Comparison of Experimental and Theoretical Study of Diffuse Reflectance of Highly Scattering Particulate Systems

Abstract

Diffuse reflectance of titanium dioxide pigment dispersion is measured in visible region for wavelengths 400(20)700 nm. Kubelka-Munk absorption and scattering coefficients are determined using two constant K-M theory. Average particle size in pigment dispersion is determined by light scattering method. Complex refractive indices of pigment are determined using particle model theory. Scattering and absorption coefficients are computed for all wavelengths using Mie theory equations. K-M coefficients are determined from Mie coefficients using appropriate formulae. Diffuse reflectance values are calculated from theoretical values of K-M coefficients. Theoretical and experimental values of reflectance agree well. The colour difference evaluated from two reflectance curves is 1.28 CIELAB units