Figure 3.

A FTIR spectrum of salicylic acid (dark cyan) in the spectral ranges 3600–3000 cm⁻¹ and 1800–480 cm⁻¹ is reported in (A). FTIR-DRIFT spectra in 3600–3000 cm⁻¹ and 1800–480 cm⁻¹ ranges of sPS fibers being: (B) semicrystalline with NC δ form; (C) semicrystalline with the dense γ form; (D) fully amorphous, which is crystallized by the guest sorption procedure. Black and red spectra correspond to fibers before and after SA sorption, respectively. Close to curves B, absorbance peaks of aggregated SA guest molecules are shown by asterisks while absorbance peaks of isolated SA guest molecules are labeled by orange wavenumbers.