Wettability Study of Super-Hydrophobic Silica Aerogel Powders

Due to the importance of super-hydrophobic silica aerogel powder as a material in the field of energy saving, its wettability in the presence of various surfactants was investigated. One anionic and two non-ionic surfactants with different molecular structures were used as wetting and dispersing agents. Wetting properties of the aerogel powders were investigated by the contact angle measurements based on sessile drop method. The experimental results demonstrated that the silica aerogel powders are highly hydrophobic which is attributed to their surface treatment with the agents containing organic end groups. Moreover, it was found that anionic surfactant (Sulfosuccinate) was more efficient than non-ionic surfactants (Alkyl EO/PO copolymer and OctylphenolEthoxylate) in reducing the contact angle of water on silica aerogel powders. Further, the sessile drop method with slide and adhesive gave consistent data with good reproducibility for the investigated powders.