Share Email Print

Proceedings Paper

Optimization of optical properties of pigmented foils for radiative cooling applications: model calculations
Author(s): Torbjorn M.J. Nilsson; Gunnar A. Niklasson
Format Member Price Non-Member Price
PDF $14.40 $18.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

Plastic foils containing nonabsorbing pigments can display a high reflectance of solar radiation combined with a high transmittance in the atmospheric window region in the thermal infrared. Such foils can be applied as selective covers enabling radiative cooling of an underlying material even in direct sunlight. Extensive calculations were performed of the optical properties of nonabsorbing foils pigmented with various oxides and sulphides. The calculations were carried out by the four flux theory using input calculations for single spheres by the Lorenz-Mie theory. The optical properties of the foils were optimized for radiative cooling applications with respect to particle radius, pigment volume fraction, thickness of the foil, and refractive index of the particles. In particular, ZnS is a suitable pigment material because of its high refractive index and low infrared absorption. It should be feasible to achieve a solar reflectance of 0.9 in combination with an infrared transmittance of 0.8 to 0.85 in the atmospheric window region by foils made of a transparent matrix material pigmented with ZnS. Initial experimental studies have been performed on pigmented polyethylene foils.

Paper Details

Date Published: 1 December 1991
PDF: 14 pages
Proc. SPIE 1536, Optical Materials Technology for Energy Efficiency and Solar Energy Conversion X, (1 December 1991); doi: 10.1117/12.49222
Show Author Affiliations
Torbjorn M.J. Nilsson, Chalmers Univ. of Technology (Sweden)
Gunnar A. Niklasson, Chalmers Univ. of Technology (Sweden)

Published in SPIE Proceedings Vol. 1536:
Optical Materials Technology for Energy Efficiency and Solar Energy Conversion X
Carl M. Lampert; Claes G. Granqvist, Editor(s)

© SPIE. Terms of Use
Back to Top