricating oil is grafted and anchored into the cavity of the mesoporous zirconia shell, which greatly improves the stability of the super-slip surface.

[0033] (3) The organic-inorganic hybrid adhesive prepared by the present invention has excellent performance. The epoxy group at one end of the silane coupling agent reacts with the amino, isocyanate and other active groups of the polyurethane, and more silane segments are introduced into the molecular chain of the polyurethane. The large number of silanol groups at the other end of the silane coupling agent can undergo dehydration condensation reaction with the active hydroxyl groups on the surface of the substrate to form hydrogen bonds and a three-dimensional cross-linked network system of silicon and oxygen. In addition, combined with the good film-forming property of the polyurethane itself, the thermal stability, water resistance, solvent resistance and mechanical properties of the organic-inorganic hybrid adhesive are greatly improved.

[0034] (4) Since the lubricating oil has good liquid repellency and lubricity, the surface obtained after grafting onto the composite particles has good liquid repellency, antifouling ability and drag reduction performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 TEM image of the composite particle with a rattle-like structure having a cavity in Example 1;

[0036] Figure 2 The friction coefficient diagram of the carbon steel substrate, Example 1 and Comparative Examples 1-4;

[0037] Figure 3It is a Tafel corrosion potential curve diagram of carbon steel substrate, comparative example 1, comparative example 2, comparative example 3, comparative example 4 and embodiment 1;

[0038] Figure 4 Bode diagrams of carbon steel substrate, comparative example 1, comparative example 2, comparative example 3, comparative example 4 and embodiment 1. DETAILED DESCRIPTION

[0039] The present invention is further described below with reference to the embodiments.

[0040] Example 1

[0041] (1) 3.5 g of acidic silica sol was diluted in 1.5 g of deionized water, and then added to 5 g of ethanol, and then 5 g of silane coupling agent KH-560 was added to obtain an organic silica sol adhesive. Then, 15 g of the organic silica sol adhesive was evenly mixed with 35 g of polyester-type waterborne polyurethane, and the organic-inorganic hybrid adhesive was obtained after ultrasonic cell pulverization;

[0042] (2) 100 g of deionized water, 10 mL of polytetrafluoroethylene latex and 8 mL of glycidyl methacrylate were stirred and mixed under nitrogen protection at 70°C for 2 h, and 30 mL of 0.0033 g / mL potassium persulfate aqueous solution was added dropwise to the obtained mixed solution, and the mixture was kept warm for 2 h to obtain a mixed system containing polytetrafluoroethylene latex particles; then, the pH value of the obtained system was adjusted to 7 with 0.05 g / mL ammonia water, and 10 mL of 0.0033 g / mL potassium persulfate aqueous solution, 2 mL of γ-methacryloxypropyltrimethoxysilane, 2 mL of hydroxyethyl methacrylate and 1 mL of glycidyl methacrylate were added dropwise to the system, and the mixture was reacted for 5 h after the addition was completed; the obtained product system was centrifuged and washed 3 times with ethanol, and then placed in a vacuum drying oven and dried at 60°C for 2 h to obtain a core-shell composite material;

[0043] (3) The core-shell composite material and ethanol were mixed in a mass ratio of 1:50 and ultrasonically dispersed for 30 minutes to obtain a core-shell composite material dispersion liquid; 0.4 mL of 28 wt% ammonia water, 50 mL of deionized water and 10 g of hexadecyltrimethylammonium bromide were added to 60 mL of the core-shell composite material dispersion liquid, and the mixture was stirred at 50° C. for 30 minutes to obtain a first mixed liquid; 8 mL of zirconium oxychloride was mixed with 60 mL of cyclohexane to obtain a second mixed liquid;

