Mussel-imitated anti-corrosion super-hydrophobic coating for surface of bamboo laminated wood and preparation method of mussel-imitated anti-corrosion super-hydrophobic coating

Abstract

The invention belongs to the technical field of paint and coating, and particularly relates to a mussel-imitated anti-corrosion super-hydrophobic coating for the surface of bamboo laminated wood and a preparation method of the mussel-imitated anti-corrosion super-hydrophobic coating. Comprising the following steps that gamma-aminopropyltriethoxysilane, tea polyphenol and nano calcium carbonate are mixed in an absolute ethyl alcohol solution according to a certain proportion and stirred through a magnetic stirrer, then n-octyltriethoxysilane is added, stirring continues to be conducted, and the super-hydrophobic coating is obtained and smeared on the surface of the bamboo laminated wood through a brush coating or spraying force method. The super-hydrophobic bamboo laminated wood-based coating disclosed by the invention meets the requirements of super-hydrophobic materials, has excellent corrosion resistance and cohesiveness, and also has the advantages of simple process, high efficiency, no toxicity, environment friendliness, low carbon and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of coatings and coatings, and in particular relates to a mussel-like anti-corrosion super-hydrophobic coating for the surface of bamboo laminated materials and a preparation method thereof. Background Art

[0002] Global warming is primarily caused by greenhouse gases (such as CO2, CO, and CH4), with CO2 being a key factor. The construction industry contributes over 8% of global CO2 emissions, and this is expected to increase further with infrastructure expansion. Therefore, the development of sustainable building materials is crucial. Bamboo and wood, traditional building materials, have regained attention due to their lightweight, high-strength, and environmentally friendly properties. However, the conflict between surging demand for wood and resource shortages, compounded by the implementation of natural forest protection policies, has further exacerbated the problem. Bamboo is considered a potential alternative to wood due to its fast growth, renewable nature, low cost, and strong rigidity. However, its natural form is limited by its small size, thin walls, and hollow core, resulting in radial variations in mechanical properties, making it difficult to meet the demands of modern construction. To overcome these limitations, researchers have developed engineered bamboo materials, such as bamboo laminated timber. This material uses bonding and hot-pressing processes to improve dimensional stability and optimize fiber distribution to reduce radial variability in mechanical properties. However, bamboo laminated timber still suffers from issues such as water absorption, liquid adhesion, and impurity accumulation, which hinder its durability and practical application.

[0003] There have been relevant studies on the preparation of super-hydrophobic bamboo-based coatings at home and abroad. The paper (Progress in Organic Coatings, 2020, 139: 105453) proposes a nano-hybrid method to create a super-hydrophobic wood surface. This method combines the densification and reinforcement of nano-titanium dioxide with perfluorooctyltriethoxysilane to give the substrate super-hydrophobic properties. The paper (Applied Surface Science, 2018, 450: 102-111) studied the effect of modifying acidic nano-silica sol using methyltrimethoxysilane, ethyltriethoxysilane and low surface energy compounds 1H, 1H, 2H, 2H-perfluorooctyltriethoxysilane alone or in combination to obtain a super-hydrophobic coating. Patent CN105032731A discloses a method for preparing a super-hydrophobic coating. The method uses commercial fumed silica modified with fluorosilane, and then mixed with a resin in a certain proportion to finally obtain a super-hydrophobic coating. Although these studies have produced excellent super-hydrophobic coatings, the fluorinated compounds used can cause certain environmental pollution. In addition, the adhesive materials used in current research are relatively expensive. These problems limit the large-scale application of super-hydrophobic coatings.

[0004] Tea polyphenols are a green and low-cost polyphenolic substance. Their molecular structure is rich in hydroxyl functional groups, which can not only provide ligands for metal ions, but also improve interfacial compatibility and enhance the adhesion between the coating and the substrate. This paper selects low-priced tea polyphenols as a bonding substance and constructs a surface roughness structure together with nano-calcium carbonate particles. At the same time, non-fluorine low surface energy substances γ-aminopropyltriethoxysilane and n-octyltriethoxysilane are introduced for hydrophobic modification to obtain a super-hydrophobic mixed liquid, wherein γ-aminopropyltriethoxysilane can react with the hydroxyl groups in bamboo to further improve the adhesion of the substrate. The solution is sprayed on the surface of bamboo glulam in a one-step method to obtain a super-hydrophobic bamboo glulam-based coating. The present invention solves the problems of environmental pollution caused by fluorine-containing compounds and the high price of bonding substances, and is prepared in combination with the difficulties faced by bamboo in the outdoors and its own characteristics.

