Small particle adhesion: measurement and control

A number of technologies, including electrophotographic printing, require a n understanding of particle-surface adhesion forces. At Xerox, we have deve loped and applied new techniques in order to understand the dependence of p article adhesion on physical properties, such as particle charge, shape and surface roughness. Atomic force microscopy and computer modeling were used to investigate the effects of surface roughness, external additives and ap plied electric fields on the adhesion of single particles. Centrifugal deta chment was used to measure the adhesion force distribution of several hundr ed particles simultaneously and to determine its sensitivity to particle ch arge and size. Electric field detachment has enabled rapid characterization s of the adhesion of particle layers, providing insight into the roles of p article-surface contact area and nonuniform particle charging on the adhesi on of ensembles of particles. The addition of digital photography to the de tachment techniques has allowed in-situ visualization of particle detachmen t, enabling us to probe interparticle effects on adhesion. (C) 2000 Elsevie r Science B.V. All rights reserved.