The following is an abstract for the selected article. A PDF download of the full text of this article is available here. Members may download full texts at no charge. Non-members may be charged a small fee for certain articles.

Flocculation Gradient Technique in Terms of KubelkaMunk Coefficients: Quantifying Black-Pigmented Dispersions

Volume 49, Number 12 (Dec. 1995) Page 1756-1761

Gunde, Marta Klanjšek; Orel, Zorica Crnjak; Logar, Jasmina Kožar; Orel, Boris

The diffuse reflectance from a painted layer depends upon the layer thickness. The rate of change of diffuse reflectance when thickness increases is the flocculation gradient, which is valuable information about the degree of pigment dispersion in paint. The simple determination method is called the flocculation gradient technique and is suitable to quantify the pigment dispersions in low-absorptive and high-scattering paints. To make the method useful for black-pigmented paints as well, we modified it by applying the Kubelka-Munk theory. This makes it possible to solve the problem of the very narrow linearity region that appears in the diffuse reflectance vs. thickness curve because of high absorption. The modified method allows one to quantify the degree of dispersion in black thickness-sensitive spectrally selective paints, which are used as absorbers in solar collectors.