A method for preparing a long-lasting interfacial lubricating coating

Abstract

The application discloses a preparation method of a long-acting interface lubricating coating, which comprises the following steps: (1) adding 5-7 mass parts of nano sol, 4-6 mass parts of micrometer porous powder, 1.0-1.2 mass parts of low surface energy substance and 4-6 mass parts of ammonia water into 80-120 mass parts of ethanol, stirring under water bath heating condition, obtaining modified micrometer particle suspension, drying the suspension into powder at high temperature, and obtaining modified porous powder; (2) fully mixing 0.8-1.2 mass parts of the modified porous powder with 3-5 mass parts of silicone oil, putting into a vacuum pump to vacuumize, enabling the silicone oil to enter the modified porous powder, separating the excess silicone oil after the vacuum state is removed, and obtaining the porous powder containing silicone oil; (3) carrying out hole sealing treatment on the porous powder containing silicone oil, mixing the porous powder with silicone oil after high-temperature drying, and obtaining a mixed solution of the hole sealing powder and the silicone oil; (4) adding 2.5-4 mass parts of resin into 2-5 mass parts of diluent, then adding 0.5-0.6 mass parts of silane coupling agent, then adding 0.5-0.8 mass parts of the mixed solution of step (3), finally adding 0.75-1.2 mass parts of curing agent, uniformly mixing, brushing or spraying onto a substrate, and air-drying to obtain the interface lubricating coating.

Description

TECHNICAL FIELD

[0001] The application relates to a preparation method of a long-acting interfacial lubricating coating. BACKGROUND

[0002] In nature, a biological organism such as a pitcher plant or a poison dart frog can secrete a lubricating substance on the surface of the skin for hunting prey. Inspired by this, people have developed a porous material filled with lubricant, which plays a lubricating role by injecting lubricating oil into the surface microstructure to achieve easy cleaning and anti-icing effects. The lubricant added in the currently reported interfacial lubricating coating is generally silicone oil, because silicone oil has good chemical stability and good lubricity.

[0003] However, the interfacial lubricating coating based on silicone oil has the problems of poor wear resistance, low anti-icing and anti-bioadhesion effects due to the insufficient compactness and long-acting lubricity of the structure (low oil storage capacity of the carrier and fast release). SUMMARY

[0004] The application aims to provide a preparation method of a long-acting interfacial lubricating coating.

[0005] The preparation method of the long-acting interfacial lubricating coating comprises the following steps:

[0006] (1) 5-7 parts by mass of nanosol, 4-6 parts by mass of microporous powder, 1.0-1.2 parts by mass of a low-surface-energy substance and 4-6 parts by mass of ammonia water are added into 80-120 parts by mass of ethanol, and stirring is conducted under water bath heating to obtain a modified microparticle suspension, the suspension is dried into powder at high temperature to obtain modified microporous powder;

[0007] (2) 0.8-1.2 parts by mass of the modified microporous powder is fully mixed with 3-5 parts by mass of silicone oil, and the mixture is placed in a vacuum pump to be vacuumized, so that the silicone oil can enter the modified microporous powder; after the vacuum state is removed, the mixture is left to stand, and the upper layer of silicone oil is absorbed by using a rubber head dropper after the silicone oil and the powder are completely layered, to obtain microporous powder containing silicone oil;

[0008] (3) The microporous powder containing silicone oil is subjected to a pore sealing treatment, and the microporous powder is mixed with silicone oil after high-temperature drying, to obtain a mixed solution of the sealed microporous powder and the silicone oil;

[0009] (4) in 2-5 parts by mass of diluent, first add 2.5-4 parts by mass of resin, then add 0.5-0.6 parts by mass of silane coupling agent, then add 0.5-0.8 parts by mass of the mixed solution of step (3), finally add 0.75-1.2 parts by mass of curing agent, mix uniformly, then brush or spray on the substrate, dry to obtain the interface lubricating coating.

[0010] In step (1), the nanosol is a nanosilica sol or a nanotitania sol; the particle size of the nanosol is 5-40 nm; the solid content of the nanosol is 10wt.%-35wt.% and the pH value is 9-12.

[0011] In step (1), the microporous powder is one of ceramic, diatomite or glass porous microspheres with a particle size of 10-50 μm.

[0012] In step (1), the low surface energy substance is perfluorodecyltriethoxysilane or perfluorooctyltriethoxysilane.

[0013] In step (1), the water bath heating temperature is not lower than 50℃.

[0014] In step (1), the suspension is dried into powder in an oven at 90-100℃ for 32-36 h, then ground and sieved with a 200 mesh sieve.

[0015] In step (2), the reaction is carried out under vacuum for not less than 24 h.

[0016] The hole sealing of the present application is carried out as follows: a cationic polymer (at least one of chitosan, polyethyleneimine, polystyrene or polyacrylamine) solution is mixed with the porous powder containing silicon oil at a mass ratio of 1:2, and the cationic polymer is coated on the surface of the porous powder by electrostatic action under the condition of mechanical stirring at 300 r / 30 min, and then the excess cationic polymer is removed by centrifugation at 8000 r / 3 min and cleaning with ethanol or water; the porous powder surface is positively charged after being coated with the cationic polymer; then an anionic polymer (at least one of sodium polystyrene sulfonate, polyacrylic acid or polyacrylonitrile) solution is mixed with the porous powder at a volume ratio of 1:2 (as above), and the anionic polymer is coated on the surface of the porous powder by electrostatic action under the condition of mechanical stirring at 300 r / 30 min, and then the excess anionic polymer is removed by centrifugation at 8000 r / 3 min and cleaning with ethanol or water; a composite film layer of cationic polymer-anionic polymer is obtained on the surface of the porous powder, and the hole sealing treatment of the porous powder is completed, the composite film layer is in a loose network structure, which can release the silicon oil and slow down the release speed of the silicon oil.

