Communications: Appearing, disappearing, and reappearing fumed silica nanoparticles: Tapping-mode AFM evidence in a condensation cured polydimethylsiloxane hybrid elastomer


Preparation of Fumed Silica nanoparticles (FSN) poly(dimethylsiloxane) (PDMS) hybrids coating by utilizing polydithoxysiloxane 9PDES) as the siliceous domain (SD) precursor of Fumed Silica nanoparticles (FSN) was discussed. The surface analysis is done by tapping-mode atomic force microscopy (TM-AFM) of the hybrid materials. It was observed that for certain compositions and cure conditions the near surface FSN seemed to disappear. The inability to image near-surface nanoparticles was explained by the formation of an amorphous reticular siliceous surface domain that mechanically isolated near surface nanoparticles. Nanoparticles reappear or never appear depending on composition and nanoparticle surface chemistry. An identical phase image was observed after 100°C cure, and the results demonstrated that at low volume fractions of siliceous phase, the near surface nanostructure is independent of cure temperature.

Publication Title

Chemistry of Materials