Hi! Can i use the Rayleigh scattering formula in a colloidal system to analyse the scattering of a specific particle that is smaller than the incident ligh wavelength? I know about Tyndall effect but i couldn´t find any mathematic representation of it.
"Can I use" is a loaded question.
For example, are you interested in the geometry of the scattering, the wavelength dependence, or the forward transmittance or something else?
The Rayleigh approximation describes scattering from a single particle that is much smaller than the wavelength. It is applied whenever you can get away with it because it is relatively easy to use and understand. It will tell you why the sky is blue but not why the clouds are white! (This refers to a famous final exam question for classical electrodynamics)
So what is it you need to characterize? There are programs extant to calculate Mie Scattering but they are less inviting.