Preparation of surface-charged CNF aerogels and investigation of their ion adsorption properties

Abstract

Cross-linked cellulose nanofibril (CNF) aerogel with positive and negative surface charge was prepared. For the surface charge modification of CNF from its intrinsic negative charge to positive charge, glycidyltrimethylammonium chloride was used. To stabilize the network structure of CNF aerogel in aqueous condition, maleic acid and sodium hypophosphite cross-linking treatment was applied. The ion adsorption properties of positive and negative charged cross-linked CNF aerogels were evaluated using the Langmuir adsorption model, and it was affected by pH of the ion solution. The maximum ion adsorption capacity of negatively charged cross-linked CNF aerogel was 0.79 mmol/g for the nickel cation while that of the positively charged cross-linked aerogel was 0.62 mmol/g for the permanganate anion.