Facal Marina, P.Delcheva, I.Beattie, D.A.2020-08-252020-08-252018Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2018; 538:765-7730927-77571873-4359http://hdl.handle.net/2440/127195Data source: Supplementary data, https://doi.org/10.1016/j.colsurfa.2017.11.074Emulsions have been formed using non-traditional particle stabilisers: hydrophilic silica particles which themselves are stabilised in suspension by l-lysine. The particles are produced using an adapted recipe for the production of monodisperse nanoparticles (NPs) of small size (15 nm), with l-lysine used as a stabiliser and catalyst during particle synthesis – and are termed SiO₂@Lysine. The resultant SiO₂@Lysine suspensions (particles and residual l-lysine) are used to study the pH-dependent stabilisation of hexadecane-in-water emulsions. Our results show that it is possible to stabilise hexadecane-in-water emulsions using these 15 nm SiO₂@Lysine NPs when the pH of the system is fixed either at acidic pH (e.g. pH = 2.5) or alkaline pH (e.g. pH = 9.0). At high pH, the experimental evidence indicates that l-lysine acts as the primary stabiliser. In contrast, at low pH, silica nanoparticles can stabilise an oil-in-water emulsion, apparently without the aid of the free l-lysine molecules. This multi-modal action of the silica/amino acid suspension has produced an emulsion that is stable at extreme pH values and unstable at intermediate pH values, and one that is a Pickering emulsion at low pH and a traditional emulsion at high pH. Such divergent properties and behaviour may be of relevance for food or pharmaceutical applications.en© 2017 Elsevier B.V. All rights reserved.Emulsion; silica nanoparticles; l-lysine; hexadecane; emulsion stabilityJournal article100002432010.1016/j.colsurfa.2017.11.0740004185866000912-s2.0-85035780618541193Facal Marina, P. [0000-0001-6550-876X]