Our nanoparticle characterisation expertise and equipment is extensive. Particle sizing capability is critical and enables size and volume distributions to be made of nanoparticles in both fluid and airborne environments. These approaches complement our microscopy techniques such as TEM which provide high resolution shape and morphology data.

In Dynamic Light Scattering (DLS) particles in a clear mobile solution undergoing Brownian motion are illuminated with a laser. The interference of scattered light from the particles causes a fluctuation in the intensity of light scattered at a particular observation angle which reflects the particle size. This fluctuation is observed using a suitable detector. A signal processor is used to integrate the data which is converted into a mean diffusion speed and distribution and then to a particle size distribution. The image below shows the size distribution of silver nanoparticles suspended in ethylene glycol,

Airborne particle size distributions can be measured using a Scanning Mobility Particle Analyser. This is comprised of an Electrostatic Classifier (Differential Mobility Analyser) and a Condensation Particle Counter. Particles entering the system are charged using a radioactive source and are classified according to electrical mobility, with only particles of a narrow range of mobility exiting through the output slit. This monodispersed distribution then goes to a Condensation Particle Counter which determines the particle concentration at that size by swelling particles in butanol and subsequently detecting size via light scattering.

• Mean particle size
• Particle size distribution by intensity and volume
• Particle size range (DLS): 0 – 6 microns
• Particle size range (Scanning Mobility): 0 - 1 micron

• Emissions testing
• Atmospheric testing
• Soot characterisation
• Powder inhalers particle sizing
• Quality control of commercially available nanoparticles
• Emulsion, lattices, and colloid characterisation
• Protein and bio-molecule sizing

• Multiple techniques for analysis in air and solution
• Soot particle generator for analysis of fuels etc
• Can be combined with visualisation techniques (TEM, SEM, AFM)
• Fast turnaround service