Dispersion of Luminescent Nanoparticles in Different Derivatives of Poly(ethyl methacrylate)

Gd₂O₃:Tb(5%) nanoparticles were prepared via the polyol route and dispersed without any stabilizer in several ethyl methacrylate derivatives matrices such as poly(ethyl methacrylate), poly(2-methoxyethyl methacrylate) and poly(2-hydroxyethyl methacrylate) (PHEMA). Nanocomposites were obtained via free-radical polymerization of methacrylic monomers with ethylene glycol dimethacrylate as crosslinker and colloidal solution of Gd₂O₃:Tb(5%) nanoparticles. Best results are obtained with PHEMA in which the dispersed Gd₂O₃:Tb(5%) nanoparticles are spherical with a mean diameter of 15 nm, as measured by TEM. The obtained solid Gd₂O₃:Tb(5%)/PHEMA nanocomposites are highly transparent (in the visible spectral range) and exhibit characteristic photoluminescence of Tb^{3+ 5}D₄–⁷F_J (J = 6–3), with ⁵D₄–⁷F₅ strong green emission at 536 nm upon UV excitation. The nanoparticles and nanocomposites have been well characterized by high-resolution transmission electron microscope (TEM), UV/Vis transmission spectra, photoluminescence excitation, and emission spectra.