Surface Functionalization of Anatase Nanopowders with Stearic Acid by Ball Milling

This contribution is focused on the functionalization of the surface of anatase nanopowders following their mechanical processing by ball milling in the presence of stearic acid. We performed ball milling experiments using a ball mill that makes the reactor undergo three-dimensional oscillations, which result in an effective stirring of the powder mixture, employing a single milling ball. We changed the milling intensity by changing the ball mass. Analysis of the Fourier-transform infrared spectra suggests that surface functionalization occurs only within a relatively narrow range of milling intensity. Within such a range, we studied in great detail the kinetics of the surface modification. We also developed a kinetic model to interpret the experimental data and deepen the insight into the physical and chemical processes occurring on the microscopic scale.