4.5. Fourier Transform Infrared Spectroscopy (FTIR) Analysis

First, the polyacrylic hydrogel films were dried at 50 °C for 24 h and the dried polyacrylic hydrogel films were then ground and mixed with potassium bromide in a 1:99 mixture and compressed into pellets. These pellets were then analyzed using FTIR (Spectrum One, PerkinElmer, Waltham, MA, USA). The monomers and polymers were analyzed on the basis of their functional groups and the wavelengths were scanned from 4000~450 cm⁻¹.