[0017] In step (3), the mixing mass ratio of the pore sealing powder and the silicone oil is 1:1-1.5, and a mixed solution is obtained.

[0018] In step (4), the resin is one of fluorocarbon resin, acrylic resin, polyurethane resin or urea-formaldehyde resin.

[0019] In step (4), the silane coupling agent is one of KH550, KH560 or KH570.

[0020] The present application first hydrophobically modifies the microporous particles with low surface energy molecules and retains part of the hydroxyl groups, then loads nanoparticles in the porous structure, subsequently injects silicone oil into the pores, and finally constructs a three-dimensional dense interfacial lubricating organic-inorganic hybrid coating on the surface of the substrate with an epoxy adhesive layer by spraying or brushing process, which has good anti-icing performance and long-term wear resistance.

[0021] Compared with the prior art, the present application has the following remarkable effects: the interfacial lubricating coating prepared by the method has a dense structure (ensuring the structural strength) and good lubricating performance (small friction resistance and small friction coefficient), the improvement of the lubricating performance is because the load of the carrier on the silicone oil is greatly increased while it is slowly released, thus on the basis of high strength and good lubricating performance, the coating has good long-term wear resistance (after 500 cycles of linear friction under a load of 500g with a dust-free cloth, the mass loss is only 0.4%, and the sliding angle does not change too much), anti-icing (the ice adhesion force is reduced by more than 50% compared with the untreated glass slide surface) and anti-bioattachment performance (compared with the continuous growth of chlorella on the original glass slide, there is almost no growth of chlorella on the interfacial lubricating coating); the long-term interfacial lubricating coating of the present application can be applied to high-pressure towers, high-voltage cables, building glass curtain walls, wind power generation wheels, solar power generation panels and airplanes. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 SEM image of the modified diatomite;

[0023] Figure 2 FTIR spectrum of the modified diatomite before and after modification;

[0024] Figure 3 Thermogravimetric analysis curve of the oil-containing porous powder in Example 1;

[0025] Figure 4 Wetting angle (a) of the modified diatomite and contact angle (b) of the interfacial lubricating coating in Example 1;

[0026] Figure 5Self-cleaning effect of different contaminants on the interfacial lubricating coating of Example 1: (a) cement (b) chocolate sauce (c) artificial feces;

[0027] Figure 6 Variation of the contact angle and sliding angle of the interfacial lubricating coating of Example 1 with the number of days of immersion (left) and a picture of the coating after two weeks of immersion with silicone oil floating on the water surface (right);

[0028] Figure 7 Morphology of the surface of the interfacial lubricating coating of Example 1 before and after the tape was pressed: (a) before the tape was pressed, (b) after the tape was pressed;

[0029] Figure 8 Adhesion of ice on the original glass slide and on the glass slide containing the interfacial lubricating coating of Example 1;

[0030] Figure 9 Variation of the performance of the interfacial lubricating coating of Example 1 with temperature; the left picture is the mass loss of the interfacial lubricating coating of Example 1 in the oven at 100°C over time, and the right picture is the variation of the contact angle and sliding angle of the coating of Example 1 with heating time;

[0031] Figure 10 Variation of the performance of the interfacial lubricating coating of Example 1 with friction; the left picture is the mass loss of the interfacial lubricating coating of Example 1 over the number of times of friction, and the right picture is the variation of the contact angle and sliding angle of the coating of Example 1 over the number of times of friction;

[0032] Figure 11 Electrochemical impedance spectroscopy (EIS) test of the interfacial lubricating coating of Example 1, the upper picture is the Bode plot, and the lower picture is the Nyquist plot;

[0033] Figure 12 Surface morphology of the interfacial lubricating coating of Example 1 before and after the salt spray corrosion resistance test;

[0034] Figure 13 Comparison of the performance of the pure resin coating and the interfacial lubricating coating of Example 1 in resisting the adhesion and growth of chlorella; from top to bottom are the surface photos of chlorella after 7 days of immersion and culture, the photos of chlorella after 7 days of immersion and culture and removal of the chlorella not attached to the surface of the coating with sterile artificial seawater (ASW), and the fluorescence pictures obtained by capturing the adhesion of the microalgae on the coating with a fluorescence microscope;

[0035] Figure 14 SEM morphology of the surface of the interfacial lubricating coating of Example 1 before (a) and after (b) the Tabour abrasion tester wear test under a load of 500g;

[0036] Figure 15 Thermogravimetric analysis curve of the oil-containing porous powder of Example 2;

[0037] Figure 16 Morphology of the surface of the interface lubricating coating of Example 2 after the tape was pressed and the grid was drawn;

[0038] Figure 17 Adhesion of ice on the original glass and on the glass containing the interface lubricating coating of Example 2;

[0039] Figure 18 Changes in the performance of the interface lubricating coating of Example 2 with temperature; where the left picture is the change in the mass loss of the interface lubricating coating of Example 2 in a 100°C oven over time, and the right picture is the change in the contact angle and sliding angle of the coating of Example 2 over heating time;

[0040] Figure 19 Changes in the performance of the interface lubricating coating of Example 2 with friction; where the left picture is the change in the mass loss of the interface lubricating coating of Example 2 over the number of times of friction, and the right picture is the change in the contact angle and sliding angle of the coating of Example 2 over the number of times of friction;