[0005] The prepared super-hydrophobic bamboo-based composite coating has the characteristics of high adhesion, high air permeability, green environmental protection, anti-fouling and anti-corrosion, anti-icing, and low cost, providing a scalable solution for outdoor bamboo composite construction applications. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a mussel-like anti-corrosion super-hydrophobic coating for the surface of bamboo composite materials and a preparation method thereof. The coating has the advantages of high adhesion, low cost and environmental protection, simple preparation process and excellent corrosion resistance.

[0007] To achieve the above objectives, the technical solution of the present invention is:

[0008] A mussel-like anti-corrosion super-hydrophobic coating for the surface of bamboo laminated wood and a preparation method thereof are characterized in that: n-octyl triethoxysilane is selected as a low surface energy material; nano-calcium carbonate is selected as inorganic nanoparticles, the main purpose of which is to enrich the surface roughness of the specimen; natural polyphenols such as tea polyphenols assist the nano-calcium carbonate in constructing roughness; the method comprises the following steps: (1) adding γ-aminopropyl triethoxysilane and different concentrations of tea polyphenols / nano-calcium carbonate nanoparticles to an anhydrous ethanol solution; (2) stirring the solution with a magnetic stirrer, then adding n-octyl triethoxysilane and continuing to stir; (3) pouring the prepared super-hydrophobic coating solution into a spray gun, and spraying the pre-made solution evenly onto the surface of the bamboo laminated wood with the spray gun.

[0009] Furthermore, in the step (1), 3-aminopropyltriethoxysilane and tea polyphenols / nano-calcium carbonate of different concentrations (with concentrations of 1 to 10 mg / ml) are added to the anhydrous ethanol solution.

[0010] Furthermore, in the step (2), the mixture is placed in a magnetic stirrer and magnetically stirred at a rate of 700 to 1500 r / min for 0.5 h to 1 h, and then n-octyltriethoxysilane is added and magnetically stirred at a rate of 700 to 1500 r / min for 0.5 h to 1 h at room temperature to prepare a superphobic aqueous solution.

[0011] Furthermore, in the step (3), the prepared super-hydrophobic coating solution is poured into a spray gun, and the spray gun evenly sprays the prefabricated solution onto the bamboo integrated wood at a pressure of 0.15 to 0.4 MPa, and then dried at 50° C. to obtain a super-hydrophobic bamboo integrated wood-based material.

[0012] Compared with the existing invention, the beneficial effects of the present invention are as follows:

[0013] The mussel-like super-hydrophobic coating described in this invention belongs to the field of new green building materials. Suitable for use in bamboo engineering applications, it can prevent corrosion and extend the service life of bamboo laminated timber. The coating consists of two components, solid and liquid. After mixing and blending, it is applied by brushing or spraying. After hardening, it adheres tightly to the substrate, forming a "line of defense" against external forces.

[0014] The mussel-like super-hydrophobic coating of the present invention has abundant main raw materials and low cost, and avoids the pollution of fluorine-containing organic matter to the environment. It is non-toxic and environmentally friendly, and is easy to use over a large area, and is suitable for surface protection of bamboo integrated timber structures.

[0015] The mussel-like super-hydrophobic coating of the present invention does not use epoxy resin or other glue as a binder. By adding natural polyphenols such as tea polyphenols, the interfacial compatibility is improved, thereby enhancing the adhesion between the coating and the substrate. It is a green formaldehyde-free coating.

[0016] The mussel-like super-hydrophobic bamboo laminated wood coating of the present invention solves the defects of bamboo laminated wood causing expansion, deformation and mildew after absorbing water, so that the bamboo laminated wood can be better applied in practical projects.

[0017] The mussel-like super-hydrophobic bamboo composite material-based coating of the present invention has a simple preparation process, and the coating has application advantages such as high adhesion, excellent water repellency, corrosion resistance, and the like. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of contact angles of Examples 1-4 of the present invention.

[0019] Figure 2 This is a graph showing the wear performance of sandpaper according to Example 4 of the present invention.

[0020] Figure 3 This is the surface microstructure of Example 4 of the present invention. DETAILED DESCRIPTION

[0021] The present invention is described in detail below with reference to specific embodiments, but the protection scope of the present invention is not limited to the following embodiments.

[0022] A mussel-like anti-corrosion super-hydrophobic coating for the surface of bamboo laminated timber and a preparation method thereof are characterized in that: n-octyltriethoxysilane is selected as a low-surface-energy substance; nano-calcium carbonate is selected as an inorganic nanoparticle, the main purpose of which is to enrich the surface roughness of the specimen. Tea polyphenols, a natural polyphenol substance, assist the nano-calcium carbonate in constructing the roughness. The method comprises the following steps: (1) adding γ-aminopropyltriethoxysilane and different concentrations of tea polyphenols / nano-calcium carbonate nanoparticles to an anhydrous ethanol solution; (2) stirring the solution with a magnetic stirrer, then adding n-octyltriethoxysilane and continuing to stir; (3) pouring the prepared super-hydrophobic coating solution into a spray gun, and spraying the pre-prepared solution evenly onto the surface of the bamboo laminated timber using the spray gun.

