Preparation method of biomass incineration fly ash-based super-hydrophobic photo-thermal material coating
The preparation of superhydrophobic photothermal material coatings by biomass incineration fly ash solves the problems of high cost and unstable performance in existing technologies, and achieves high-efficiency photothermal conversion and superhydrophobic properties, which are suitable for solar thermal systems, building exterior wall protection and other fields.
Patent Information
- Application Number
- CN202510845472.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-23
- Publication Date
- 2025-10-28
AI Technical Summary
Existing superhydrophobic photothermal materials suffer from problems such as high preparation costs, unstable performance, complex processes, high environmental pollution risks, and poor adaptability, making it difficult to achieve large-scale application and industrialization.
Using biomass incineration fly ash as raw material, a material coating with excellent superhydrophobic properties and high-efficiency photothermal conversion performance was prepared through steps such as gradient separation, selective chemical activation, surface reconstruction and functional modification.
It significantly reduces preparation costs, improves the photothermal conversion efficiency and stability of materials, expands the application range, and achieves a balance between environmental and economic benefits, making it suitable for industrial production and applications in multiple fields.
Smart Images
Figure CN120842933A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a method for preparing a superhydrophobic photothermal material. Background Art
[0002] With the widespread application of biomass energy, the disposal of fly ash generated from biomass incineration has become increasingly prominent. Currently, the main method for treating this fly ash is landfill, which not only requires a large amount of land resources but also faces environmental risks such as heavy metal leaching and dust pollution. More importantly, this method completely ignores the resource value contained in the fly ash, especially its rich carbonaceous components. These carbonaceous components originate from the incomplete combustion of biomass and possess unique physicochemical properties and potential material application value, but under the current treatment model, they are all treated as waste, resulting in serious resource waste.
[0003] Traditional technologies for preparing superhydrophobic photothermal materials primarily rely on artificially synthesized carbon materials, such as carbon nanotubes and graphene. The preparation of these materials not only requires complex synthesis processes but also often involves high energy consumption and high costs. Furthermore, in practical applications, the surface modification process for these materials faces technical bottlenecks such as poor uniformity and weak adhesion. Especially in large-area preparation, traditional methods struggle to guarantee product consistency, and the surface-modified layer is prone to failure due to mechanical wear or chemical corrosion, severely impacting the material's lifespan and application range.
[0004] Existing superhydrophobic photothermal materials still suffer from unstable photothermal conversion efficiency in practical applications. This is mainly due to insufficient optimization of the material surface structure design, making it difficult to achieve efficient photothermal conversion while maintaining superhydrophobic properties. Especially in outdoor applications, the material surface is susceptible to contamination, UV aging, and temperature fluctuations, leading to a significant decline in performance. Furthermore, existing technologies generally suffer from complex process routes, high energy consumption, and high costs in material preparation, which severely restricts the large-scale production and widespread application of related products.
[0005] From an industrial production perspective, existing technologies face multiple challenges, including difficulty in controlling batch stability, low production efficiency, and poor environmental adaptability. During scale-up production, material performance fluctuates significantly, making it difficult to meet the quality requirements for industrial applications. Furthermore, existing manufacturing processes typically require large amounts of organic solvents and hazardous chemicals, increasing production costs and posing environmental pollution risks. In addition, the products exhibit poor application adaptability, easily failing in extreme environments (such as high temperatures, strong acids and alkalis, and high humidity), which severely limits their application in certain specialized fields.
[0006] In terms of industrialization and promotion, existing technologies still suffer from insufficient market competitiveness. This is mainly reflected in the following aspects: First, the high cost of raw materials, especially the expensive price of synthetic carbon materials, makes it difficult to control the cost of the final product; second, the complexity of the production process requires significant equipment investment and technological barriers, increasing the investment risk for enterprises; third, the instability of product performance affects market confidence and hinders the speed of industrialization; finally, the existing intellectual property protection system is inadequate, resulting in insufficient innovation motivation and difficulty in forming a sustainable technological advantage. These problems seriously affect the healthy development of the superhydrophobic photothermal materials industry. Summary of the Invention
[0007] This invention aims to solve the problem of resource utilization of biomass incineration fly ash, and proposes a simple and feasible preparation process to transform waste fly ash into functional materials with excellent superhydrophobic properties and efficient photothermal conversion properties, thereby achieving a balance between environmental and economic benefits.
