Release Studies on Mesoporous Microcapsules for New Corrosion Protection Systems

The present work has been motivated by a particular concept of corrosion protection; however, it addresses the generic field of storage and delivery of functional molecules. After processing of galvanized steel sheets a so-called cut-edge is exposed. Its cathodic protection is mostly insufficient and a solution is sought in the incorporation of functional microcapsules into the metallic coating. In detail, mesoporous silica particles have been studied with respect to compatibility as well as loading and release properties. The development and application of two methods, one based on microscopic and one spectroscopic measurement, allowed the characterization of release kinetics for single particles as well as particle assemblies. Anisotropic diffusion coefficients and surface diffusion barriers have been determined.