The understanding of rheological properties of suspensions of titania particles is of great importance for a lot of industrial processes. The rheological behavior of such suspensions employing two kinds of TiO_2 from a sulfate process has been investigated. The goal was to understand the influence of synthesis parameters in the aggregation behavior of these powders. Aggregate strength was investigated via oscillatory stress rheometry. Specifically, G' and G" were measured as a function of the applied oscillatory stress. Oscillatory rheometry indicated a strong variation as a function of the sulfate level of the particles in the viscoelastic yield strengths. To assess different degrees of aggregation of titania powders in suspensions, a modified freeze-drying technique combined with FE-SEM imaging has been developed to investigate the degree of aggregation at different stages of rheological measurements. The results will be discussed taking into account powder characteristics, including electrokinetic properties.
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