[0041] Figure 20 Morphology of the surface of the interface lubricating coating of Example 3 after the tape was pressed and the grid was drawn;

[0042] Figure 21 Adhesion of ice on the original glass and on the glass containing the interface lubricating coating of Example 3;

[0043] Figure 22 Changes in the performance of the interface lubricating coating of Example 3 with temperature; where the left picture is the change in the mass loss of the interface lubricating coating of Example 3 in a 100°C oven over time, and the right picture is the change in the contact angle and sliding angle of the coating of Example 3 over heating time;

[0044] Figure 23 Changes in the performance of the interface lubricating coating of Example 3 with friction; where the left picture is the change in the mass loss of the interface lubricating coating of Example 3 over the number of times of friction, and the right picture is the change in the contact angle and sliding angle of the coating of Example 3 over the number of times of friction;

[0045] Figure 24 Pictures of the coatings formed after the particles of Comparative Example 1 and Example 1 were mixed with the resin; where the upper picture is the standing state of the solution after the particles of Comparative Example 1 were mixed with the resin without the silane coupling agent, and the surface picture of the coating prepared; and the lower picture is the standing state of the solution after the particles of Example 1 were mixed with the resin after the silane coupling agent was added, and the surface picture of the coating prepared. DETAILED DESCRIPTION

[0046] Example 1

[0047] The preparation method of the long-acting interface lubricating coating of the application comprises the following steps:

[0048] (1) Under the conditions of 50℃ water bath heating and magnetic stirring, 5 parts by mass of silica sol, 0.5 parts by mass of perfluorodecyl triethoxysilane and 4 parts by mass of ammonia water are added into 80 parts by mass of ethanol, and after stirring for 3 hours, 4 parts by mass of diatomite and 0.5 parts by mass of perfluorodecyl triethoxysilane are further added into the solution, and stirring is performed for 3 hours to obtain a modified micron particle suspension; the suspension is dried into powder in an oven at 90℃ for 36 hours, and after grinding, the powder is passed through a 200-mesh sieve to obtain modified porous powder;

[0049] (2) 0.8 parts by mass of the modified porous powder of step (1) is mixed with 3 parts by mass of silicone oil, and then is placed in a vacuum pump for vacuumizing, so that the silicone oil can enter the porous powder; after 24 hours under vacuum, the silicone oil and the powder are completely layered, and then the upper layer of silicone oil is absorbed by using a rubber head dropper to obtain the porous powder containing silicone oil;

[0050] (3) The porous powder containing silicone oil is subjected to a pore sealing treatment, and after drying in an oven at 100℃, the porous powder is mixed with silicone oil at a mass ratio of 1:1 to obtain a mixed solution of the sealed powder and silicone oil;

[0051] (4) In 2 parts by mass of butyl acetate, 2.5 parts by mass of resin is first added, followed by adding 0.5 parts by mass of silane coupling agent, then adding 0.5 parts by mass of the mixed solution of step (3), and finally adding 0.75 parts by mass of isocyanate curing agent; after mixing, the mixture is brushed or sprayed onto a substrate, and after air drying at room temperature for 24 hours, an interface lubricating coating is obtained.

[0052] Figure 1 The SEM image of the diatomite after modification in step (1) shows that there are many particle structures aggregated together in the pores of the diatomite, and these aggregates are the modified SiO2 particles. This morphology shows that the diatomite successfully loads the hydrophobic SiO2 particles, and the pore structure of the diatomite is filled with the hydrophobic SiO2 particles. Such a structure can ensure that the silicone oil is not easily released after being injected into the pores of the diatomite particles, thereby ensuring the long-acting property of the coating.

[0053] Figure 2 The FTIR spectra of the diatomite before and after modification in step (1) show that the transmittance of the -OH group near 3400 cm -1 of the diatomite after modification is weakened but still exists, and the C-F peak appears near 300 cm -1 of the diatomite after modification, indicating the success of the modification. Moreover, the existence of the -OH group enables the modified diatomite particles to participate in the subsequent curing process of the resin, complete the bonding with the resin, solve the compatibility problem between the resin and the powder particles, and thereby enhance the strength and wear resistance of the coating.

[0054] Figure 3 The thermal gravimetric analysis curve of the oil-containing porous powder in step (2) shows that the heat loss of the particles before and after heating is 57%, which is basically the loss of silicone oil, i.e. the oil absorption rate of the particles is about 57%, and the particles have good performance of loading silicone oil due to the natural porous structure of diatomite and the rough structure of hydrophobic SiO2, thereby ensuring that the prepared coating has good long-acting lubricating effect.

[0055] Figure 4 (a) The wetting angle of the modified diatomite, it can be seen that the hydrophobic performance of the modified diatomite is very excellent, the contact angle is greater than 150°, the sliding angle is less than 1°, and the super-hydrophobic performance is achieved, and the water droplets are adsorbed on the needle tube, showing very low adhesion between the water droplets and the surface. Figure 4 (b) The wetting angle of the interface lubricating coating of Example 1, it can be seen that the contact angle of the coating is 107.4°, and the water droplets on the surface are in a hemispherical shape, which is caused by the dimethyl silicone oil covering the surface of the coating, but the sliding angle is as low as 17.3°, showing good lubricating performance.

[0056] Figure 5 The self-cleaning effect of different pollutants on the coating: (a) cement (b) chocolate sauce (c) artificial feces, it can be seen that no matter for low-viscosity or high-viscosity substances, or for substances dissolved in water or other substances such as oil, the coating of this example can have very good self-cleaning effect, and its cleaning function is not limited to aqueous solution.

