Structure and properties of Ti4+-ureasil organic-inorganic hybrids

• Main Authors: Molina Celso, Dahmouche Karim, Hammer Peter, Bermudez Verónica de Zea, Carlos Luís D., Ferrari Maurizio, Montagna Maurizio, Gonçalves Rogéria R., Oliveira Luiz. F. C. de, Edwards Howell. G. M., Messaddeq Younes, Ribeiro Sidney J. L.
• Format: Article
• Language: English
• Published: Sociedade Brasileira de Química 2006-01-01
• Series: Journal of the Brazilian Chemical Society
• Subjects: planar waveguides; sol-gel; hybrid materials; ureasil
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532006000300003
• ISSN: 0103-5053; 1678-4790

Hybrid planar waveguides were prepared from Ti4+-acetylacetone (acac)-Ureasil sols deposited on glass substrates. Structural features have been investigated by spectroscopic measurements (Fourier Transform Infrared Spectroscopy (FTIR), X-ray Photoelectron Spectroscopy (XPS) and Raman scattering) and Small Angle X-ray Scattering (SAXS). Addition of Ti4+-acac to the ureasil (Ti:Si molar ratio 1:1) leads to the formation of bonds between the Ti complex and the siloxane groups, whereas further addition of Ti4+ (Ti:Si molar ratio 5:1) leads to the additional formation of titanium-rich nanoclusters. The optical parameters of the waveguides such as refractive index, thickness, propagating modes and attenuation coefficient were measured at 632.8, 543.5 and 1550 nm by the prism coupling technique. The refractive index can be tuned by the Ti4+ relative content. The few microns thick planar waveguides support well confined propagating modes with low attenuation loss for all compositions.