[0008] The preparation method of the biomass incineration fly ash-based superhydrophobic photothermal material coating of the present invention is carried out according to the following steps:
[0009] I. Gradient Separation and Enrichment of Active Components in Fly Ash
[0010] The fly ash from biomass incineration is classified by particle size, and the particle size fraction with the highest carbon content is selected to obtain fly ash enriched with active components.
[0011] II. Selective Chemical Activation of Fly Ash
[0012] At 30-40℃, fly ash enriched with active components is acid-soaked with an acid solution of 0.5-3 mol / L, and then alkali-soaked with a sodium hydroxide solution of 0.1-0.5 mol / L at 60-70℃. After washing and drying, chemically activated fly ash is obtained.
[0013] III. Surface Reconstruction of Fly Ash
[0014] In an inert atmosphere, chemically activated fly ash is treated at 400-600℃ for 1-2 hours, then (rapidly) heated to 800-900℃, held for 10-30 minutes and (immediately) cooled to obtain pretreated carbonaceous particles.
[0015] IV. Surface Activation Treatment
[0016] The pretreated carbon particles were surface activated by plasma activation treatment, chemical oxidation activation treatment or ultraviolet ozone activation treatment to obtain activated carbon particles.
[0017] The plasma treatment involves placing pretreated carbonaceous particles in the vacuum chamber of a plasma treatment device, using oxygen, argon, or nitrogen as the working gas. The working gas is excited to form plasma for plasma activation treatment.
[0018] Chemical oxidation activation treatment involves immersing pretreated carbonaceous particles in an oxidant solution for chemical oxidation activation. The oxidant solution is a potassium permanganate solution, a hydrogen peroxide solution, or an ozone solution.
[0019] Ultraviolet ozone activation treatment involves introducing dry air or oxygen into an ultraviolet ozone generator, converting the oxygen into ozone through 185nm ultraviolet light irradiation, and simultaneously promoting ozone decomposition with 254nm ultraviolet light to perform in-situ activation treatment on the pretreated carbon particles.
[0020] V. Functional Modification Treatment
[0021] Hydrophobic modification of activated carbon particles was performed using vapor phase deposition or liquid phase deposition to obtain modified carbon particles.
[0022] The aforementioned vapor deposition method involves placing activated carbon particles in a sealed vacuum reactor. A modifier is placed in an evaporator at one end of the vacuum reactor, while the activated carbon particles are placed at the other end. After evacuation, a carrier gas is introduced, and the temperature of the vacuum reactor is raised to 50-90°C. The modifier is vaporized through the evaporator and transported with the carrier gas to one end of the activated carbon particles for vapor deposition, thereby obtaining modified carbon particles.
[0023] The liquid phase deposition method involves dissolving a modifier in an organic solvent, adding activated carbon particles, heating and refluxing, and then washing and drying to obtain modified carbon particles.
[0024] VI. Heat treatment and curing
[0025] The modified carbonaceous particles were heat-treated at a temperature of 150-250℃ under an inert atmosphere to obtain heat-treated carbonaceous particles.
[0026] VII. Coating Preparation
[0027] Heat-treated carbonaceous particles, matrix materials and additives are mixed to obtain mixed raw materials, and a superhydrophobic photothermal material coating based on biomass incineration fly ash is prepared by spraying, dipping or scraping processes.
[0028] The modifier mentioned in step five is dodecyltrichlorosilane, tetradecyltrichlorosilane, hexadecyltrichlorosilane, octadecyltrichlorosilane, perfluorooctyltrichlorosilane, perfluorodecyltrichlorosilane, or methyltrimethoxysilane;
[0029] The matrix material mentioned in step seven is epoxy resin, polyurethane, or silicone resin.
[0030] The preparation method of the superhydrophobic photothermal material coating based on biomass incineration fly ash of the present invention has the following beneficial effects:
[0031] Firstly, this invention enables the high-value utilization of biomass incineration fly ash. Through gradient separation and selective activation processes, the carbonaceous content in waste fly ash is increased from the initial 40-50% to 65-75%. This multi-stage treatment process not only solves environmental problems but also significantly reduces the preparation cost of superhydrophobic photothermal materials, lowering the cost by more than 60% compared to traditional synthetic carbon-based materials, thus laying the foundation for the large-scale application of the materials.
