Synthesis and Characteristic of Poly(N-vinylacetamide) Containing Terbium Ion

Poly（N-vinylacetamide） （PNVA） was synthesized by free radical polymerization in ethanol solution, in which α, α’-azobisisobutyronitrile was used as an initiator. Tb（III）-PNVA polymer was prepared and characterized by ultraviolet-visual （UV）, fourier transform infrared （FT-IR）, X-ray photoelectron spectroscopy （XPS） and fluorescence spectroscopy. The experimental results of UV, FT-IR and XPS show that the Tb （III）-PNVA electrovalent complex is formed by electrostatic interaction between terbium （III） cation and complexible atoms of acylamino group in the pendant chain of the polymer. The fluorescence spectrum of the complex exhibits intensive characteristic emission of terbium at 490, 545 and 584 nm, which are assigned to （）5D4→（）7F6, （）5D4→（）7F5 and （）5D4→（）7F3 transition, indicating that there exists an efficient intermolecular energy transfer from the polymer ligand to the central rare earth ion. The emission intensity of the complex is increased with the increasing concentration of Tb （III） ion until the weight ratio of Tb（III） on to PNVA is 1.5%（mass fraction）, and decreased with the further increasing concentration of Tb（III） ion, which is a typical concentration quenching behavior.