Comparative study of the optical behavior of a porphyrin encapsulated in sol-gel silica coatings and in solution as a function of pH

Based on the generalization of research results on the processes of obtaining SiO2 sols using tetraethoxysilane and ethyl silicates, the main factors influencing the elasticity of silica coatings on cotton fabrics and their fire-retardant properties are considered. The possibility of forming covalent bonds between the functional groups of cellulose, gel coating and flame retardant layer is considered, which explains the strong fixation of a thin layer of coating on the fibers of the fabric and improve its fire protection. The use of the developed compositions for fire-retardant elastic coatings based on ethyl silicate allows to increase the time of complete burning of cotton from 30s (untreated fabric) to 600s (treated with binary coating).

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Synthesis, Structural, Morphological and Optical Characterization of TiO2 and Nd3+ Doped TiO2 Nanoparticles by Sol Gel Method: A Comparative Study for Photovoltaic Application

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/360/1/012011 ◽

2018 ◽

Vol 360 ◽

pp. 012011 ◽

Cited By ~ 1

Author(s):

P Sanjay ◽

E Chinnasamy ◽

K Deepa ◽

J Madhavan ◽

S Senthil

Keyword(s):

Comparative Study ◽

Tio2 Nanoparticles ◽

Sol Gel ◽

Optical Characterization ◽

Gel Method ◽

Doped Tio2 ◽

Sol Gel Method ◽

Photovoltaic Application

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Effect of Modified Silica Materials on Polyvinyl Chloride (PVC) Substrates to Obtain Transparent and Hydrophobic Hybrid Coatings

Applied Sciences ◽

10.3390/app112211044 ◽

2021 ◽

Vol 11 (22) ◽

pp. 11044

Author(s):

Violeta Purcar ◽

Valentin Rădițoiu ◽

Alina Rădițoiu ◽

Florentina Monica Raduly ◽

Georgiana Cornelia Ispas ◽

...

Keyword(s):

Polyvinyl Chloride ◽

Sol Gel ◽

Contact Angles ◽

Hybrid Coatings ◽

Water Contact ◽

Silica Coatings ◽

Transmission Electron ◽

Vis Spectroscopy ◽

Silica Materials ◽

Window Blinds

In this research, we report a simple and inexpensive way to prepare transparent and hydrophobic hybrid coatings through deposition of different silica materials on polyvinyl chloride (PVC) substrates. The silica materials were prepared using an acid-catalyzed sol–gel method at room temperature (25 ± 2 °C), using alkoxysilanes: tetraethoxysilane (TEOS), as the silica source, and ethoxydimethylvinylsilane (DMVES), triethoxyoctylsilane (OTES), and trimethoxyhexadecylsilane (HDTMES), as modifier agents. The obtained materials were characterized (either as powders or as thin films) by Fourier-transform infrared spectroscopy (FTIR), UV/Vis spectroscopy, transmission electron microscopy (TEM), thermogravimetric analysis (TGA), atomic force microscopy (AFM), spectroscopic ellipsometry (SE), and water contact-angle measurements. UV/Vis spectra showed that the PVC substrate coated with the silica material containing TEOS/DMVES/OTES had a transmittance of about 90% in the wavelength range of 650–780 nm. The water contact angles increased from 83° for uncoated PVC substrate to ~94° for PVC substrates coated with the sol–gel silica materials. These PVC films with hybrid silica coatings can be used as the materials for outdoor applications, such as energy-generating solar panel window blinds or PVC clear Windmaster outdoor blinds.

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