Optical characterization method for black pigments applied to solar-selective absorbing paints

Area of Science:

• Materials Science
• Optical Physics
• Spectroscopy

Background:

• Accurate characterization of pigment optical properties is crucial for material science applications.
• Existing methods may have limitations in determining scattering and absorption coefficients for dispersed particles.
• Understanding optical properties informs pigment performance in various matrices.

Purpose of the Study:

• To introduce a novel method for characterizing the optical properties of pigment particles or powders.
• To determine effective scattering and absorption coefficients per unit length for dispersed pigments.
• To validate the method using FeMnCuO(x) and black carbon pigments.

Main Methods:

• Measurements of diffuse and total transmittance and reflectance.
• Calculation of effective scattering and absorption coefficients.
• Application to dilute dispersions in a KBr matrix within the single-scattering regime.

Main Results:

• Effective scattering and absorption coefficients were obtained for FeMnCuO(x) and black carbon pigments.
• Scattering and absorption cross sections were determined for dilute dispersions.
• Linear dependence of coefficients on volume fraction was observed, consistent with single-scattering theory.

Conclusions:

• The proposed method effectively characterizes the optical properties of pigment powders.
• The technique provides reliable scattering and absorption coefficients for dispersed pigments.
• This method offers a valuable tool for pigment research and development.