[0057] Figure 6 The change of the contact angle and sliding angle of the interface lubricating coating with the immersion time (left) and the actual picture of the silicone oil floating on the water surface after the coating is immersed for two weeks (right). It can be seen from the figure that the contact angle and sliding angle of the coating do not change significantly within 11 days, showing that the coating has a certain long-acting performance in water. In addition, from the right figure, it can be seen that a layer of light silicone oil can be observed on the surface of the water, indicating that the silicone oil in the coating is continuously released to continuously maintain the self-cleaning performance of the surface.

[0058] The grid method is used for qualitative testing of the coating, and the specific operation method is to draw a grid on the surface of the coating with a grid tool as shown in Figure 7 , the grid is a square with a size of 1 mm x 1 mm, then the grid is adhered to the upper part of the grid with adhesive tape, and a weight of 1 kg is rolled on the adhesive tape to apply pressure, and after pressing for 1 min, the adhesive tape is torn off from the grid on the surface of the coating, and the grid is observed to determine the adhesion grade of the coating according to the test standard of the cross-cut adhesive tape adhesion test. Figure 7(a) The morphology of the interface lubricating coating surface before and after the tape pressing: (a) before the tape pressing, (b) after the tape pressing, it can be seen that the grid does not have any shedding, according to the test standard, the adhesion level of the coating is qualitatively judged as 0 level, the coating of example 1 has better substrate adhesion.

[0059] The ice adhesion of the coating of example 1 is compared, Figure 8 The ice adhesion of the coating of example 1 is compared,

[0060] Figure 9 The left graph is the change of the mass loss of the interface lubricating coating in the 100℃ oven with time, it can be seen that the coating has good heat resistance, the mass loss of the coating is only 1.7% after heating in the 100℃ oven for nine days; the right graph is the change of the contact angle and sliding angle of the coating with heating time, it can be seen that the change range of the contact angle and sliding angle of the coating is small within a week, and the coating can have a relatively stable lubrication effect.

[0061] Figure 10 The left graph is the change of the mass loss of the interface lubricating coating with the number of rubbings, it can be seen that the coating has good wear resistance, the mass loss of the coating is only 0.4% after rubbing with a dust-free cloth under a load of 500g for 500 times, the right graph is the change of the contact angle and sliding angle of the coating with the number of rubbings, it can be seen that the change range of the contact angle and sliding angle of the coating is small after 400 rubbings, and the coating can still maintain stable lubrication effect.

[0062] Figure 11 The left graph is the impedance analysis graph of the interface lubricating coating, the electrochemical workstation Reference 600 produced by the United States Gamary Company is used to test the electrochemical impedance spectrum (EIS) of the Q345B substrate, the pure resin sample and the SLIPS sample at room temperature, a three-electrode system is used, the saturated calomel electrode is used as the reference electrode (SCE), the test sample is used as the working electrode, and the platinum electrode is used as the auxiliary electrode. The simulated seawater (3.5% NaCl aqueous solution) is used as the corrosion medium for electrochemical test. The electrochemical impedance spectrum uses a sine wave as the excitation signal, the amplitude (loading alternating disturbance voltage) is 10mV, and the scanning frequency range is 100kHz-10mHz. The samples are soaked in 3.5% NaCl aqueous solution for 1 hour before test. Large impedance indicates that the corrosion resistance of the coating of example 1 is good.

[0063] Figure 12The surface morphology of the interface lubricating coating before and after salt spray corrosion test. The prepared sample was tested by neutral salt spray test using a salt spray chamber according to GB / T10125-2021 "Artificial weathering of plastics- Salt spray tests", using a 5wt.% NaCl solution with a pH value of 6.5-7.2, the test environment temperature was set to 35℃±2, the saturated barrel temperature was set to 47℃, the sample coating was upward and at an angle of 20° with the vertical line, the salt spray collection device with a size of 80cm2 was controlled at a salt spray deposition amount of 1mL / h~3mL / h. Before the test, the sample needs to be treated with paraffin sealing, and the changes of the coating during the salt spray test are observed regularly, including the blistering, rusting, peeling and corrosion development around the scratch of the coating. The sample size is 150mm×75mm, and the thickness is (1±0.2)mm. Before the experiment, the state adjustment is at least 16h under the condition of (23±2)℃ and relative humidity (50±5)%, with air circulation and no direct exposure to sunlight, and then the test is carried out as soon as possible. From the results, the coating surface did not show obvious corrosion phenomenon after 1500h of neutral salt spray corrosion test, showing excellent corrosion resistance. Because the oil-containing porous powder of example 1 has high oil content and can release slowly, the obtained coating has good corrosion resistance.

[0064] Figure 13 The anti-chlorella adhesion performance of pure resin coating (left three pictures) and interface lubricating coating (right three pictures) was compared. Sterile marine microalgae medium was added to sterile artificial seawater (ASW), and the obtained medium was used to incubate chlorella. Different coatings with the same area were respectively immersed in culture dishes containing 30mL of chlorella (5×106cell / mL), and were grown in a 23℃ light incubator with a 12h light and 12h dark cycle for 7d (upper picture). Then the unattached chlorella on the surface of the coating was removed with sterile ASW (middle picture), and the microalgae adhesion was captured by fluorescence microscopy (lower picture). The obtained fluorescence pictures were calculated for coverage using Image J software. The results showed that the chlorella coverage rate on the surface of the pure resin was 18.3% after 6d of culture, and the chlorella coverage rate on the surface of the SLIPS coating was 0.12%, which was significantly less than that of the pure resin, showing excellent anti-chlorella adhesion performance.

