authors |
Freitas, VT; Lima, PP; Ferreira, RAS; Carlos, LD; Pecoraro, E; Ribeiro, SJL; Bermudez, VD |
nationality |
International |
journal |
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY |
author keywords |
Tripodal organic-inorganic hybrids; Tri-ureasils; Sol-gel; Photoluminescence; Laboratory controlled atmosphere |
keywords |
ORGANIC-INORGANIC NANOCOMPOSITES; CARBOXYLIC-ACID SOLVOLYSIS; METAL ACTIVATOR IONS; BRIDGED SILSESQUIOXANES; ORGANIC/INORGANIC HYBRIDS; LIGHT-EMISSION; TUNABLE PHOTOLUMINESCENCE; LAMELLAR STRUCTURE; ENERGY-TRANSFER; SILICA SPHERES |
abstract |
Transparent monoliths and films of urea cross-linked tripodal siloxane-based hybrids (named tri-ureasils) were prepared by the sol-gel process, under controlled atmosphere (inside a glove box) and ambient conditions and their structure and optical features were compared. X-ray diffraction data point out that all the materials are essentially amorphous and Si-29 NMR reveal an increase in the condensation degree (0.97) for the hybrids prepared under controlled atmosphere relatively to that found for those prepared under ambient conditions (0.84-0.91). The tri-ureasils are white light emitters under UV/Visible excitation (from 250 to 453 nm) being observed for the composites prepared inside the glove box a significant enhancement (60-80 %) of the absorption coefficient and higher emission quantum yield values (similar to 0.27 and similar to 0.20 for monoliths and films, respectively) relatively to those synthesized under ambient condition. |
publisher |
SPRINGER |
issn |
0928-0707 |
year published |
2014 |
volume |
70 |
issue |
2 |
beginning page |
227 |
ending page |
235 |
digital object identifier (doi) |
10.1007/s10971-013-3244-x |
web of science category |
Materials Science, Ceramics |
subject category |
Materials Science |
unique article identifier |
WOS:000335639600009
|