Solvent tunable optical properties of a polymerized vinyl- and thienyl-substituted ionic liquid.
Thermal free radical polymerization of a self-assembled, bifunctional imidazolium-based ionic liquid (IL) monomer bearing both vinyl and thienyl groups is reported. FT-IR spectroscopy proves that the polymerization occurs through both the vinyl and thienyl groups. The polymer is resistant to swelling in water and common organic solvents. The as-synthesized polymer can be readily chemically doped and de-doped. Small-angle X-ray scattering studies indicate that the dried polymer adopts a weakly ordered lamellar structure. The p-doped, ethanol-solvated polymer undergoes a structural conversion to a nonlamellar phase. The absorption and photoluminescence spectra can be modulated in both the neutral (thiophene) and p-doped states depending on whether the polymer is dry or ethanol-solvated. The results demonstrate the possibility of incorporating solvent responsive optical characteristics in a π-conjugated polymer.
Becht
Gregory A
GA
Materials Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, USA.
Lee
Sungwon
S
Seifert
Sönke
S
Firestone
Millicent A
MA