Aggregation in Charged Nano Suspensions
  In order to control aggregation phenomena in suspensions of nanoparticles, one often charges the particles electrically, e.g. by triboelectric charging. Stabilization of suspensions against aggregation of particles is an important issue, which may be realized by monopolar charging, where particles repel each other. Contrarily, bipolar charging may be used in coating processes, where smaller particles of one material coat larger particles of another material. When the two particle fractions are charged oppositely, aggregation between equally charged particles is hindered whereas aggregation between oppositely charged particles is preferred, thereby improving the coating process. We study various aspects of these two situations by theoretical investigations and computer simulations. 
J.H. Werth, S.M. Dammer, H.A. Knudsen, H. Hinrichsen, D.E. Wolf