ABSTRACT
This chapter reviews several known or hypothesized origins of charge nonuniformity on oxide and polymer particles; and discusses techniques for measuring charge nonuniformity on particles. It also reviews the literature on charge nonuniformity for various particulate systems; describes some ramifications of charge nonuniformity for colloidal stability and assembly; and aims to predict the future opportunities in studying and controlling charge nonuniformity for colloidal systems. Charge nonuniformity has different origins on oxide particles, polymer particles, bacteria, and viruses. A number of techniques exist for measuring charge nonuniformity and other heterogeneity on surfaces, but few techniques exist for measuring charge nonuniformity on colloidal particles. Direct imaging of particles also provides a method for measuring charge nonuniformity. For particles with random charge nonuniformity, it is nearly impossible to get useful information from translational electrophoresis. Charge nonuniformity has a significant impact on colloidal interactions, and this has been studied mostly through theory.
