%0 Journal Article
%K cool roofs
%K Pigment characterization
%K Solar spectral optical properties
%K Kubelka-Munk absorption and backscattering coefficients
%K Titanium dioxide
%A Ronnen M Levinson
%A Paul H Berdahl
%A Hashem Akbari
%B Solar Energy Materials and Solar Cells
%D 2005
%G eng
%N 4
%P 351-389
%R 10.1016/j.solmat.2004.11.013
%T Solar spectral optical properties of pigments—Part II: survey of common colorants
%V 89
%8 12/2005
%X <p>Various pigments are characterized by determination of parameters <em>S</em> (backscattering) and <em>K</em> (absorption) as functions of wavelength in the solar spectral range of 300–2500&nbsp;nm. Measured values of <em>S</em> for generic titanium dioxide (rutile) white pigment are in rough agreement with values computed from the Mie theory, supplemented by a simple multiple scattering model. Pigments in widespread use are examined, with particular emphasis on those that may be useful for formulating non-white materials that can reflect the near-infrared (NIR) portion of sunlight, such as the complex inorganic color pigments (mixed metal oxides). These materials remain cooler in sunlight than comparable NIR-absorbing colors. NIR-absorptive pigments are to be avoided. High NIR reflectance can be produced by a reflective metal substrate, an NIR-reflective underlayer, and/or by the use of a pigment that scatters strongly in the NIR.</p>