[0065] The coating of example 1 was subjected to Tabour wear test under a load of 500g, and the surface of the coating before and after wear was characterized by SEM, and the comparison results are shown in Figure 14 The coating of example 1 greatly reduced the resistance generated during the rolling friction process due to the presence of the lubricating layer, so the surface morphology of the coating before and after wear did not change much, and the coating of example 1 had excellent mechanical wear resistance.

[0066] Example 2

[0067] The preparation method of the long-acting interface lubricating coating of the application comprises the following steps:

[0068] (1) Under the conditions of 50℃ water bath heating and magnetic stirring, 5 parts by mass of silica sol, 0.5 parts by mass of perfluorodecyl triethoxysilane and 4 parts by mass of ammonia water are added into 80 parts by mass of ethanol, after stirring for 3h, 4 parts by mass of diatomite and 0.5 parts by mass of perfluorodecyl triethoxysilane are further added into the solution, and stirring for 3h, a modified micron particle suspension is obtained; the suspension is dried into powder in an oven at 90℃ for 36h, and after grinding, the modified porous powder is obtained by passing through a 200-mesh sieve;

[0069] (2) 0.8 parts by mass of the modified porous powder of step (1) is mixed with 3 parts by mass of silicone oil, and then is placed in a vacuum pump for vacuumizing, so that the silicone oil can enter the porous powder, after 24h under vacuum, the silicone oil and the porous powder are completely layered, and then the upper layer of silicone oil is absorbed by using a rubber head dropper, and the porous powder containing silicone oil is obtained;

[0070] (3) The porous powder containing silicone oil is subjected to sealing treatment, and after drying in an oven at 100℃, the sealing treatment powder is mixed with silicone oil at a mass ratio of 1:1, and a mixed solution of sealing treatment powder and silicone oil is obtained;

[0071] (4) In 2 parts by mass of butyl acetate, 2.5 parts by mass of resin is first added, then 0.5 parts by mass of silane coupling agent is added, followed by adding 0.5 parts by mass of the mixed solution of step (3), and finally 0.75 parts by mass of isocyanate curing agent is added, and after mixing, the interface lubricating coating is obtained by brushing or spraying on the substrate and air drying for 24h at room temperature.

[0072] The porous particle containing oil of example 2 is subjected to thermogravimetric analysis, and the results are shown in Figure 15 It can be seen that the heat loss of the particle before and after heating is 60%, which is basically the loss amount of silicone oil, that is, the oil absorption rate of the particle is about 60%, which indicates that the application can greatly improve the loading capacity of the carrier to the silicone oil, so as to ensure that the prepared coating has good long-acting lubricating effect.

[0073] The coating of example 2 is subjected to qualitative test by using grid method, and the specific operation method is that a grid as shown in Figure 7 is drawn on the surface of the coating by using a grid tool, the grid is a square with a size of 1mm×1mm, then the grid is adhered above by using adhesive tape, a weight of 1kg is rolled on the adhesive tape to apply pressure, after pressing for 1min, the adhesive tape is torn off from the surface of the coating with the grid, and the falling-off condition of the grid is observed, and the adhesive force grade of the coating is determined according to the test standard of cross-cut adhesive force test. The results are shown in Figure 16 The adhesive force grade of the coating of example 2 is still 0 grade, and the coating of example 2 has good substrate adhesion.

[0074] The ice adhesion force of the coating of Example 2 was compared, and the data results are shown in Figure 17 The ice adhesion force of the original untreated glass was as high as 61.3 kPa, while the ice adhesion force on the superlubricating coating was only 22.5 kPa, and the anti-icing effect was increased by more than 50%, showing good anti-icing performance.

[0075] The coating of Example 2 was placed in a 100℃ oven, and the mass loss with time was recorded, and the results are shown in Figure 18 It can be seen that the coating has good heat resistance, and the mass loss of the coating is only 1.8% after heating in a 100℃ oven for nine days; and the contact angle and sliding angle of the coating hardly change, and it can be seen that the contact angle and sliding angle of the coating change little within a week, and can have a relatively stable lubricating effect.

[0076] The wear resistance of the coating of Example 2 was tested, and the friction tester was used to rub with a dust-free cloth under a load of 500g for 500 times, and the results are shown in Figure 19 The mass loss is only 0.4%, and the mass loss tends to be stable after 300 times of friction, and the contact angle and sliding angle change little, and can still maintain stable lubricating effect.

[0077] The anti-chlorella adhesion performance of the pure resin coating and the coating of Example 2 was compared. Sterile marine microalgae culture medium was added to sterile artificial seawater (ASW), and the obtained culture medium was used to incubate chlorella. Different coatings with the same area were respectively immersed in a culture dish containing 30mL of chlorella (5x106 cell / mL), and were grown in a 23℃ light incubator with a 12h light and 12h dark cycle for 7d. Then, sterile ASW was used to remove the chlorella not attached to the surface of the coating, and the microalgae adhesion was captured by fluorescence microscopy. The obtained fluorescence pictures were calculated for coverage using Image J software. The results show that the chlorella coverage on the pure resin surface after 6 days of culture was 18.9%, and the chlorella coverage on the SLIPS coating surface was 0.09%, which was significantly less than that of the pure resin, showing excellent anti-chlorella adhesion performance.

