Super-hydrophobic anti-pollution environment-friendly coating, electrical equipment, preparation method and application

Abstract

The invention belongs to the technical field of electrical equipment maintenance, and particularly relates to a super-hydrophobic anti-pollution environment-friendly coating, electrical equipment, a preparation method and application. The super-hydrophobic anti-pollution environment-friendly coating provided by the invention comprises nano fibrillated cellulose, silanol, a polycondensation product polysiloxane hydrophobic modified film-forming agent and other components, and after the surfaces of various electrical equipment are coated with the coating, a continuous, uniform and compact polysiloxane high polymer coating can be formed through a hydrolytic condensation reaction; the environment-friendly nano fibrillated cellulose with a net-shaped structure is doped and is a polysiloxane high polymer composite coating, water permeation, microorganism colonization and pollutants such as kieselguhr are effectively blocked through double mechanisms of chemical inertness and physical barrier, and surface pollution of electrical equipment is reduced; meanwhile, a'contact sterilization + ion release 'dual-mode antibacterial mechanism is introduced, so that the antibacterial effect is remarkably improved, and the technical problem of lack of a super-hydrophobic anti-pollution environment-friendly coating at present is solved.

Description

Technical Field

[0001] This application belongs to the technical field of electrical equipment maintenance, and particularly relates to a superhydrophobic anti-pollution environmental protection coating, an electrical equipment, and a preparation method and application thereof. Background Art

[0002] High-temperature and high-humidity environmental conditions provide favorable conditions for the growth of microorganisms such as green algae and molds. Once these microorganisms parasitize on the surfaces of electrical equipment such as insulators, insulating sleeves, equipment bases, and lightning protection wires, especially on the surfaces of external insulation equipment, they will pose a serious threat to the safe operation of electrical equipment; these microorganisms will continuously absorb moisture in the environment to form a humid environment, further promoting the growth and reproduction of microorganisms, resulting in a decline in equipment performance, and even causing faults such as short circuits and insulation failures.

[0003] With the progress of technology, the maintenance technology for the surfaces of electrical equipment is also constantly developing and improving. Since the surface energy of fluorides is extremely low, some superhydrophobic fluoride coatings doped with fluorides have been used to prevent microorganism parasitism; however, toxic substances may be released during the long-term use of fluoride coatings, causing environmental pollution and potential health risks. In addition, in addition to microorganism pollution, electrical equipment will also be contaminated by pollutants such as diatomaceous earth. For example, when electrical equipment is installed in industrial areas such as ceramic factories and glass factories or in areas such as lakes, oceans, or diatomaceous earth mines, since ceramic factories and glass factories are prone to emit waste gases containing silicon dust and diatomaceous earth components during the production process, and the content of diatomaceous earth particles in the atmosphere in areas such as lakes, oceans, or diatomaceous earth mines is relatively high, when electrical equipment operates in these areas for a long time, it is easy for electrical equipment to deposit pollutants such as diatomaceous earth. The deposition of pollutants such as diatomaceous earth on the surface of electrical equipment affects the insulation performance of electrical equipment, makes the electric field distribution on the surface of electrical equipment uneven, and increases the risk of insulation faults of electrical equipment, while conventional superhydrophobic fluoride coatings doped with fluorides are difficult to resist the pollution of pollutants such as diatomaceous earth.

[0004] Therefore, currently conventional superhydrophobic fluoride coatings doped with fluorides are difficult to meet the requirements of superhydrophobic anti-pollution environmental protection on the surfaces of electrical equipment, and it is necessary to develop a superhydrophobic anti-pollution environmental protection coating to meet the requirements of superhydrophobic anti-pollution environmental protection on the surfaces of electrical equipment. Summary of the Invention

[0005] In view of this, this application provides a superhydrophobic anti-pollution environmental protection coating, an electrical equipment, and a preparation method and application thereof, which are used to solve the technical problem of the current lack of superhydrophobic anti-pollution environmental protection coatings.

[0006] In the first aspect of this application, a superhydrophobic anti-pollution environmental protection coating is provided, and the raw materials include nanofibrillated cellulose, silanol, and its polycondensation product polysiloxane hydrophobic modified film-forming agent.

[0007] Preferably, the nanofibrillated cellulose has a diameter of 20 to 50 nm and a length of 5 to 15 μm.

[0008] Preferably, the silanol and its polycondensation product polysiloxane hydrophobic modified film-forming agent are specifically: a silanol and its polycondensation product polysiloxane hydrophobic modified film-forming agent formed by hydrolysis and condensation of tetraethyl orthosilicate and / or long-chain alkyltrimethoxysilane.

[0009] Preferably, the long-chain alkyltrimethoxysilane is selected from at least one of dodecyltrimethoxysilane, cetyltrimethoxysilane, octadecyltrimethoxysilane, isooctyltrimethoxysilane, octyltrimethoxysilane, and glycidyltrimethoxysilane.

