Centrifugal liquid sedimentation methods

Centrifugal liquid sedimentation (CLS) is a type of analytical centrifuge used to measure particles and nanoparticles properties, primarily Stokes diameter and buoyant density. It is traditionally used for the characterization of particle formulations in a broad range of industries, from food to pharmaceuticals. Although well established, the CLS method experiences continuous technical innovation and its areas of application are expanding continuously. We discuss the method in this chapter, its underpinning principle and the main types of instrumentations, as well as some of the main areas of applications with a focus on recent developments. We discuss the measurement by CLS of particle characteristics such as particle size distributions, effective density, particle number concentration, coating thickness, and agglomeration profiles. We also provide some practical measurement guidelines examples of analysis of complex particle systems, including nonspherical, agglomerated, highly concentrated, heterogeneous, and structurally complex particles.