Author:
Nunes S. C.,de Zea Bermudez V.,Sá Ferreira R. A.,Carlos L. D.,Morales E.,Marques P. V. S.
Abstract
ABSTRACTThe sol-gel method was employed to obtain poly(oxyethylene) (POE)/siloxane hybrids (di-ureasils) doped with erbium triflate (Er(CF3SO3)3). The host hybrid matrix employed is composed of a siliceous framework to which short POE chains are covalently bonded through urea linkages (-NH(C(=O)NH-). Xerogels with ∞ > n ≥ 5 (where n, salt composition, is the molar ratio of OCH2CH2 moieties per Er ion) were analyzed. Samples with n ≥ 20 are amorphous. Those with n > 20 are thermally stable up to about 325 °C. In the di-ureasils proposed, the Er ions are active at room temperature (RT). Concentration effects on the quenching of the 1.53 mm emission intensity (excited at 488 nm) are negligible.
Publisher
Springer Science and Business Media LLC