[0010] Preferably, the superhydrophobic anti-pollution environmental protection coating further comprises an antibacterial agent.

[0011] Preferably, the antibacterial agent is selected from at least one of silver nanoparticles, zinc oxide nanoparticles, quaternary ammonium salt compounds, copper ion compounds, and antibacterial natural essential oils.

[0012] Preferably, calculated by mass, the superhydrophobic anti-pollution environmental protection coating comprises 10 to 20 parts by mass of nanofibrillated cellulose, 15 to 25 parts by mass of a silanol and its polycondensation product polysiloxane hydrophobic modified film-forming agent, and 0.5 to 5 parts by mass of an antibacterial agent.

[0013] The second aspect of the present application provides a preparation method of a superhydrophobic anti-pollution environmental protection coating, which can prepare the superhydrophobic anti-pollution environmental protection coating described in the first aspect. The preparation method includes the following steps:

[0014] Step S1: Mix tetraethyl orthosilicate, long-chain alkyltrimethoxysilane, ammonia water, and absolute ethanol to obtain a mixed solution;

[0015] Step S2: Add an alkali solution to the mixed solution to adjust the pH, and perform a hydrolysis and polycondensation reaction to obtain a silanol and its polycondensation product polysiloxane hydrophobic modified film-forming agent;

[0016] Step S3: Add nanofibrillated cellulose to the silanol and its polycondensation product polysiloxane hydrophobic modified film-forming agent for hydrophobic modification to obtain a coating containing hydrophobic nanofibrillated cellulose;

[0017] Step S4: Add an antibacterial agent to the coating containing hydrophobic nanofibrillated cellulose and mix evenly to obtain a superhydrophobic anti-pollution environmental protection coating.

[0018] Preferably, in step S3, the preparation method of the nanofibrillated cellulose includes the following steps:

[0019] Step S31: Grind bleached softwood kraft pulp to obtain a cellulose slurry;

[0020] Step S32: Mix the cellulose slurry, enzyme citrate - sodium citrate buffer solution, and endoglucanase, and perform an enzymatic reaction to obtain a fibrillated precursor;

[0021] Step S33: Perform high - shear treatment on the fibrillated precursor to obtain a fibrillated cellulose slurry;

[0022] Step S34: Perform solid - liquid separation, dilution, microfluidization circulation treatment, washing, and drying on the fibrillated cellulose slurry in sequence to obtain nanofibrillated cellulose.

[0023] Preferably, in step S31, the rotation speed of the grinding is 500 - 2000 r / min, and the time is 2 - 4 h.

[0024] Preferably, in step S32, the temperature of the enzymatic reaction is , the time is 2 - 4 h, and pH = 4 - 6.

[0025] The dosage ratio of the cellulose slurry to the enzyme citrate - sodium citrate buffer solution is 1 - 5:20 (w / v);

[0026] The concentration of the endoglucanase is 2 - 10 U / g.

[0027] Preferably, in step S33, the high - shear treatment is: using an ultrafine colloid mill to process at a rotation speed of 1000 - 3000 r / min for 10 - 60 min.

[0028] Preferably, in step S34, the method of solid - liquid separation is: centrifugation or suction filtration;

[0029] The dilution is: diluting 1.0 wt% using deionized water, a buffer system with pH = 5 - 8, and an electrolyte solution containing 0.1 - 1.0 mM NaCl;

[0030] The microfluidization circulation treatment is: performing microfluidization circulation treatment 20 - 50 times at 10 - 30 MPa;

[0031] The solvent used for washing is ethanol.

[0032] Preferably, in step S1, the dosage of tetraethyl orthosilicate is 5 - 15 ml;

[0033] The dosage of long - chain alkyltrimethoxysilane is 5 - 15 ml;

[0034] The dosage of ammonia water is 2 - 10 ml;

[0035] The dosage of absolute ethanol is 100 - 200 ml.

[0036] Preferably, in step S2, the alkaline solution is selected from at least one of sodium hydroxide, potassium hydroxide, and magnesium hydroxide.

[0037] Preferably, in step S2, adjusting the pH is to adjust the pH value to 8 - 12;

[0038] The temperature of the hydrolysis polycondensation reaction is room temperature, and the time is 1 - 3 h.

[0039] Preferably, in step S3, the temperature of the hydrophobic modification is , and the time is 2 - 6 h.

[0040] Preferably, in the coating containing hydrophobic nanofibrillated cellulose in step S3, the solid content is 5 - 20 wt%;

[0041] Preferably, in step S4, in the superhydrophobic anti - pollution environmental protection coating, the addition amount of the antibacterial agent is 1 - 5 wt%.

[0042] The third aspect of the present application provides an application of a superhydrophobic anti - pollution environmental protection coating in the field of electrical equipment maintenance.

