Adhesion properties of nanoparticle-coated emulsion aggregation toner

Toner is the key material in printing and copying processes. Fundamental understanding of toner detachment and adhesion during the printing process is critical to improve both the efficiency of toner usage and the quality of print. To control their adhesion property, toner particles can be surface-coated with nanoparticle additives to modify their surface roughness, and consequently, to tune their adhesion properties. In this study, a technique based on the rolling resistance moment of the particle–substrate adhesion bond is used to quantify the effect of nanoparticle surface area coverage (SAC) on the effective work of adhesion of individual toner particles. Nanoparticle-coated model emulsion aggregation (EA) toner microparticles with the specified SAC levels of 0%, 10%, 50% and 100% were studied and the corresponding particle–substrate work of adhesion values were determined and compared. It is quantitatively demonstrated that the work of adhesion between a surface-coated toner particle and a flat silicon substrate decreases significantly with increasing nanoparticle SAC, which provides an effective means to tailor the adhesion performance of the EA toner. Also, based on the experimental data, for a nanoparticle-coated microparticle on a flat substrate, two possible modes of contact formation were identified and discussed.