Phosphorylated-CNC/modified-chitosan nanocomplexes for the stabilization of Pickering emulsions

[Display omitted] •Phosphorylated cellulose nanocrystal (P-CNC), prepared via three steps, was used as a crosslinking agent.•GTMAC-Chitosan (GCh) was modified to improve solubility in water.•P-CNC and GCh nanocomplexes were formed through ionic gelation.•An optimal ratio of 2.5:1 for GCh:P-CNC was needed to form a hard sphere structure.•O/W Pickering emulsion with the nanocomplexes possessed high stability over 3 months. Cellulose nanocrystals (CNC) are sustainable nanomaterials that possess high tensile strength, stiffness and surface functional groups suitable for various types of modifications. In this study, phosphorylated cellulose nanocrystals (P-CNC) were prepared via acid hydrolysis with phosphoric acid to decorate phosphate groups on the surface of CNC. Also, chitosan was modified with glycidyltrimethylammonium chloride (GTMAC) to improve its solubility. GTMAC-Chitosan (GCh) and phosphorylated cellulose nanocrystals (P-CNC) were complexed via ionic gelation to produce GCh-P-CNC nanoparticles under mild sonication. Although sodium tripolyphosphate (TPP) is a common cross-linking agent used with chitosan, its application is compromised by its metastable structure that resulted in the rapid release of its encapsulated compound. Therefore, phosphorylated cellulose nanocrystal was developed as a “nanoparticle” cross-linker and a Pickering emulsifier. The nanocomplexes transformed from a rod-like to hard sphere and random coil morphology with increasing ratio of GCh/P-CNC. In comparison with TPP-Chitosan emulsion, Pickering emulsion prepared using GCh-P-CNC complex was more stable over 3 months without coalescence and phase separation.