Fig. 3
From: Direct observation of polymer surface mobility via nanoparticle vibrations
Temperature-dependent trend of eigenfrequencies. a Brillouin light scattering spectra (black line) of PSA-707 at different temperature up to the formation of a contiguous polystyrene film with (s,1,2) mode peak fitted by a Lorentzian curve (red line). b The temperature dependent f(s,1,2). Red and blue circles represent the scaled frequency f(s,1,2)·d for NPs (left y-axis) and the longitudinal sound velocity (c1) of annealed bulk film (right y-axis), respectively. The hatched and filled areas in (b) indicate the softening Ts and glass-transition Tg temperatures, respectively
