Particle sizing for flowing colloidal suspensions using flow-differential dynamic microscopy

Particle size is a key variable in understanding the behaviour of particulate products that underpin much our modern lives. Typically obtained from suspensions at rest, measuring particle under flowing conditions would enable advances for in-line testing during manufacture and high-throughput development. However, samples are often turbid, multiply scattering light preventing direct use common sizing techniques. Differential dynamic microscopy (DDM) powerful technique analysing video such samples, diffusion hence without need to resolve individual particles while free substantial user input. when applying DDM sample, diffusive dynamics rapidly dominated by flow effects, sizing. Here, we develop "flow-DDM", novel analysis scheme combines optimised imaging conditions, drift-velocity correction modelling impact flow. Flow-DDM allows decoupling motion facilitates successful measurements speeds an order magnitude higher than DDM. We demonstrate generality flow-DDM two separate methods geometries.