(70dx) - Nanoparticle Sizing – Advances through New Technology

New technology, which has become available in 2005, has led to the advancement of particle measurement by the optical methods of angular (diffraction) light scattering and dynamic light scattering. Nanoparticles are distinguished by low particle scattering coefficients resulting in low optical signal levels for both angular and dynamic light scattering and ultimately limiting particle size distribution accuracy. This paper describes the use of two technological advances which greatly enhance the measurement of particle size by Angular Light Scattering and Dynamic Light Scattering.

The use of short wavelength Blue Laser Diodes increases the scattering coefficients of nanoparticles and greatly enhances scattering distinction between nano and micro particles. Angular Light Scattering particle sizing takes advantage of these Blue Laser scattering attributes. New measurement capability is presented illustrating improved resolution and accuracy in the measurement of nanoparticles.

The development of low noise, high coherence fiber optic systems extends the nanoparticle measurement capability of to smaller sizes at lower concentrations. Particle Sizing by dynamic light scattering analyzes the constantly varying optical light signal scattered from particles in Brownian motion. Size analysis is limited by the ratio of signal level to of external noise level. Measurements will be presented to illustrate the enhanced capability of Dynamic Light Scattering in the low concentration low nanometer measurement region utilizing a new low noise, high coherence fiber optic system.