CN-118165557-B - Cement-based super-hydrophobic coating with anti-freezing and anti-icing characteristics, and preparation method and application thereof

Abstract

The invention discloses a cement-based super-hydrophobic coating with anti-freezing and anti-icing characteristics, and a preparation method and application thereof, and belongs to the technical field of coating compositions. The cement-based super-hydrophobic coating is prepared from the following raw materials, by mass, 12% -16% of propyl trimethoxy silane, 3% -5% of hydroxyl-terminated polydimethylsiloxane, 30% -35% of alkaline silica sol and 47% -52% of deionized water, wherein the total proportion of the components is 100%. The coating has good permeability and air permeability and excellent superhydrophobic performance, is nontoxic and environment-friendly as a whole, has anti-icing property, can reduce the binding force of ice and cement base materials, and improves deicing efficiency. The preparation method disclosed by the invention has the advantages of simple, fast and efficient process flow without complex equipment. The cement-based superhydrophobic coating is simple to use, can greatly weaken the damage of freeze thawing cycle to cement-based materials, and improves the durability of a building structure in cold areas.

Inventors

• WANG QIAO
• CAO YUE
• ZHOU WEI
• CHANG XIAOLIN
• Gong Xuncong
• WANG YUAN

Assignees

• 武汉大学

Dates

Publication Date

20260505

Application Date

20240327

Claims (3)

1. 1. The cement-based superhydrophobic coating is characterized by comprising the following raw materials in percentage by mass: 12-16% of propyl trimethoxy silane, 3-5% of hydroxyl-terminated polydimethylsiloxane, 30-35% of alkaline silica sol and 47-52% of deionized water, wherein the sum of the components is 100%; The alkaline silica sol consists of 25-30% of nano silicon dioxide by mass, wherein the average particle size is 20-30 nm, and the pH is 10-12; The preparation method of the cement-based super-hydrophobic coating comprises the following steps: (1) Mixing a certain proportion of propyl trimethoxy silane, hydroxyl-terminated polydimethylsiloxane, alkaline silica sol and deionized water to obtain a raw material mixture; (2) Stirring the raw material mixture at a certain temperature and a certain rotating speed to obtain the cement-based super-hydrophobic coating, wherein the temperature is 28-32 ℃, the stirring speed is 750-1000 rpm, and the stirring time is 3-4.5 h.
2. 2. The method of claim 1, wherein the coating material is a coating material that improves freeze-thaw resistance of the cementitious material.
3. 3. The application according to claim 2, characterized in that it comprises the specific operations of applying a cement-based superhydrophobic coating on the surface of a cement-based material, curing at normal temperature and forming an anti-freeze-thawing superhydrophobic coating by self-assembly.

Description

Cement-based super-hydrophobic coating with anti-freezing and anti-icing characteristics, and preparation method and application thereof Technical Field The invention relates to the technical field of coating compositions, in particular to a cement-based super-hydrophobic coating with anti-freezing and anti-icing characteristics, and a preparation method and application thereof. Background The cement-based material has the advantages of rich production raw materials, low price, high compressive strength and the like, and is one of the building materials with the most consumption and the most application at present. However, cement-based materials are relatively complex in service environments and have varying durability requirements. In cold climates, ice and snow accumulation and freezing often pose serious risks to the stability and service life of the cement-based materials. The removal of ice layers frozen on the surface of materials is a major problem, and conventional deicing methods, such as mechanical deicing, chemical deicing and the like, solve the problems in a short time, but have the problems of material damage, high energy consumption, environmental pollution and the like. At the same time, freeze-thawing cycles also pose a threat to the life of cement-based materials. Moisture enters the cement-based material through the pores, and the internal pore pressure is gradually increased after multiple ice water conversions, so that the structural damage is finally caused. There are two main common treatment modes at present, the first is to increase the compactness of the material by adding cementing material to reduce the water cement ratio, so as to improve the freezing resistance, but the inherent hydrophilicity of the cement-based material cannot be changed. The second is to reduce the penetration of water into the surface of the structure by applying some organic coatings, but these organic coatings have limited durability and some coatings can bulge and fall off in a humid environment. The traditional improvement method has not effectively solved the problem of cement-based material performance degradation in cold areas, and the finding of a new protection method has important significance. For example, chinese patent publication No. CN105131830A discloses a long-acting nano hydrophobic coating composition and a preparation method thereof, wherein the long-acting nano hydrophobic coating composition comprises the following components in percentage by weight. The preparation method comprises the steps of adding fluorine-containing chlorosilane, polyorganosiloxane, rare earth salt and a film forming agent into the nano silicon dioxide sol at the temperature of 30-70 ℃ and mixing and reacting to obtain the long-acting nano hydrophobic coating. The paint is convenient to use, after the paint is sprayed on the surface of clean and dry glass, the paint is uniformly rubbed by using dry cloth, namely, a transparent nano hydrophobic coating layer is formed on the surface of the glass, the paint has a strong water repellent effect, the effective time after one-time rubbing can reach more than 3 months, and the glass becomes clear and transparent. However, the coating composition is designed for glass applications, has insufficient permeability for cement-based materials, and requires the use of organic solvents for its preparation, is costly and may have adverse environmental effects. The Chinese patent with the publication number of CN113292896A provides a finishing paint for a coating, which comprises, by mass, 47-60 parts of alkali-resistant emulsion, 0-30 parts of silica sol, 0.5-1 part of bactericide, 0.5-1 part of wetting agent, 2-4 parts of film forming auxiliary agent, 0.5-1 part of defoamer, 0.5-1 part of thickener, 15-40 parts of deionized water and 1-2 parts of hydrophobing agent. The finishing paint in the invention can completely overcome the defects of poor water resistance and weather resistance, long time, easy yellowing and the like of the finishing paint in the existing market. The deionized water is used as a solvent, and the paint is formed by matching with an auxiliary agent, so that the adhesive force of the paint is increased by using alkaline silica sol, and the hardness of the paint is enhanced. However, the increased hardness can lead to brittleness improvement, and the ice crystals expand and squeeze under repeated freeze-thawing cycles, so that the ice crystals are damaged and fall off, and the application requirements of cold areas are difficult to meet. Therefore, it is necessary to research a cement-based superhydrophobic coating for cold regions, and the superhydrophobic performance of the coating is utilized to make it difficult for ice and snow to form stable adhesion on the surface of the cement-based material, so that an efficient deicing effect is achieved, and the maintenance cost of a building is reduced. Meanwhile, the adhesion and penetration of moisture on the