In suspensions of colloidal particles different types of interactions are in a subtle interplay. In this report we are interested in sub-micro meter sized Al2O3 particles which are suspended in water. Their interactions can be adjusted by tuning the pH-value and the salt concentration. In this manner different microscopic structures can be obtained. Industrial processes for the production of ce...

We present a theoretical study of dielectrophoretic (DEP) crossover spectrum of two polarizable particles under the action of a nonuniform ac electric field. For two approaching particles, the mutual polarization interaction yields a change in their respective dipole moments, and hence, in the DEP crossover spectrum. The induced polarization effects are captured by the multiple image method. Us...

OF DOCTORAL DISSERTATION HELSINKI UNIVERSITY OF TECHNOLOGY P. O. BOX 1000, FI-02015 TKK http://www.tkk.fi Author Lei Dong Name of the dissertation Manuscript submitted 14.10.2008 Manuscript revised 12.12.2008 Date of the defence 19.01.2009 at 13 o’clock, TKK main building, Otakaari 1, lecture hall E Article dissertation (summary + original articles) Monograph Faculty Department Field of researc...