Malvern Instruments discusses how laser diffraction particle sizing techniques enable effective measurements of particle size and other characteristics at a wider range of concentrations than has previously been feasible. The document uses the configuration of an emulsification system for creating oil/water emulsions as a case study to demonstrate the capabilities and advantages of laser diffraction techniques.
Laser diffraction delivers particle size measurements for a range of wet materials including suspensions, emulsions and slurries. The system can be used on a continuous basis for applications in process control and in the detection of manufacturing issues. This can benefit a range of commercial operations including milling, flocculation and emulsification. For example, in the food industry, droplet size affects mouth feel, stability, "whippability", flavour release and colour in products ranging from mayonaise to ice cream.
Laser diffraction techniques rely on the fact that particles and droplets will deflect and scatter light passing through a sample, with larger particles scattering light more strongly, and at higher angles compared with smaller particles. Whilst this is simple in principle, it is complicated by the fact that light may be scattered by multiple particles before it reaches a detector. Malvern Instruments has developed and patented techniques that can effectively address this issue using advanced mathematics, allowing DLS to be applied at higher concentrations. For further information, view the full article by Malvern's Henrique Kajiyama.