Thermal Stability and Water Affinity of Highly Fluorinated Silica

5 Thermal Stability and Water Affinity of Highly Fluorinated Silica 

The thermal stability of the fluorinated silica samples can be determined using a thermo-gravimetric analysis (TGA) coupled with a mass spectrometry. These techniques allow the determination of the various species released at critical temperatures and the identification 

Previous studies conducted on fluorinated silica obtained via various synthesis routes pointed out that these materials exhibit some drawbacks like strong sensitivity to moisture 

The hydrophobic character of fluorinated silica was estimated by water adsorption a 75 % humidity atmosphere [43]. After 50 days in such atmosphere all fluorinated silicas have a drastically lower water adsorption (between 2 and 13 %) than unfluorinated silica (around 30 %) [28]. This result can easily be correlated with the lower hydroxyl content in fluorinated sihca, these groups being at the origin of the surface water adsorption. 

---