Light-scattering efficiency of starch acetate pigments as a function of size and packing density

Antti Penttilä, Kari Lumme, Lauri Kuutti

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14 Citations (Scopus)


We study theoretically the light-scattering efficiency of paper coatings made of starch acetate pigments. For the light-scattering code we use a discrete dipole approximation method. The coating layer is assumed to consists of roughly equal-sized spherical pigments packed either at a packing density of 50% (large cylindrical slabs) or at 37% or 57% (large spheres). Because the scanning electron microscope images of starch acetate samples show either a particulate or a porous structure, we model the coatings in two complementary ways. The material can be either inside the constituent spheres (particulate case) or outside of those (cheeselike, porous medium). For the packing of our spheres we use either a simulated annealing or a dropping code. We can estimate, among other things, that the ideal sphere diameter is in the range 0.25–0.4  μm.
Original languageEnglish
Pages (from-to)3501-3509
Number of pages9
JournalApplied Optics
Issue number15
Publication statusPublished - 2006
MoE publication typeA1 Journal article-refereed


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