Sintering rates for pristine and doped titanium dioxide determined using a tandem differential mobility analyzer system

Abstract

Sintering rates of pristine and V-doped TiO2 were obtained using a tandem DMA system. A range of experiments were conducted to first map out the variation of mobility size of a monodisperse (by mobility) agglomerate with time at three fixed temperatures. Using relationships of the surface area to the mobility size, the sintering equation was solved to determine the activation energy and pre-exponential factor. The value of the activation energy was 236 (±46) kJ/mol for pristine TiO2 and 363 (±1) kJ/mol for V-doped TiO2. The corresponding pre-exponential factors were 7.22 × 1019 and 2.22 × 1012 s/m4K, respectively. These values were then used to predict changes in mobility diameter at different temperatures, and good agreement was obtained with measurements. Possible reasons for faster sintering rates of V-TiO2 relative to pristine TiO2 were conjectured. Copyright © American Association for Aerosol Research.