New Insights into the Formulation and Polymerization of Pickering Emulsions Stabilized by Natural Organic Particles

Abstract

Pickering emulsions are known to be an efficient and greener alternative to surfactant-stabilized emulsions. Particles, as key component of these systems, are responsible for their higher kinetic stability and in recent years, the use of natural organic stabilizers has emerged as a solution to promote sustainability. By conferring them stimuli-responsiveness and/or by polymerizing the Pickering emulsion itself, the design of smart and advanced systems can be achieved. Radical polymerization has been by far the most studied polymerization route, and a wide range of materials were successfully synthesized: foams, composites, capsules, or imprinted microspheres. Not only the sustainability of these materials is improved, but their

Green Hydrophilic Capsules from Cellulose Nanocrystal-Stabilized Pickering Emulsion Polymerization: Morphology Control and Spongelike Behavior

“…Pickering emulsions, originally discovered in the beginning of the 20th century, , regained interest in the early 2000s because of their high kinetic stability and their ease of implementation. , The use of particles also enabled the substitution of molecular-scale surfactants, which are often deleterious regarding environmental and health concerns. For the particle choice, organic particles with natural origin have gained increasing interest over their inorganic and synthetic counterparts because they appear as an economic and sustainable solution suitable for biorelated applications, for instance . From this perspective, cellulose nanocrystals (CNCs) constitute an interesting brick material: they are biosourced, biodegradable, with a well-known structure, and they offer an easily modifiable surface and possess interesting intrinsic mechanical properties (Young’s modulus of 150 GPa) .…”

Recent progress in oil-in-water-in-oil (O/W/O) double emulsions

“…Apart from biopolymers and their complexes, solid particles (such as paraffin, triacylglycerols, polymers, or clay) can generate a network and be adsorbed at the interface between different phases, providing a physical barrier to inhibit fusion (Low et al 2020;Szumała and Luty 2016). Such kind of stabilization mechanism is termed as Pickering stabilization, and the as-prepared emulsions are named Pickering emulsions (Dupont et al 2021). Since the irreversibly adsorbed solid particles can function at the oil-water interface by controlling the wettability and contact angle of the solid colloidal particles, the Pickering emulsion possesses higher stability (resistance to deformation) than conventional emulsions for the long-term storage (Low et al 2020;Yu et al 2021).…”

Crosslinkable dextrin-coated latex via surfactant-free emulsion polymerization

“…In this stabilization mode, particles partially wetting oil and water provide a steric barrier against coalescence by adsorbing at the oil-water interface. This approach has been raising interest over the last decade, especially for biobased solid nanoparticles, the presence of which induced specific functionalities in addition to their stabilizing effect [7].…”