A hybrid polymer brush coating resistant to wear in dry / wet environments and methods of making the same

Abstract

The present application relates to the technical field of surface modification, and provides a mixed polymer brush coating resistant to wear in dry / wet environment and a preparation method thereof.The present application first prepares a silica sol-initiator coating on the surface of a substrate;then grafts self-lubricating hydrophobic polymer brushes under UV irradiation;finally grafts hydrophilic polymer brushes on the surface of the coating through ATRP reaction, so as to realize the preparation of the mixed polymer brush coating.The present application makes the mixed polymer brush coating have stronger bonding strength and wear resistance through the interaction between the initiator layer and the polymer brush layer;in water, the hydrophilic polymer brushes in the coating are combined with water molecules to swell and form an effective hydration layer, thereby playing a hydration lubrication function;in the dry state, the hydrophilic polymer brushes shrink after dehydration, so that the hydrophobic silicone brushes are exposed, thereby endowing the surface with a dry-state self-lubrication function.The method provided by the present application can be carried out under air condition, does not need a deoxygenation step, is simple to operate and easy to realize batch preparation.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of surface modification, in particular to a mixed polymer brush coating with wear resistance in dry / wet environment and a preparation method thereof. BACKGROUND

[0002] Polymer brush refers to a kind of ultra-thin polymer coating formed by fixing one end of polymer chain on the surface or interface and extending the other end outwards. By adjusting the chemical composition, structure and thickness of polymer brush, the physical and chemical properties of the material surface can be effectively adjusted. Therefore, polymer brush has a wide application prospect in the fields of surface antifouling, lubrication, biological materials, etc.

[0003] Atom transfer radical polymerization (ATRP) is one of the commonly used methods for preparing polymer brush. By introducing halogen initiator group on the surface of the material, ATRP polymerization of these molecules can be initiated on the surface of the material under the action of catalyst. As for hydrophilic polymer brush, its water lubrication performance depends on the adsorption and anchoring of polymer brush to the interface water, thereby generating a hydration layer between the friction interface. In the friction process, the shear slip of the hydration layer can greatly reduce the friction between the interfaces.

[0004] Although the surface of hydrophilic polymer brush has excellent water lubrication performance, there are still some problems in popularizing hydrophilic polymer brush to practical application. One of the most critical problems is how to improve the wear resistance of polymer brush in different environments (including wet state (underwater) and dry state (air)) and improve the service life of polymer brush. SUMMARY

[0005] Therefore, the present application provides a mixed polymer brush coating with wear resistance in dry / wet environment and a preparation method thereof. The mixed polymer brush coating provided by the present application has excellent wear resistance in air (dry) and water (wet), good lubrication performance and long service life.

[0006] In order to achieve the above-mentioned application purposes, the present application provides the following technical solutions:

[0007] A preparation method of a mixed polymer brush coating with wear resistance in dry / wet environment, comprising the following steps:

[0008] Mixing tetraethyl orthosilicate, ATRP initiator, mercaptosilane, first alcohol solvent, water and inorganic acid to carry out hydrolysis reaction, and obtaining a silica sol-initiator mixed coating after standing and aging;

[0009] Drying the silica sol-initiator mixed coating after coating on the surface of the substrate to form a silica sol-initiator coating;

[0010] immersing the substrate modified with the coating of grafted self-lubricating hydrophobic polymer brushes into a solution of hydrophilic vinylic monomers for ATRP reaction to obtain a mixed polymer brush coating with wear resistance in dry / wet environment; the solution of hydrophilic vinylic monomers comprises hydrophilic vinylic monomers, water, a second alcoholic solvent, a reducing agent, a catalyst and a ligand.

[0011] immersing the substrate modified with the coating of grafted self-lubricating hydrophobic polymer brushes into a solution of hydrophilic vinylic monomers for ATRP reaction to obtain a mixed polymer brush coating with wear resistance in dry / wet environment; the solution of hydrophilic vinylic monomers comprises hydrophilic vinylic monomers, water, a second alcoholic solvent, a reducing agent, a catalyst and a ligand.

[0012] Preferably, the inorganic acid is nitric acid and / or hydrochloric acid; the first alcoholic solvent is ethanol or isopropanol; the volume ratio of the first alcoholic solvent, tetraethyl orthosilicate, water and acid is 10-15:2-6:1:0.2-0.5; the standing aging time is 3-7 days.

[0013] Preferably, the ATRP initiator is 2-bromo-2-methylpropionic acid (3-trimethoxysil) propyl ester; the mass ratio of the tetraethyl orthosilicate to the ATRP initiator is 20-100:1; the mercaptosilane is 3-mercaptopropyl trimethoxysilane; the mass ratio of the tetraethyl orthosilicate to the mercaptosilane is 10-100:1.