[0023] Furthermore, in the step (1), γ-aminopropyltriethoxysilane and tea polyphenols / nano-calcium carbonate of different concentrations (with concentrations of 1 to 10 mg / ml) are added to the anhydrous ethanol solution.

[0024] Furthermore, in the step (2), the mixture is placed in a magnetic stirrer and magnetically stirred at a rate of 700 to 1500 r / min for 0.5 h to 1 h, and then n-octyltriethoxysilane is added and magnetically stirred at a rate of 700 to 1500 r / min for 0.5 h to 1 h at room temperature to prepare a superphobic aqueous solution.

[0025] Furthermore, in the step (3), the prepared super-hydrophobic coating solution is poured into a spray gun, and the spray gun evenly sprays the prefabricated solution onto the bamboo integrated wood at a pressure of 0.15 to 0.4 MPa, and then dried at 50° C. to obtain a super-hydrophobic bamboo integrated wood-based material.

[0026] Example 1

[0027] A mussel-like anti-corrosion super-hydrophobic coating for the surface of bamboo laminated materials and a preparation method thereof, comprising the following steps: Step 1: Weigh 2 g of γ-aminopropyltriethoxysilane, and add a 1 mg / ml tea polyphenol / nano-calcium carbonate mixture to 50 mL of anhydrous ethanol solution while maintaining a 1:1 ratio of tea polyphenol to nano-calcium carbonate. Step 2: Place the mixture in a magnetic stirrer and stir it magnetically at a rate of 700 to 1500 r / min for 0.5 to 1 hour, then add 2 g of n-octyltriethoxysilane and stir it magnetically at a rate of 700 to 1500 r / min for 0.5 to 1 hour at room temperature to prepare a super-hydrophobic solution. Step 3: Apply the prepared mussel-like super-hydrophobic coating to the surface of the bamboo laminated materials by brushing or spraying, and cure at 50°C. The result is a mussel-like super-hydrophobic coating for the surface of the bamboo laminated materials.

[0028] Example 2

[0029] A mussel-like antiseptic super-hydrophobic coating for the surface of bamboo laminated materials and a preparation method thereof, comprising the following steps: Step 1: Weigh 2 g of γ-aminopropyltriethoxysilane, and add a 2 mg / ml tea polyphenol / nano-calcium carbonate mixture to 50 mL of anhydrous ethanol solution while maintaining a 1:1 ratio of tea polyphenol to nano-calcium carbonate. Step 2: Place the mixture in a magnetic stirrer and stir it magnetically at a rate of 700 to 1500 r / min for 0.5 to 1 hour, then add 2 g of n-octyltriethoxysilane and stir it magnetically at a rate of 700 to 1500 r / min for 0.5 to 1 hour at room temperature to prepare a super-hydrophobic solution. Step 3: Apply the prepared mussel-like super-hydrophobic coating to the surface of the bamboo laminated materials by brushing or spraying, and cure at 50°C. The result is a mussel-like super-hydrophobic coating for the surface of the bamboo laminated materials.

[0030] Example 3

[0031] A mussel-like anti-corrosion super-hydrophobic coating for the surface of bamboo laminated materials and a preparation method thereof, comprising the following steps: Step 1: Weigh 2 g of γ-aminopropyltriethoxysilane, and add a 4 mg / ml tea polyphenol / nano-calcium carbonate mixture to 50 mL of anhydrous ethanol solution while maintaining a 1:1 ratio of tea polyphenol to nano-calcium carbonate. Step 2: Place the mixture in a magnetic stirrer and stir it magnetically at a rate of 700 to 1500 r / min for 0.5 to 1 hour, then add 2 g of n-octyltriethoxysilane and stir it magnetically at a rate of 700 to 1500 r / min for 0.5 to 1 hour at room temperature to prepare a super-hydrophobic solution. Step 3: Apply the prepared mussel-like super-hydrophobic coating to the surface of the bamboo laminated materials by brushing or spraying, and cure at 50°C. The result is a mussel-like super-hydrophobic coating for the surface of the bamboo laminated materials.

