Photon Cross-correlation Spectroscopy (PCCS) is a novel technique allowing for the simultaneous measurement of particle size and stability in the range of about 1 nm to some µm in opaque suspensions and emulsions.
The key principle of PCCS is a 3D cross correlation technique. In a special scattering geometry, the cross correlation of the scattered light allows for the precise separation of the single and the multiple scattered fractions. This is important, as the well established theory for the evaluation of Photon Correlation Spectroscopy (PCS) data is only valid for light being scattered once. Any contribution of multiple scattered light would lead to erroneous results and misinterpretations. As a consequence, the former PCS required highly diluted suspensions in order to avoid multiple scattering. PCCS overcomes this limitation and extends the field of application to opaque suspensions and emulsion.
A novel instrument has been developed and optimised for industrial use. Housed in a small table top unit it contains light source, detectors, the correlator, tempering basin and the sample containing vial and is ready for routine measurements in any laboratory. The operation is much simpler than with a conventional PCS system, because the samples are not extremely diluted. Costly cleaning and sample preparation effort is avoided.