Investigation on factors affecting water-based slurry based on silica aerogel

The particle size and addition amount of aerogel, as well as the type and addition amount of the dispersant, are all important factors influencing the water-based slurry of silica aerogel. The test results showed that the preferred particle size of 50 μm for the hydrophobic silica aerogel had a large particle size, relatively low surface energy, and weak agglomeration tendency, which was conducive to its dispersion stability in the water-based system. An individual dispersant could not achieve the stability of the water-based slurry based on silica aerogel. By combining dispersants, the stability of the water-based slurry based on silica aerogel could be further improved. The BX24/ZKYT231 composite dispersant could significantly improve the agglomeration phenomenon of silica aerogel in the silica aerogel slurry. When the ratio of the composite dispersant to silica aerogel was 1:10 and the silica aerogel addition amount was 10%, an excellent silica aerogel slurry with an excellent dispersion effect could be obtained. Its transmittance was 44%, the average particle size was 48 μm, and after being stored for 180 days under standard conditions, no sedimentation, stratification, or water separation occurred. The thermal conductivity of the silica aerogel slurry was 0.01912 W/(m·K), and the contact angle was 152.22°. The silica aerogel slurry modified by composite dispersant exhibits excellent dispersion stability and storage stability, while maintaining the high hydrophobicity and thermal insulation properties of the silica aerogel to the greatest extent.