[0032] Example 4

[0033] A mussel-like anti-corrosion super-hydrophobic coating for the surface of bamboo laminated materials and a preparation method thereof, comprising the following steps: Step 1: Weigh 2 g of γ-aminopropyltriethoxysilane, and add an 8 mg / ml tea polyphenol / nano-calcium carbonate mixture to 50 mL of anhydrous ethanol solution while maintaining a 1:1 ratio of tea polyphenol to nano-calcium carbonate. Step 2: Place the mixture in a magnetic stirrer and stir it magnetically at a rate of 700 to 1500 r / min for 0.5 to 1 hour, then add 2 g of n-octyltriethoxysilane and stir it magnetically at a rate of 700 to 1500 r / min for 0.5 to 1 hour at room temperature to prepare a super-hydrophobic solution. Step 3: Apply the prepared mussel-like super-hydrophobic coating to the surface of the bamboo laminated materials by brushing or spraying, and cure at 50°C. The result is a mussel-like super-hydrophobic coating for the surface of the bamboo laminated materials.

[0034] Experimental Example Static water contact angle test.

[0035] To test the water molecule penetration resistance of the mussel-like super-hydrophobic bamboo laminated wood coatings prepared in Examples 1-4 in a 3.5% Na₂SO₄ solution, static water contact angle measurements were performed on the test specimens after immersion in the 3.5% Na₂SO₄ solution for 0, 24, 48, 72, and 96 hours. The static contact angle values for each example are shown in Table 1.

[0036] As can be seen from Table 1, with the extension of the immersion time in the 3.5% Na2SO4 solution, the static water contact angle of the coating of each embodiment shows a downward trend. At the same time, it can be seen that its static water contact angle is less affected by the corrosive environment, and its numerical downward trend is smaller. After immersion for 96 hours, the water contact angle can still reach 159°.

[0037] Table 1 Variation of static water contact angle of coating

[0038] Experimental Example 3 Wear resistance test.

[0039] The adhesion performance of the coating was evaluated by a sandpaper friction test. The surface of the super-hydrophobic coating obtained in Specific Embodiment 2 was repeatedly polished with 320# sandpaper, and moved back and forth for a distance of 5 cm under a 200g weight. Different numbers of cycles were set, and the static contact angle after each cycle was measured to obtain the following: Figure 2 The sandpaper wear performance bar graph is shown.

[0040] Figure 3 This is a microscopic image of the surface morphology of a mussel-like superhydrophobic bamboo laminate coating. The image shows the interweaving of nanomaterials and n-octyltriethoxysilane to form a three-dimensional structure, and the resulting coating possesses a micro-nanostructure, which contributes to its superhydrophobic properties.

[0041] The above description is only a preferred embodiment of the present invention, which is only used to facilitate the description of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements and improvements made without departing from the technical features of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A mussel-like anticorrosive super-hydrophobic coating for the surface of bamboo laminated timber and a preparation method thereof, characterized by: Low surface energy substances are selected as γ-aminopropyltriethoxysilane and n-octyltriethoxysilane; nano-calcium carbonate is selected as inorganic nanoparticles, the main purpose of which is to enrich the surface roughness of the specimen; natural polyphenols such as tea polyphenols assist in constructing the roughness of nano-calcium carbonate; the method comprises the following steps: (1) adding γ-aminopropyltriethoxysilane and different concentrations of tea polyphenols / nano-calcium carbonate nanoparticles to an anhydrous ethanol solution; (2) stirring with a magnetic stirrer, then adding n-octyltriethoxysilane and continuing to stir; (3) pouring the prepared super-hydrophobic coating solution into a spray gun, and spraying the pre-prepared solution evenly onto the surface of the bamboo composite material through the spray gun.

2. The mussel-like anticorrosive super-hydrophobic coating for the surface of bamboo laminated timber and its preparation method according to claim 1, characterized in that: In the step (1), γ-aminopropyltriethoxysilane and tea polyphenols / nano-calcium carbonate of different concentrations (with concentrations of 1 to 10 mg / ml) are added to an anhydrous ethanol solution.

3. The mussel-like anticorrosive super-hydrophobic coating for the surface of bamboo laminated timber and its preparation method according to claim 1, characterized in that: In the step (2), the mixture is placed in a magnetic stirrer and magnetically stirred at a rate of 700 to 1500 r / min for 0.5 to 1 hour, and then n-octyltriethoxysilane is added and magnetically stirred at a rate of 700 to 1500 r / min for 0.5 to 1 hour at room temperature to prepare a superphobic aqueous solution.

4. The mussel-like anticorrosive super-hydrophobic coating for bamboo laminated timber surface and its preparation method according to claim 1, characterized in that: In the step (3), the prepared super-hydrophobic coating solution is poured into a spray gun, and the spray gun evenly sprays the prefabricated solution onto the bamboo laminated wood at a pressure of 0.15 to 0.4 MPa, and then dried at 50° C. to obtain a super-hydrophobic bamboo laminated wood base material.

Images