Ellipsometric light scattering to probe the interface of colloids - current applications and future challenges

In recent years, ellipsometric light scattering (ELS) has been developed into a technique which can be used to characterise the interface between spherical colloidal particles and their surrounding medium. Here, we give an overview over previous successful applications of the technique, and its current limits. The successful applications include the characterisation of temperature-dependent swelling of a thermo-sensitive polymer coating on a latex particle, the measurement of birefringence and molecular orientation in a vescile shell, and the characterisation of the ion distribution around electrostatically stabilised latex particles. As a result of the characterisation of the ion distribution, disagreement with the Poisson-Boltzmann description has been reported before. Here, a few more experimental results on latex particles in the presence of CsBr are discussed.