Is Your Sample Dispersing or Milling? Hydro Sight’s In-Line Insight
Application Note Aug 19, 2015
Malvern Instruments Limited
Accurately measuring the particle size distribution of a sample relies on various factors. Foremost amongst these is a reliable, high-precision sizing instrument, and equally as important is the successful dispersion of the sample to its constituent primary particles.
Efficient dispersion of a sample relies on careful selection of the dispersing medium and a range of surfactants and additives. Additionally, the application of ultrasound to physically separate particles can ensure a good dispersion.
Achieving the correct dispersion conditions for your particular sample is a fine balance. The instrument will report a particle size distribution which is inclusive of any agglomerations of particles in the sample, often leading to a skewed reported particle size. Conversely, if dispersion conditions are too harsh, the primary particles may be broken up or ‘milled’. This is equally undesirable as it too is unrepresentative of the sample being analyzed.
Determining the point at which agglomerated particles have been fully dispersed but the primary particles are not being milled is the realm of the particle sizing method development specialist. Traditionally, an aliquot of the sample is observed off-line using microscopy to identify if milling or dispersion is taking place. In this application communication we demonstrate how the Hydro Sight imaging accessory can be used to facilitate this process in-line.