Flexible cellulose nanofibrils as novel pickering stabilizers: The emulsifying property and packing behavior

In this work, high pressure homogenization (HPH) was applied to alter the physical size of bacterial cellulose, and the obtained bacterial cellulose nanofibrils (BCNFs) with different size were used as stabilizers for O/W Pickering emulsions. The average width of the BCNFs was decreased from 127 to 97 nm with the increasing the homogenized times from 10 to 80 times at 750 Bar, and the obtained BCNFs suspensions was pseudoplastic fluid and exhibited a typical shear thinning behavior. The physical size of the BCNFs had an obvious influence on their emulsifying capacity, and the surface coverage ratio of the emulsion droplets was increased from 0.63 to 9.77 with the changing the volume of oil and solid content of BCNFs. Moreover, the temperature, ionic strength and pH had insignificant influence on the stability of the emulsion. It suggested that the flexible BCNFs played an important role in the stabilization of the emulsions, and the higher content of BCNFs increased the intermolecular noncovalent physical cross-links. Moreover, stable medium-internal-phase-emulsions (MIPEs) could also be fabricated by using BCNFs as stabilizers.