Super-hydrophobic road ice-inhibiting coating based on photothermal effect and nano modified particles and preparation method of super-hydrophobic road ice-inhibiting coating

Abstract

The invention discloses a super-hydrophobic road ice-inhibiting coating based on a photothermal effect and nano modified particles and a preparation method of the super-hydrophobic road ice-inhibiting coating. The preparation method comprises the following steps: introducing silane modified nano silicon dioxide (SiO2) and titanium dioxide (TiO2) particles into a polyaniline solution, and preparing the composite super-hydrophobic powder through a chemical oxidation polymerization method. The preparation method comprises the following steps: firstly, modifying the surfaces of SiO2 and TiO2 nanoparticles by adopting a silane coupling agent, and endowing the SiO2 and TiO2 nanoparticles with low surface energy and hydrophobic property; and then adding the modified nano-particles into an aniline monomer solution, reacting with doped acid and an oxidizing agent, so that polyaniline molecules are subjected to in-situ polymerization on the surfaces of the particles, and the composite super-hydrophobic powder with a micro-nano structure is formed. The obtained composite material has excellent photothermal conversion performance and super-hydrophobic performance at the same time, and the efficient photothermal material heat absorption ice melting effect and the synergistic ice restraining effect of the photothermal material and the super-hydrophobic material can be achieved. Compared with a traditional ice-inhibiting coating, the coating disclosed by the invention shows stronger ice-resisting capability in a low-temperature and high-humidity environment, has good durability, mechanical stability and environmental protection property, and is suitable for the field of ice prevention and ice inhibition in cold regions such as roads, bridges, airport runways and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of road engineering materials, and in particular to a super-hydrophobic road ice-suppressing coating based on photothermal effect and nano-modified particles and a preparation method thereof, which is suitable for preventing and controlling road icing in winter. Background Art

[0002] Winter road icing is a major threat to traffic safety, easily causing accidents such as vehicle skidding and brake failure, resulting in significant economic losses and casualties. Traditional road deicing technology mainly relies on spreading chloride-based chemical deicing agents or mechanical deicing. Although effective in the short term, it has significant drawbacks. The long-term use of chemical deicing agents (such as sodium chloride and calcium chloride) will corrode road infrastructure (such as steel bars and asphalt layers), and at the same time cause soil salinization and water pollution. Mechanical deicing has problems such as high energy consumption, low efficiency, and easy damage to the road surface. In recent years, with the deepening of the concept of environmental protection and sustainable development, the development of new, efficient, low-cost, green deicing technologies has become a research focus.

[0003] In this context, photothermal effect materials and superhydrophobic materials have gradually attracted attention. Photothermal materials (such as polyaniline, carbon-based materials, and metal oxides) can actively melt ice by absorbing solar energy and converting it into heat energy; superhydrophobic materials reduce the adhesion between ice and the road surface and delay the icing process through micro-nano rough structures and low surface energy modifications. However, single-functional materials face significant bottlenecks in road applications: on the one hand, pure photothermal materials (such as graphene) are limited by their narrow light absorption band and low photothermal conversion efficiency (especially in rainy or low-light conditions), and are prone to failure due to UV aging or mechanical wear after long-term exposure to the outdoors; on the other hand, although traditional superhydrophobic coatings (such as hydrophobic modified materials based on SiO2 or TiO2) can reduce ice adhesion, their passive ice suppression mechanism is greatly attenuated in extremely low temperature or high humidity environments, and the surface micro-nanostructure is easily damaged by mechanical loads such as vehicle rolling and gravel friction, resulting in insufficient durability.

[0004] Existing research attempts to improve performance by composite materials, such as mixing photothermal particles with hydrophobic resins, but such simple physical blending is difficult to achieve functional synergy, and the photothermal component has weak interfacial bonding with the hydrophobic matrix, and phase separation or functional degradation is likely to occur after long-term use. In addition, the existing composite coating preparation process is complex (such as chemical vapor deposition, sol-gel method), and it is difficult to meet the large-scale construction needs of road engineering. Therefore, how to enhance the mechanical stability, environmental adaptability and construction convenience of the coating while ensuring photothermal conversion efficiency and super-hydrophobic performance has become a technical problem to be solved in this field.

