Poly(p-phenylene vinylene-b-ethylene glycol) dispersed in butyltrimethylammonium bis(trifluoromethanesulfonyl)imide as luminescent ionic liquids

Abstract

Block copolymers show great promise and are widely studied due to their improved properties (thermal, luminescent). However, the combination of these compounds with ionic liquids (ILs) can alter/improve the physical properties of the formed composite even further. In this study a composite formed by the poly(p-phenylene vinylene-b-ethylene glycol) PPV/PEG block copolymer and the IL butyltrimethylammonium bis(trifluoromethanesulfonyl) imide was prepared, and its interactions and properties analyzed. Composites with two different proportions were prepared (PPV/PEG + IL 1:1 and 3:1) and later analyzed by different techniques: FTIR, TGA, DSC, XRD, UV–vis and fluorescence spectroscopy. FTIR results demonstrated the occurrence of an interesting physical interaction between the IL and PEG fraction of the block copolymer, an observation confirmed by the DSC and XRD analyses. The addition of the IL also results in the alteration of degradation events and a decrease in the crystallinity of the copolymer. Finally, the absorption and emission spectra showed that the block copolymer preserves its luminescent characteristics, even when a higher amount of IL is added. In addition, an interesting increase in the emission intensity for the two composites was noted due to the addition of IL in the material, being an promising feature for future devices.