[0014] Preferably, the coating method is dip-coating; the dip-coating speed is 20-200 mm / min; the drying temperature is 60-150℃, and the drying time is 1-3 h.

[0015] Preferably, the hydrophobic vinylic monomer is vinyl polydimethylsiloxane; the photoinitiator is benzophenone and / or 2-hydroxy-2-methyl-1-phenyl-1-propanone; the solvent in the solution of hydrophobic vinylic monomers is xylene and / or ethyl acetate; the concentration of the hydrophobic vinylic monomer in the solution of hydrophobic vinylic monomers is 0.01-0.1 g / mL; the mass ratio of the hydrophobic vinylic monomer to the photoinitiator is 100-200:1.

[0016] Preferably, the wavelength of the UV light is 320-365 nm, the light intensity is 500-3000 mW / cm 2 , and the light exposure time is 0.5-3 h.

[0017] Preferably, the hydrophilic vinylic monomer is one or more of 3-sulfopropyl potassium methacrylate, sulfobetaine methacrylate, acrylamide, hydroxyethyl methacrylate and methacryloyl propyl trimethyl ammonium chloride;

[0018] The second alcoholic solvent is methanol or ethanol;

[0019] The reducing agent is ascorbic acid and / or copper;

[0020] The catalyst is cuprous bromide and / or copper chloride dihydrate;

[0021] The ligand is 2,2-bipyridine and / or pentamethyldiethylenetriamine;

[0022] The concentration of the hydrophilic alkenyl monomer in the hydrophilic alkenyl monomer solution is 0.01-0.1 g / mL; the volume ratio of the second alcohol solvent to water is 1:1; the mass ratio of the hydrophilic alkenyl monomer to the catalyst is 5-200:1; the mass ratio of the reducing agent to the catalyst is 1-30:1; and the mass ratio of the ligand to the catalyst is 1-5:1.

[0023] Preferably, the temperature of the ATRP reaction is room temperature, and the reaction time is 1-6 h.

[0024] The application also provides a mixed polymer brush coating layer prepared by the preparation method described in the above scheme, which is resistant to abrasion in dry / wet environments.

[0025] The application also provides a coating, which comprises a separately packaged silica sol-initiator mixed coating, a hydrophobic alkenyl monomer solution and a hydrophilic alkenyl monomer solution; the preparation method of the silica sol-initiator mixed coating comprises: mixing tetraethyl orthosilicate, an ATRP initiator, a mercapto silane, a first alcohol solvent, water and an inorganic acid to perform a hydrolysis reaction, and obtaining the silica sol-initiator mixed coating after standing and aging.

[0026] The components of the hydrophobic alkenyl monomer solution include a hydrophobic alkenyl monomer, a photoinitiator and a solvent.

[0027] The components of the hydrophilic alkenyl monomer solution include a hydrophilic alkenyl monomer, water, a second alcohol solvent, a reducing agent, a catalyst and a ligand.

[0028] The application provides a preparation method of a wear-resistant mixed polymer brush coating in dry / wet environments, comprising the following steps: mixing tetraethyl orthosilicate, an ATRP initiator, a mercaptosilane, a first alcohol solvent, water and an inorganic acid to perform a hydrolysis reaction, and obtaining a silica sol-initiator mixed coating after standing and aging; drying the silica sol-initiator mixed coating after being coated on the surface of a substrate to form a silica sol-initiator coating; immersing the substrate modified with the silica sol-initiator coating in a hydrophobic alkenyl monomer solution to perform UV irradiation, and obtaining a coating of grafted self-lubricating hydrophobic polymer brushes; the components of the hydrophobic alkenyl monomer solution include a hydrophobic alkenyl monomer, a photoinitiator and a solvent; immersing the substrate modified with the coating of grafted self-lubricating hydrophobic polymer brushes in a hydrophilic alkenyl monomer solution to perform an ATRP reaction, and obtaining a wear-resistant mixed polymer brush coating in dry / wet environments; the components of the hydrophilic alkenyl monomer solution include a hydrophilic alkenyl monomer, water, a second alcohol solvent, a reducing agent, a catalyst and a ligand. The application utilizes the characteristics of high bonding strength of silica sol and substrates, forms a silica sol coating on the surface, and embeds an ATRP initiator in the silica sol coating (i.e., a silica sol-initiator coating); then, under UV irradiation, grafted self-lubricating hydrophobic polymer brushes based on a “mercapto-olefin addition reaction” are obtained, and the material is endowed with dry-state self-lubricating properties; finally, based on the subsurface structure of the silica sol-initiator, hydrophilic polymer brushes are grafted on the surface of the coating through an ATRP reaction, so that a mixed polymer brush coating is prepared on the surface of the substrate. The method provided by the application is suitable for most materials, is simple to operate, has strong universality, has low required cost, and can meet the actual application requirements. Further, in the method, the Cu 2+ performs ATRP polymerization, and the polymerization process can be performed in air without deoxygenation.