[0005] Based on this, the present invention proposes a superhydrophobic road anti-icing coating based on the synergistic effect of photothermal effect and nano-modified particles. Through surface modification of nanoparticles and in-situ polymerization technology of polyaniline, a composite coating with efficient photothermal conversion, persistent superhydrophobic properties and excellent mechanical properties is constructed, providing an innovative solution to solve the defects of traditional technologies. Summary of the Invention

[0006] (1) Technical Problem

[0007] The object of the present invention is to provide a superhydrophobic road anti-icing coating based on the photothermal effect and nano-modified particles and its preparation method. By enhancing the photothermal conversion efficiency with nano-modified particles and combining the surface characteristics of superhydrophobic materials, an efficient and persistent road anti-icing effect is achieved. This coating can not only actively melt ice under light conditions, but also delay the ice formation process through the superhydrophobic surface. At the same time, it has excellent mechanical stability and environmental adaptability, meeting the anti-icing and de-icing requirements of traffic infrastructure such as roads, bridges, and airport runways in cold regions.

[0008] (2) Technical Solution

[0009] The technical solution of the present invention includes the following core contents:

[0010] 1. Coating Composition

[0011] Photothermal material: Using polyaniline as the main photothermal functional component, its broad-spectrum absorption characteristics (ultraviolet light, visible light, and near-infrared light) enable it to efficiently absorb solar energy and convert light energy into heat energy through the non-radiative transition mechanism within the molecule.

[0012] Nano-modified particles: The surface of nano-silica (SiO2, particle size 20 - 50nm) and nano-TiO2 is modified with silane coupling agent KH550 to form stable Si - O - Si and Si - O - Ti bonds, improving the particle dispersion and interfacial bonding force.

[0013] Superhydrophobic material: By introducing low surface energy groups through KH550 modification and combining with the micro-nano rough structure of nanoparticles, the coating is given superhydrophobic properties (water contact angle ≥ 150°, rolling angle ≤ 10°).

[0014] Matrix material: A two-component polyurethane resin is selected as the coating matrix to ensure the coating adhesion and weather resistance, adapting to the complex mechanical loads and environmental erosion of roads.

[0015] 2 Preparation Method

[0016] Step 1: Modification of Nanoparticles

[0017] Disperse nano-SiO2 and TiO2 in absolute ethanol and ultrasonically oscillate for 30 minutes to ensure uniform dispersion of the nanoparticles; add KH550 silane coupling agent to the dispersion (the dosage is 10%-15% of the total solution volume), adjust the pH value of the solution to 4-6 with acetic acid, and react at 70°C for 4-8 hours to cause the condensation reaction between the silanol groups of KH550 and the hydroxyl groups (-OH) on the surface of the nanoparticles, forming stable Si-O-Si and Si-O-Ti bonds to complete the modification process; after centrifugal separation, wash and dry to obtain modified nanoparticles.

[0018] Step 2: Preparation of photothermal superhydrophobic composite powder

[0019] In this step, through chemical oxidative polymerization reaction, polyaniline is in-situ polymerized on the surface of the modified nanoparticles to form a composite powder with photothermal conversion performance and superhydrophobic performance. The specific method is as follows: First, dissolve aniline monomer in hydrochloric acid solution, adjust the concentration of aniline monomer to 0.2-0.6 mol / L, and stir evenly to form an aniline monomer solution; then, add the modified nanoparticles to the aniline monomer solution and ultrasonically disperse for 30 minutes to ensure uniform distribution of the particles; next, under the condition of an ice bath (0-5°C), dissolve ammonium persulfate (APS), the oxidant, in deionized water to make an oxidant solution, and slowly drop it into the mixture, control the reaction temperature at 0-5°C, and react for 3-6 hours to oxidize the aniline monomer to generate polyaniline and deposit it in-situ on the particle surface; after the reaction, collect the precipitate by centrifugal separation, and alternately wash it with deionized water and absolute ethanol until neutral, and finally dry it at 70-100°C for 4-8 hours to obtain the photothermal superhydrophobic composite powder.

