Influence of droplet characteristics on the optical properties of colored oil-in-water emulsions

The influence of droplet characteristics on the optical properties of oil-in-water emulsions containing different colored dyes was investigated. The spectral reflectance and tristimulus color coordinates (L, a, b) of a series of n-hexadecane oil-in-water emulsions with different droplet concentrations (0-20 wt.%), mean droplet diameters (0.26-26 mu m) and dye-types (red, green and blue) were measured. Spectral reflectances increased with increasing droplet concentration and decreasing droplet size, and had troughs at the same wavelengths as the peaks in the absorption spectra of the dyes. The influence of droplet size and concentration on the lightness and color of emulsions containing different types of dye was fairly similar. (C) 1999 Elsevier Science B.V. All rights reserved.