Long-term durability of sol–gel porous coatings for solar glass covers

• Published in: Thin solid films 2009-03, Vol.517 (10), p.3157-3160
• Main Authors: San Vicente, G., Bayón, R., Germán, N., Morales, A.
• Format: Article
• Language: English
• Subjects: Antireflective properties; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Durability; Exact sciences and technology; Liquid phase epitaxy; deposition from liquid phases (melts, solutions, and surface layers on liquids); Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of specific thin films; Physics; Porous coatings
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2008.11.079

The application of antireflective coatings to the glass covers of solar thermal collectors, allows to increase the efficiency of the whole system. In this sense, sol–gel silica porous coatings have been deposited on borosilicate glass and solar transmittance values as high as 0.97 have been obtained. The densification process of the films has been studied and the optimal heat treatment conditions have been established. The durability of the materials used in solar systems is a key point since they should keep their initial properties during the operation life-time. In this work, the stability of the optical properties of the films after 2200 h at 50 °C under condensation exposure has been achieved, thanks to the application of a hydrophobic treatment to the coating surface.