Silica (silica) plays a crucial role in dry cleaning sprays as a highly efficient adsorbent material. Its unique physicochemical properties make it a key component in dry cleaning spray formulations, but it also presents challenges in dispersibility optimization.

Oil Absorption Properties of Silica
Silica exhibits excellent oil absorption capacity, with its oil absorption value typically ranging from 1.42 to 4.41 mL/g (DBP oil absorption value). This range reflects the ability of silica particles to adsorb oils and is closely related to its physical properties such as BET specific surface area. The oil absorption mechanism of silica is mainly achieved through two mechanisms:

Surface Adsorption: The abundant silanol groups (-OH) on the surface of silica create a lipophilic effect with oil molecules, adsorbing them through electrostatic interactions.

Microporous Adsorption: Silica possesses a porous structure and high specific surface area, and its internal pores effectively capture oil molecules.
Compared to traditional adsorbents such as calcium carbonate, precipitated silica exhibits superior oil absorption performance, primarily due to its larger specific surface area and finer particle size. Experimental studies have shown that precipitated silica demonstrates significant adsorption performance for various liquid oils and solutions, not only adsorbing oils but also improving concentration and flow characteristics, thereby enhancing the stability and lifespan of liquid oils.

In dry cleaning spray formulations, precipitated silica mainly performs the following functions:
Oil Adsorption: As the main active ingredient, it adsorbs grease and stains from the surface of clothing.
Thickening Effect: It increases the viscosity of the spray system, improving the user experience.
Stabilizer: It helps maintain the uniform dispersion of other components in the formulation.

The effectiveness of precipitated silica in dry cleaning sprays is closely related to its particle size. Precipitated silica produced by the gas-phase method has an average particle size of 8-19 nm, which is finer than that of precipitated products (particle size 11-100 nm), resulting in a higher specific surface area and adsorption capacity. However, the excessively small particle size also presents dispersibility challenges, requiring surface treatment for improvement.