The preparation of porous silica antireflection films on glass and plastic substrates is described briefly, and it is shown to be possible to obtain solar reflectance values of 2 per cent per sheet by the use of such films. There is some increase in this reflectance value during exposure tests, but in the outdoor trials described here the average year-long increase is less than 0.6 per cent. This increase is attributed to adsorption of airborne contaminants partially filling the pores of the film, leading to an increase in the refractive index and hence in the reflectance value. © 1981.
Cathro, K. J., Constable, D. C., & Solaga, T. (1981). Durability of porous silica antireflection coatings for solar collector cover plates. Solar Energy, 27(6), 491–496. https://doi.org/10.1016/0038-092X(81)90044-X