Pickering Emulsions via Interfacial Nanoparticle Complexation of Oppositely Charged Nanopolysaccharides.

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 and size 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.

[1]  Saad A. Khan,et al.  Associative structures formed from cellulose nanofibrils and nanochitins are pH-responsive and exhibit tunable rheology. , 2020, Journal of colloid and interface science.

[2]  D. Mcclements,et al.  Recent Advances in Food Emulsions and Engineering Foodstuffs Using Plant-Based Nanocelluloses. , 2020, Annual review of food science and technology.

[3]  V. Breedveld,et al.  Synergistic Reinforcement of Composite Hydrogels with Nanofiber Mixtures of Cellulose Nanocrystals and Chitin Nanofibers. , 2020, Biomacromolecules.

[4]  Yan Wang,et al.  Stability of pH-responsive Pickering emulsion stabilized by carboxymethyl starch/xanthan gum combinations , 2020 .

[5]  Hui Liu,et al.  Cinnamon Cassia Oil Emulsions Stabilized by Chitin Nanofibrils: Physicochemical Properties and Antibacterial Activities. , 2020, Journal of agricultural and food chemistry.

[6]  D. Mcclements,et al.  Development of food-grade Pickering emulsions stabilized by a mixture of cellulose nanofibrils and nanochitin , 2020 .

[7]  E. Zussman,et al.  All-Aqueous Liquid Crystal Nanocellulose Emulsions with Permeable Interfacial Assembly. , 2020, ACS nano.

[8]  D. Mcclements,et al.  Nanochitin-stabilized pickering emulsions: Influence of nanochitin on lipid digestibility and vitamin bioaccessibility , 2020 .

[9]  O. Rojas,et al.  Chirality from Cryo-Electron Tomograms of Nanocrystals Obtained by Lateral Disassembly and Surface Etching of Never-Dried Chitin. , 2020, ACS nano.

[10]  K. Tam,et al.  Double stabilization mechanism of O/W Pickering emulsions using cationic nanofibrillated cellulose. , 2020, Journal of colloid and interface science.

[11]  S. Royer,et al.  Emulsion Stabilized with Alumina-Functionalized Mesoporous Silica Particles. , 2020, Langmuir : the ACS journal of surfaces and colloids.

[12]  Yoshikuni Teramoto,et al.  Scalable Pickering Stabilization to Design Cellulose Nanofiber-wrapped Block Copolymer Microspheres for Thermal Energy Storage , 2020 .

[13]  O. Rojas,et al.  High Internal Phase Oil-in-Water Pickering Emulsions Stabilized by Chitin Nanofibrils: 3D Structuring and Solid Foam  , 2020, ACS applied materials & interfaces.

[14]  A. Isogai,et al.  Synthesis of Chitin Nanofiber-Coated Polymer Microparticles via Pickering Emulsion. , 2020, Biomacromolecules.

[15]  D. Mcclements,et al.  Modulation of Physicochemical Characteristics of Pickering Emulsions: Utilization of Nanocellulose- and Nanochitin-coated Lipid Droplet Blends. , 2019, Journal of agricultural and food chemistry.

[16]  Yixiang Wang,et al.  Surface modification of cellulose nanofibrils with protein nanoparticles for enhancing the stabilization of O/W pickering emulsions , 2019 .

[17]  Yixiang Wang,et al.  Cellulose nanofibrils from Miscanthus floridulus straw as green particle emulsifier for O/W Pickering emulsion , 2019, Food Hydrocolloids.

[18]  R. Mezzenga,et al.  Designing Cellulose Nanofibrils for Stabilization of Fluid Interfaces. , 2019, Biomacromolecules.

[19]  D. Mcclements,et al.  Oil-in-water Pickering emulsions via microfluidization with cellulose nanocrystals: 1. Formation and stability , 2019, Food Hydrocolloids.

[20]  H. Minami,et al.  The interface adsorption behavior in a Pickering emulsion stabilized by cylindrical polystyrene particles. , 2019, Journal of colloid and interface science.

[21]  Defeng Wu,et al.  Rheology of the sesame oil-in-water emulsions stabilized by cellulose nanofibers , 2019, Food Hydrocolloids.

[22]  B. D. Mattos,et al.  Two‐Phase Emulgels for Direct Ink Writing of Skin‐Bearing Architectures , 2019, Advanced Functional Materials.

[23]  Akira Isogai,et al.  Dual Functions of TEMPO-Oxidized Cellulose Nanofibers in Oil-in-Water Emulsions: a Pickering Emulsifier and a Unique Dispersion Stabilizer. , 2019, Langmuir : the ACS journal of surfaces and colloids.

[24]  K. Syverud,et al.  The potential of TEMPO-oxidized cellulose nanofibrils as rheology modifiers in food systems , 2019, Cellulose.

[25]  O. Rojas,et al.  Self-Assembled Networks of Short and Long Chitin Nanoparticles for Oil/Water Interfacial Superstabilization , 2019, ACS sustainable chemistry & engineering.

[26]  Zhiguo Wang,et al.  High Axial Ratio Nanochitins for Ultrastrong and Shape-Recoverable Hydrogels and Cryogels via Ice Templating , 2019, ACS nano.

[27]  D. Mcclements,et al.  Encapsulation of vitamin D3 in pickering emulsions stabilized by nanofibrillated mangosteen cellulose: Impact on in vitro digestion and bioaccessibility , 2018, Food Hydrocolloids.

