Optical properties of colloidal films

The optical properties of colloidal films with thickness ranging from <1 nm, formed by dendrimer molecules, to >1 μm, formed by proteins and latex particles, are discussed. The experimental technique used is scanning angle reflectometry which is shown to provide extremely accurate information on dielectric thin films. Even though the analysis of these properties requires sophisticated electromagnetic theory, simple approximations are derived and their use is demonstrated. The inherent errors are quantified using the full electromagnetic theory.