[0044] (4) The first mixed solution and the second mixed solution were mixed and stirred at 50°C for 12 hours for hydrolysis and condensation reaction, and then centrifuged and dried to obtain a core-shell type mesoporous composite material. Subsequently, 1 g of the core-shell type mesoporous composite material, 1 g of ammonium nitrate and 79 g of ethanol were mixed, refluxed at 60°C for 12 hours, and then calcined at 310°C for 5 hours to prepare composite particles with a cavity and a rattle-like structure. The surface morphology of the composite particles with a cavity and a rattle-like structure is as follows: Figure 1 As shown;

[0045] (5) dispersing 1 g of the hollow rattle-shaped composite particles and 5 g of γ-glycidylpropylmethyldimethoxysilane in 44 g of ethanol and stirring at 40° C. for 2 h. After the reaction, washing the particles three times by centrifugation with ethanol and drying the particles to obtain modified composite particles.

[0046] (6) The modified composite particles of step (5) are dispersed in ethanol to prepare a modified composite particle dispersion with a mass concentration of 20%, and then the organic-inorganic hybrid adhesive in step (1) is sprayed on the surface of carbon steel and cured at 60°C for 1 hour. Then, the modified composite particle dispersion with a mass concentration of 20% is sprayed on the surface of the organic-inorganic hybrid adhesive, and cured at 100°C for 2 hours to obtain carbon steel loaded with modified composite particles; the carbon steel loaded with modified composite particles is immersed in amino-terminated perfluoropolyether lubricating oil, and then benzoin with a mass of 0.2% of the mass of the amino-terminated perfluoropolyether lubricating oil is added and irradiated under a 5W ultraviolet lamp for 60 minutes. After washing with ethanol three times and drying, it is placed vertically for 10 minutes to obtain an ultra-slip surface based on the modified composite particles.

[0047] Example 2

[0048] (1) 3 g of alkaline silica sol was diluted in 1 g of deionized water, then added to 4 g of ethanol, and then 5 g of silane coupling agent KH-570 was added to obtain an organic silica sol adhesive. Then 13 g of the organic silica sol adhesive was evenly mixed with 1.44 g of polyether type waterborne polyurethane, and the organic-inorganic hybrid adhesive was obtained after ultrasonic cell pulverization;

[0049] (2) 100 g of deionized water, 10 mL of polyvinylidene fluoride latex and 8 mL of glycidyl methacrylate were stirred and mixed under nitrogen protection at 65°C for 2 h, and 30 mL of 0.0033 g / mL potassium persulfate aqueous solution was added dropwise to the obtained mixed solution, and the mixture was kept warm for 2 h to obtain a mixed system containing polytetrafluoroethylene latex particles; then, the pH value of the obtained system was adjusted to 7 with 0.05 g / mL ammonia water, and a mixed solution of 10 mL of 0.0033 g / mL potassium persulfate aqueous solution, 3 mL of γ-methacryloxypropyltrimethoxysilane, 1 mL of hydroxyethyl methacrylate and 0.5 mL of glycidyl methacrylate was added dropwise to the system; after the addition was completed, the mixture was reacted for 5 h; the obtained product system was centrifuged and washed 5 times with ethanol, and then placed in a vacuum drying oven and dried at 55°C for 2.5 h to obtain a core-shell composite material;

[0050] (3) The core-shell composite material and ethanol were mixed in a mass ratio of 1:55 and ultrasonically dispersed for 30 minutes to obtain a core-shell composite material dispersion liquid; 0.9 g urea, 90 mL deionized water and 7 g hexadecyltrimethylammonium bromide were added to 140 mL of the core-shell composite material dispersion liquid, and the mixture was stirred at 90° C. for 30 minutes to obtain a first mixed liquid; 14 mL of zirconium oxychloride was mixed with 60 mL of cyclohexane to obtain a second mixed liquid;

[0051] (4) The first mixed solution and the second mixed solution were mixed, stirred at 100° C. for 10 hours for hydrolysis and condensation reaction, and centrifuged and dried to obtain a core-shell type mesoporous composite material. Subsequently, 1 g of the core-shell type mesoporous composite material, 1 g of ammonium nitrate and 79 g of ethanol were mixed, refluxed at 50° C. for 15 hours, and then calcined at 320° C. for 4 hours to prepare composite particles with a rattle-shaped structure having a cavity;

[0052] (5) dispersing 1 g of the hollow rattle-shaped composite particles and 14 g of γ-glycidylpropylmethyldimethoxysilane in 35 g of ethanol and stirring at 40° C. for 2 h. After the reaction, washing the particles three times by centrifugation with ethanol and drying the particles to obtain modified composite particles.

