Sedimentation Dynamics of Colloidal Formulations through Direct Visualization: Implications for Fuel Cell Catalyst Inks

Quantitative appraisal of real-world colloidal systems in their native state is key for knowledge-based nanoparticle formulations. Analytical centrifugation (AC) is touted as a quantitative methodology examining settling and creaming of dispersions, but an understanding of the main transmission readout is often nonintuitive and complex. Herein, we introduce a new visualization technique, called transmittograms, that readily depicts the time-resolved settling behavior of solid-liquid dispersions, measured by AC. We validate the utility of transmittogram analysis using silica particles. Further, we demonstrate the strength of the approach to study the nanoscale dynamics in complex fuel cell inks.