Direct observation of water droplet on graphite by non-contacting AFM

The small water droplets which adhere the material surface cause corrosion and a photo catalytic reaction. So it is very important to study the behavior of water droplet. We used a graphite to obtain the atomically flat and clean surface and study the behavior of water droplets of nano meter scale by a atomic force microscope (AFM) with the non-contacting mode. A lot of nano-scale water droplets were observed on the surface freshly created by peeling then pouring pure water and sprayed with cleaner gas. The water film was formed and the water droplets moved when the surface was slowly scanned while applying a certain bias. Multi-layer water films and water droplets were observed on the surface freshly created then pouring pure water. These water film and droplets show a different behavior from ordinary water droplets.