Langmuir, Vol.18, No.16, 5989-5994, 2002
Emulsions which appear brightly colored upon illumination with white light
Particular emulsion compositions of divinylbenzene, octane, and methyl methacrylate, dispersed with sodium dodecyl sulfate surfactant into a glycerol suspension medium, exhibit bright colors upon illumination with white light. The colors shift across the visible spectrum as a function of temperature and emulsion composition. As described in this paper, the "colored" emulsions are the consequence of an exact matching of the refractive index of the droplet phase with that of the continuous phase over a narrow range of wavelengths of light. Other wavelengths of light scatter. Light extinction spectra measure the wavelength at which the refractive index of droplet and continuum match and allow calculation of the refractive index of the droplet phase. The Rayleigh-Gans-Debye model of light scattering semiquantitatively describes the trends in color as a function of temperature and emulsion composition.