[0043] The fourth aspect provides a superhydrophobic anti - pollution environmental protection electrical equipment, including an electrical equipment and a superhydrophobic anti - pollution environmental protection coating;

[0044] The superhydrophobic anti - pollution environmental protection coating is formed by curing the superhydrophobic anti - pollution environmental protection coating described in the first aspect on the surface of the electrical equipment.

[0045] Preferably, the electrical equipment is selected from at least one of insulators, insulating bushings, equipment bases, and lightning arresters.

[0046] Compared with the prior art, the superhydrophobic anti - pollution environmental protection coating, electrical equipment, preparation method, and application provided by the present application at least include the following technical effects:

[0047] 1. The superhydrophobic anti - pollution environmental protection coating provided by the present application, through components such as nanofibrillated cellulose, silanol, and its polycondensation product polysiloxane hydrophobic modification film - forming agent introduced in the coating, forms a continuous, uniform, and dense polysiloxane polymer coating through hydrolysis condensation reaction, and is doped with nanofibrillated cellulose with a network structure. Through the dual mechanisms of chemical inertness and physical barrier, it effectively blocks the penetration of moisture and reduces the deposition of pollutants such as diatomaceous earth, reducing the surface pollution of electrical equipment such as insulators.

[0048] 2. The superhydrophobic anti - pollution environmental protection coating provided by the present application realizes a "contact sterilization + ion release" dual - mode antibacterial mechanism through the combination of quaternary ammonium salt - type antibacterial agents and nano - zinc oxide, achieving dual - mode antibacterial, and can significantly inhibit the growth and reproduction of microorganisms such as Escherichia coli and Staphylococcus aureus.

[0049] 3. The superhydrophobic and anti-pollution environmental protection coating provided by this application incorporates nanofibrillated cellulose (NFC), which is derived from plant fibers. It is a green, environmentally friendly, renewable, and biodegradable material that does not contain harmful substances such as fluorides. It is environmentally friendly, has good biocompatibility and safety, and has a wide range of applications. It can be used on the surfaces of various electrical equipment such as ceramics, glass, composite insulators, and metal structural components. Description of the Drawings

[0050] To more clearly illustrate the specific embodiments of this application or the technical solutions in the prior art, the following

[0051] will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of this application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0052] Figure 1 is a schematic flowchart of the preparation method of the superhydrophobic and anti-pollution environmental protection coating provided in Embodiment 1 of this application;

[0053] Figure 2 is a schematic flowchart of the preparation method of nanofibrillated cellulose in the superhydrophobic and anti-pollution environmental protection coating provided in Embodiment 1 of this application. Detailed Description of the Embodiments

[0054] This application provides a superhydrophobic and anti-pollution environmental protection coating, electrical equipment, and preparation methods and applications thereof to solve the current technical problem of the lack of superhydrophobic and anti-pollution environmental protection coatings.

[0055] The technical solutions of this application will be clearly and completely described below with reference to the drawings. Obviously, the described embodiments are some, but not all, of the embodiments of this application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of this application without creative efforts fall within the scope of protection of this application.

[0056] In view of the fact that the current superhydrophobic fluoride coatings doped with fluorides used on the surfaces of electrical equipment are difficult to resist the deposition of pollutants such as diatomaceous earth, and the potential hazards caused by the released fluorides; this application provides a superhydrophobic and anti-pollution environmental protection coating. The composition of the superhydrophobic and anti-pollution environmental protection coating provided by this application includes nanofibrillated cellulose, silanol, and its polycondensation product polysiloxane hydrophobic modified film-forming agent.

[0057] After the superhydrophobic and anti-pollution environmental protection coating provided by this application is coated on the surfaces of various electrical equipment, the nanofibrillated cellulose (NFC) in the coating is derived from plant fibers and is a green, environmentally friendly, renewable and degradable material. Its diameter is usually between dozens and hundreds of nanometers, and its length reaches the micron level or even longer. It is distributed with abundant hydroxyl functional groups. The silicon hydroxyl group in the hydrophobic modified film-forming agent of silanol and its polycondensation product polysiloxane undergoes dehydration condensation with the hydroxyl group on the nanofibrillated cellulose to form a silicon-oxygen bond cross-linked structure. The nanofibrillated cellulose is hydrophobically modified and introduced into the silicon-oxygen bond cross-linked structure. The molecular chains of polysiloxane are connected to each other to form a three-dimensional network structure. As the dehydration condensation reaction continues, silanol and its polycondensation product polysiloxane form a continuous, uniform and dense polysiloxane polymer coating, doped with nanofibrillated cellulose with a network structure, which is a polysiloxane polymer composite coating. After the hydrolysis and condensation reaction of the silanol and its polycondensation product polysiloxane and nanofibrillated cellulose introduced in the coating to form a film, the silicon-oxygen bond network contained will make the coating have good hydrophobicity and weather resistance, while the nanofibrillated cellulose with a network structure will further improve the hydrophobicity of the coating and reduce the deposition of pollutants such as diatomite. This application effectively blocks the penetration of moisture, the colonization of microorganisms and the deposition of pollutants such as diatomite through the dual mechanisms of chemical inertness and physical barrier, and avoids the environmental pollution problems brought by traditional fluoride superhydrophobic coatings, making it an environmental protection coating. Therefore, the superhydrophobic and anti-pollution environmental protection coating developed in this application can effectively prevent the parasitism of microorganisms and the deposition of pollutants such as diatomite on the coating after the coating is cured, and ensure environmental friendliness. On the one hand, by effectively preventing the penetration of moisture and microorganisms and reducing the deposition of pollutants such as diatomite, the surface pollution of electrical equipment is reduced, thereby protecting electrical equipment and extending the service life of the equipment. On the other hand, it is prepared by using environmentally friendly materials and processes such as nanofibrillated cellulose, avoiding the environmental pollution problems brought by traditional fluoride superhydrophobic coatings, and conforming to the concept of sustainable development.

