Chitin/deacetylated chitin nanocomposite film for effective adsorption of organic pollutant from aqueous solution

Cross-linked chitin/deacetylated chitin nanocomposite films can be considered as a potential industrial adsorbent for the removal of organic pollutants for water purification. Chitin (C) and deacetylated chitin (dC) nanofibers were extracted from raw chitin and characterized using FTIR, XRD and TGA techniques. The TEM image confirmed the formation of chitin nanofibers with a diameter range of 10-45 nm. The deacetylated chitin nanofibers (DDA-46 %) having 30 nm diameter was evidenced using FESEM. Further, the C/dC nanofibers were prepared at different ratios (80/20, 70/30, 60/40 & 50/50 ratios) and cross-linked. The highest tensile strength of 40 MPa and Young's modulus of 3872 MPa was exhibited by 50/50C/dC. The DMA studies revealed that the storage modulus enhanced by 86 % for 50/50C/dC (9.06 GPa) in comparison to 80/20C/dC nanocomposite. Further, the 50/50C/dC exhibited a maximum adsorption capacity of 30.8 mg/g at pH = 4 in 30 mg/L of Methyl Orange (MO) dye within 120 min. The experimental data agreed with pseudo-second-order model indicating chemisorption process. The adsorption isotherm data was best described by Freundlich model. The nanocomposite film is an effective adsorbent that can be regenerated and recycled for five adsorption-desorption cycle.