Optical properties of two novel terbium thermo-sensitive poly(N-isopropylacrylamide) gels

摘要

Two novel silica based terbium complexes (Tb(Bipy)_3 and Tb(Tyr)_3) were encapsulated into poly(N-isopropylacrylamide) and two hydrogels with intense green emission were developed. The variation of intensity changes by Tb(III) ~5D_4 → ~7F_5 transition indicated the gradual reduction tendency upon the increasing temperature. The declined luminescence behaviors of the two gels undergo the linear decay process (5～30°C). During lower critical solution temperature (33°C) stage, the emission responses significantly improved unexpectedly. Moreover, the terbium emissive species-loaded hydrogels exhibited much enhanced mechanical properties than pure gel.