Oil-in-oil pickering emulsions stabilized by diblock copolymer nanoparticles

• Published in: Journal of colloid and interface science 2020-11, Vol.580, p.354-364
• Main Authors: Rymaruk, Matthew J., Cunningham, Victoria J., Brown, Steven L., Williams, Clive N., Armes, Steven P.
• Format: Article
• Language: English
• Subjects: Block copolymers; Nanoparticles; Pickering emulsions; Self-assembly
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2020.07.010

[Display omitted] Diblock copolymer nanoparticles have been shown to be Pickering emulsifiers for both oil-in-water and water-in-oil emulsions. Recently, we reported the preparation of sterically-stabilized diblock copolymer spheres in a low-viscosity silicone oil (Macromolecules 53 (2020) 1785–1794). We hypothesized that such spheres could be used as a Pickering emulsifier for a range of oil-in-oil emulsions comprising droplets of a bio-sourced oil dispersed in silicone oil. Diblock copolymer spheres were prepared via reversible addition-fragmentation chain transfer (RAFT) dispersion polymerization of benzyl methacrylate in silicone oil and characterized by dynamic light scattering and transmission electron microscopy. These spheres were evaluated as Pickering emulsifiers for a series of oil-in-oil Pickering emulsions. The influence of both sphere size and core-forming block composition was investigated. Optimization of the nanoparticle size and core-forming block composition enabled stable bio-sourced oil-in-silicone emulsions to be obtained for nine out of the ten bio-sourced oils investigated. These emulsions were characterized in terms of their mean droplet size by optical microscopy.