Sustainable production of cellulose nanofibrils from Kraft pulp for the stabilization of oil-in-water Pickering emulsions

Cellulose nanofibers (CNFs) have been shown to assemble at oil/water interface and act as Pickering emulsions stabilizers. Developing a simple approach to fabricate CNFs with tunable surface properties and elucidating the influence of the surface properties of the CNFs on their emulsifying performance are of great significance and highly demanded. Herein, a facile approach, namely FeCl3-catalyzed formic acid hydrolysis in combination with high pressure homogenization was reported to produce CNFs using industrial Kraft pulp as raw materials. The surface properties, especially the surface wettability of the CNFs could be easily adjusted by changing the hydrolysis time. Additionally, the emulsifying performance of the CNFs and the stability of CNF-stabilized Pickering emulsions were also evaluated. The obtained CNF-stabilized Pickering emulsions demonstrated great stability under various ionic strengths ranging from 0 to 1 M NaCl and high temperature of 80 °C. This work would greatly improve the possibility of sustainable production of CNFs for practical emulsions.