2.2.3. Fourier Transform Infrared (FTIR) Spectroscopy

The chemical structure of the synthesized WPI hydrogels was investigated by using Fourier Transform Infrared spectroscopy using a Fourier-transform infrared (FTIR) spectrophotometer (Agilent Technology, Oxfordshire, UK) in attenuated total reflectance (ATR) mode. Spectra were collected in the 500–4000 cm−<sup>1</sup> spectral range with a resolution of 4 cm−<sup>1</sup> and an average of 8 scans.
