Mechanism and Factors Influencing Formation and Stability of Chitosan/Lignosulfonate Nanoparticles

A set of new nanoparticles are synthesized in this work at room temperature by combining two oppositely charged non-toxic biopolymer polyelectrolytes in the form of chitosan and lignosulfonate. The effects of intensity of mixing, solid content, and reactant ratio on nanoparticle size and composition are investigated using turbidity measurements, dynamic light scattering data, zeta potential values, surface tension data, and electron microscopy. The data support nanoparticle structures with a dense hydrophobic core surrounded by a positively charged hydrophilic shell. The chitosan and lignosulfonate domains are held in these nanoparticles primarily by the electrostatic force while hydrogen bonding plays a minor role. The particle size increases with an increase of the total solid content, while the ratio of the two reactants determines the number of particles.