Scattering properties of rutile pigments located eccentrically within microvoids

We study the optical properties of opaque polymer pigmented coatings. The s ystem consists of spherical rutile particles encapsulated in spherical micr ovoids embedded in a transparent polymer resin, The single-scattering prope rties of this system have been analyzed already, in case the rutile particl e is located at the center of the microvoid. Here, we use a T-matrix approa ch to generalize and extend this analysis to the more realistic case when t he rutile particles is located off-center within the microvoid. We also con sider the multiple-scattering effects of a cluster composed by a collection of air bubbles with off-center rutile inclusions. Our calculations take in to account the multiple scattering and the dependent-scattering processes o f each pigment particle of the aggregate, using a new recursive T-matrix al gorithm. (C) 2001 Elsevier Science Ltd. All rights reserved.