Mineralization and particle growth kinetics of ZnO in the presence of gelatin

We have investigated the mineralization of zinc oxide and the kinetics of formation of zinc oxide - gelatin composites in colloidal suspensions at temperatures between 30 °C and 45 °C. Particle growth was studied in situ using dynamic light scattering (DLS). The activation energy of particle growth was determined by kinetic analysis of the DLS data. We obtained an activation energy of EA,g = (9.6 ± 2.4) kJ mol-1 in presence and an activation energy of EA,ZnO = (71.0 ± 10) kJ mol-1 in absence of gelatin B 225. Furthermore, the precipitation process and the morphology of the occurring particles were analyzed applying diverse methods. The phase formation and the crystallite size were investigated by X-ray diffractometry (XRD). The morphology of the particles was studied by scanning electron microscopy (SEM), where spherical particles in absence of gelatin B 225 and plate-like particles in presence of gelatin were found. The combination of these analytical techniques allowed us to develop a model for describing the particle formation.