[0020] Step 3: Coating preparation and application

[0021] Coat the two-component polyurethane as a bonding layer on the target surface (such as roads, bridges, airport runways, etc.). When the polyurethane is semi-cured, evenly spray the photothermal superhydrophobic powder to ensure full combination of the powder and the polyurethane; then cure at room temperature or at 60-80°C for 4-8 hours to form a photothermal ice suppression coating with a thickness of 10-100 μm. The static water contact angle of the coating surface is ≥150°, the rolling angle is ≤10°, and it can quickly achieve active ice melting under light conditions, while significantly reducing ice adhesion, which is suitable for the anti-icing and ice suppression requirements of transportation infrastructure in cold regions.

[0022] 3. Mechanism of action

[0023] Photothermal effect: The synergistic effect of nano-TiO2 and polyaniline causes the temperature on the coating surface to rise by 40°C within 300 seconds under simulated sunlight (1000W / m 2 ) to achieve active ice melting.

[0024] Superhydrophobic property: The combined action of micro-nano rough structures and low-surface-energy groups reduces the ice adhesion strength.

[0025] Synergistic effect: The photothermal effect actively raises the road surface temperature, and the superhydrophobic surface delays icing. The two work together to significantly improve the ice suppression efficiency and durability.

[0026] Compared with the existing effects, the beneficial effects of the present invention are as follows:

[0027] 1. High-efficiency ice suppression: Through the synergistic effect of the broad-spectrum light absorption ability of polyaniline and the ultraviolet light absorption performance of nano-TiO2 in the composite material, the coating can quickly convert light energy into heat energy under light irradiation, thereby achieving an efficient active ice melting effect. This photothermal conversion ability can not only effectively accelerate the melting of ice and snow but also significantly reduce the risk of road icing.

[0028] 2. Environmentally friendly and energy-saving: This coating relies on sunlight as the energy source, avoiding additional energy consumption. Compared with traditional de-icing methods, it does not require the use of chemical de-icing agents, thus effectively reducing environmental pollution. The coating can achieve photothermal ice melting only relying on natural light or low-energy artificial light sources, significantly reducing energy consumption, and having good environmental friendliness and economic benefits.

[0029] 3. Strong durability: The surface modification of nano-SiO2 and TiO2 particles with KH550 silane coupling agent improves the dispersion of the particles and the photothermal conversion efficiency. At the same time, the KH550 modification enhances the interfacial bonding force between the particles and the polyaniline matrix, enabling the coating of the composite powder to maintain good photothermal ice suppression and superhydrophobic properties under complex mechanical loads (such as vehicle rolling) and extreme environments (such as low temperature and high humidity). In addition, the coating shows excellent anti-aging performance in multiple freeze-thaw cycles, ensuring long-term stability.

[0030] 4. Simple construction: The preparation process of the coating is simple, and the construction method is flexible. It can be directly coated on the road surface and is suitable for large-scale popularization and application. Compared with traditional chemical de-icing agents, the application of this coating does not require complex construction equipment or chemical materials, has higher promotion value, and is suitable for wide application in the field of public infrastructure.

[0031] The present invention provides a superhydrophobic road ice suppression coating based on photothermal effect and nano-modified particles and its preparation method, which has the advantages of high-efficiency ice suppression, environmental friendliness and energy saving, strong durability, etc., is suitable for preventing road icing in winter, and has broad application prospects. Brief Description of the Drawings

[0032] Figure 1 is the flowchart for the preparation of the photothermal superhydrophobic coating; Detailed Embodiments

[0034] The following is an explanation of a super-hydrophobic road anti-icing coating based on photothermal effect and nano-modified particles and its preparation method of the present invention through specific examples, including the modification of nanoparticles, the preparation of polyaniline and the preparation process of photothermal super-hydrophobic composite powder. At the same time, the effect of the present invention is verified by adjusting parameters and setting comparative examples, but the present invention is not limited to the following examples.

[0035] The experimental methods described in the examples of the present invention are conventional methods unless otherwise specified. The raw materials and reagents used are all commercially available unless otherwise specified.

[0036] Example 1

[0037] A super-hydrophobic road anti-icing coating based on photothermal effect and nano-modified particles and a preparation method thereof, the raw material dosage conditions are as follows:

[0038] (1) Surface modification of nanoparticles

[0039] Weigh 6 g of nano-silicon dioxide (SiO2, particle size 20-50 nm) and 12 g of nano-titanium dioxide (TiO2, particle size 10-30 nm), add them to 300 mL of anhydrous ethanol, and use an ultrasonic disperser to sonicate for 30 minutes to evenly disperse the particles.