[0029] The application also provides a wear-resistant mixed polymer brush coating in dry / wet environments prepared by the preparation method. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 is a static contact angle diagram, and from left to right, the glass sheet of Example 1, the glass sheet modified with the hydrophobic polymer brush in Example 1, the glass sheet modified with the coating of grafted hydrophobic polymer brushes, and the glass sheet modified with the coating of mixed polymer brushes.

[0031] Figure 2 A comparison chart of the surface abrasion resistance of the pure hydrophilic polymer brush coating of Comparative Example 1 and the mixed polymer brush coating of Example 1;

[0032] Figure 3 A chart of the test results of the lubrication performance of the mixed polymer brush coating of Example 1 in dry and wet states. DETAILED DESCRIPTION

[0033] The present application provides a preparation method of a mixed polymer brush coating resistant to abrasion in dry / wet environments, comprising the following steps:

[0034] Hydrolysis reaction is carried out by mixing tetraethyl orthosilicate, ATRP initiator, mercaptosilane, a first alcohol solvent, water and an inorganic acid, and a silica sol-initiator mixed coating is obtained after standing and aging;

[0035] The silica sol-initiator mixed coating is coated on the surface of a substrate and dried to form a silica sol-initiator coating;

[0036] The substrate modified with the silica sol-initiator coating is immersed in a hydrophobic alkenyl monomer solution and subjected to UV irradiation to obtain a coating of grafted self-lubricating hydrophobic polymer brushes; the components of the hydrophobic alkenyl monomer solution include a hydrophobic alkenyl monomer, a photoinitiator and a solvent;

[0037] The substrate modified with the coating of grafted self-lubricating hydrophobic polymer brushes is immersed in a hydrophilic alkenyl monomer solution and subjected to ATRP reaction to obtain a mixed polymer brush coating resistant to abrasion in dry / wet environments; the components of the hydrophilic alkenyl monomer solution include a hydrophilic alkenyl monomer, water, a second alcohol solvent, a reducing agent, a catalyst and a ligand.

[0038] The present application mixes tetraethyl orthosilicate, ATRP initiator, mercapto silane, first alcohol solvent, water and inorganic acid to carry out hydrolysis reaction, and obtains silica sol-initiator mixed coating after standing and aging. In the present application, the inorganic acid is preferably nitric acid and / or hydrochloric acid, the nitric acid is preferably concentrated nitric acid (68wt%), the hydrochloric acid is preferably concentrated hydrochloric acid (36wt%); the first alcohol solvent is preferably ethanol or isopropanol; the volume ratio of the first alcohol solvent, tetraethyl orthosilicate, water and acid is preferably 10-15:2-6:1:0.2-0.5, more preferably 12:3-6:1:0.2; the ATRP initiator is preferably 2-bromo-2-methylpropionic acid (3-trimethoxysil) propyl ester; the mass ratio of the tetraethyl orthosilicate and ATRP initiator is preferably 20-100:1, more preferably 20-80:1, further preferably 40-80:1, most preferably 40-60:1; the mercapto silane is preferably 3-mercaptopropyl trimethoxysilane, and the mass ratio of the tetraethyl orthosilicate and mercapto silane is preferably 10-100:1, more preferably 20-50:1.

[0039] In the present application, the time of the hydrolysis reaction is preferably 1h, and the temperature is preferably room temperature; the time of the standing and aging is preferably 3-7 days, more preferably 4-5 days, and the temperature of the standing and aging is preferably room temperature. In the specific embodiment of the present application, the first alcohol solvent, tetraethyl orthosilicate, water and inorganic acid are mixed first, and then the ATRP initiator and mercapto silane are added after uniform stirring, and the standing and aging is carried out after 1h of continuous stirring.

[0040] After obtaining the silica sol-initiator mixed coating, the silica sol-initiator mixed coating is coated on the surface of the substrate and dried to form a silica sol-initiator coating layer. In the present application, the coating method is preferably dip-coating method, and the pulling speed of the dip-coating method is preferably 20-200mm / min, more preferably 20-100mm / min, and the thickness of the silica sol-initiator coating layer can be controlled by the pulling speed; in the specific embodiment of the present application, the substrate is preferably dipped in the silica sol-initiator mixed coating first, and then pulled, and the dipping time is preferably 20s; in the present application, the thickness of the silica sol-initiator coating layer is preferably 70-100nm, and is more preferably 70nm, 85nm or 100nm. The present application does not have special requirements for the material of the substrate, and in the specific embodiment of the present application, the substrate is preferably glass.

