The 38th General Meeting of the German Colloid Society was held at the University of Essen, Germany, from September 29th to October 2nd, 1997. The selection of papers presented in this volume covers a broad range of fundamental aspects as well as recent developments. - It focuses the following sections: - Technical applications; - Advanced experimental techniques; - Thin films and interfaces; - Suspensions and microcapsules; - Emulsions, microemulsions and foams; - Macromolecules; - Association colloids; - Colloidal systems in environmental science.