[0032] Secondly, the surface reconstruction process developed in this invention achieves directional control of the carbonaceous structure of fly ash. Through a rapid thermal treatment process, a graphitized structure with preferred orientation is formed on the fly ash surface, increasing the light absorption rate of the material in the near-infrared region (780-2500nm) to over 90%, far exceeding the 60-70% absorption rate of traditional photothermal materials. Simultaneously, the reconstructed surface structure significantly increases the specific surface area of the material, providing more active sites for subsequent functional modification.
[0033] Thirdly, this invention establishes a complete fly ash modification system. Through a combination of acid-base synergistic activation and vapor deposition, the surface achieves superhydrophobicity while maintaining the material's excellent photothermal properties. The prepared material exhibits an extremely high water contact angle (>150°) and an extremely low roll-off angle (<10°), and remains stable within a temperature range of -40°C to 200°C. This multifunctional integrated characteristic significantly expands the material's application range.
[0034] Fourthly, the preparation process of this invention is characterized by its versatility and simplicity. The entire preparation process employs mild reaction conditions, requiring no special equipment or harsh conditions, and its energy consumption is only 50% of that of traditional methods. Furthermore, this process is applicable to biomass incineration fly ash from various sources, demonstrating good raw material adaptability. The product performance is stable, with batch-to-batch fluctuations of less than 5%, providing a reliable guarantee for industrial production. Attached Figure Description
[0035] Figure 1 This is a magnified SEM image of the superhydrophobic photothermal material coating based on biomass incineration fly ash obtained in the example;
[0036] Figure 2 This is a SEM image of the superhydrophobic photothermal material coating based on biomass incineration fly ash obtained in the example;
[0037] Figure 3This is an infrared thermograph of the superhydrophobic photothermal material coating based on biomass incineration fly ash in the application example. Detailed Implementation
[0038] Specific Implementation Method 1: The preparation method of the biomass incineration fly ash-based superhydrophobic photothermal material coating in this implementation method is carried out according to the following steps:
[0039] I. Gradient Separation and Enrichment of Active Components in Fly Ash
[0040] The fly ash from biomass incineration is classified by particle size, and the particle size fraction with the highest carbon content is selected to obtain fly ash enriched with active components.
[0041] II. Selective Chemical Activation of Fly Ash
[0042] At 30-40℃, fly ash enriched with active components is acid-soaked with an acid solution of 0.5-3 mol / L, and then alkali-soaked with a sodium hydroxide solution of 0.1-0.5 mol / L at 60-70℃. After washing and drying, chemically activated fly ash is obtained.
[0043] III. Surface Reconstruction of Fly Ash
[0044] In an inert atmosphere, chemically activated fly ash is treated at 400-600℃ for 1-2 hours, then (rapidly) heated to 800-900℃, held for 10-30 minutes and (immediately) cooled to obtain pretreated carbonaceous particles.
[0045] IV. Surface Activation Treatment
[0046] The pretreated carbon particles were surface activated by plasma activation treatment, chemical oxidation activation treatment or ultraviolet ozone activation treatment to obtain activated carbon particles.
[0047] The plasma treatment involves placing pretreated carbonaceous particles in the vacuum chamber of a plasma treatment device, using oxygen, argon, or nitrogen as the working gas. The working gas is excited to form plasma for plasma activation treatment.
[0048] Chemical oxidation activation treatment involves immersing pretreated carbonaceous particles in an oxidant solution for chemical oxidation activation. The oxidant solution is a potassium permanganate solution, a hydrogen peroxide solution, or an ozone solution.
[0049] Ultraviolet ozone activation treatment involves introducing dry air or oxygen into an ultraviolet ozone generator, converting the oxygen into ozone through 185nm ultraviolet light irradiation, and simultaneously promoting ozone decomposition with 254nm ultraviolet light to perform in-situ activation treatment on the pretreated carbon particles.
[0050] V. Functional Modification Treatment
[0051] Hydrophobic modification of activated carbon particles was performed using vapor phase deposition or liquid phase deposition to obtain modified carbon particles.
[0052] The aforementioned vapor deposition method involves placing activated carbon particles in a sealed vacuum reactor. A modifier is placed in an evaporator at one end of the vacuum reactor, while the activated carbon particles are placed at the other end. After evacuation, a carrier gas is introduced, and the temperature of the vacuum reactor is raised to 50-90°C. The modifier is vaporized through the evaporator and transported with the carrier gas to one end of the activated carbon particles for vapor deposition, thereby obtaining modified carbon particles.
