Photophysical studies of novel lanthanide (Eu3+ and Tb3+) luminescent hydrogels

A group of lanthanide luminescent xerogels, CMa, CMb, CMc, and CMd, exhibited specific emission responses towards to the temperature variation in polyelectrolyte hydrogels. The europium(III) containing materials decrease at a rate that follows the exponential function (y=122.03e(-0.0175x) and y=93.054e(-0.0162x)) whereas the terbium(III) systems undergo the linear decay process (y=7.1733x +677.64 and y=-6.5467x+653.62). Interestingly, it has been shown that the excitation wavelengths for europium silica materials (CM, and CMb) embedded hydrogels can be extended into the visible region (415 and 465 nm respectively). In addition, the incorporation of lanthanide xerogels into polymeric hydrogel can obviously improve their thermal stabilities in water. (C) 2011 Elsevier B.V. All rights reserved.