title: Size distribution effect on the power law regime of the structure factor of fractal aggregates.
abstract: We consider the large qR(g), where q is the magnitude of the scattering wave vector and R(g) is the aggregate radius of gyration, part of the structure factor of fractal aggregates, and quantify the coefficient C of the power law, S(q) approximately C(qR(g))(-D), where D is the fractal dimension, for various structure factors proposed in the literature. With the aid of earlier work, we conclude the most accurate structure factors have C=1.0. We then calculate the effects of polydispersity on this coefficient, and show the effects are significant, enough so to allow a measurement of the distribution width. These concepts are accurately supported with scattering data from a diffusion limited aerosol and a reaction limited colloid.
authors.affiliation: Department of Physics and Program for Complex Fluid Flows, Kansas State University, Manhattan, Kansas 66506-2601, USA.
authors.forename: C M
authors.initials: CM
authors.lastname: Sorensen
authors.forename: G M
authors.initials: GM
authors.lastname: Wang