[0053] (6) The modified composite particles of step (5) are dispersed in ethanol to prepare a modified composite particle dispersion with a mass concentration of 10%, and then the organic-inorganic hybrid adhesive in step (1) is sprayed on the copper surface and cured at 60°C for 1 hour. Then, the modified composite particle dispersion with a mass concentration of 10% is sprayed on the surface of the organic-inorganic hybrid adhesive, and cured at 100°C for 2 hours to obtain copper loaded with modified composite particles; the copper loaded with modified composite particles is immersed in a mercapto-terminated perfluoropolyether lubricant, and then benzoin ethyl ether with a mass of 0.1% of the mass of the mercapto-terminated perfluoropolyether lubricant is added and irradiated under a 3W ultraviolet lamp for 80 minutes, washed three times with ethanol, dried, and placed vertically for 10 minutes to obtain an ultra-slip surface based on the modified composite particles.

[0054] Example 3

[0055] (1) 2 g of neutral silica sol was diluted in 0.5 g of deionized water, then added to 3 g of ethanol, and then 3 g of silane coupling agent KH-550 was added to obtain an organic silica sol adhesive. Then 8.5 g of the organic silica sol adhesive was mixed with 8.5 g of polycarbonate type waterborne polyurethane, and the organic-inorganic hybrid adhesive was obtained after ultrasonic cell crushing;

[0056] (2) 100 g of deionized water, 8 mL of polyvinyl fluoride latex and 6 mL of glycidyl methacrylate were stirred and mixed under nitrogen protection at 75°C for 2 h, and 25 mL of 0.0033 g / mL potassium persulfate aqueous solution was added dropwise to the obtained mixed solution, and the mixture was kept warm for 2 h to obtain a mixed system containing polytetrafluoroethylene latex particles; then, the pH value of the obtained system was adjusted to 7 with 0.05 g / mL ammonia water, and 7 mL of 0.0033 g / mL potassium persulfate aqueous solution, 5 mL of γ-methacryloxypropyltrimethoxysilane, 3 mL of hydroxyethyl methacrylate and 2 mL of glycidyl methacrylate were added dropwise to the system; after the addition was completed, the mixture was reacted for 5 h; the obtained product system was centrifuged and washed 3 times with ethanol, and then placed in a vacuum drying oven and dried at 65°C for 1.5 h to obtain a core-shell composite material;

[0057] (3) The core-shell composite material and ethanol were mixed in a mass ratio of 1:45 and ultrasonically dispersed for 30 minutes to obtain a core-shell composite material dispersion liquid; 1 g of triethanolamine, 36 mL of deionized water and 4 g of hexadecyltrimethylammonium bromide were added to 110 mL of the core-shell composite material dispersion liquid, and the mixture was stirred at 50° C. for 30 minutes to obtain a first mixed liquid; 5 mL of zirconium oxynitrate was mixed with 23 mL of cyclohexane to obtain a second mixed liquid;

[0058] (4) After mixing the first mixed solution and the second mixed solution, stirring at 55° C. for 15 hours for hydrolysis and condensation reaction, centrifugally drying to obtain a core-shell type mesoporous composite material, then mixing 1 g of the core-shell type mesoporous composite material, 5 g of ammonium nitrate and 70 g of ethanol, refluxed at 70° C. for 10 hours, and then calcined at 300° C. for 5 hours to prepare composite particles with a rattle-shaped structure having a cavity;

[0059] (5) dispersing 1 g of the hollow rattle-shaped composite particles and 11.3 g of 3-glycidyloxypropyltrimethoxysilane in 37.7 g of ethanol and stirring at 35° C. for 5 h. After the reaction, washing by centrifugation with ethanol three times and drying the particles were performed to obtain modified composite particles.