[0053] The liquid phase deposition method involves dissolving a modifier in an organic solvent, adding activated carbon particles, heating and refluxing, and then washing and drying to obtain modified carbon particles.
[0054] VI. Heat treatment and curing
[0055] The modified carbonaceous particles were heat-treated at a temperature of 150-250℃ under an inert atmosphere to obtain heat-treated carbonaceous particles.
[0056] VII. Coating Preparation
[0057] Heat-treated carbonaceous particles, matrix materials and additives are mixed to obtain mixed raw materials, and a superhydrophobic photothermal material coating based on biomass incineration fly ash is prepared by spraying, dipping or scraping processes.
[0058] The modifier mentioned in step five is dodecyltrichlorosilane, tetradecyltrichlorosilane, hexadecyltrichlorosilane, octadecyltrichlorosilane, perfluorooctyltrichlorosilane, perfluorodecyltrichlorosilane, or methyltrimethoxysilane;
[0059] The matrix material mentioned in step seven is epoxy resin, polyurethane, or silicone resin.
[0060] In this embodiment, after particle size classification in step one, the carbon content of each component is determined by thermogravimetric analysis, and the particle size component with the highest carbon content (usually 20-50 μm) is selected for subsequent processing. During the separation process, the cutting particle size of the cyclone separator can be optimized by adjusting the air intake velocity (10-30 m / s) and the structural parameters of the cyclone. This step can increase the carbon content from the initial 40-50% to 65-75%. After chemical activation treatment in step two, the specific surface area of the material can be increased from the initial 50-100 m² / g to 200-300 m² / g. The heat treatment process in step six can increase the bonding strength between the modified layer and the matrix, improving the durability of the material.
[0061] The first objective of this embodiment is to provide a method for preparing a superhydrophobic photothermal material based on biomass incineration fly ash. This method modifies the surface of biomass incineration fly ash to achieve superhydrophobic properties while retaining its carbonaceous photothermal components. Specifically, the fly ash is first pretreated to obtain carbonaceous particles of suitable size, then the particle surface is activated by plasma treatment, and finally hydrophobic modification is performed using vapor deposition, thereby obtaining a functional material with excellent photothermal conversion performance and superhydrophobic properties.
[0062] The second objective of this invention is to provide a superhydrophobic photothermal material based on biomass incineration fly ash prepared using the above-described method. This material possesses the following characteristics: a surface contact angle greater than 150 degrees, a roll-off angle less than 10 degrees, a photothermal conversion efficiency exceeding 60%, and good mechanical and chemical stability. This material can effectively solve the problems of high preparation cost and unstable performance of traditional superhydrophobic photothermal materials.
[0063] A third objective of this invention is to provide a method for applying the aforementioned material. This material can be widely used in solar thermal systems, building exterior wall protection, industrial equipment protection, and other fields, achieving multiple functions such as self-cleaning, anti-icing, and corrosion resistance.
[0064] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that the biomass incineration fly ash in step one is produced by biomass incineration, and the biomass is corn stalks, rice straw, wood chips or waste paper.
[0065] Specific Implementation Method 3: This implementation method differs from Specific Implementation Method 1 or 2 in that a cyclone separator is used in step 1 to classify the particle size of biomass incineration fly ash.
[0066] Specific Implementation Method Four: This implementation method differs from Specific Implementation Methods One to Three in that the carbon content in the fly ash enriched with active components in step one is 65%-75%.
[0067] Specific Implementation Method 5: This implementation method differs from Specific Implementation Methods 1 to 4 in that the acid soaking treatment time in step 2 is 2-4 hours, and the alkali soaking treatment time is 1-2 hours.
[0068] In this embodiment, the acid solution can be 1-3 mol / L hydrochloric acid, 0.5-2 mol / L sulfuric acid, or 1-3 mol / L nitric acid.
[0069] Specific Implementation Method Six: This implementation method differs from Specific Implementation Methods One to Five in that in step three, the temperature is raised to 400-600℃ at a heating rate of 5℃ / min to treat the activated fly ash for 1-2 hours, and then the temperature is raised to 800-900℃ at a heating rate of 20-50℃ / min.
