Pickering Emulsions via Interfacial Nanoparticle Complexation of Oppositely Charged Nanopolysaccharides

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A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
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ACS Applied Materials and Interfaces, Volume 13, issue 10
We consider the variables relevant to adsorption of renewable nanoparticles and stabilization of multiphase systems, including the particle's hydrophilicity, electrostatic charge, axial aspect, and entanglement. Exploiting the complexation of two oppositely charged nanopolysaccharides, cellulose nanofibrils (CNFs) 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, below and above net neutrality conditions, we produced sunflower oil-in-water Pickering emulsions with adjustable droplet diameters and stability against creaming and oiling-off. The adsorption of CNF/NCh complexes at the oil/water interface occurred with simultaneous partitioning (accumulation) of the 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 andsize distribution were preserved during storage for at least 6 months under 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 the 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.
| openaire: EC/H2020/788489/EU//BioELCell Funding Information: This work was supported by the Canada Excellence Research Chair initiative, the European Research Council under the European Union’s Horizon 2020 research and innovation program (ERC Advanced grant no. 788489, “BioElCell”), and the Canada Foundation for Innovation (CFI). This work was also part of the Academy of Finland’s Flagship Programme (Competence Center for Materials Bioeconomy, FinnCERES) under project no. 318890 and 318891. Publisher Copyright: © Copyright: Copyright 2021 Elsevier B.V., All rights reserved.
cellulose nanofibrils, food emulsions, interfacial adsorption, nanochitin, pH tolerance, Pickering emulsions, salt resistance
Huan , S , Zhu , Y , Xu , W , McClements , D J , Bai , L & Rojas , O J 2021 , ' Pickering Emulsions via Interfacial Nanoparticle Complexation of Oppositely Charged Nanopolysaccharides ' , ACS Applied Materials and Interfaces , vol. 13 , no. 10 , pp. 12581-12593 . https://doi.org/10.1021/acsami.0c22560