Silica Sol-gel Coatings with Improved Light Transmittance and Stability

  • Lenke Kócs Department of Physical Chemistry and Materials Science, Centre for Colloid Chemistry, Faculty of Chemical Technology and Biotechnology, Budapest University of Technology and Economics, Budapest, Hungary
  • Emőke Albert Department of Physical Chemistry and Materials Science, Centre for Colloid Chemistry, Faculty of Chemical Technology and Biotechnology, Budapest University of Technology and Economics, Budapest, Hungary
  • Borbála Tegze Department of Physical Chemistry and Materials Science, Centre for Colloid Chemistry, Faculty of Chemical Technology and Biotechnology, Budapest University of Technology and Economics, Budapest, Hungary
  • Márta Kabai-Faix Department of Physical Chemistry and Materials Science, Centre for Colloid Chemistry, Faculty of Chemical Technology and Biotechnology, Budapest University of Technology and Economics, Budapest, Hungary
  • Csaba Major Hungaro Lux Light Ltd., Budapest, Hungary
  • András Szalai Hungaro Lux Light Ltd., Budapest, Hungary
  • Péter Basa Semilab Semiconductor Physics Laboratory Co. Ltd., Budapest, Hungary
  • Zoltán Hórvölgyi Department of Physical Chemistry and Materials Science, Centre for Colloid Chemistry, Faculty of Chemical Technology and Biotechnology, Budapest University of Technology and Economics, Budapest, Hungary

Abstract

Silica sol-gel coatings on different substrate materials and their use as model systems have been studied. Mesoporous silica coatings with thicknesses of 85 - 135 nm and porosity of 18 ˗ 37% were prepared by dip-coating on polycarbonate and glass substrates. In order to eliminate the shrinkage of the porous structure acid or base vapour treatment was applied. Thickness and refractive index of the coatings were determined by analysing the transmittance spectra of the samples. Ellipsometric porosimetry measurements were carried out to determine the porosity, pore radius distribution, thickness and refractive index. The thickness of the samples was further confirmed by scanning electron microscopy. The adsorption capacity of the porous coatings was also studied by dye impregnation tests. The temporal stability of the samples was investigated by UV-Vis spectrometry and it was found that the advantageous optical properties (Tmax = 98 – 99%) of the samples remained constant even after a 1 year storage period.

Keywords: sol-gel coating, improved light transmittance, long-term optical stability, network strengthening, porosity
Published online
2017-07-24
How to Cite
Kócs, L., Albert, E., Tegze, B., Kabai-Faix, M., Major, C., Szalai, A., Basa, P. and Hórvölgyi, Z. (2018) “Silica Sol-gel Coatings with Improved Light Transmittance and Stability”, Periodica Polytechnica Chemical Engineering, 62(1), pp. 21-31. doi: https://doi.org/10.3311/PPch.10550.
Section
Articles