A fluoroalkyl end-capped <Emphasis Type="Italic">N</Emphasis>-(1,1-dimethyl-3-oxobutyl)acrylamide oligomer/silica gel nanocomposite with no weight loss even at 800 °C equal to an original silica gel

Fluoroalkyl end-capped N-(1,1-dimethyl-3-oxobutyl)acrylamide oligomer R_F-(DOBAA)_n-R_F]/silica gel nanocomposite, which was prepared by reaction of the corresponding fluorinated oligomer with tetraethoxysilane and silica gel nanoparticles under alkaline conditions, exhibited no weight loss even at 800 °C equal to the original silica gel, although the corresponding parent R_F-(DOBAA)_n-R_F oligomer was completely degraded at 600 °C. Thermogravimetric analyses/mass spectra of fluorinated nanocomposite showed that this nanocomposite decomposed around 280 °C to afford CO₂ and H₂O as the major evolved gaseous products including some minor fluoro- and hydrocarbons. X-ray photoelectron spectroscopy analyses also showed that the contents of C, F, and Si atoms in R_F-(DOBAA)_n-R_F/SiO₂ nanocomposite after the calcination at 800 °C were similar to those before the calcination. These findings suggest that the evolved gaseous products should be encapsulated quantitatively into nanometer-size-controlled silica matrices to give the fluorinated silica gel nanocomposite with no weight loss even at 800 °C equal to the original silica gel.