[0041] In the present application, the drying method is preferably oven drying; the drying temperature is preferably 60-150℃, more preferably 80-100℃; and the drying time is preferably 1-3h, more preferably 1-2h.

[0042] After obtaining the silica sol-initiator coating, the substrate modified with the silica sol-initiator coating is immersed in a hydrophobic alkenyl monomer solution and subjected to UV irradiation to obtain a coating of grafted self-lubricating hydrophobic polymer brushes; the components of the hydrophobic alkenyl monomer solution include a hydrophobic alkenyl monomer, a photoinitiator, and a solvent. In the present application, the hydrophobic alkenyl monomer is preferably vinyl polydimethylsiloxane; the photoinitiator is preferably benzophenone and / or 2-hydroxy-2-methyl-1-phenyl-1-propanone, more preferably benzophenone; the solvent in the hydrophobic alkenyl monomer solution is preferably xylene and / or ethyl acetate, more preferably xylene; the concentration of the hydrophobic alkenyl monomer in the hydrophobic alkenyl monomer solution is preferably 0.01-0.1 g / mL, more preferably 0.02-0.05 g / mL; and the mass ratio of the hydrophobic alkenyl monomer to the photoinitiator is preferably 100-200:1, more preferably 100:1.

[0043] In the present application, the wavelength of the UV irradiation is preferably 320-365 nm, more preferably 365 nm, the irradiation intensity is preferably 500-3000 mW / cm 2 , more preferably 1000 mW / cm 2 , and the irradiation time is preferably 0.5-3 hours, more preferably 1-2 hours. Under the UV irradiation conditions, the hydrophobic alkenyl monomer and the mercapto silane in the silica sol-initiator coating undergo a mercapto-alkene addition reaction, thereby grafting self-lubricating hydrophobic polymer brushes on the surface of the coating.

[0044] After the UV irradiation is completed, the substrate modified with the coating of grafted self-lubricating hydrophobic polymer brushes is preferably removed, rinsed with xylene, and dried with nitrogen.

[0045] After obtaining the coating grafted with the self-lubricating hydrophobic polymer brush, the substrate modified with the coating grafted with the self-lubricating hydrophobic polymer brush is immersed in a hydrophilic alkenyl monomer solution for ATRP reaction to obtain a mixed polymer brush coating resistant to wear in dry / wet environments; the components of the hydrophilic alkenyl monomer solution include a hydrophilic alkenyl monomer, water, a second alcohol solvent, a reducing agent, a catalyst and a ligand. In the present application, the hydrophilic alkenyl monomer is preferably one or more of potassium methacrylate-3-sulfopropyl ester, sulfobetaine methacrylate, acrylamide, hydroxyethyl methacrylate and methacryloyl propyl trimethyl ammonium chloride; the second alcohol solvent is preferably methanol or ethanol; the reducing agent is preferably ascorbic acid and / or copper, more preferably ascorbic acid; the catalyst is preferably cuprous bromide and / or copper chloride dihydrate, more preferably cuprous bromide; the ligand is preferably 2,2-bipyridine and / or pentamethyldiethylene triamine, more preferably 2,2-bipyridine; the concentration of the hydrophilic alkenyl monomer in the hydrophilic alkenyl monomer solution is preferably 0.01-0.1 g / mL, more preferably 0.01-0.05 g / mL; the volume ratio of the second alcohol solvent to water is preferably 1:1; the mass ratio of the hydrophilic alkenyl monomer to the catalyst is 5-200:1, more preferably 20-150:1, and further preferably 50-150:1; the mass ratio of the reducing agent to the catalyst is preferably 1-30:1, more preferably 5-20:1; and the mass ratio of the ligand to the catalyst is preferably 1-5:1, more preferably 2-3:1.

[0046] In the present application, the temperature of the ATRP reaction is preferably room temperature, and the reaction time is preferably 1-6 h, and further preferably 2-4 h; and the ATRP reaction is preferably carried out under a closed condition. During the ATRP reaction, the hydrophilic alkenyl monomer is grafted onto the surface by free radical addition polymerization, so that a water-lubricating polymer brush is grafted on the surface of the coating, i.e. the mixed polymer brush coating of the present application is obtained.

[0047] After the ATRP reaction is completed, the substrate modified with the mixed polymer brush coating is preferably taken out and then rinsed with water, and then dried with nitrogen.

