Nanocomposites with fumed silica/poly(vinyl pyrrolidone) prepared at a low content of solvents

Highly disperse nanocomposites with fumed silica/poly(vinyl pyrrolidone) (PVP) prepared using different methods were studied by infrared spectroscopy, adsorption, and quantum chemistry methods. Low amounts of water or ethanol (30 wt.% with respect to the silica content) promote appropriate distribution of PVP on silica particles. The use of ethanol leads to a smaller loss of the specific surface area (SBET) than in the case of water used as a solvent. On PVP distribution on a silica surface, treatment of the system in a pseudo-liquid state reactor (PLSR) provides slightly better results (a lower loss in SBET) in comparison with mechanochemical activation (MCA) in a ball mill at the PVP monolayer coverage. An increase in the activation time to 6-9 h leads to an increase in the |ΔSBET/SBET| value to 0.29-0.35 for both treatment methods.