[28]  O. Rojas,et al.  Low Solids Emulsion Gels Based on Nanocellulose for 3D-Printing. , 2018, Biomacromolecules.

[29]  L. D. Del Valle,et al.  Comparison of nanocrystals and nanofibers produced from shrimp shell α-chitin: From energy production to material cytotoxicity and Pickering emulsion properties. , 2018, Carbohydrate polymers.

[30]  Lianfu Zhang,et al.  Driving Forces for Accumulation of Cellulose Nanofibrils at the Oil/Water Interface. , 2018, Langmuir : the ACS journal of surfaces and colloids.

[31]  B. Tardy,et al.  Adsorption and Assembly of Cellulosic and Lignin Colloids at Oil/Water Interfaces , 2018, Langmuir : the ACS journal of surfaces and colloids.

[32]  Lina Zhang,et al.  Recent advances in chitin based materials constructed via physical methods , 2018, Progress in Polymer Science.

[33]  D. Kaplan,et al.  Biopolymer nanofibrils: structure, modeling, preparation, and applications. , 2018, Progress in polymer science.

[34]  O. Rojas,et al.  Electronic Supporting Information for Pickering emulsions by combining cellulose nanofibrils and nanocrystals : Phase behavior and depletion stabilization , 2018 .

[35]  O. Rojas,et al.  Formulation and Stabilization of Concentrated Edible Oil-in-Water Emulsions Based on Electrostatic Complexes of a Food-Grade Cationic Surfactant (Ethyl Lauroyl Arginate) and Cellulose Nanocrystals , 2018, Biomacromolecules.

[36]  O. Rojas,et al.  Formulation and Composition Effects in Phase Transitions of Emulsions Costabilized by Cellulose Nanofibrils and an Ionic Surfactant. , 2017, Biomacromolecules.

[37]  V. Schmitt,et al.  Synthesis of surfactant-free micro- and nanolatexes from Pickering emulsions stabilized by acetylated cellulose nanocrystals , 2017 .

[38]  Jianming Zhang,et al.  High-yield preparation of a zwitterionically charged chitin nanofiber and its application in a doubly pH-responsive Pickering emulsion , 2017 .

[39]  X. Sui,et al.  Cellulose nanofibril-reinforced biodegradable polymer composites obtained via a Pickering emulsion approach , 2017, Cellulose.

[40]  D. Mcclements,et al.  Comparison of emulsifying properties of food-grade polysaccharides in oil-in-water emulsions: Gum arabic, beet pectin, and corn fiber gum , 2017 .

[41]  J. Sjöblom,et al.  Phase behaviour and droplet size of oil-in-water Pickering emulsions stabilised with plant-derived nanocellulosic materials , 2017 .

[42]  D. Mcclements,et al.  Recent Advances in the Utilization of Natural Emulsifiers to Form and Stabilize Emulsions. , 2017, Annual review of food science and technology.

[43]  David Julian McClements,et al.  Fabrication of oil-in-water nanoemulsions by dual-channel microfluidization using natural emulsifiers: Saponins, phospholipids, proteins, and polysaccharides , 2016 .

[44]  D. Mcclements,et al.  Formation and stabilization of nanoemulsions using biosurfactants: Rhamnolipids. , 2016, Journal of colloid and interface science.

[45]  Jie Wu,et al.  Recent Studies of Pickering Emulsions: Particles Make the Difference. , 2016, Small.

[46]  K. Schroën,et al.  Pickering emulsions for food applications: background, trends, and challenges. , 2015, Annual review of food science and technology.

[47]  H. Bizot,et al.  Chitin nanocrystals for Pickering high internal phase emulsions. , 2014, Biomacromolecules.

[48]  Kevin W Eliceiri,et al.  NIH Image to ImageJ: 25 years of image analysis , 2012, Nature Methods.

[49]  A. Mohraz,et al.  Characteristics of pickering emulsion gels formed by droplet bridging. , 2012, Langmuir : the ACS journal of surfaces and colloids.

[50]  H. Bizot,et al.  New Pickering emulsions stabilized by bacterial cellulose nanocrystals. , 2011, Langmuir : the ACS journal of surfaces and colloids.

[51]  Y. Chevalier,et al.  Effects of solid particle content on properties of o/w Pickering emulsions. , 2010, Journal of colloid and interface science.

[52]  L. Lucia,et al.  Cellulose nanocrystals: chemistry, self-assembly, and applications. , 2010, Chemical reviews.

[53]  David Julian McClements,et al.  Critical Review of Techniques and Methodologies for Characterization of Emulsion Stability , 2007, Critical reviews in food science and nutrition.

[54]  C. P. Whitby,et al.  Some general features of limited coalescence in solid-stabilized emulsions , 2003, The European physical journal. E, Soft matter.

[55]  B. Binks.  Particles as surfactants—similarities and differences , 2002 .

[56]  H. Bizot,et al.  Cellulosic nanorods of various aspect ratios for oil in water Pickering emulsions , 2013 .

[57]  W. Ramsden,et al.  Separation of solids in the surface-layers of solutions and ‘suspensions’ (observations on surface-membranes, bubbles, emulsions, and mechanical coagulation).—Preliminary account , 1904, Proceedings of the Royal Society of London.