[0040] Add 50 ml of KH550 silane coupling agent (γ-aminopropyltriethoxysilane) to the dispersion, stir evenly, and then slowly add 150 mL of deionized water (pH adjusted to 4-5 with 0.2 mol / L hydrochloric acid) to promote the hydrolysis of KH550 to generate silanol (Si-OH).

[0041] The mixed solution was heated to 70°C and reacted for 2 hours under stirring conditions to allow the KH550 silanol groups to undergo condensation reactions with the hydroxyl groups (-OH) on the surface of the nanoparticles to form stable Si-O-Si and Si-O-Ti bonds.

[0042] After the reaction, the reaction solution was separated using a centrifuge (4000 rpm, 20 minutes), and the precipitate was washed three times with anhydrous ethanol to remove unreacted silane coupling agent and byproducts. The washed particles were dried at 70°C for 6 hours to obtain modified nano-superhydrophobic particles.

[0043] (2) Preparation of photothermal superhydrophobic composite powder (in situ polymerization method)

[0044] Weigh 3 g of aniline monomer and dissolve it in 50 mL of 0.5 mol / L hydrochloric acid solution, and stir evenly to form an aniline monomer solution.

[0045] The modified nanoparticles (5 g) prepared in step (1) were gradually added to the aniline monomer solution and ultrasonically distributed for 30 minutes.

[0046] Dissolve 5 g of ammonium persulfate (APS) in 50 mL of deionized water to make an oxidant solution.

[0047] Place the mixed solution of modified nanoparticles and aniline monomer in an ice bath (temperature controlled at 0 - 5 °C), and slowly add the oxidant solution dropwise under stirring conditions. The reaction time is 4 hours. During this process, aniline monomers are oxidized to form polyaniline molecular chains, and at the same time, the polyaniline molecular chains are in-situ deposited on the surface of the modified nanoparticles by chemical bonding or physical adsorption to form a polyaniline-coated photothermal superhydrophobic composite powder.

[0048] (3) Separation and drying

[0049] After the reaction, wash the obtained composite powder alternately with deionized water and absolute ethanol until the washing liquid becomes neutral. Dry the washed powder in a vacuum at 70 °C for 12 hours to obtain the photothermal superhydrophobic composite powder.

[0050] (4) Preparation and application of the photothermal superhydrophobic coating

[0051] Mix the photothermal superhydrophobic composite powder prepared in step (3) with polyurethane resin at a mass ratio of 1:5, add an appropriate amount of ethanol as a dispersant, and stir evenly to prepare a spraying solution.

[0052] Spray the spraying solution evenly on the surface of the glass slide, and cure it at 70 °C for 3 hours after spraying to form a photothermal superhydrophobic coating with a thickness of 100 μm.

[0053] (5) Coating performance test

[0054] The static contact angle of the obtained coating is 153°, and the rolling angle is 8°, showing excellent superhydrophobic performance. Under the simulated sunlight irradiation conditions (light intensity 1000 W / m 2 ), the surface temperature of the coating rises rapidly, reaching 40 °C within 300 seconds, showing good photothermal conversion performance.

[0055] Comparative Example 1: Composite powder prepared from unmodified nanoparticles and aniline

[0056] To verify the influence of modified nanoparticles on the properties of the composite material, unmodified nano-silica and nano-titanium dioxide particles and aniline were used to prepare photothermal superhydrophobic composite powder by the same in-situ composite method. The preparation process was the same as that of Example 1, and KH550 was not used for modification. The specific preparation process is as follows:

[0057] (1) In-situ polymerization of unmodified nanoparticles and aniline

[0058] Weigh 6 g of unmodified nano-silica (SiO₂) and nano-titanium dioxide (TiO₂), and directly add them to the aniline monomer solution in 50 mL of 0.5 mol / L hydrochloric acid solution. Disperse them ultrasonically for 30 minutes to make the unmodified nanoparticles evenly dispersed.

[0059] Subsequently, slowly add the oxidant solution (5 g of ammonium persulfate dissolved in 50 mL of deionized water) dropwise under ice bath conditions, and react for 4 hours under stirring conditions to complete chemical oxidative polymerization, generating a composite powder with unmodified particles coated with aniline.