[0060] (6) The modified composite particles of step (5) are dispersed in ethanol to prepare a modified composite particle dispersion with a mass concentration of 20%, and then the organic-inorganic hybrid adhesive of step (1) is sprayed on the surface of the aluminum alloy and cured at 60°C for 1 hour. Then, the modified composite particle dispersion with a mass concentration of 20% is sprayed on the surface of the organic-inorganic hybrid adhesive, and cured at 70°C for 3 hours to obtain an aluminum alloy loaded with modified composite particles; the aluminum alloy loaded with modified composite particles is immersed in a mercapto-terminated perfluoropolyether lubricant, and then benzoin butyl ether with a mass of 0.3% of the mass of the mercapto-terminated perfluoropolyether lubricant is added and irradiated under a 1W ultraviolet lamp for 120 minutes, washed three times with ethanol, dried, and placed vertically for 10 minutes to obtain an ultra-slip surface based on the modified composite particles.

[0061] Example 4

[0062] (1) 2.5 g of methyl orthosilicate was diluted in 1 g of deionized water, then added to 3.5 g of ethanol, and then 4 g of methyltriethylsilane was added to obtain an organic silica sol adhesive, and then 11 g of the organic silica sol adhesive was mixed with 111 g of polyester-type waterborne polyurethane, and then the organic-inorganic hybrid adhesive was obtained after ultrasonic cell pulverization;

[0063] (2) 100 g of deionized water, 12 mL of polyperfluoroethylene propylene latex and 10 mL of glycidyl methacrylate were stirred and mixed under nitrogen protection at 70°C for 2 h, and 35 mL of a 0.0033 g / mL potassium persulfate aqueous solution was added dropwise to the obtained mixed solution, and the mixture was kept warm for 2 h to obtain a mixed system containing polytetrafluoroethylene latex particles; then, the pH value of the obtained system was adjusted to 7 with 0.05 g / mL ammonia water, and 9 mL of a 0.0033 g / mL potassium persulfate aqueous solution, 4 mL of γ-methacryloxypropyltrimethoxysilane, 2 mL of hydroxyethyl methacrylate and 1 mL of glycidyl methacrylate were added dropwise to the system; after the addition was completed, the mixture was reacted for 5 h; the obtained product system was centrifuged and washed 5 times with ethanol, and then placed in a vacuum drying oven and dried at 60°C for 2.5 h to obtain a core-shell composite material;

[0064] (3) The core-shell composite material and ethanol were mixed in a mass ratio of 1:50 and ultrasonically dispersed for 30 minutes to obtain a core-shell composite material dispersion liquid; 0.9 mL of 28 wt% ammonia water, 140 mL of deionized water and 10 g of hexadecyltrimethylammonium chloride were added to 90 mL of the core-shell composite material dispersion liquid, and the mixture was stirred at 70° C. for 30 minutes to obtain a first mixed liquid; 5 mL of zirconium acetate was mixed with 40 mL of cyclohexane to obtain a second mixed liquid;

[0065] (4) The first mixed solution and the second mixed solution were mixed and stirred at 50° C. for 13 h for hydrolysis and condensation reaction, and then centrifuged and dried to obtain a core-shell type mesoporous composite material. Subsequently, 1 g of the core-shell type mesoporous composite material, 3 g of ammonium nitrate and 75 g of ethanol were mixed, refluxed at 60° C. for 15 h, and then calcined at 370° C. for 2 h to prepare composite particles with a rattle-shaped structure having a cavity;

[0066] (5) dispersing 1 g of the hollow rattle-shaped composite particles and 5 g of 3-glycidyloxypropylmethyldimethoxysilane in 44 g of ethanol and stirring at 50° C. for 2 h. After the reaction, washing by centrifugation with ethanol three times and drying the mixture to obtain modified composite particles.

