Formulation and characterization of lignin modified chitosan beads

Abstract

A simple manual flow injection method was used to formulate chitosan-lignin composite beads in a ratio of 1:1. The beads were then characterized using FT-IR (Fourier Transform Infrared Spectroscopy), SEM (Scanning Electron Microscopy), TGA (Thermogravimetric Analysis), and XRD (X-ray Diffraction). The FT-IR results indicate the chemical composition, revealing the presence of C-O, NH, C-H, and OH on chitosan, as well as OH, C-O-C, C = C, -O-CH3, and C-H, showing the presence and dispersion of lignin within chitosan molecules. SEM was useful for looking at the surface shape and showed structural differences between pure chitosan (which had a smooth surface with few holes) and composite beads (which had sharp edges and a rough, wrinkled shape). The TGA sheds light on the thermal stability and degradation properties of the beads. The thermograms show a similar pattern; however, the degradation temperature improved with the addition of lignin. An XRD investigation revealed the crystalline nature of the beads. Chitosan beads showed a sharp peak at 2θ = 21.8°, whereas in composites, the first peak was observed at 2θ = 9.9° second at 2θ = 20.130° and the third at 2θ = 28°. These findings allowed for the possibility that chitosan/lignin composite beads may be a good adsorbent for use in wastewater treatment systems.