[0060] (2) Separation and drying

[0061] After the reaction, wash the composite powder alternately with deionized water and absolute ethanol until the washing liquid becomes neutral. Dry the washed powder in vacuum at 70 °C for 12 hours to obtain a composite powder of unmodified particles and aniline.

[0062] Performance comparison

[0063] (1) Photothermal effect test of aniline

[0064] In unmodified particles, aniline monomers polymerize to form polyaniline, and its photothermal effect is mainly reflected in the broad-spectrum absorption characteristics. Comparing the photothermal performance of the coating prepared from pure aniline, although the photothermal effect of the composite powder coating has increased, the enhancement effect of unmodified particles on the photothermal conversion efficiency is limited. Tests show that the surface temperature of the coating of the unmodified particle composite powder rises by 25 °C within 300 seconds under simulated sunlight irradiation (light intensity 1000 W / m 2 ), while the pure polyaniline coating can reach 22 °C, indicating that the enhancement effect of unmodified particles on the photothermal effect is weak.

[0065] (2) Superhydrophobic performance comparison

[0066] The static contact angle of the coating prepared from the unmodified particle composite powder is 130°, and the rolling angle is 25°, showing lower superhydrophobic performance compared to the coating in Example 1. The lack of low-surface-energy groups and micro-nano structures on the surface of unmodified particles results in weak binding ability with polyaniline, and it is difficult for the coating to form a significant superhydrophobic effect.

[0067] (3) Comparison of comprehensive photothermal and superhydrophobic performance

[0068] Although the photothermal effect of aniline monomers enables the composite coating to still have certain photothermal performance, the unmodified particles fail to effectively synergize with the photothermal performance of aniline during the photothermal conversion process, and the superhydrophobic performance is poor. In contrast, in Example 1, the modified particles and polyaniline form a stable composite structure through interfacial bonding, and are significantly superior to the composite coating of unmodified particles in both photothermal performance and superhydrophobic performance.

Claims

1. A superhydrophobic road anti-icing coating based on the photothermal effect and nano-modified particles and its preparation method, characterized in that, It includes nano-silica (SiO2) and nano-titanium dioxide (TiO2) particles modified by a silane coupling agent, as well as polyaniline in-situ polymerized on the surface of the modified particles through a chemical oxidative polymerization reaction, forming a composite powder with photothermal conversion performance and superhydrophobic performance.

2. The coating according to claim 1, characterized in that The silane coupling agent is Y-aminopropyltriethoxysilane (KH550), and its ratio to absolute ethanol is 1:5 - 1:8, the reaction temperature is from room temperature to 70 °C, and the reaction time is 4 - 8 hours.

3. The coating according to claim 1, characterized in that, The nano-modified particles are achieved through specific surface modification or doping modification.

4. The coating according to claim 1, characterized in that In the chemical oxidative polymerization reaction, the photothermal material is polyaniline, and the mass ratio of nano-SiO2 and TiO2 particles to aniline monomer is 3:1 to 6:1, the reaction temperature is 0 - 5 °C, and the reaction time is 3 - 6 hours. The composite material realizes an efficient active ice melting effect through the synergistic effect of the broadband light absorption ability of polyaniline and the ultraviolet light absorption performance of nano-TiO2.

5. A method for preparing the coating according to any one of claims 1 to 4, characterized in that: It includes the following steps: (1) Surface-modify nano-silica (SiO2) and nano-titanium dioxide (TiO2) particles with KH550 silane coupling agent to obtain modified particles with low surface energy and superhydrophobic performance; (2) Add the modified particles in step (1) into a solution containing aniline monomer, doping acid (hydrochloric acid), and oxidant (ammonium persulfate). In the chemical oxidative polymerization reaction, polyaniline molecules are in-situ polymerized on the surface of the modified particles to obtain a composite superhydrophobic powder with photothermal conversion performance and superhydrophobic performance.

6. The coating according to claim 1, characterized in that, The coating is applied to the surface of the substrate by spraying, scraping, or dipping, and the coating thickness is 10 - 100 microns, which is suitable for anti-icing and ice suppression on roads, bridges, airport runways, and other cold regions.

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