[0067] (6) The modified composite particles of step (5) are dispersed in ethanol to prepare a modified composite particle dispersion with a mass concentration of 1%, and then the organic-inorganic hybrid adhesive of step (1) is sprayed on the glass surface and cured at 50°C for 1 hour. Then, the modified composite particle dispersion with a mass concentration of 1% is sprayed on the surface of the organic-inorganic hybrid adhesive, and cured at 100°C for 1 hour to obtain a glass loaded with modified composite particles; the glass loaded with modified composite particles is immersed in an amino-terminated perfluoropolyether lubricant, and then benzoin with a mass of 0.5% of the mass of the amino-terminated perfluoropolyether lubricant is added and irradiated under a 10W ultraviolet lamp for 30 minutes. After washing with ethanol three times and drying, the glass is placed vertically for 10 minutes to obtain an ultra-slippery surface based on the modified composite particles.

[0068] Comparative Example 1

[0069] Referring to the method of Example 1, the preparation and use of the organic-inorganic hybrid adhesive in steps (1) and (6) are omitted, and the remaining steps are the same as in Example 1.

[0070] Comparative Example 2

[0071] Referring to the method of Example 1, in step (6), only the organic-inorganic hybrid adhesive is sprayed to prepare the ultra-slippery surface without using modified composite particles, and the remaining operations are the same as in Example 1.

[0072] Comparative Example 3

[0073] Referring to the method of Example 1, in step (6), the carbon steel loaded with modified composite particles is not immersed in lubricating oil, and the remaining steps are the same as in Example 1.

[0074] Comparative Example 4

[0075] Referring to the method of Example 1, no calcination is performed after refluxing in step (4), and the remaining steps are the same as in Example 1.

[0076] Test method:

[0077] Friction test: The tribological properties were tested using a pin-on-disc friction tester (MPX-3X, Jinan Hengxu Testing Machine Technology Co., Ltd.).

[0078] Electrochemical test: The open circuit potential (OCP), electrochemical impedance spectroscopy (EIS) and polarization curve (Tafel) of the superslippery surface were tested using an IVIUM electrochemical workstation (Netherlands). The test used a three-electrode system, with the sample as the working electrode, the auxiliary electrode as a platinum electrode, the reference electrode as a saturated calomel electrode, the corrosive medium as a 3.5% mass fraction NaCl solution, and the test environment at (25±2)°C. The measurement frequency during the EIS test was 0.01Hz to 100kHz, and the sine wave amplitude was 10mV. The scan rate of the potentiodynamic polarization curve was set to 10mV / s. To ensure the reliability of the test results, at least three tests were carried out at different sample points under each test condition.

[0079] Contact angle: The static contact angle of the superslippery surface was measured by the JC2000DM contact angle meter (Shanghai Zhongchen Digital Technology Equipment Co., Ltd.). The test liquid was water or organic liquids with different surface tensions such as DMF. The volume of the test liquid was 10 microliters. After the droplet fell on the superslippery surface, the time for reading the contact angle remained consistent. Five points were selected for each sample for contact angle measurement, and the average value was taken and the standard deviation was calculated.

[0080] Sliding angle: The instrument for measuring the sliding angle of the super-slippery surface is the JC2000DM contact angle meter (Shanghai Zhongchen Digital Technology Co., Ltd.). The test liquid is water or organic liquids with different surface tensions such as DMF. The volume of the test liquid is 10 microliters. After the droplet falls on the super-slippery surface, the rotating table changes the sample inclination angle. The angle at which the droplet starts to slide is the sliding angle of the droplet. Five points are selected for each sample to measure the sliding angle, and the average value is taken and the standard deviation is calculated.