[0058] As a preferred technical solution, in a superhydrophobic and anti-pollution environmental protection coating provided by this application, the diameter of the nanofibrillated cellulose is 20-50 nm, and the length is 5-15 μm; due to the higher aspect ratio of the nanofibrillated cellulose used in this application, the hydrophobic and anti-pollution performance of the coating is improved.

[0059] As a preferred technical solution, in a superhydrophobic and anti-pollution environmental protection coating provided by this application, the hydrophobic modified film-forming agent of silanol and its polycondensation product polysiloxane is formed by the hydrolysis and condensation of tetraethyl orthosilicate and / or long-chain alkyltrimethoxysilane, and the long-chain alkyltrimethoxysilane is selected from long-chain alkyltrimethoxysilanes such as dodecyltrimethoxysilane. Due to the introduction of long branched chains such as dodecyl, the hydrophobic performance of the superhydrophobic and anti-pollution environmental protection coating is improved.

[0060] As a preferred technical solution, in a superhydrophobic anti-pollution environmental protection coating provided by the present application, antibacterial agents such as silver nanoparticles, zinc oxide nanoparticles, quaternary ammonium salt compounds, copper ion compounds, and antibacterial natural essential oils are also added. The introduction of the antibacterial agents endows the anti-pollution superhydrophobic coating with excellent antibacterial properties, which can inhibit the growth and reproduction of microorganisms, reduce the corrosion and damage of microorganisms to electrical equipment, and improve the operation safety and reliability of the power system.

[0061] As a further improvement to the antibacterial agents in the superhydrophobic anti-pollution environmental protection coating provided by the present application, the antibacterial agents are preferably a combination of quaternary ammonium salt antibacterial agents and zinc oxide nanoparticles; the combination of quaternary ammonium salt antibacterial agents and zinc oxide nanoparticles. The quaternary ammonium salt antibacterial agent can adsorb on the surface of the bacterial cell membrane, and its cationic part will interact with negatively charged phospholipids and other components on the cell membrane, changing the permeability of the cell membrane, interfering with the normal metabolism and physiological functions of bacteria, and causing bacteria to die. Zinc oxide nanoparticles will slowly release zinc ions, which will combine with groups such as sulfhydryl (-SH) in bacterial cells, making the enzymes of bacteria lose their activity and interfering with the metabolic process of bacteria, resulting in the death of bacteria. The antibacterial agents provided by the present application achieve a "contact sterilization + ion release" dual-mode antibacterial mechanism. By antibacterial through the dual-mode mechanism, the antibacterial effect can be improved and the defect of easy drug resistance in the long-term use of a single antibacterial agent can be avoided.

[0062] Correspondingly, the present application also provides a preparation method for the superhydrophobic anti-pollution environmental protection coating, as Figure 1 shown. The preparation method includes: mixing tetraethyl orthosilicate, long-chain alkyltrimethoxysilane, ammonia water, and absolute ethanol, and then adding an alkali solution to adjust the pH to catalyze the hydrolysis and polycondensation reaction to obtain a hydrophobic modified film-forming agent of silanol and its polycondensation product polysiloxane; then using the hydrophobic modified film-forming agent of silanol and its polycondensation product polysiloxane to hydrophobically modify nanofibrillated cellulose, and adding antibacterial agents to prepare the coating.

[0063] In addition, the present application also provides an application of the superhydrophobic anti-pollution environmental protection coating. The application is to coat the surface of electrical equipment such as insulators by methods such as brushing, spraying, or dipping for maintenance. For example, it is sprayed on the surface of composite insulators at a pressure of 0.5 MPa, a distance of 20 cm, and a speed of 1.0 m / min, and cured at room temperature for 72 hours to obtain a superhydrophobic anti-pollution environmental protection coating, which can replace maintenance means such as live water cleaning and manual cleaning during power outages.

