Pattern formation during catalytic surface reactions at increased reaction pressures and imaging and prevention of meta-stable pitting corrosion of stainless steels in salt water.

The Dalhousie Surface Reaction Imaging Group is providing innovative techniques to explore the complex nature of physical and chemical interactions on surfaces. We concentrate on understanding fundamental issues of catalytic and other surface reactions manifesting as self-organizing pattern forming phenomena. Insight into the chemical processes on solid surfaces will have great importance in developing better materials and exploiting their dynamic properties will foster our understanding for quite different systems like the stock market or biological rhythms and clocks. We focus attention on the carbon monoxide oxidation of Platinum to illuminate non-linear pattern formation dynamics, the study of deterministic yet unpredictable reactions. The beauty of this simple chemical system is it exemplifies the diverse phenomena of far more complex systems. A new avenue of research is to find what happens at higher pressures when the heat of the reaction begins to influence pattern evolution. Until now these reactions have only been investigated under constant temperature conditions. As the temperature becomes locally different, more complex behaviors will evolve. We are developing world unique imaging tools to observe surface reactions at higher pressure and temperature conditions than have previously been investigated. One spinoff of this approach will allow us to take advantage of the elevated reaction heat to create new rigid, highly sensitive, chemo-thermo-mechanical sensors to detect reaction rates. A target will be to design an inexpensive robust sensor for field operations, which could have far-reaching influence in many applications. Another spinoff of the newly developed tools is to directly visualize pitting corrosion on stainless steels and other materials in salt water in real-time. An important goal here is to find surface treatments to dramatically enhance their resistance to corrosion. We will extend our studies to alloys, including nitinol, which are also meaningful in biomedical applications. Progress in these areas will have a large impact on the durability of materials ranging from underwater tidal turbines to orthodontic wires and cardiovascular stents.