[0081] The carbon steel substrate, Example 1 and Comparative Examples 1-4 were subjected to friction tests. The test results are as follows: Figure 2 :

[0082] Depend on Figure 2It can be seen that the friction coefficient of the carbon steel substrate begins to rise rapidly with the increase of time; in Comparative Example 1, the sample initially has an extremely low friction coefficient, but as time goes by, its friction coefficient also increases rapidly, indicating that the stability of the sample is greatly reduced after the lack of organic-inorganic hybrid adhesive, and its surface is easily destroyed quickly; in Comparative Example 2, the friction coefficient of the surface has been maintained at a high level and remains in a stable range over time, indicating that the friction coefficient is high after the modified composite particles are not used; in Comparative Example 3, due to the lack of lubricating oil injection, the modified composite particles are constantly worn, and the friction coefficient of the surface gradually increases; in Comparative Example 4, the surface has just begun to stabilize, and its friction coefficient increases slowly with the increase of time. This is because the modified composite particles lack cavities for storing lubricating oil, which makes the lubricating oil on the surface easy to lose; in Example 1, the super-slip surface has always maintained a low friction coefficient, indicating that the super-slip surface based on the modified composite particles is relatively stable, has good anti-fouling properties, is not easy to change, and has a strong protection for the carbon steel substrate.

[0083] The super-slippery surfaces of Examples 1-4 were tested for liquid repellency, and the test results are shown in Table 1:

[0084]

[0085] It can be seen from Table 1 that in Examples 1-4, the ultra-slippery surface of each sample has an excellent sliding angle, which allows dust and dirt falling thereon to be easily removed, keeping the surface clean and having self-cleaning ability.

[0086] The carbon steel substrate, Example 1 and Comparative Examples 1-4 were subjected to Tafel corrosion tests, and the test data are shown in Table 2:

[0087]

[0088] It can be seen from Table 2 that although the corrosion resistance of each sample is better than that of the carbon steel substrate, it can be seen from the corrosion potential that the corrosion potential from low to high is: Example 1 < Comparative Example 4 < Comparative Example 2 < Comparative Example 3 < Comparative Example 1 < Carbon steel, and the lower the corrosion potential, the better its corrosion resistance; therefore, Example 1 has better corrosion resistance than other samples, and grafting lubricating oil into the modified composite particles and storing the lubricating oil in a high-capacity cavity can form an extremely stable oil film, which prevents the corrosive medium from invading the metal substrate and thus improves the corrosion resistance efficiency.

[0089] Tafel corrosion potential curve Figure 3 As shown, from Figure 3 It can be clearly seen that the lowest points of corrosion potential of carbon steel, Comparative Example 1, Comparative Example 3, Comparative Example 2, Comparative Example 4 and Example 1 are shifted to the right in turn, which shows that spraying a super-slippery surface on a metal substrate can provide corrosion protection for the metal, and the lubricating oil on the super-slippery surface can greatly enhance the shielding effect.

[0090] The carbon steel substrate, Example 1 and Comparative Examples 1-4 were subjected to electrochemical impedance spectroscopy corrosion tests, and the test data are shown in Table 3:

[0091]

[0092] R s , R c , R ct , C c and C cpe They represent the solution resistance, super-smooth surface resistance, charge transfer resistance, super-smooth surface capacitance and the constant phase angle element of the super-smooth surface respectively;

[0093] Among them, R ct The larger the R is, the more difficult it is for the corrosive medium (oxygen, chloride ions, water) to penetrate into the metal. ct It is much larger than the R ct , indicating that the lubricating oil added in Example 1 has good corrosion resistance.

[0094] The carbon steel substrate, comparative example 1, comparative example 2, comparative example 3, comparative example 4 and the super-slip surface of embodiment 1 were subjected to EIS test. The test results are as follows: Figure 4 As shown, Figure 4 It is a Bode plot.