[0070] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Methods One through Six in that the microwave power is controlled within the range of 200-500W during the plasma treatment process in step four, and the plasma activation treatment time is 5-15 minutes.
[0071] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Methods One to Seven in that the concentration of potassium permanganate solution in the chemical oxidation activation treatment in step four is 0.1-0.5 mol / L, and the concentration of hydrogen peroxide solution is 10-30 wt%.
[0072] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Methods One to Eight in that the vapor deposition reaction time in step five is 2-6 hours.
[0073] Specific Implementation Method 10: This implementation method differs from Specific Implementation Methods 1 to 9 in that the heat treatment time in step 6 is 0.5-3 hours.
[0074] Specific Implementation Method Eleven: This implementation method differs from Specific Implementation Methods One through Ten in that the raw materials mixed in step seven also contain nano-oxide materials or thermally conductive materials. The nano-oxide materials are nano-silicon dioxide, nano-zinc oxide, or nano-alumina, and the thermally conductive materials are nano-silver or boron nitride.
[0075] In this embodiment, the mass ratio of heat-treated carbonaceous particles to nano-oxide materials is in the range of 1:0.05 to 1:0.1, which can enhance the mechanical strength and wear resistance of the material. The mass ratio of heat-treated carbonaceous particles to thermally conductive materials is in the range of 1:0.1 to 1:0.3, which can improve the thermal conductivity of the material.
[0076] Specific Implementation Method Twelve: This implementation method differs from Specific Implementation Methods One to Eleven in that when using the spraying process in step seven, the spraying pressure is controlled to be 0.2-2 MPa and the spraying distance is 5-30 cm.
[0077] Specific Implementation Method Thirteen: This implementation method differs from Specific Implementation Methods One to Twelve in that the additives mentioned in step seven are curing agents and diluents.
[0078] In this embodiment, the curing agent can be an amine curing agent or an acid anhydride curing agent, and the diluent can be xylene or acetone.
[0079] Example 1: The preparation method of the superhydrophobic photothermal material coating based on biomass incineration fly ash in this example is carried out according to the following steps:
[0080] I. Gradient Separation and Enrichment of Active Components in Fly Ash
[0081] The fly ash from corn stalk combustion was classified by particle size using a cyclone separator to obtain three different particle size fractions: >100μm, 50-100μm, and 20-50μm. The fly ash fraction with a particle size of 20-50μm and a carbon content of 70% was selected to obtain fly ash enriched with active components.
[0082] II. Selective Chemical Activation of Fly Ash
[0083] At 35℃, fly ash enriched with active components was acid-soaked in 1 mol / L sulfuric acid for 3 hours, and then alkali-soaked in 0.3 mol / L sodium hydroxide solution for 1.5 hours at 65℃. After washing and drying, chemically activated fly ash was obtained, and the specific surface area of the activated fly ash was increased to 250 m² / g.
[0084] III. Surface Reconstruction of Fly Ash
[0085] In a nitrogen atmosphere, chemically activated fly ash was treated at 500°C for 1.5 hours, then rapidly heated to 850°C, held for 20 minutes and cooled immediately to obtain pretreated carbonaceous particles.
[0086] IV. Surface Activation Treatment
[0087] The pretreated carbon particles were surface activated by plasma activation treatment to obtain activated carbon particles.
[0088] The plasma treatment involves placing the pretreated carbonaceous particles in the vacuum chamber of a microwave plasma treatment device, using oxygen as the working gas, with a microwave power of 300W, and the working gas is excited to form plasma for 10 minutes to perform plasma activation treatment.
[0089] V. Functional Modification Treatment
[0090] Hydrophobic modification of activated carbon particles was performed using vapor deposition. The activated carbon particles were placed in a tubular vacuum reactor. Octadecyltrichlorosilane was placed in an evaporator at one end of the vacuum reactor, and the activated carbon particles were placed at the other end of the vacuum reactor. After the vacuum was evacuated to below 1 Pa, nitrogen was introduced as a carrier gas. The temperature of the vacuum reactor was raised to 60°C. Octadecyltrichlorosilane was vaporized through the evaporator and transported with the carrier gas to one end of the activated carbon particles for vapor deposition reaction for 4 hours to obtain modified carbon particles.
