Synthesis, Texture, and Photoluminescence of Lanthanide-Containing Chitosan-Silica Hybrids

Three different types of photoluminescent hybrid materials containing trivalent lanthanide (Ln(3+) = Eu3+, Tb3+) ions, chitosan, and silica have been prepared with different structural features. The different silica sources lead to diverse microstructures of hybrid materials, with silica being homogeneously dispersed in the chitosan materials (LnChS-H), or forming a core-shell morphology. Postsynthesis treatment is necessary for embedding the luminescent probe. The Ln(3+)-based materials have been investigated by photoluminescence spectroscopy (12-300 K). The chitosan-Eu3+-related local environment is maintained in the EuChS-H hybrid material. The emission features of the core-shell materials are characterized by the presence of two Eu3+ distinct local environments, one associated with the chitosan core and the other with the silica shell.