[0078] Example 3

[0079] The preparation method of the long-acting interfacial lubricating coating of the present application comprises the following steps:

[0080] (1) Under the conditions of heating in a 50°C water bath and magnetic stirring, 5 parts by mass of silica sol, 0.5 parts by mass of perfluorodecyltriethoxysilane and 4 parts by mass of ammonia water were added to 80 parts by mass of ethanol, stirred for 3 h, then 4 parts by mass of diatomite and 0.5 parts by mass of perfluorodecyltriethoxysilane were added to the solution, stirred for 3 h, to obtain a modified micron particle suspension; the suspension was dried into powder in an oven at 90°C for 36 h, ground and passed through a 200-mesh sieve to obtain a modified porous powder;

[0081] (2) 0.8 parts by mass of the modified porous powder of step (1) were mixed with 3 parts by mass of silicone oil, then placed in a vacuum pump to vacuumize, so that the silicone oil could enter the porous powder, after 24 h under vacuum, the silicone oil and the powder were completely layered, the upper layer of silicone oil was removed using a rubber-tipped dropper, to obtain a porous powder containing silicone oil;

[0082] (3) The porous powder containing silicone oil was subjected to a pore sealing treatment, dried in an oven at 100°C, then mixed with silicone oil at a mass ratio of 1:1 to obtain a mixed solution of the sealed powder and silicone oil;

[0083] (4) In 2 parts by mass of butyl acetate, 2.5 parts by mass of resin were first added, then 0.5 parts by mass of silane coupling agent, followed by 0.5 parts by mass of the mixed solution of step (3), and finally 0.75 parts by mass of isocyanate curing agent, mixed and uniformly coated or sprayed onto a substrate, and air-dried at room temperature for 24 h to obtain an interfacial lubricating coating.

[0084] The oil-containing porous particles of Example 3 were subjected to thermogravimetric analysis, and the results showed that the heat loss of the particles before and after heating was 55%, which was basically the loss of silicone oil, i.e. the oil absorption rate of the particles was about 55%.

[0085] The coating of this Example 3 was subjected to a qualitative test by the grid method, the specific operation method being that a grid tool was used to draw a grid on the surface of the coating as shown in Figure 7 The grid was a square of 1 mm x 1 mm, then a tape was adhered above the grid, a weight of 1 kg was rolled on the tape to apply pressure, the tape was peeled off from the grid-drawn surface of the coating after 1 min of pressing, and the grid detachment was observed, and the adhesion grade of the coating was determined according to the test standard of the cross-cut tape adhesion test. The results are shown in Figure 20 It can be seen that the adhesion grade of the coating of Example 3 was still 0 grade.

[0086] The ice adhesion of the coating of Example 3 was compared, and the data results are shown in Figure 21 It can be seen that the ice adhesion of the original untreated glass was as high as 58.2 kPa, while the ice adhesion on the super-lubricating coating was only 25.3 kPa, the anti-icing effect was improved by more than 50%, and the coating showed good anti-icing performance.

[0087] The coating of Example 3 was placed in a 100℃ oven, and the change of mass loss with time was recorded, and the results are shown in Figure 22 It can be seen that the coating has good heat resistance, the mass loss of the coating is only 1.6% after heating in the oven at 100℃ for nine days; and the contact angle and sliding angle of the coating hardly change, and it can be seen that the contact angle and sliding angle of the coating change little within a week, and both can have a relatively stable lubricating effect.

[0088] The wear resistance of the coating of Example 3 was tested, and the friction tester was used to rub with a dust-free cloth under a load of 500g for 500 times, and the results are shown in Figure 23 It can be seen that the mass loss is only 0.4%, and the mass loss tends to be stable after rubbing for 300 times, and the change range of the contact angle and sliding angle is small, and the stable lubricating effect can still be maintained.

[0089] The anti-chlorella adhesion performance of the pure resin coating and the coating of Example 3 was compared. Sterile marine microalgae culture medium was added to sterile artificial seawater (ASW), and the obtained culture medium was used to incubate chlorella. Different coatings with the same area were respectively immersed in culture dishes containing 30mL of chlorella (5×106 cell / mL), and were grown in a 23℃ light incubator with a 12h light and 12h dark cycle for 7d. Then the surface of the coating was removed with sterile ASW to remove the chlorella not attached to the surface, and the adhesion of the microalgae was captured by fluorescence microscopy. The obtained fluorescence pictures were calculated for the coverage rate by using Image J software. The results show that the coverage rate of chlorella on the surface of the pure resin is 20.3% after 6 days of culture, and the coverage rate of chlorella on the surface of the SLIPS coating is 0.30%, which is significantly less than that of the pure resin, and the SLIPS coating has excellent anti-chlorella adhesion performance.

[0090] Example 4

[0091] The preparation method of the long-acting interfacial lubricating coating of the present application comprises the following steps:

[0092] (1) Under the conditions of 50℃ water bath heating and magnetic stirring, 5 parts by mass of silica sol, 0.5 parts by mass of perfluorodecyltriethoxysilane and 4 parts by mass of ammonia water were added to 80 parts by mass of ethanol, and after stirring for 3h, 4 parts by mass of diatomite and 0.5 parts by mass of perfluorodecyltriethoxysilane were further added to the solution, and stirring was performed for 3h to obtain a modified micron particle suspension; the suspension was placed in a 90℃ oven for 36h to dry into a powder, which was ground and then passed through a 200-mesh sieve to obtain a modified porous powder;

[0093] (2) 0.8 parts by mass of the modified porous powder of step (1) was fully mixed with 3 parts by mass of silicone oil, and then placed in a vacuum pump to evacuate the mixture so that the silicone oil could enter the porous powder. After 24 hours under vacuum, the mixture was allowed to stand. After the silicone oil and powder were completely separated, the excess silicone oil was filtered out by vacuum filtration to obtain porous powder particles containing silicone oil;

[0094] (3) sealing the porous powder containing silicone oil, drying it in an oven at 100° C., and then mixing it with silicone oil in a mass ratio of 1:1 to obtain a mixture of sealing powder and silicone oil;

[0095] (4) First, add 2.5 parts by mass of resin to 2 parts by mass of butyl acetate, then add 0.5 parts by mass of silane coupling agent, then add 0.5 parts by mass of the mixed solution of step (3), and finally add 0.75 parts by mass of isocyanate curing agent. After mixing, brush or spray it onto the substrate and dry it at room temperature for 24 hours to obtain an interface lubricating coating.

