English

Optical extinction, refractive index, and multiple scattering for suspensions of interacting colloidal particles

Soft Condensed Matter 2014-10-01 v1

Abstract

We provide a general microscopic theory of the scattering cross-section and of the refractive index for a system of interacting colloidal particles, exact at second order in the molecular polarizabilities. In particular: a) we show that the structural features of the suspension are encoded into the forward scattered field by multiple scattering effects, whose contribution is essential for the so-called "optical theorem" to hold in the presence of interactions; b) we investigate the role of radiation reaction on light extinction; c) we discuss our results in the framework of effective medium theories, presenting a general result for the effective refractive index valid, whatever the structural properties of the suspension, in the limit of particles much larger than the wavelength; d) by discussing strongly-interacting suspensions, we unravel subtle anomalous dispersion effects for the suspension refractive index.

Keywords

Cite

@article{arxiv.1407.5467,
  title  = {Optical extinction, refractive index, and multiple scattering for suspensions of interacting colloidal particles},
  author = {Alberto Parola and Roberto Piazza and Vittorio Degiorgio},
  journal= {arXiv preprint arXiv:1407.5467},
  year   = {2014}
}

Comments

Submitted to Journal of Chemical Physics 37 pages, 4 figures