Light Scattering From Fractal Colloid Aggregates

We present a detailed description of both static and dynamic light scattering from fractal colloid aggregates. By properly including the effects of rotational diffusion, we can account for the shape of the autocorrelation functions measured by photon correlation spectroscopy (PCS). We show that the first cumulants measured as a function of time and scattering wavevector can be scaled into a single master curve. The shape of this curve is critically dependent on the details of the aggregation process and aggregate structure, and we use this to demonstrate the universality of colloid aggregation.