Open AccessSilica Sol-gel Coatings with Improved Light Transmittance and Stability
Author(s) -
Lenke Kócs,
Emőke Albert,
Borbála Tegze,
M. Kabai-Faix,
C. Major,
András Szalai,
P. Basa,
Zoltán Hórvölgyi
Publication year - 2017
Publication title -
periodica polytechnica. chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.322
H-Index - 19
eISSN - 1587-3765
pISSN - 0324-5853
DOI - 10.3311/ppch.10550
Subject(s) - materials science , porosity , refractive index , porosimetry , scanning electron microscope , transmittance , mesoporous material , sol gel , coating , shrinkage , composite material , polycarbonate , substrate (aquarium) , porous medium , chemistry , nanotechnology , optoelectronics , biochemistry , oceanography , geology , catalysis
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.