Table 1: FTIR spectra peak position and assignments for collagen sponges.

AssignmentWavenumber (1/cm)
Collagen sponge piroxicam sponge piroxicam sponge piroxicam sponge

N-H stretch (νNH) of amide A [29, 30]3540356935523550
Hydrogen bonding of the N-H group with a carbonyl group of the peptide chain [29]
CH2 asymmetrical stretch (νasCH2) by amide B band [29, 30]3017300830163007
C-O stretching vibration (νCO) [29]1681168116801680
Amide I C=O stretching [30, 31]
Hydrogen bond between N-H stretch (νNH) and C-O (νCO) [29]1607160616081610
Helical structure of collagen [29]1494149914991496
Stretching vibration of the C-N group [29]
C=N stretching of piroxicam [31]
CH2 deformation (δCH2) [32]
CH3 bend (δCH3) [32]1443144114431443
CH2 bending vibration (δCH2) [30]
CH2 group wagging vibration [29]1376137913871380
NH deformation of amide III (δNH) [32]1274127412731275
Hydrogen bonding of N-H bending [29, 30]1241123712401240
NH deformation of amide III (δNH) [32]1191119211891190
S=O asymmetric stretching [31]
Ester bond [29]1113111311151113
ν(C-O), ν(C-O-C) of carbohydrate moieties (collagen) [32]1062106310621063
Skeletal stretching vibrations [30]899899900900