Atomic force microscopy was used to study the surfaces of oxygen-plasma-treated polypropylene (PP), kraft pulp, filter paper, and wood. The effect of plasma treatment on the adhesion properties between PP film and wood was evaluated by means of a peel test. The highest adhesion to wood resulted from the shortest treatment times used. The effects of plasma on the adhesion properties were more pronounced when both the PP film and the wood surface were treated. Oxygen plasma caused changes in the morphology of the materials: the treated PP surface was covered by a nodular structure, which was not seen on the untreated film. A similar nodular structure was also seen on the lignocellulosic materials. These nodules seemed to have poor interaction with the PP surface, resulting in a weak interface between the plastic film and wood.

We have characterized electrically conductive polymer, polypyrrole (Ppy), films on mild steel with atomic force microscopy (AFM) and x‐ray photoelectron spectroscopy (XPS). The Ppy films were polymerized electrochemically from sodium p‐toluene sulphonate (ToS) water–ethanol solution. A very good corrosion protective effect of those films on mild steel has been observed previously. After drying in air, thin Ppy films (∽200 nm) were highly adhesive, whereas thicker films (∽7.5 μm) could easily be peeled off from the metal. All films had a nodular surface structure. Thin films were very smooth and their roughness increased with their thickness. The AFM study of the interface between the metal and the polymer showed areas of different morphology, which suggests that adhesive and cohesive failure of the polymer film occurs. A strong variation of the chemical composition at the interfacial layer was observed. A sulphur‐rich layer was formed at the interface, indicating that the counter‐anions (ToS) were accumulated on the surface of the metal. High‐binding energy iron and imine‐type nitrogen were detected in a thin Ppy film. Moreover, thin films were substantially overoxidized. The number of anions incorporated into the Ppy matrix varied as a function of film thickness: the ‘doping level’ was about 30% for thicker films and only 12% for thin ones. Nitrate counter‐anion‐containing Ppy films were also studied in some cases for comparison. © 1997 John Wiley & Sons, Ltd.

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To clarify the mechanism of mercury adsorption on gold surfaces thin epitaxial gold films have been exposed to trace amounts of gaseous mercury under laboratory conditions for different periods of time. The changes in the surface morphology of the thin films caused by the exposure have been studied by scanning tunneling microscopy (STM). The evolution of the surface structures with time has been also investigated, in the course of a few days after the exposure. The adsorption of mercury on the gold surfaces has caused drastic changes in the morphology of the surfaces. Pits and islands of 2 to 30 nm in diameter have appeared on the surface, their size and density per unit area depending on the amount of exposure to mercury. The formation of pits and islands followed a certain path of events.