Computer simulation on particle agglomeration during the synthesis of titania powders

The agglomeration of titania particles with radii ranging from 20 to 40 nm was simulated based on the colloidal stability using van der Waals attracti on and the electrostatic repulsion energy. With an increase in particle rad ius from 20 to 40 nm, the shape of the energy barrier was changed to allow the bigger particles to agglomerate more easily. For the zeta potential inc rease from 4.5 to 16.8 mV, both the height and width of the energy barrier increased to make the dispersed state stable. This tendency explains the ex perimentally observed agglomeration behaviour where smaller particles with higher zeta potential exhibited higher stability but formed bigger and hard er agglomerates with irregular shapes after drying.