Tunable Emission of a Samarium Macrocyclic Complex in Poly(vinylidene difluoride)/Poly(methyl Methacrylate) Thin Films with Controlled Microstructure

Transparent and flexible thin films were obtained from poly(vinylidene difluoride)/poly(methyl methacrylate) (PVDF/PMMA) blends in the electroactive β and γ phases doped with a Schiff base macrocyclic Samarium(III) complex, SmL, and were investigated for the potential use in optoelectronics. SmL has a double emission in either solution or as a powder, pointing to an incomplete energy transfer from the ligand to the Sm(III) center. The microstructure of the PVDF/PMMA blends and their interaction with SmL were investigated by infrared spectroscopy, X-ray diffraction, and electronic and optical microscopy. The photophysical properties of SmL in the composite films were studied by steady-state and time-resolved fluorescence measurements. The emission lines specific to Sm(III) centers were absent in the PVDF/PMMA blends. The molecular fluorescence was highly tunable by varying the SmL concentration, the PMMA content, and the excitation wavelength. The biexponential fluorescence decay of SmL in powder form was observed only in the PVDF-rich blends and became a triexponential law for intermediate PVDF/PMMA compositions. Our results show that, on the basis of the fluorescence lifetime distribution and the emission wavelength variability, the macrocyclic Samarium(III) complex has great potential as a fluorescent probe in discriminating the microdomains in the blends.