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Published online by Cambridge University Press: 01 February 2011
The 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.