Circular dichroism, surface-enhanced Raman scattering, and spectroscopic ellipsometry studies of chiral polyfluorene-phenylene films

Abstract

To understand the chiroptical responses of polyfluorenephenylene (PFP) films, circular dichroism (CD), surface-enhanced Raman scattering (SERS), attenuated total reflection (ATR), and spectroscopic ellipsometry studies were performed. The pristine PFP films exhibited significant CD at room temperature, and the chirality increased by thermal annealing at 120 degrees C (above the glass transition temperature). SERS and ATR spectra indicated that the chirality enhancement was due to the rearrangement of the polymer backbones on the glass substrate by thermal annealing and/or self-organization. In addition, comparison of PFP and polyfluorene polymers indicated that molecular structure of polymer backbone plays an important role in the chiroptical responses of the chiral polymers. (C) 2016 Optical Society of America