[0095] For Bode diagrams, low-frequency impedance modulus (|Z|0.01Hz) is generally used to measure the corrosion resistance of super-slip surfaces. Generally speaking, the larger the impedance value at the lowest frequency, the better the corrosion resistance. Figure 4 It can be seen that the logarithms of the absolute values ​​of impedance of Example 1, Comparative Example 4, Comparative Example 2, Comparative Example 3, Comparative Example 1 and the carbon steel substrate are 2.04×10 7 Ω·cm 2 , 6.98×10 6 Ω·cm 2 , 1.01×10 6 Ω·cm 2 , 1.47×10 4 Ω·cm 2 , 1.36×10 3 Ω·cm 2 , 5.88×10 2 Ω·cm 2 The impedance from large to small is respectively Example 1>Comparative Example 4>Comparative Example 2>Comparative Example 3>Comparative Example 1>Carbon steel, which shows that the ultra-slip surface based on the modified composite particles itself has a certain corrosion resistance, and its anti-corrosion performance is greatly improved after grafting lubricating oil.

[0096] In summary, the ultra-slippery surface based on modified composite particles prepared in the present invention has excellent anti-friction, anti-corrosion and anti-fouling self-cleaning properties, and can be used for material surfaces with more stringent requirements on physical properties and chemical stability.

Claims

1. A method for preparing a super-slippery surface based on modified composite particles, characterized in that: The steps include: (1) diluting silica sol or silica sol precursor in deionized water, then adding it to a solvent, and then adding a modifier to obtain an organic silica sol adhesive, and then compounding the organic silica sol adhesive with polyurethane, and crushing it to obtain an organic-inorganic hybrid adhesive; (2) reacting the fluorinated polymer latex particles with the mixed solution, washing and drying to obtain a core-shell composite material; The mixed solution is a mixed solution of glycidyl methacrylate, hydroxyethyl methacrylate, γ-methacryloxypropyltrimethoxysilane and an initiator; (3) dispersing the core-shell composite material in ethanol to obtain a core-shell composite material dispersion, adding an amine reagent, a pore-forming agent and water thereto, mixing to obtain a first mixed solution, and mixing a zirconium source and an auxiliary pore-forming agent to obtain a second mixed solution; (4) mixing the first mixed solution and the second mixed solution and performing a hydrolysis condensation reaction to obtain a core-shell type mesoporous composite material, and extracting and calcining the core-shell type mesoporous composite material to prepare composite particles with a rattle-shaped structure having a cavity; (5) dispersing the rattle-shaped composite particles with cavities and a modifier in a solvent for reaction, and centrifuging, washing, and drying after the reaction to obtain modified composite particles; The modifier is γ-glycidylpropylmethyldimethoxysilane or 3-glycidyloxypropylmethyldimethoxysilane; (6) The modified composite particles of step (5) are prepared into a modified composite particle dispersion, and then the organic-inorganic hybrid adhesive of step (1) is sprayed on the surface of the substrate for curing, and then the modified composite particle dispersion is sprayed on the surface of the organic-inorganic hybrid adhesive for curing to obtain a substrate carrying the modified composite particles, and finally the substrate carrying the modified composite particles is immersed in a lubricating oil added with a photoinitiator, and irradiated under ultraviolet light to obtain an ultra-smooth surface based on the modified composite particles.

2. The method for preparing an ultra-slippery surface based on modified composite particles according to claim 1, characterized in that: In step (1), the silica sol is one or more of acidic silica sol, alkaline silica sol or neutral silica sol; the silica sol precursor is one or both of methyl orthosilicate or ethyl orthosilicate, the solvent is anhydrous ethanol, and the modifier is one or more of silane coupling agent KH-550, silane coupling agent KH-560, silane coupling agent KH-570 or methyl triethyl silane.

3. The method for preparing an ultra-slippery surface based on modified composite particles according to claim 1, characterized in that: In step (1), the polyurethane is one or more of polyester waterborne polyurethane, polyether waterborne polyurethane or polycarbonate waterborne polyurethane; the mass ratio of silica sol or silica sol precursor to deionized water, solvent and modifier is (2-3.5):(0.5-1.5):(3-5):(3-5); the compounding is uniformly mixed, the mass ratio of the organic silica sol binder to the polyurethane is (0.01-9):1, and the pulverization is ultrasonic cell pulverization.

