Analytical Ultracentrifugation Characterization of Differential Sedimentation Size‐Separated Graphene Dispersions

Abstract Analytical ultracentrifugation (AUC) is applied to the characterization of as‐dispersed graphene nanoplatelet dispersions and differential sedimentation separated daughter dispersions. The liquid‐phase characterization of AUC is demonstrated to resolve both the broad sedimentation coefficient distributions of as‐dispersed samples and changes in daughter dispersions determined by a protocol of applied differential sedimentation process steps. Comparison is made to measurements on deposited samples by scanning electron microscopy and atomic force microscopy. The value of AUC to rapidly monitor changes in the sedimentation distribution of each particle population is demonstrated to allow tailoring of the differential sedimentation protocol to produce significantly narrower population distributions. This rapid characterization is particularly important for technologies in which dispersed nanoparticles cannot be removed from a solvent solution for microscopy analysis.