Oxidation and acetylation of corn cob lignin and its effects on the stabilization of Pickering emulsions

H NMR analysis confirmed the acetylation of lignin; however, the route may lead to greater structural condensation due to heating and a strong acid used. None of the functionalization reactions led to significant changes in the size of lignin nanoparticles (LNPs) (∼20-50 nm). The emulsions prepared with oxidized and acetylated LNPs had a higher emulsification index (>65% at 0.5 g/L LNP) and smaller droplet size than those prepared with unmodified LNPs. Hollow microcapsules prepared in emulsions with acetylated lignin had a mean size two-fold smaller (∼30 µm) and a narrower size distribution. These findings showed that chemical functionalization can tune the properties of LNPs and improve performance in Pickering emulsions.