4. The method for preparing an ultra-slippery surface based on modified composite particles according to claim 1, characterized in that: The fluorinated polymer latex particles in step (2) are prepared by adding a crosslinking agent and an initiator to a fluorinated polymer emulsion for reaction. The fluorinated polymer emulsion is one of polyvinylidene fluoride emulsion, polytetrafluoroethylene emulsion or polyperfluoroethylene propylene emulsion. The crosslinking agent is glycidyl methacrylate and the initiator is potassium persulfate. The ratio of the fluorinated polymer emulsion, the crosslinking agent and the initiator is (8-12): (6-10): (0.83-0.12). The fluorinated polymer emulsion and the crosslinking agent are both measured in ml, and the initiator is measured in g.

5. The method for preparing an ultra-slippery surface based on modified composite particles according to claim 4, characterized in that: In step (2), the initiator is potassium persulfate, and the ratio of potassium persulfate, glycidyl methacrylate, hydroxyethyl methacrylate and γ-methacryloxypropyltrimethoxysilane is (0.0231-0.033): (2-5): (1-3): (0.5-2), potassium persulfate is measured in g, glycidyl methacrylate, hydroxyethyl methacrylate and γ-methacryloxypropyltrimethoxysilane are all measured in ml; the volume ratio of the fluorinated polymer emulsion to the mixed solution is 1:1.45-1.7, the reaction time is 9-11.5h, the reaction temperature is 65-75°C, the washing is 3-5 times of ethanol washing, the drying temperature is 55-65°C, and the drying time is 1.5-2.5h.

6. The method for preparing an ultra-slippery surface based on modified composite particles according to claim 1, characterized in that: In step (3), the amine reagent is one of ammonia water, triethanolamine or urea, the pore-forming agent is hexadecyltrimethylammonium bromide or hexadecyltrimethylammonium chloride, the zirconium source is one of zirconium oxychloride, zirconium oxynitrate or zirconium acetate, and the auxiliary pore-forming agent is cyclohexane or ether; the mass ratio of the core-shell composite material to ethanol is 1:45-55, the volume ratio of the core-shell composite material dispersion to water is 1:0.33-1.56, and the mass ratio of the core-shell composite material, the amine reagent, the pore-forming agent, the zirconium source and the auxiliary pore-forming agent is (30-70): (0.2-0.5): (3.5-5): (2.5-7): (12-30).

7. The method for preparing an ultra-slippery surface based on modified composite particles according to claim 1, characterized in that: In step (4), the temperature of the hydrolysis condensation reaction is 50-100° C., and the time of the hydrolysis condensation reaction is 10-15 hours. The extraction is performed by mixing the core-shell mesoporous composite material, ammonium nitrate and ethanol and extracting them under reflux conditions at 50-75° C. for 10-15 hours, and the mass ratio of the core-shell mesoporous composite material, ammonium nitrate and ethanol is 1:1-5:70-79. The calcination is performed at 300-370° C. for 2-5 hours.

8. The method for preparing an ultra-slippery surface based on modified composite particles according to claim 1, characterized in that: In step (5), the mass ratio of the rattle-shaped composite particles with a cavity, the modifier and the solvent is 1:(5-14):(35-44), the solvent is ethanol; the reaction time is 2-5h, and the reaction temperature is 35-50°C.

9. The method for preparing an ultra-slippery surface based on modified composite particles according to claim 1, characterized in that: In step (6), the mass concentration of the modified composite particle dispersion is 1-20%; the substrate is one of glass, carbon steel, stainless steel, copper, magnesium alloy or aluminum alloy; the curing temperature is 50-100° C., and the curing time is 1-3 hours.

10. The method for preparing an ultra-slippery surface based on modified composite particles according to claim 1, characterized in that: In step (6), the mass ratio of the photoinitiator to the lubricant is 1:(199-999); the lubricant is an amino-terminated perfluoropolyether lubricant or a thiol-terminated perfluoropolyether lubricant; the photoinitiator is one of benzoin, benzoin ethyl ether or benzoin butyl ether; the irradiation power is 1-10 W, and the irradiation time is 30-120 min.

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