Analysis of action mechanism of anionic polymer dispersant with different molecular structure in dense silicon nitride suspension by using colloidal probe afm

摘要

The present paper focused on the action mechanism of anionic polymer dispersants in dense Si_3N_4 suspension with oxide additives.New preparation method of colloidal probe in which spherical single particle with several mu m in diameter was adhered on the top of a commercial tip for AFM,was developed by using micro-manipulation system for bio-technology.Copolymer of ammonium acrylate and methyl acrylate with different hydrophilic to hydrophobic group ratios,m:n,was prepared and added to the suspension.Microscopic surface interaction between Si_3N_4 and Si_3N_4 or oxide in solution was characterized by using colloidal probe atomic force microscopy (AFM) and model anionic polymer dispersants.The relationships between macroscopic suspension viscosity and the microscopic surface interaction were analyzed.Based on these results,the adsorbed mechanisms of polymer dispersant on silicon nitride and oxide particles and hetero-coagulation phenomena in suspension were discussed.