I. Core Properties and Waterproofing Mechanism of Silicone Oil Emulsions
Silicone oil emulsions are based on silicone oil, forming a stable dispersion system through emulsification technology. They combine the hydrophobicity of silicone oil with the ease of application of emulsions. Their core component, polysiloxane (such as hydroxy silicone oil and polyether-modified silicone oil), has a main chain composed of silane-oxygen bonds (Si-O-Si), with side chains connected to methyl, hydroxyl, or polyether groups, giving them unique waterproofing properties:
Low surface energy: The hydrophobicity of the methyl groups (—CH₃) in the silicone oil molecules significantly increases the liquid contact angle (up to 120°), creating a "lotus effect" that prevents water penetration.
Chemical film-forming properties: The active hydroxyl groups (—OH) in hydroxy silicone oil emulsions react chemically with calcium hydroxide (Ca(OH)₂) in substrates such as concrete and mortar to form calcium silicate gel, forming a dense waterproof layer. Balanced Air Permeability: Polyether-modified silicone oil emulsions, by introducing hydrophilic polyether segments, create a microporous structure within the hydrophobic film layer, allowing water vapor to permeate and preventing coating peeling caused by internal moisture accumulation.

II. Typical Applications of Silicone Oil Emulsions in Building Waterproofing
Concrete Structure Waterproofing:
In concrete projects such as basements, bridges, and tunnels, silicone oil emulsions can be used as penetrating waterproofing agents. Applied by spray or roller, they penetrate deep into the substrate and block capillary pores. For example, concrete treated with hydroxyl silicone oil emulsions can reduce water absorption by over 80%, achieving a water resistance rating of P12 or higher.
Roof and Exterior Wall Waterproofing:
Silicone oil emulsions are compounded with film-forming materials such as acrylates and polyurethanes to create elastic waterproof coatings suitable for joints such as irregular roofs and parapets. They offer excellent weather resistance, resisting cracking caused by UV rays and temperature fluctuations, and have a service life exceeding 15 years. Tile Grouting and Stone Protection:
Polyether-modified silicone oil emulsion added to grout enhances water repellency, preventing rainwater from seeping into tile gaps and causing hollowing. Its low volatile organic compound (VOC) content also meets green building standards, making it suitable for indoor and outdoor decoration projects.

III. Technical Advantages and Development Trends
Silicone oil emulsion waterproofing technology combines environmental and economic benefits:
Environmental Benefits: Water-based systems replace traditional solvent-based waterproofing materials, reducing VOC emissions by 90% and complying with the JG/T 475-2015 "Limits of Hazardous Substances in Building Waterproofing Coatings" standard.
Easy Application: The emulsion form supports a variety of application methods, including spraying and brushing. Single-component products eliminate the need for on-site mixing, shortening construction times by over 30%.
In the future, silicone oil emulsions will develop towards integrated functionality, such as self-healing waterproofing emulsions (using microencapsulation to release silicone oil to repair cracks) and photocatalytic waterproofing emulsions (decomposing organic pollutants to maintain a self-cleaning coating), to meet the needs of emerging applications such as super-high-rise buildings and sponge cities.