Adsorption of different molecular weight lignosulfonates on dimethomorph powder in an aqueous system

Different molecular weight lignosulfonates were acquired by ultrafiltration and their adsorption behavior on dimethomorph powder were investigated. The results showed that as the molecular weight of lignosulfonates increased the adsorption amounts increased and the adsorption processes were driven by van der Waals forces and hydrophobic effects. The adsorption isotherms were fitted well by Langmuir model. Relations of adsorption amounts and zeta potentials with particle size of dimethomorph particles were established to disclose the dispersing mechanism of dimethomorph suspensions. The average particle sizes were determined by zeta potentials rather than adsorption amounts, which confirmed the dispersing mechanisms were electrostatic repulsive forces.