Pickering Emulsions via Interfacial Nanoparticle Complexation of Oppositely Charged Nanopolysaccharides

Abstract

We consider the variables relevant to adsorption of renewable nanoparticles and stabilization of multiphase systems, including particle's hydrophilicity, electrostatic charge, axial aspect, and entanglement. Exploiting the complexation of two oppositely charged nanopolysaccharides, cellulose nanofibrils (CNF) and nanochitin (NCh), we prepared CNF/NCh aqueous suspensions and identified the conditions for charge balance (turbidity and electrophoretic mobility titration). By adjusting the composition of CNF/NCh complexes close to net neutrality, we produced sunflower oil-in-water Pickering emulsions with adjustable 2 droplet diameter and stability against creaming and oiling-off. The adsorption of CNF/NCh complexes at the oil/water interface occurred with simultaneous partitioning (accumulation) of CNF on the surface of the droplets in net negative or positive systems (below and above stochiometric charge balance relative to NCh). We further show that the morphology of the droplets and size distribution were preserved during storage for at least 6-months at ambient conditions. This long-term stability was held with a remarkable tolerance to changes in pH (e.g., 3 ~ 11) and ionic strength (e.g., 100 ~ 500 mM). The mechanism explaining these observations relates to the adsorption of CNF in the complexes, counteracting the charge losses resulting from the deprotonation of NCh or charge screening. Overall, CNF/NCh complexes and the respective interfacial nanoparticle exchange greatly extend the conditions favoring highly stable, green Pickering emulsions that offer potential in applications relevant to foodstuff, pharmaceutical, and cosmetic formulations .

Nanochitin: Chemistry, Structure, Assembly, and Applications

“…Nevertheless, the optical turbidity of the complex suspension remained almost unchanged, implying a unique assembly behavior. 417 Furthermore, a complex assembly process involving ChNF and CNF in the suspension was achieved by adjusting the pH, wherein the resultant long-range interaction of ChNF and CNF depended on the initial charge of the ChNF and CNF. 463 Two distinct regimes that dominated the system were identified by isothermal titration calorimetry, including hydrophobic associations at increased pH values and ionic attraction at intermediate pH (Figure 26c).…”

Pickering emulsions stabilized with chitosan/collagen peptides nanoparticles as green topical delivery vehicles for cannabidiol (CBD)

“…Inorganic particles have been frequently used in Pickering emulsion stabilization [13,14]. However, due to the consumers' demands and industrial preference for natural and label-friendly ingredients, recent research has been directed towards developing particles of natural origin as Pickering stabilizers [15][16][17][18][19].…”

Physicochemical properties of insoluble dietary fiber from pomelo ( Citrus grandis ) peel modified by ball milling

“…The larger particle size generally exhibited weaker ability due to its low surface area to position the oil droplets. The further milled emulsifiers suffered from damage effect on their matrix structure such as crystallinity reduction and destruction of pectin‐lignocellulose network (Huang, Zhu, et al., 2021). For the emulsion emulsified by PP‐IDF‐BM6h, although there was some particle size more than 2 or 3 μm, the majority of them was distributed below 1 μm.…”