[0048] The present application also provides the mixed polymer brush coating resistant to wear in dry / wet environments prepared by the preparation method described in the above scheme; the mixed polymer brush coating provided by the present application has a self-lubricating hydrophobic polymer brush and a self-lubricating hydrophilic polymer brush grafted on the surface, in water, the hydrophilic polymer brush in the coating is combined with water molecules to swell and form an effective hydration layer, thereby playing a hydration lubrication function; in a dry state, the hydrophilic polymer brush dehydrates and shrinks, and the hydrophobic silicone brush is exposed, thereby imparting a dry-state self-lubricating function to the surface, so that good wear resistance and lubricity in dry / wet states are achieved.

[0049] The application further provides a coating, which comprises independently packed silicon sol-initiator mixed coating, hydrophobic alkyl monomer solution and hydrophilic alkyl monomer solution; the preparation method of the silicon sol-initiator mixed coating comprises: mixing tetraethyl orthosilicate, ATRP initiator, mercapto silane, first alcohol solvent, water and inorganic acid to carry out hydrolysis reaction, and obtaining the silicon sol-initiator mixed coating after standing and aging.

[0050] The components of the hydrophobic alkyl monomer solution comprise hydrophobic alkyl monomer, photoinitiator and solvent.

[0051] The components of the hydrophilic alkyl monomer solution comprise hydrophilic alkyl monomer, water, second alcohol solvent, reducing agent, catalyst and ligand.

[0052] The components in the coating are consistent with the above scheme, and will not be described here.

[0053] The technical solutions in the application will be clearly and completely described below in combination with the embodiments in the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the application.

[0054] In the following examples and application examples: the SPMA is 3-sulfopropyl methacrylate potassium salt, the SBMA is sulfobetaine methacrylate, the MAPTAC is methacryloyl propyl trimethyl ammonium chloride, the PDMS is vinyl polydimethylsiloxane, the Bp is benzophenone, the Bipy is 2,2-bipyridine, the CuBr is cuprous bromide, and the AA is ascorbic acid; the nitric acid used in the following examples and application examples is 68wt% concentrated nitric acid.

[0055] Example 1

[0056] The silicon sol-initiator coating containing ATRP initiator is configured: 12mL of ethanol, 3mL of tetraethyl orthosilicate, 1mL of water and 0.2mL of nitric acid are respectively taken, added into a flask and stirred uniformly, then 0.2mL of 2-bromo-2-methylpropionic acid (3-trimethoxysil) propyl ester and 0.1mL of 3-mercapto propyl trimethoxysilane are added, and the stirring is continued for 1 hour, and the silicon sol-initiator coating is obtained after standing and aging for 72 hours.

[0057] The glass sheet with a size of 1.5*1.5cm 2 is immersed into the above silicon sol-initiator coating at room temperature for 20s, then taken out by a pulling machine at a speed of 30mm / min, and placed in an oven at 100℃ for 2h to obtain the glass sheet modified with the silicon sol-initiator coating, and the thickness of the silicon sol-initiator coating is about 75nm.

[0058] The glass slides modified with silica sol-initiator coating were immersed in the reaction solution containing 1 g of PDMS, 0.01 g of Bp and 20 mL of xylene, and reacted under UV light (UV wavelength of 365 nm, light intensity of 1000 mW / cm 2 ) for 1 h, and then washed with xylene and dried with nitrogen to obtain the glass slides modified with coating of grafted hydrophobic polymer brushes.

[0059] The glass slides modified with coating of grafted hydrophobic polymer brushes were immersed in a deionized water / ethanol (1:1) solution containing 0.05 g / mL of SPMA, 8 mg / mL of AA, 0.8 mg / mL of CuBr and 1.6 mg / mL of Bipy, and reacted at room temperature for 1 h under airtight condition, washed with water and dried with nitrogen to obtain the glass slides modified with coating of mixed polymer brushes.

[0060] Comparative Example 1

[0061] The glass slides modified with silica sol-initiator coating obtained in Example 1 were immersed in a deionized water solution containing 0.05 g / mL of SPMA, 8 mg / mL of AA, 0.8 mg / mL of CuBr and 1.6 mg / mL of Bipy, and reacted at room temperature for 1 h under airtight condition, washed with water and dried with nitrogen to obtain the glass slides modified with coating of hydrophilic polymer brushes.

[0062] Performance test and characterization:

[0063] 1. The water contact angle of the glass slides modified with coating of silica sol-initiator obtained in Example 1 was tested, and the result showed that the water contact angle was about 60.3±0.5°, which was obviously higher than 19.1±0.1° of the surface of blank glass, indicating that the silica sol-initiator coating had been modified onto the surface of the substrate.