[0096] The oil-containing porous powders obtained in Example 4 and Example 1 were weighed to obtain an initial mass m0, and then placed in an oven and heated at 180°C. They were taken out and weighed every 24 hours until their mass did not decrease. Their mass m1 was recorded, and the oil absorption rate of the particles was m0-m1 / m0×100%. Table 1 shows a comparison of the oil absorption rates of the oil-containing particles obtained by the suction filtration method and the static sedimentation method. It can be seen from the table that the oil absorption rate of the oil-containing porous powder obtained in Example 1 is more than twice that of the comparative example 1. The high oil absorption rate ensures the lubrication performance of the powder.

[0097] Table 2 shows the contact angle and sliding angle of the interfacial lubricating coating prepared from the oil-containing porous powder obtained by the suction filtration method and the static precipitation method. It can be seen that the interfacial lubricating coating prepared from the powder obtained by the static precipitation method used in Example 1 has better lubrication performance, and its sliding angle is only 10.2°.

[0098] The ice adhesion test of the coating of Example 4 showed that the ice adhesion was 35 kPa, which was higher than that of Example 1 and lower than that of the untreated glass slide.

[0099] Table 1

[0100]

[0101] Table 2

[0102]

[0103] Example 5

[0104] The method for preparing the long-lasting interface lubricating coating of the present invention comprises the following steps:

[0105] (1) Under the conditions of heating in a 50 °C water bath and magnetic stirring, 5 parts by mass of silica sol, 0.5 parts by mass of perfluorodecyltriethoxysilane, and 4 parts by mass of aqueous ammonia were added to 80 parts by mass of ethanol, and after stirring for 3 h, 4 parts by mass of diatomite and 0.5 parts by mass of perfluorodecyltriethoxysilane were added to the solution, and stirring was performed for 3 h to obtain a modified micron particle suspension; the suspension was dried in an oven at 90 °C for 36 h to obtain a powder, which was ground and passed through a 200-mesh sieve to obtain a modified porous powder;

[0106] (2) 0.8 parts by mass of the modified porous powder of step (1) were mixed with 3 parts by mass of silicone oil, and then placed in a vacuum pump to be vacuumed, so that the silicone oil could enter the porous powder; after 24 h under vacuum, the silicone oil and the porous powder were completely separated, and the upper layer of silicone oil was removed using a rubber-tipped dropper to obtain a porous powder containing silicone oil;

[0107] (3) The porous powder containing silicone oil was subjected to a pore sealing treatment, and after drying in an oven at 100 °C, it was mixed with silicone oil at a mass ratio of 1:1 to obtain a mixed solution of the pore-sealed powder and silicone oil;

[0108] (4) In 2 parts by mass of butyl acetate, 2.5 parts by mass of a resin were first added, followed by 0.5 parts by mass of the mixed solution of step (3), and finally 0.75 parts by mass of an isocyanate curing agent was added, and after mixing, it was brushed or sprayed onto a substrate, and after air drying at room temperature for 24 h, an interfacial lubricating coating was obtained.

[0109] Figure 24 The upper figure is the standing state of the solution after mixing the pore-sealed powder with the resin in Example 5, and the surface photo of the prepared coating; the lower figure is the standing state of the solution after mixing the pore-sealed powder with the resin in Example 1, and the surface photo of the prepared coating. It can be seen that in Example 5, the particles and the resin are severely layered, and the surface of the prepared coating is very rough and uneven, which is caused by the poor compatibility of the particles and the resin, while in Example 1, the particles and the resin are well combined, and the particles can be uniformly dispersed in the resin, and the prepared coating is also very uniform and flat.

[0110] The reason for the poor compatibility of the resin and the particles in Example 5 is that no silane coupling agent is added or the amount of the added silane coupling agent is too small. The silane coupling agent can graft amino groups onto the resin before the particles are added, and these groups can better combine with the modified oil-containing porous powder, thereby ensuring good compatibility between the particles and the resin.

[0111] Since the surface of the coating in Example 5 is too rough, no further testing of its contact angle, ice adhesion, etc. is performed.

[0112] Comparative Example 1

[0113] According to the patent with the patent number CN202011216363.0, a long-acting anti-icing coating is prepared using a modified silica nano solution. The process includes the following steps:

[0114] (1) Preparation of modified porous silica powder: Mix ethanol, deionized water, and ammonia water in a ratio of 20:4:1. After stirring uniformly, add 1 vol.% of nano-chain silica sol solution drop by drop. Then, add 0.6 vol.% of TEOS as a crosslinking agent, and then add 0.6 vol.% of n-octyl triethoxysilane for surface modification. Finally, seal the beaker and stir for 24 hours to obtain the modified nano-SiO2 solution. Move the solution to a 120°C oven and dry completely. Screen with a 200-mesh sieve to obtain the modified porous powder.

[0115] (2) Preparation of anti-icing coating: Mix 10g of butyl acetate and 10g of fluorocarbon resin to obtain a resin solution. Then, add the modified porous powder prepared in step (1) to the resin solution and ultrasonically mix for 1 minute. Then, add 3.33g of polyisocyanate as a curing agent to the mixed solution, and then stir uniformly to obtain a mixed solution.

