where t is time in minutes and y is the water content in weight %, respectively. The initial water content of the sample is approximately 10 %. The fast component of the water desorption occurs in 10 minutes, and slow desorption occurs in 3 hours. subtracting the spectra before and after hydration. The spectral features that appear in  are completely different from those of nylon-6, as  is mainly due to the absorbed water molecules in the nylon films. The same experiment was performed for D2O and the results were compared. By comparing the obtained parameters between H2O and D2O, the origin of the vibrational modes can be deduced. First, the center frequencies of Peak II is close to the frequency of the S band of the liquid water, which is known as the intermolecular stretching vibration between water molecules with tetrahedral conformation. Although the exact value of the oscillating frequencies differs in the references, the center frequency of this mode always red-shifts by 1-3 % when changing from H2O to D2O. The obtained center frequencies of the Peak II also shows a similar isotope shift of about 1 %. Therefore, we initially assign this mode as S band of adsorbed water.