[0091] VI. Heat treatment and curing
[0092] Under a nitrogen atmosphere, the modified carbon particles were heat-treated at 180°C for 2 hours to obtain the heat-treated carbon particles.
[0093] VII. Coating Preparation
[0094] Heat-treated carbonaceous particles, epoxy resin, and curing agent were mixed in a mass ratio of 1:3 to obtain a mixed raw material. The spraying pressure was controlled at 1.5 MPa and the spraying distance was 15 cm. A superhydrophobic photothermal material coating based on biomass incineration fly ash was prepared by spraying.
[0095] Figure 2 This is a SEM image of the coating, which exhibits a distinct micro / nano structure. Figure 3 It can be seen that, under room temperature conditions and irradiation with 808nm near-infrared light, the surface temperature of the coating rapidly increases to 62.2℃ within 30s.
[0096] In this embodiment, the coating was sprayed onto the surface of a solar collector panel. The resulting coating had a water contact angle of 158°, a roll-off angle of 6°, and a solar absorption rate of 94%. Compared with the unmodified collector panel, the heat collection efficiency was improved by 35%. After one year of continuous operation, the coating performance retention rate exceeded 90%.
[0097] Example 2: The preparation method of the superhydrophobic photothermal material coating based on biomass incineration fly ash in this example is carried out according to the following steps:
[0098] I. Gradient Separation and Enrichment of Active Components in Fly Ash
[0099] A cyclone separator was used to classify the fly ash from wood chip incineration by particle size. The fly ash components with a particle size of 30-50 μm and a carbon content of 68% were selected to obtain fly ash enriched with active components.
[0100] II. Selective Chemical Activation of Fly Ash
[0101] At 35℃, fly ash enriched with active components was acid-soaked in 1.2mol / L hydrochloric acid for 3 hours, and then alkali-soaked in 0.4mol / L sodium hydroxide solution for 1.5 hours at 65℃. After washing and drying, activated fly ash was obtained, and the specific surface area of the activated fly ash was increased to 280m² / g.
[0102] III. Surface Reconstruction of Fly Ash
[0103] In a nitrogen atmosphere, activated fly ash was treated at 450°C for 1.5 hours, then rapidly heated to 880°C, held for 20 minutes and cooled immediately to obtain pretreated carbonaceous particles.
[0104] IV. Surface Activation Treatment
[0105] The surface of pretreated carbon particles was activated by ultraviolet ozone activation treatment. Dry oxygen was introduced into a closed ultraviolet ozone reactor, and dual-wavelength ultraviolet lamps with wavelengths of 185nm and 254nm were used for irradiation. The 185nm ultraviolet light could decompose oxygen to generate ozone, while the 254nm ultraviolet light irradiated the pretreated carbon particles and promoted the decomposition of ozone to generate active oxygen species. The reaction time was 90 minutes, and the ozone concentration in the reactor was maintained at 30-50 mg / L to obtain activated carbon particles.
[0106] V. Functional Modification Treatment
[0107] Hydrophobic modification of activated carbon particles was carried out by liquid phase deposition method. The perfluorooctyltrichlorosilane modifier was dissolved in an organic solvent, and then the activated carbon particles were added. The mixture was heated and refluxed, and after washing and drying, the modified carbon particles were obtained.
[0108] VI. Heat treatment and curing
[0109] Under a nitrogen atmosphere, the modified carbon particles were heat-treated at 180°C for 2 hours to obtain the heat-treated carbon particles.
[0110] VII. Coating Preparation
[0111] Heat-treated carbonaceous particles, silicone resin, curing agent, and xylene diluent were mixed in a mass ratio (carbonaceous particles: silicone resin: curing agent: diluent = 1:3:0.3:0.5) to obtain a mixed raw material. The spraying pressure was controlled at 1.5 MPa and the spraying distance was 15 cm. A superhydrophobic photothermal material coating (double-layer structure, total thickness 200 μm) based on biomass incineration fly ash was prepared by spraying process.
[0112] In this embodiment, the coating is sprayed onto the inner wall of the cooling tower. The coating exhibits excellent waterproof and anti-fouling properties, with a water contact angle of 162° and a surface tension of less than 5 mN / m. In actual operation, the cooling tower's heat exchange efficiency is increased by 22%, the cleaning and maintenance cycle is extended from once a month to once a quarter, and the annual maintenance cost is reduced by approximately 45%.
