Imaging of polymer monolayers attached to silica surfaces by element specific transmission electron microscopy

Transmission electron microscopy was used to study monolayers of polystyrene covalently attached to the surfaces of highly dispersed silica gels. The layers were grafted by using immobilized azo initiators and performing the polymerization reaction directly at the surface of the particles. Mono-energetic inelastically scattered electrons were used to map the silicon, oxygen and carbon distribution of the modified silica and create element specific images of the specimen. The micrographs give a direct image of the attached monolayers of the polymer molecules. From an analysis of the gray value profiles of the micrographs it can be concluded that the silica particles are surrounded by a continuous, polystyrene layer, approximately 10nm thick.