All-lignin approach to prepare cationic colloidal lignin particles: stabilization of durable Pickering emulsionsElectronic supplementary information (ESI) available. See DOI: 10.1039/c7gc02900d

Surface modification of colloidal lignin particles (CLPs), which are obtained from renewable resources, is a plausible route towards novel biomaterials. Here we show that adsorption of cationic lignin onto spherical CLPs produces positively charged particles with tailored properties for the stabilization of Pickering emulsions. The threshold dosing of cationic lignin needed to achieve colloidally stable cationic dispersions was 4% relative to the dry weight of CLPs. Compared to irregular kraft lignin particles or regular CLPs, cationic CLPs stabilized a broader array of durable Pickering emulsions. This all-lignin adsorption process to prepare cationic CLPs is advantageous because it minimizes the consumption of synthetic polymers, and opens new application opportunities for structurally defined nano- and microscale lignin particles. Adsorption of cationic lignin on colloidal lignin particles is a green route to new types of Pickering emulsion applications.