[0064] The water contact angles of the glass slides modified with coating of grafted hydrophobic polymer brushes and the glass slides modified with coating of mixed polymer brushes obtained in Example 1 were tested, and the result showed that the water contact angles were 90.1±0.7° and 6.3±0.2°, respectively. The result was obviously different from that of the silica sol-initiator coating, indicating the successful grafting of the hydrophilic / hydrophobic polymer brushes on the surface. Figure 1 The test results of the water contact angles of the glass slides, the glass slides modified with coating of silica sol-initiator, the glass slides modified with coating of grafted hydrophobic polymer brushes and the glass slides modified with coating of mixed polymer brushes.

[0065] 2. The polymer brush coatings prepared in Example 1 and Comparative Example 1 were respectively placed in air to abrade with polyester cloth under the conditions of 5N load and 1 Hz frequency, and the change of the surface contact angle with the abrasion times was as shown in the following table. Figure 2The contact angle of the hydrophilic polymer brush coating surface increases to 50 ± 0.5° after 10,000 abrasion cycles, indicating that most of the polymer brushes on the surface are abraded. The contact angle of the mixed polymer brush coating surface can still be maintained below 10° after 10,000 friction cycles. This indicates that the mixed polymer brush coating has excellent self-lubricating properties, good wear resistance, and long service life.

[0066] 3. The mixed polymer brush coating prepared in Example 1 was placed in a dry (air) and wet (underwater) environment, respectively, and subjected to abrasion with a terylene cloth and a silicone rubber ball under the conditions of a 2N load and a 1Hz frequency. The results are shown in Figure 3 Under dry conditions, the friction coefficient of the mixed polymer brush surface can be maintained at about 0.07 within 10,000 friction cycles, and has certain self-lubricating properties. Moreover, under wet conditions, the friction coefficient of the mixed polymer brush surface can still be maintained at about 0.02 within 10,000 cycles, and has good water lubricating properties. The above results show that the mixed polymer brush coating prepared by the present application has good lubricating properties in dry / wet environments, good wear resistance, and long service life.

[0067] Example 2

[0068] The ATRP initiator-containing silica sol initiator coating was prepared as follows: 12 mL of ethanol, 4 mL of tetraethyl orthosilicate, 1 mL of water, and 0.2 mL of nitric acid were weighed into a flask and stirred uniformly. Then, 0.1 mL of 2-bromo-2-methylpropionic acid (3-trimethoxysil) propyl ester and 0.1 mL of 3-mercaptopropyl trimethoxysilane were added, and stirring was continued for 1 hour. The silica sol-initiator coating was obtained after standing for 96 hours.

[0069] A 1.5 × 1.5 cm 2 glass sheet was immersed in the above silica sol-initiator coating at room temperature for 20 seconds, and then pulled out at a speed of 100 mm / min using a puller. The glass sheet modified with the silica sol-initiator coating was placed in an oven at 80°C for 1 hour to obtain a glass sheet modified with a grafted hydrophobic polymer brush coating, and the thickness of the coating was about 100 nm.

[0070] The glass sheet modified with the silica sol-initiator coating was immersed in a reaction solution containing 1 g of PDMS, 0.01 g of Bp, and 30 mL of xylene, and reacted under UV light (UV wavelength of 365 nm, light intensity of 1000 mW / cm 2 ) for 1 hour. Then, the glass sheet was washed with xylene and dried with nitrogen to obtain a glass sheet modified with a grafted hydrophobic polymer brush coating.

[0071] The glass piece with the coating of grafted hydrophobic polymer brushes was immersed in a solution containing 0.02 g / mL SBMA, 8 mg / mL AA, 0.8 mg / mL CuBr, 1.6 mg / mL Bipy in deionized water / ethanol (1:1) and reacted at room temperature for 1 h in a closed condition. After washing with water and drying with nitrogen, the glass piece with the coating of mixed polymer brushes was obtained.

[0072] The wetting, lubricating and wear resistance of the mixed polymer brush coating prepared in this embodiment were similar to those in Example 1.

[0073] Example 3

[0074] The silica sol initiator coating containing ATRP initiator was prepared as follows: 12 mL of ethanol, 4 mL of tetraethyl orthosilicate, 1 mL of water and 0.2 mL of nitric acid were weighed into a flask and stirred uniformly. Then, 0.2 mL of 2-bromo-2-methylpropionic acid (3-trimethoxysilyl) propyl ester was added, and the mixture was continuously stirred for 1 h. After standing for 96 h, the silica sol-initiator coating was obtained.

[0075] A glass piece with a size of 1.5 x 1.5 cm 2 was immersed in the above silica sol-initiator coating at room temperature for 20 s, and then pulled out by a puller at a speed of 100 mm / min. After being placed in an oven at 80°C for 2 h, the glass piece with the coating of silica sol-initiator was obtained, and the thickness of the coating was about 100 nm.