[0064] At the same time, the present application also provides electrical equipment with superhydrophobic anti-pollution environmental protection. Taking insulators as an example, the insulators can be glass, ceramic, or composite insulators; coating the above-mentioned superhydrophobic anti-pollution environmental protection coating on the surface of electrical equipment such as insulators and curing at room temperature for 72 hours can obtain superhydrophobic anti-pollution environmental protection insulators; of course, the electrical equipment can also be insulating sleeves, equipment bases, lightning protection wires, etc.

[0065] The following will specifically describe a superhydrophobic and anti-pollution environmental protection coating provided by the present application in combination with examples and experimental examples.

[0066] Example 1

[0067] This example provides a preparation method of a superhydrophobic and anti-pollution environmental protection coating. The preparation method includes steps of preparing nanofibrillated cellulose, preparing a hydrophobic modified film-forming agent of silanol and its polycondensation product polysiloxane, and preparing a superhydrophobic and anti-pollution environmental protection coating.

[0068] As Figure 2 shown, the steps of preparing nanofibrillated cellulose include:

[0069] Using a PFI grinder to grind bleached softwood kraft pulp, setting the rotation speed at 1000 r / min and the grinding time at 3 hours to obtain an initial cellulose slurry;

[0070] Suspending the cellulose slurry in an enzyme citric acid-sodium citrate buffer solution with a pH of 5 at a ratio of 1:20 (w / v), placing it in an incubator, setting the temperature at 50 °C, adding 5 U / g of endoglucanase and treating for 3 h to obtain a fibrillated precursor;

[0071] Using an ultrafine colloid mill to perform high-shear treatment on the fibrillated precursor at a rotation speed of 2000 r / min for 30 minutes to obtain a fibrillated cellulose slurry;

[0072] Centrifuging the fibrillated cellulose slurry and diluting it with deionized water to 1.0 wt%, then performing microfluidization circulation treatment 30 times at 20 MPa, washing with absolute ethanol and drying to obtain nanofibrillated cellulose.

[0073] The steps of preparing a hydrophobic modified film-forming agent of silanol and its polycondensation product polysiloxane include:

[0074] Mixing 10 ml of tetraethyl orthosilicate, 10 ml of dodecyltrimethoxysilane and 5 ml of ammonia water and adding them to a three-necked flask containing 150 ml of absolute ethanol, dropping 1 mol / L of NaOH solution to adjust its pH value to ..., and performing magnetic stirring at room temperature at 200 r / min for 2 h to prepare a hydrophobic modified film-forming agent, and the components of the hydrophobic modified film-forming agent are mainly silanol and its polycondensation product polysiloxane.

[0075] The steps of preparing a superhydrophobic and anti-pollution environmental protection coating include:

[0076] Adding 15 g of nanofibrillated cellulose (fibril diameter 20 - 50 nm, length 5 - 15 μm) to the modifier sol system in three portions, controlling the reaction temperature ; Surface graft modification was carried out in an ultrasonic reactor at a frequency of 80 kHz for 4 hours to obtain a coating containing hydrophobic nanofibrillated cellulose;

[0077] Add 1 wt% quaternary ammonium salt antibacterial agent and 1 wt% nano-zinc oxide antibacterial agent to the coating containing hydrophobic nanofibrillated cellulose, and stir evenly with a homogenizer to obtain a superhydrophobic anti-pollution environmental protection coating with a viscosity of about 300 cps.

[0078] Example 2

[0079] This example provides a preparation method of a superhydrophobic anti-pollution environmental protection coating. The difference between the preparation method and that of Example 1 lies in the adjustment of the antibacterial agent, including the steps of preparing nanofibrillated cellulose, preparing silanol and its polycondensation product polysiloxane hydrophobic modifier, and preparing the superhydrophobic anti-pollution environmental protection coating.

[0080] The steps of preparing nanofibrillated cellulose include:

[0081] Use a PFI grinder to grind bleached softwood kraft pulp, set the rotation speed at 1000 r / min, and the grinding time at 3 hours to obtain the initial cellulose slurry;

[0082] Suspend the cellulose slurry in an enzyme citric acid-sodium citrate buffer solution with a pH of 5 at a ratio of 1:20 (w / v), place it in an incubator, set the temperature at 50 °C, add 5 U / g endoglucanase and treat for 3 h to obtain a fibrillated precursor;

[0083] Use an ultra-fine colloid mill to perform high-shear treatment on the fibrillated precursor at a rotation speed of 2000 r / min for 30 minutes to obtain a fibrillated cellulose slurry;

[0084] Centrifuge the fibrillated cellulose slurry and dilute it with deionized water to 1.0 wt%, then perform microfluidization circulation treatment 30 times at 20 MPa, wash with absolute ethanol and dry to obtain nanofibrillated cellulose.

[0085] The steps of preparing silanol and its polycondensation product polysiloxane hydrophobic modifier include:

[0086] Mix 10 ml of tetraethyl orthosilicate, 10 ml of dodecyltrimethoxysilane and 5 ml of ammonia water and add them to a three-necked flask containing 150 ml of absolute ethanol, and add 1 mol / L NaOH solution to adjust its pH value to , and stir at room temperature at 200 r / min with magnetic stirring for 2 h to prepare a hydrophobic modifier. The main components of the hydrophobic modifier are silanol and its polycondensation product polysiloxane.

