Salt-Responsive Pickering Emulsions Stabilized by\nFunctionalized Cellulose Nanofibrils

Abstract

Oil-in-water\nemulsions have been stabilized by functionalized cellulose\nnanofibrils bearing either a negative (oxidized cellulose nanofibrils,\nOCNF) or a positive (cationic cellulose nanofibrils, CCNF) surface\ncharge. The size of the droplets was measured by laser diffraction,\nwhile the structure of the shell of the Pickering emulsion droplets\nwas probed using small-angle neutron scattering (SANS), confocal laser\nscanning microscopy (CLSM), scanning electron microscopy (SEM), and\nrheology measurements. Both OCNF- and CCNF-stabilized emulsions present\na very thick shell (>100 nm) comprised of densely packed CNF. OCNF-stabilized\nemulsions proved to be salt responsive, influencing the droplet aggregation\nand ultimately the gel properties of the emulsions, while CCNF emulsions,\non the other hand, showed very little salt-dependent behavior.