Colloidal aspects of Janus-like hairy cellulose nanocrystalloids

For decades, cellulose nanocrystals (CNCs) have been produced by hydrolyzing the disordered cellulose chains of hierarchical fiber structures. These colloidal particles comprise highly ordered arrays of cellulose chains, impeding the physicochemical modifications of inner crystalline layers, which in turn restrict key colloidal properties, such as dispersion stability, functionalizability and charge, response to external fields, and transportation. Controlled oxidation of fibrils permits the partial disintegration of amorphous cellulose chains while maintaining contact with the crystalline body, yielding Janus-like nanoparticles with a needle-shaped crystalline body sandwiched between two disordered cellulose regions (hairs). We refer to these nanoparticles as hairy cellulose nanocrystalloids (HCNC). The protruding soft biopolymer brushes impart significant modifications to the colloidal properties of cellulose nanocrystals, promoting their functionality, charge, stability, and self-assembly. In this article, we embark on detailing how HCNCs behave more like soft nanoparticles as compared to rigid CNCs, explain their fundamental colloidal aspects, and provide a mechanistic overview on how HCNC may expand the horizon of next generation natural soft materials.