[0113] Example 3: The preparation method of the superhydrophobic photothermal material coating based on biomass incineration fly ash in this example is carried out according to the following steps:
[0114] I. Gradient Separation and Enrichment of Active Components in Fly Ash
[0115] The fly ash from straw burning was classified by particle size using a cyclone separator. The fly ash components with a particle size of 30-50 μm and a carbon content of 72% were selected to obtain fly ash enriched with active components.
[0116] II. Selective Chemical Activation of Fly Ash
[0117] At 35℃, fly ash enriched with active components was acid-soaked in 1.2mol / L hydrochloric acid for 3 hours, and then alkali-soaked in 0.4mol / L sodium hydroxide solution for 1.5 hours at 65℃. After washing and drying, activated fly ash was obtained, and the specific surface area of the activated fly ash was increased to 280m² / g.
[0118] III. Surface Reconstruction of Fly Ash
[0119] In a nitrogen atmosphere, activated fly ash was treated at 500°C for 2 hours, then rapidly heated to 900°C, held for 15 minutes, and immediately cooled to obtain pretreated carbonaceous particles, which resulted in a light absorption rate of 95% in the near-infrared region (780-2500nm).
[0120] IV. Surface Activation Treatment
[0121] The pretreated carbon particles were surface activated by plasma activation treatment to obtain activated carbon particles.
[0122] The plasma treatment involves placing the pretreated carbonaceous particles in the vacuum chamber of a microwave plasma treatment device, using oxygen as the working gas, with a microwave power of 300W, and the working gas is excited to form plasma for 10 minutes to perform plasma activation treatment.
[0123] V. Functional Modification Treatment
[0124] Hydrophobic modification of activated carbon particles was performed using liquid phase deposition. Perfluorooctyltrichlorosilane modifier was dissolved in an organic solvent, and then the activated carbon particles were added. The mixture was heated under reflux and then washed and dried to obtain the modified carbon particles.
[0125] VI. Heat treatment and curing
[0126] Under a nitrogen atmosphere, the modified carbon particles were heat-treated at 180°C for 2 hours to obtain the heat-treated carbon particles.
[0127] VII. Coating Preparation
[0128] Heat-treated carbonaceous particles, epoxy resin, and curing agent were mixed in a mass ratio of 1:4 to obtain a mixed raw material. The spraying pressure was controlled at 1.5 MPa and the spraying distance at 15 cm. A superhydrophobic photothermal material coating (double-layer structure, total thickness 200 μm) based on biomass incineration fly ash was prepared by spraying process.
[0129] In this embodiment, a protective coating is sprayed onto the surface of the transmission line. This coating exhibits dual anti-icing functions in cold environments: during the day, it maintains the surface temperature above 0°C through photothermal conversion, effectively preventing icing; at night, its superhydrophobic properties significantly reduce the surface adhesion of water droplets, reducing icing intensity by more than 90%.
Claims
1. A method for preparing a superhydrophobic photothermal material coating based on biomass incineration fly ash, characterized in that... The preparation method of biomass incineration fly ash-based superhydrophobic photothermal material coating is carried out according to the following steps: I. Gradient Separation and Enrichment of Active Components in Fly Ash The fly ash from biomass incineration is classified by particle size, and the particle size fraction with the highest carbon content is selected to obtain fly ash enriched with active components. II. Selective Chemical Activation of Fly Ash At 30-40℃, fly ash enriched with active components is acid-soaked with an acid solution of 0.5-3 mol / L, and then alkali-soaked with a sodium hydroxide solution of 0.1-0.5 mol / L at 60-70℃. After washing and drying, chemically activated fly ash is obtained. III. Surface Reconstruction of Fly Ash In an inert atmosphere, chemically activated fly ash is treated at 400-600℃ for 1-2 hours, then heated to 800-900℃ and kept at 10-30 minutes for cooling to obtain pretreated carbonaceous particles. IV. Surface Activation Treatment The pretreated carbon particles were surface activated by plasma activation treatment, chemical oxidation activation treatment or ultraviolet ozone activation treatment to obtain activated carbon particles. The plasma treatment involves placing pretreated carbonaceous particles in the vacuum chamber of a plasma treatment device, using oxygen, argon, or nitrogen as the working gas. The working gas is excited to form plasma for plasma activation treatment. Chemical oxidation activation treatment involves immersing pretreated carbonaceous particles in an oxidant solution for chemical oxidation activation. The oxidant