FLUID INTERFACIAL SEPARATIONS FOR SECONDARY FIBER RECOVERY AS PROBED WITH ATOMIC-FORCE MICROSCOPY

Oil-assisted agglomeration is one process used to reclaim fibre from r ecycled toner-printed paper. The key step in the process is the attach ment of the oil droplets to the toner particles to produce aggregates of adequate size and strength. The interactions of toner particles and large, model colloids (5-20 mu m diameter) with oil-water interfaces are observed using atomic force microscopy (AFM) to determine the effe ct of adsorbed polymers, surfactants, and collision rate on particle a ttachment and detachment, i.e. the success and efficiency of toner rem oval. A particle glued to a cantilever tip probes the oil interface wh ile submerged in a water-filled cell to simulate oil-assisted agglomer ation. Our studies investigate the strength of colloid attachment, fil m drainage and rupture (induction times), and steric stability as impa rted by adsorbed macromolecules.