[0076] The glass piece with the coating of silica sol-initiator was immersed in a reaction solution containing 1 g of PDMS, 0.01 g of Bp and 40 mL of dimethylbenzene, and reacted under UV light (UV wavelength was 365 nm, and light intensity was 1000 mW / cm 2 ) for 1.5 h. After washing with dimethylbenzene and drying with nitrogen, the glass piece with the coating of grafted hydrophobic polymer brushes was obtained.

[0077] The glass piece with the coating of grafted hydrophobic polymer brushes was immersed in a solution containing 0.02 g / mL SBMA, 8 mg / mL AA, 0.8 mg / mL CuBr, 1.6 mg / mL Bipy in deionized water / ethanol (1:1) and reacted at room temperature for 1 h in a closed condition. After washing with water and drying with nitrogen, the glass piece with the coating of mixed polymer brushes was obtained.

[0078] The wetting, lubricating and wear resistance of the mixed polymer brush coating prepared in this embodiment were similar to those in Example 1.

[0079] Example 4

[0080] Preparation of the silica sol-initiator coating solution: 12 mL of ethanol, 4 mL of tetraethyl orthosilicate, 1 mL of water and 0.2 mL of nitric acid were measured into a flask and stirred until homogeneous. Then 0.1 mL of 2-bromo-2-methylpropionic acid (3-trimethoxysilyl) propyl ester and 0.1 mL of 3-mercaptopropyltrimethoxysilane were added and stirring was continued for 1 hour. The silica sol-initiator coating solution was obtained after aging for 72 hours.

[0081] A 1.5 x 1.5 cm 2 glass slide was immersed in the above silica sol-initiator coating solution for 20 seconds at room temperature and then pulled out at a rate of 100 mm / min using a puller. The glass slide modified with the silica sol-initiator coating was obtained after being placed in an oven at 80°C for 3 hours. The thickness of the coating was about 100 nm.

[0082] The glass slide modified with the silica sol-initiator coating was immersed in a reaction solution containing 1 g of PDMS, 0.01 g of Bp and 50 mL of xylene and reacted under UV irradiation (UV wavelength of 365 nm, light intensity of 1000 mW / cm 2 ) for 2 hours. The glass slide modified with the coating of grafted hydrophobic polymer brushes was obtained after being washed with xylene and dried with nitrogen.

[0083] The glass slide modified with the coating of grafted hydrophobic polymer brushes was immersed in a solution containing 0.02 g / mL of MAPTAC, 8 mg / mL of AA, 0.8 mg / mL of CuBr and 1.6 mg / mL of Bipy in deionized water / ethanol (1:1) and reacted at room temperature for 2 hours in a sealed condition. The glass slide modified with the coating of mixed polymer brushes was obtained after being washed with water and dried with nitrogen.

[0084] It was tested that the wettability, lubricity and wear resistance of the mixed polymer brush coating prepared in this embodiment were similar to those in Example 1.

[0085] Example 5

[0086] Preparation of the silica sol-initiator coating solution: 12 mL of ethanol, 4 mL of tetraethyl orthosilicate, 1 mL of water and 0.2 mL of nitric acid were measured into a flask and stirred until homogeneous. Then 0.1 mL of 2-bromo-2-methylpropionic acid (3-trimethoxysilyl) propyl ester and 0.1 mL of 3-mercaptopropyltrimethoxysilane were added and stirring was continued for 1 hour. The silica sol-initiator coating solution was obtained after aging for 72 hours.

[0087] A 1.5 x 1.5 cm 2The glass pieces modified with the sol-gel initiator coating were immersed in the reaction solution containing 1 g of PDMS, 0.01 g of Bp and 20 mL of xylene for 20 s, and then pulled out at a speed of 100 mm / min by a pulling machine, and placed in an oven at 80 °C for 3 h to obtain glass pieces modified with a sol-gel initiator coating, and the thickness of the coating was about 100 nm.

[0088] The glass pieces modified with the sol-gel initiator coating were immersed in the reaction solution containing 1 g of PDMS, 0.01 g of Bp and 20 mL of xylene for 20 s, and then pulled out at a speed of 100 mm / min by a pulling machine, and placed in an oven at 80 °C for 3 h to obtain glass pieces modified with a sol-gel initiator coating, and the thickness of the coating was about 100 nm. 2 ) for 2 h, and then washed with xylene and dried with nitrogen to obtain glass pieces modified with a coating of grafted hydrophobic polymer brushes.

