Production and Characterisation of Pickering Emulsions Stabilised by Colloidal Lignin Particles Produced from Various Bulk Lignins

Abstract

The use of lignin, an abundant phenolic bio-polymer, allows us to transform our fossil-based economy into a sustainable and bio-based economy. The transformation of bulk lignin into colloidal lignin particles (CLPs) with well-defined surface chemistry and morphology is a possible way to cope with the heterogeneity of lignin and use it for material applications. These CLPs can be used as emulsifiers in so-called Pickering emulsions, where solid particles stabilise the emulsion instead of environmentally harmful synthetic surfactants. This work investigates the application of CLPs produced from various bulk lignins as a stabiliser in o/w Pickering emulsions with two different oil phases (solid and liquid state). The CLPs had a primary particle size of 28 to 55 nm. They were successful in stabilising oil-in-water Pickering emulsions with high resistance to coalescence and a strong gel-like network. This enables novel applications for CLPs in the chemical and cosmetic industries, and can replace fossil-based and synthetic ingredients.