Particle size and size distribution of rutile pigment from spectral turbidity

Abstract

The study of the light scattering of particulate rutile involves some special problems due to the high refractive index, high optical dispersion and strong birefringence of the material. The method here is similar to that used by R. J. Gledhill for silver halide sols. The average particle size determined from the spectral turbidity is compared with the corresponding averages from B.E.T. and EM measurements. The agreement is good especially when the B.E.T. average is based on the area for solid nitrogen. The geometric standard deviation determined from the spectral turbidity is compared with the same parameter determined by electron microscopy. Here there are cases of good agreement and instances where it is less satisfactory. The present study has not been sufficient to suggest an explanation for the variance.