Synthesis and characterization of crystalline carboxymethylated lignin–TEOS nanocomposites for metal adsorption and antibacterial activity

Bioresources and Bioprocessing

Table 2 Peak positions of various modes of vibration in the FT-IR spectra of lignin, carboxymethylated lignin and CML–T composites during sol–gel reaction

Chemical bond	Chemical structure	Wavenumbers (cm⁻¹)
C–C stretch	Aromatic ring	1595.83 cm⁻¹
C–C stretch	Aromatic ring	1412.70 cm⁻¹
C–stretch	Carbonyl group	1096.18
=C–H	Alkenes	699 and 767
–C≡C–H or C–H bend	Different functional groups of lignin	620
C–H stretch	Alkanes	2929.40
O–H stretch	Phenolic group and carboxyl	3500
C=O stretch	Carboxylic acid	1780
–C=C– stretch	Alkenes	1634.05
–C=C–	Alkenes	1634.05
C–C stretch	Aromatic ring	1431.12
–	Carboxyl ring	1412.70
=C–H bend and O–H bend	Carboxyl ring	800 and 996
O–H stretch		3441
–C=C– stretch	Alkenes	1641.74
C–C stretch	Aromatics group	1561.93
C–H bend	Alkanes	1453.22
C–H group	Aromatic ring	849.19
=C–H bend	Alkenes	849.19
O–H stretch	Phenolic group and carboxyl	3456.01