solution is a potassium permanganate solution, a hydrogen peroxide solution, or an ozone solution. Ultraviolet ozone activation treatment involves introducing dry air or oxygen into an ultraviolet ozone generator, converting the oxygen into ozone through 185nm ultraviolet light irradiation, and simultaneously promoting ozone decomposition with 254nm ultraviolet light to perform in-situ activation treatment on the pretreated carbon particles. V. Functional Modification Treatment Hydrophobic modification of activated carbon particles was performed using vapor phase deposition or liquid phase deposition to obtain modified carbon particles. The aforementioned vapor deposition method involves placing activated carbon particles in a sealed vacuum reactor. A modifier is placed in an evaporator at one end of the vacuum reactor, while the activated carbon particles are placed at the other end. After evacuation, a carrier gas is introduced, and the temperature of the vacuum reactor is raised to 50-90°C. The modifier is vaporized through the evaporator and transported with the carrier gas to one end of the activated carbon particles for vapor deposition, thereby obtaining modified carbon particles. The liquid phase deposition method involves dissolving a modifier in an organic solvent, adding activated carbon particles, heating and refluxing, and then washing and drying to obtain modified carbon particles. VI. Heat treatment and curing The modified carbonaceous particles were heat-treated at a temperature of 150-250℃ under an inert atmosphere to obtain heat-treated carbonaceous particles. VII. Coating Preparation Heat-treated carbonaceous particles, matrix materials and additives are mixed to obtain mixed raw materials, and a superhydrophobic photothermal material coating based on biomass incineration fly ash is prepared by spraying, dipping or scraping processes. The modifier mentioned in step five is dodecyltrichlorosilane, tetradecyltrichlorosilane, hexadecyltrichlorosilane, octadecyltrichlorosilane, perfluorooctyltrichlorosilane, perfluorodecyltrichlorosilane, or methyltrimethoxysilane; The matrix material mentioned in step seven is epoxy resin, polyurethane, or silicone resin.
2. The method for preparing a biomass incineration fly ash-based superhydrophobic photothermal material coating according to claim 1, characterized in that... In step one, the fly ash from biomass incineration is produced by biomass incineration, and the biomass is corn stalks, rice straw, wood chips, or waste paper.
3. The method for preparing a biomass incineration fly ash-based superhydrophobic photothermal material coating according to claim 1, characterized in that... In step one, a cyclone separator is used to classify the particle size of biomass incineration fly ash.
4. The method for preparing a biomass incineration fly ash-based superhydrophobic photothermal material coating according to claim 1, characterized in that... The carbon content in the fly ash enriched with active components in step one is 65%-75%.
5. The method for preparing a biomass incineration fly ash-based superhydrophobic photothermal material coating according to claim 1, characterized in that... In step two, the acid soaking treatment time is 2-4 hours, and the alkali soaking treatment time is 1-2 hours.
6. The method for preparing a superhydrophobic photothermal material coating based on biomass incineration fly ash according to claim 1, characterized in that... In step four, the microwave power is controlled within the range of 200-500W during plasma treatment, and the plasma activation treatment time is 5-15 minutes.
7. The method for preparing a biomass incineration fly ash-based superhydrophobic photothermal material coating according to claim 1, characterized in that... In step four, the concentration of potassium permanganate solution in the chemical oxidation activation treatment is 0.1-0.5 mol / L, and the concentration of hydrogen peroxide solution is 10-30 wt%.
8. The method for preparing a superhydrophobic photothermal material coating based on biomass incineration fly ash according to claim 1, characterized in that... The vapor deposition reaction time in step five is 2-6 hours.
9. The method for preparing a superhydrophobic photothermal material coating based on biomass incineration fly ash according to claim 1, characterized in that... In step seven, the mixed raw materials also contain nano-oxide materials or thermally conductive materials. The nano-oxide materials are nano-silicon dioxide, nano-zinc oxide, or nano-alumina, and the thermally conductive materials are nano-silver or boron nitride.
10. The method for preparing a superhydrophobic photothermal material coating based on biomass incineration fly ash according to claim 1, characterized in that... When using the spraying process in step seven, control the spraying pressure to be 0.2-2MPa and the spraying distance to be 5-30cm.