Biography
Biography: David Pugh
Abstract
Dynamic Light Scattering (DLS) is a tool for determining particle size distributions in fine particulate material suspensions, micro-emulsions and nano-scale matter in general. Usually optical arrangements in lower angles are used that demand heavy dilution of samples. Backscattering, however, allows for considerably higher concentrations and is the right choice for concentrated samples which incur in processes. Furthermore, the 180° backscattering is especially suitable for direct in-line use in reactors, because the handling of the measurement probe head with a diameter of 8 mm is just as easy as a pH head. A probe sheath effectively shields the Brownian motion from the process fluidics. At higher concentrations, where particle-particle interactions are present, on-line systems with automated dilution can be used but with dilution comes the potential aggregation problems due to Chemistry. By not needing dilution in all cases DLS has finally arrived as an automatized tool for process analytics in the nanometer range of Pharmaceutics and Biotech.