[0116] (3) Preparation of long-acting anti-icing coating: Spin coat the mixed solution obtained in step (2) on the surface of a glass substrate, and then place it in an 80°C oven for 2 hours to obtain the anti-icing coating.

[0117] Compare the adhesion of the coatings of Example 1 and Comparative Example 1. Both coatings are qualitatively tested using the crosshatch method. The specific operation method is to draw a grid on the surface of the coating using a crosshatch tool, as shown in Figure 7 The grid is a square with a size of 1mm x 1mm. Then, use adhesive tape to stick over the grid, and use a 1kg weight to apply pressure on the tape. After pressing for 1 minute, tear the tape off the grid-drawn coating surface, and observe the grid detachment. According to the test standard for crosshatch adhesive force testing, determine the adhesion level of the coating. Figure 7 (a) is the morphology of the interface lubricating coating surface before and after the tape is pressed: (a) before the tape is pressed, (b) after the tape is pressed. It can be seen that the grid does not detach at all. According to the test standard, the adhesion level of the coating is determined to be 0 level. The result of Comparative Example 1 shows that the paint film adhesion is 1 level. The coating of Example 1 has better substrate adhesion.

[0118] Compare the ice adhesion of Example 1 and Comparative Example 1. The ice adhesion on the surface of the coating of Example 1 is only 23.8kPa, which is more than 50% higher than that of Comparative Example 1, showing good anti-icing performance. The ice adhesion on the surface of the coating of Comparative Example 1 is 58kPa.

Claims

1. A method for preparing a long-lasting interface lubricating coating, characterized in that: The steps include: (1) Add 5-7 parts by mass of nanosol, 4-6 parts by mass of micron porous powder, 1.0-1.2 parts by mass of low surface energy material and 4-6 parts by mass of ammonia water to 80-120 parts by mass of ethanol, stir under heating conditions in a water bath to obtain a modified micron particle suspension, and dry the suspension into powder at high temperature to obtain a modified porous powder; (2) 0.8-1.2 parts by mass of the modified porous powder and 3-5 parts by mass of silicone oil are fully mixed, and the mixture is placed in a vacuum pump to evacuate the mixture so that the silicone oil can enter the modified porous powder. After removing the vacuum state, the excess silicone oil is separated to obtain a porous powder containing silicone oil; (3) sealing the porous powder containing silicone oil, drying it at high temperature, and then mixing it with silicone oil to obtain a mixture of sealing powder and silicone oil; (4) First add 2.5-4 parts by mass of resin to 2-5 parts by mass of diluent, then add 0.5-0.6 parts by mass of silane coupling agent, then add 0.5-0.8 parts by mass of the mixed solution of step (3), and finally add 0.75-1.2 parts by mass of curing agent, mix well, brush or spray onto the substrate, and dry to obtain an interface lubricating coating; The specific process of the sealing treatment in step (3) is as follows: the cationic polymer solution and the porous powder containing silicone oil are mixed in a mass ratio of 1:2, the cationic polymer is covered on the surface of the porous powder by electrostatic action under mechanical stirring conditions of 300r / 30min, and after centrifugation at 8000r / 3min, the excess cationic polymer is washed with ethanol or water to remove the excess cationic polymer; after being covered with the cationic polymer, the surface of the porous powder is positively charged; then the anionic polymer solution and the porous powder are mixed in a volume ratio of 1:2, the anionic polymer is covered on the surface of the porous powder by electrostatic action under mechanical stirring conditions of 300r / 30min, and after centrifugation at 8000r / 3min, the excess anionic polymer is washed with ethanol or water to remove the excess anionic polymer; a composite membrane layer constructed of cationic polymer and anionic polymer is obtained on the surface of the porous powder, completing the sealing treatment of the porous powder, and the composite membrane layer has a loose network structure; the cationic polymer is at least one of chitosan, polyethyleneimine, polystyrene or polyacrylamine, and the anionic polymer is at least one of sodium polystyrene sulfonate, polyacrylic acid or polyacrylonitrile.

2. The preparation method according to claim 1, wherein: In step (1), the nanosol is a silicon dioxide nanosol or a titanium dioxide nanosol; the particle size of the nanosol is 5 to 40 nm; the solid content of the nanosol is 10 wt.% to 35 wt.%, and the pH value is 9 to 12.

3. The preparation method according to claim 1, wherein: In step (1), the micron porous powder is one of ceramic, diatomaceous earth or glass porous microspheres with a particle size of 10 to 50 μm.

4. The preparation method according to claim 1, wherein: In step (1), the low surface energy substance is perfluorodecyltriethoxysilane or perfluorooctyltriethoxysilane.

5. The preparation method according to claim 1, wherein: In step (1), the water bath heating temperature is not less than 50°C.

6. The preparation method according to claim 1, wherein: In step (1), the suspension is placed in an oven at 90-100° C. for 32-36 hours to dry into powder, and then ground and sieved using a 150-200 mesh sieve.

7. The preparation method according to claim 1, wherein: In step (2), the reaction is carried out under vacuum for not less than 24 hours.

8. The preparation method according to claim 1, wherein: In step (3), the mixing mass ratio of the sealing powder and the silicone oil is 1:1-1.5 to obtain a mixed liquid.

9. The preparation method according to claim 1, wherein: In step (4), the resin is one of fluorocarbon resin, acrylic resin, polyurethane resin or urea-formaldehyde resin.

10. The preparation method according to claim 1, characterized in that: In step (4), the silane coupling agent is one of silane coupling agent KH550, silane coupling agent KH560 or silane coupling agent KH570.

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