Controlled synthesis of charged lignin nanocarriers by electrospray

Abstract

An experimental investigation of synthesis of lignin nanoparticles using an electrospray system was systematically performed. This investigation demonstrated the control of size and charge distribution of lignin nanoparticles in the single-step electrospray process by tuning the operation parameters and precursor properties. The most important parameters include the liquid flow rate, the initial precursor concentration, and the electrical conductivity. A generalized theoretical model to predict the size and charge developed in our previous work is then verified for a variety of experimental conditions. Finally, we explored the formation mechanism of lignin nanoparticles with three different morphologies: solid sphere, hollow sphere, and elliptical solid. The lignin nanoparticle morphology depends on the competition between the solvent evaporation, the polymer diffusion inside the droplet, and the Coulombic fission processes. This work provides significant insights for fabricating charged nanocarriers for drug delivery applications.