Oil-in-water Emulsions Stabilised by Deep Eutectic Solvent-Extracted Lignins

Deep eutectic solvents (DES) represent an emerging class of mixtures, distinguished by strong intermolecular interaction among the components leading to notable reduction in melting point of the resulting solvent. These ‘designer’ solvents, whose properties can be tailored based on the hydrogen bond donor and acceptor species, have emerged as a promising alternative to organic solvents for lignocellulosic biomass fractionation. Notably, DES can also tailor the structure and thereby the properties of lignin during extraction based on the chosen components. Emulsions, stabilized by the lignin extracted via DES, present a potential sustainable solution for emulsion systems. In this study, we aim to investigate the structure of non-polar cyclohexane:water and polar hexanol:water emulsions stabilized by four different types of DES-extracted lignin-rich particles by utilizing the contrast match conditions of small-angle neutron scattering (SANS). We will determine whether the extracted lignins form particles at the oil-water interface, acting as Pickering stabilisers or act more as polymeric stabilisers. This research will provide valuable insights into the structural organization of lignin at the oil-water interface, enhancing our understanding on how lignin species contribute to (Pickering) emulsion stability.