Cationic cellulose nanocrystals (CCNCs) and chitosan nanocomposite films filled with CCNCs for removal of reactive dyes from aqueous solutions

Cationic cellulose nanocrystals (CCNCs) with more cationic groups were yielded when dialdehyde cellulose nanocrystals with more aldehyde groups were reacted with (2-hydrazinyl-2-oxoethyl)-trimethylazanium chloride (GT reagent), keeping the other conditions constant. CCNCs were proved to possess high adsorption capacity toward reactive blue 19 (RB 19). To make nanocrystals more easily separated from aqueous solutions at the end of dye adsorption and simultaneously improve the acid resistance of chitosan (CTS), CCNC 3 with 1.914 mmol g −1 of nitrogen was filled into CTS to fabricate the nanocomposite films by solution casting technique. Equilibrium and dynamic studies indicated that both the filler of CCNC 3 and the matrix of CTS in the nanocomposite films made a synergistic contribution to dye removal. The nanocomposite film with the CCNC 3 /CTS weight ratio of 12/100 got the dye adsorption capacity of 900 mg g −1 at the adsorbent dosage of 100 mg L −1 , 25 °C and pH 3 of RB 19 solution. Graphical Abstract