[0087] The steps of preparing the superhydrophobic anti-pollution environmental protection coating include:

[0088] Add 15 g of nanofibrillated cellulose (fiber diameter 20 - 50 nm, length 5 - 15 μm) to the modifier sol system in three portions, and control the reaction temperature ; perform surface graft modification in an ultrasonic reactor at a frequency of 80 kHz for 4 hours to obtain a coating containing hydrophobic nanofibrillated cellulose;

[0089] Add 2 wt% of a quaternary ammonium salt antibacterial agent to the coating containing hydrophobic nanofibrillated cellulose, and stir evenly using a homogenizer to obtain a superhydrophobic anti-pollution environmental protection coating.

[0090] Example 3

[0091] This example provides a preparation method of a superhydrophobic anti-pollution environmental protection coating. The difference between the preparation method and that of Example 1 lies in the adjustment of the antibacterial agent, including the steps of preparing nanofibrillated cellulose, preparing a silanol and its polycondensation product polysiloxane hydrophobic modifier film-forming agent, and preparing a superhydrophobic anti-pollution environmental protection coating.

[0092] The steps of preparing nanofibrillated cellulose include:

[0093] Use a PFI grinder to grind bleached softwood kraft pulp, set the rotation speed at 1000 r / min, and the grinding time at 3 hours to obtain an initial cellulose pulp;

[0094] Suspend the cellulose pulp in an enzyme citrate-sodium citrate buffer solution with a pH of 5 at a ratio of 1:20 (w / v), place it in an incubator, set the temperature at 50 °C, add 5 U / g of endoglucanase and treat for 3 h to obtain a fibrillated precursor;

[0095] Use an ultra-fine colloid mill to perform high-shear treatment on the fibrillated precursor at a rotation speed of 2000 r / min for 30 minutes to obtain a fibrillated cellulose pulp;

[0096] Centrifuge the fibrillated cellulose pulp, dilute it with deionized water to 1.0 wt%, then perform microfluidization circulation treatment 30 times at 20 MPa, wash with absolute ethanol and dry to obtain nanofibrillated cellulose.

[0097] The steps of preparing a silanol and its polycondensation product polysiloxane hydrophobic modifier film-forming agent include:

[0098] Mix 10 ml of tetraethyl orthosilicate, 10 ml of dodecyltrimethoxysilane and 5 ml of ammonia water, add them to a three-necked flask containing 150 ml of absolute ethanol, and dropwise add 1 mol / L NaOH solution to adjust its pH value to , magnetic stirring was adopted to stir at room temperature at 200 r / min for 2 h to prepare a hydrophobic modified film-forming agent, and the components of the hydrophobic modified film-forming agent were mainly silanol and its polycondensation product polysiloxane.

[0099] The steps for preparing the superhydrophobic anti-pollution environmental protection coating include:

[0100] 15 g of nanofibrillated cellulose (fiber diameter 20 - 50 nm, length 5 - 15 μm) was added to the modifier sol system in three portions, and the reaction temperature was controlled ; surface grafting modification was carried out in an ultrasonic reactor at a frequency of 80 kHz for 4 hours to obtain a coating containing hydrophobic nanofibrillated cellulose;

[0101] 2 wt% of nano-zinc oxide antibacterial agent was added to the coating containing hydrophobic nanofibrillated cellulose, and it was stirred evenly with a homogenizer to obtain the superhydrophobic anti-pollution environmental protection coating.

[0102] Example 4

[0103] This example provides a preparation method of a coating, which can be used as a comparative example of the example. The preparation method includes the steps of preparing a hydrophobic modified film-forming agent of silanol and its polycondensation product polysiloxane, and the steps of preparing the coating.

[0104] The steps for preparing a hydrophobic modified film-forming agent of silanol and its polycondensation product polysiloxane include:

[0105] 10 ml of tetraethyl orthosilicate, 10 ml of dodecyltrimethoxysilane and 5 ml of ammonia water were mixed and added to a three-necked flask containing 150 ml of absolute ethanol, and 1 mol / L NaOH solution was added dropwise to adjust its pH value to , magnetic stirring was adopted to stir at room temperature at 200 r / min for 2 h to prepare a hydrophobic modified film-forming agent, and the components of the hydrophobic modified film-forming agent were mainly silanol and its polycondensation product polysiloxane.

[0106] The steps for preparing the coating include:

[0107] 1 wt% of quaternary ammonium salt antibacterial agent and 1 wt% of nano-zinc oxide were added to the hydrophobic modified film-forming agent, and it was stirred evenly with a homogenizer to obtain the coating.

[0108] Experimental Example 1

[0109] In Experimental Example 1 of this application, the coatings provided in Examples 1 - 4 were subjected to performance tests, and the performance tests included hydrophobic anti-pollution performance tests, antibacterial performance tests, and weather resistance tests.

