FOAM AND CLUSTER STRUCTURE FORMATION BY LATEX-PARTICLES AT THE AIR WATER INTERFACE/

We report the formation of two-dimensional foam and cluster structures by spherical polystyrene particles trapped at the air/water interface . The colloidal foam is a transient structure that evolves to the form ation of clusters, but clusters can also be formed after deposition of the sample. We also observed the formation of small aggregates, whose formation along with the cluster stabilization can be explained in te rms of a balance between electrostatic repulsive and van der Waals att ractive interactions.