[0089] The glass pieces modified with the coating of grafted hydrophobic polymer brushes were immersed in a solution containing 0.05 g / mL of MAPTAC, 16 mg / mL of AA, 0.8 mg / mL of CuBr and 1.6 mg / mL of Bipy in deionized water / ethanol (1:1) at room temperature for 3 h in a sealed condition, washed with water and dried with nitrogen to obtain glass pieces modified with a coating of mixed polymer brushes.

[0090] It was tested that the wettability, lubricity and wear resistance of the mixed polymer brush coating prepared in this embodiment were similar to those in Example 1.

[0091] The above only describes the preferred embodiments of the present application, and it should be noted that for those skilled in the art, several improvements and refinements can be made without departing from the principles of the present application, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A process for the preparation of a mixed polymer brush coating resistant to wear in dry / wet environments, characterized by, The method comprises the following steps: mixing tetraethyl orthosilicate, ATRP initiator, mercapto silane, first alcohol solvent, water and inorganic acid to carry out hydrolysis reaction, and obtaining silica sol-initiator mixed coating after standing and aging; the mass ratio of the tetraethyl orthosilicate to the ATRP initiator is 20-100:1; the mass ratio of the tetraethyl orthosilicate to the mercapto silane is 10-100:1; coating the silica sol-initiator mixed coating to the surface of a substrate and drying to form a silica sol-initiator coating; immersing the substrate modified with the silica sol-initiator coating into a hydrophobic alkenyl monomer solution to carry out UV irradiation, and obtaining a coating of grafted self-lubricating hydrophobic polymer brush; the composition of the hydrophobic alkenyl monomer solution comprises hydrophobic alkenyl monomer, photoinitiator and solvent; the hydrophobic alkenyl monomer is vinyl polydimethylsiloxane; the concentration of the hydrophobic alkenyl monomer in the hydrophobic alkenyl monomer solution is 0.01-0.1 g / mL; immersing the substrate modified with the coating of grafted self-lubricating hydrophobic polymer brush into a hydrophilic alkenyl monomer solution to carry out ATRP reaction, and obtaining a wear-resistant mixed polymer brush coating in dry / wet environment; the composition of the hydrophilic alkenyl monomer solution comprises hydrophilic alkenyl monomer, water, second alcohol solvent, reducing agent, catalyst and ligand; the hydrophilic alkenyl monomer is one or more of potassium methacrylate-3-sulfopropyl ester, sulfobetaine methacrylate, acrylamide, hydroxyethyl methacrylate and methacryloyl propyl trimethyl ammonium chloride; the concentration of the hydrophilic alkenyl monomer in the hydrophilic alkenyl monomer solution is 0.01-0.1 g / mL.

2. The production method according to claim 1, characterized by, The inorganic acid is nitric acid and / or hydrochloric acid; the first alcohol solvent is ethanol or isopropanol; the volume ratio of the first alcohol solvent, tetraethyl orthosilicate, water and inorganic acid is 10-15:2-6:1:0.2-0.5; the standing and aging time is 3-7 days.

3. The preparation method according to claim 1, characterized in that, The ATRP initiator is 2-bromo-2-methylpropionic acid (3-trimethoxysil) propyl ester; the mercapto silane is 3-mercaptopropyl trimethoxysilane.

4. The method of claim 1, wherein, The coating method is dip coating; the dip coating speed is 20-200 mm / min; the drying temperature is 60-150 DEG C, and the time is 1-3 h.

5. The preparation method according to claim 1, characterized in that, The photoinitiator is benzophenone and / or 2-hydroxy-2-methyl-1-phenyl-1-propanone; the solvent in the hydrophobic alkenyl monomer solution is xylene and / or ethyl acetate; the mass ratio of the hydrophobic alkenyl monomer to the photoinitiator is 100-200:

1.

6. The method of claim 1, wherein, The wavelength of the UV light is 320-365 nm, the illumination intensity is 500-3000 mW / cm 2 , and the illumination time is 0.5-3 hours.

7. The preparation method according to claim 1, characterized in that, The second alcohol solvent is methanol or ethanol; The reducing agent is ascorbic acid and / or copper; The catalyst is cuprous bromide and / or copper chloride dihydrate; The ligand is 2,2-bipyridine and / or pentamethyldiethylenetriamine; The volume ratio of the second alcohol solvent to water is 1:1; the mass ratio of the hydrophilic alkenyl monomer to the catalyst is 5-200:1; the mass ratio of the reducing agent to the catalyst is 1-30:1; the mass ratio of the ligand to the catalyst is 1-5:

1.

8. The method of claim 1, wherein, The temperature of the ATRP reaction is room temperature, and the reaction time is 1-6 h.

9. The abrasion resistant hybrid polymer brush coating prepared by the method of any one of claims 1 to 8 in dry / wet environments.

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