[0110] In the process of performance testing, the surface of the insulator is first cleaned to remove impurities such as oil stains and dust; one insulator is left without coating, and the remaining insulators are coated with the coatings provided in Examples 1-4 on the insulators at a pressure of 0.5 MPa, a distance of 20 cm, and a speed of 1.0 m / min, and then cured at room temperature to form a coating; subsequently, performance testing is carried out. The hydrophobic performance of the coating is tested by the contact angle test method. A suspension of Escherichia coli and Staphylococcus aureus with a certain number of colonies is inoculated on the coating surface according to the ISO 22196 standard, and then tested after being cultured in a 28-day damp heat environment ( / 95% RH). The weather resistance is tested by the salt spray accelerated aging test (ASTM B117, 500 h); the results of the hydrophobic anti-pollution performance test and the antibacterial performance test are shown in Tables 1 and 2.

[0111] Table 1: Test results of hydrophobic anti-pollution performance

[0112]

[0113] Table 2: Test results of antibacterial performance

[0114]

[0115] For the insulator without coating, there is no coating on the surface, and its water contact angle is , which is hydrophilic, and it is easy to be parasitized by microorganisms and grow and reproduce, causing pollution. From Table 1, it can be seen that after the coating provided in Example 4 of the present application is cured on the insulator at room temperature to form a coating, the water contact angle exceeds , reaching or so, indicating hydrophobicity. After the coating provided in Example 1 is cured on the insulator at room temperature to form a coating, the water contact angle is even higher, reaching or so, indicating that in the coating provided in Example 1 of the present application, hydrolysis and condensation are carried out through silanol and its polycondensation product polysiloxane and nanofibrillated cellulose, and at the same time, the nanofibrillated cellulose is hydrophobically modified. Network-structured nanofibrillated cellulose is introduced into the polysiloxane polymer structure, making the hydrophobicity of the coating further improved. Further, the rolling angle test method is used to test the coating provided in Example 1 after being coated on the insulator and cured at room temperature to form a coating. The water droplet rolling angle is or so, which is much lower than , indicating strong hydrophobicity; at the same time, according to the IEC 60507 standard, an artificial pollution test is carried out. The results show that for the insulator without coating, there is no coating on the surface, and the diatomaceous earth deposition amount reaches . After the coating provided in Example 4 is cured on the insulator at room temperature to form a coating, the diatomaceous earth deposition amount is reduced to , while after the coating provided in Example 1 cures at room temperature on the insulator to form a coating, the deposition amount of diatomaceous earth is only , and the deposition amount of pollutants such as diatomaceous earth is further reduced; through the hydrophobicity performance test and the artificial pollution test of diatomaceous earth, it shows that after the coatings provided in Examples 1 and 4 of the present application cure at room temperature on the insulator to form coatings, the dense cross-linked polysiloxane film is used to enhance the hydrophobic and anti-pollution performance of the coating. After doping nanofibrillated cellulose into the coating, through the dual mechanisms of chemical inertness and physical barrier, it can effectively block the penetration of moisture and reduce the deposition of pollutants such as diatomaceous earth, reduce the surface pollution of electrical equipment such as insulators, thereby protecting electrical equipment such as insulators and extending the service life of the equipment; on the other hand, it is prepared by using environmentally friendly materials and processes such as nanofibrillated cellulose, avoiding the environmental pollution problems brought by traditional fluoride superhydrophobic coatings, which conforms to the concept of sustainable development.

[0116] For the insulator without coating, there is no coating on the surface. After inoculating the number of colonies with Escherichia coli (E.coli) and Staphylococcus aureus (S.aureus) each ; after culturing in a humid and hot environment (40°C / 95% RH) for 28 days, the number of surface colonies respectively proliferates to (E.coli) and (S.aureus). The significant increase in the number of colonies indicates that ordinary insulators are hydrophilic and are easily parasitized and grow by microorganisms, causing pollution; while after the coating provided in Example 2 cures at room temperature on the insulator to form a coating, the number of surface colonies is (E.coli) and (S.aureus). After the coating provided in Example 3 cures at room temperature on the insulator to form a coating, the number of surface colonies is (E.coli) and (S.aureus). This shows that after introducing quaternary ammonium salt or nano-zinc oxide particle antibacterial agents into the coating, it can inhibit the growth and reproduction of Escherichia coli and Staphylococcus aureus and exert antibacterial effects; while after the coating provided in Example 1 cures at room temperature on the insulator to form a coating, the number of surface colonies is (E.coli) and (S.aureus). This shows that the present application realizes the "contact sterilization + ion release" dual-mode antibacterial mechanism through the combination of quaternary ammonium salt antibacterial agents and nano-zinc oxide. Through the dual-mode mechanism of antibacterial, it can significantly inhibit the growth and reproduction of Escherichia coli and Staphylococcus aureus, improve the antibacterial effect. The antibacterial rate of Escherichia coli reaches 99.15%, and the antibacterial rate of Staphylococcus aureus reaches 99.37%. Moreover, the combined effect of the dual-mode mechanism of antibacterial can also avoid the defect that a single antibacterial agent is prone to drug resistance after long-term use.

