Hydrogels dispersed by doped rare earth fluoride nanocrystals: Ionic liquid dispersion and down/up-conversion luminescence

Two typical kinds of rare earth fluoride nanocrystals codoped with rare earth ions (Eu 3+ and Tm 3+ /Er 3+ ,Yb 3+ ) are synthesized and dispersed in ionic liquid compound (1-chlorohexane-3-methylimidazolium chloride, abbreviated as [C 6 mim][Cl]). Assisted by agarose, the luminescent hydrogels are prepared homogeneously. The down/up-conversion luminescence of these hydrogels can be realized for the dispersed rare earth fluoride nanocrystals. The results provide a strategy to prepare luminescent (especially up-conversion luminescent) hydrogels with ionic liquid to disperse rare earth fluoride nanocrystals.