[0117] After the coating provided in Example 1 was cured on the insulator at room temperature to form a coating, after undergoing a salt spray accelerated aging test (500 h) according to ASTM B117 standard, the coating still maintained the contact angle , there were no corrosion points on the surface, indicating that the coating provided in the present application has strong corrosion resistance and good weather resistance; after the coating provided in Example 1 was cured on the insulator at room temperature to form a coating, after 100 dry-wet cycles, according to ISO 22196 standard, when the inoculated colony counts were each of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), after being cultured in a humid and hot environment (40 °C / 95% RH) for 28 days, the surface colony counts were respectively (E. coli), and (S. aureus), and the antibacterial effect remained good, which shows that the coating provided in Example 1 of the present application has significantly improved stability due to the use of silanol and its polycondensation product polysiloxane as film-forming components.

[0118] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A superhydrophobic anti-pollution environmental protection coating, characterized in that It includes nanofibrillated cellulose, silanol and its polycondensation product polysiloxane hydrophobic modified film-forming agent and antibacterial agent.

2. The superhydrophobic anti-pollution environmental protection coating according to claim 1, wherein The diameter of the nanofibrillated cellulose is 20 - 50 nm, and the length is 5 - 15 μm.

3. The superhydrophobic anti-pollution environmental protection coating according to claim 1, wherein The silanol and its polycondensation product polysiloxane hydrophobic modified film-forming agent are specifically: the silanol and its polycondensation product polysiloxane hydrophobic modified film-forming agent obtained by hydrolysis and condensation of tetraethyl orthosilicate and / or long-chain alkyltrimethoxysilane.

4. The superhydrophobic anti-pollution environmental protection coating according to claim 3, wherein The long-chain alkyltrimethoxysilane is selected from at least one of dodecyltrimethoxysilane, cetyltrimethoxysilane, octadecyltrimethoxysilane, isooctyltrimethoxysilane, octyltrimethoxysilane, and glycidyltrimethoxysilane.

5. The superhydrophobic anti-pollution environmental protection coating according to claim 1, wherein The superhydrophobic anti-pollution environmental protection coating further includes an antibacterial agent.

6. The superhydrophobic anti-pollution environmental protection coating according to claim 5, characterized in that, The antibacterial agent is selected from at least one of silver nanoparticles, zinc oxide nanoparticles, quaternary ammonium salt compounds, copper ion compounds, and antibacterial natural essential oils.

7. A method for preparing a superhydrophobic and anti-pollution environmental protection coating according to any one of claims 1-6, characterized in that, It includes the following steps: Step S1: Mix tetraethyl orthosilicate, long-chain alkyltrimethoxysilane, ammonia water, and absolute ethanol to obtain a mixed solution. Step S2: Add an alkali solution to the mixed solution to adjust the pH, and carry out a hydrolysis and polycondensation reaction to obtain a silanol and its polycondensation product polysiloxane hydrophobic modified film-forming agent. Step S3: Add nanofibrillated cellulose to the silanol and its polycondensation product polysiloxane hydrophobic modified film-forming agent for hydrophobic modification to obtain a coating containing hydrophobic nanofibrillated cellulose. Step S4: Add an antibacterial agent to the coating containing hydrophobic nanofibrillated cellulose and mix evenly to obtain a superhydrophobic anti-pollution environmental protection coating.

8. The preparation method of a superhydrophobic anti-pollution environmental protection coating according to claim 7, characterized in that, In step S3, the preparation method of the nanofibrillated cellulose includes the following steps: Step S31: Grind bleached softwood kraft pulp to obtain a cellulose pulp. Step S32: Mix the cellulose pulp, enzyme citrate-sodium citrate buffer solution, and endoglucanase, and carry out an enzymatic reaction to obtain a fibrillated precursor. Step S33: Carry out high-shear treatment on the fibrillated precursor to obtain a fibrillated cellulose pulp. Step S34: Carry out solid-liquid separation, dilution, microfluidization circulation treatment, washing, and drying on the fibrillated cellulose pulp in sequence to obtain nanofibrillated cellulose.

9. Application of the superhydrophobic anti-pollution environmental protection coating according to any one of claims 1 - 6 in the field of electrical equipment maintenance.

10. A superhydrophobic, anti-pollution and environmentally friendly electrical device, characterized in that, It includes an electrical equipment and a superhydrophobic anti-pollution environmental protection coating; The superhydrophobic anti-pollution environmental protection coating is formed by curing the superhydrophobic anti-pollution environmental protection coating according to any one of claims 1 - 6 on the surface of the electrical equipment.

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