Gas-surface interactions are everywhere

Even as you read this, molecules of gas are colliding with your skin and the walls around you. These kinds of interactions between gases and surfaces are important in many different fields. For example, consider an important problem in the life sciences: respiration. Breathing itself is a process that involves a gas-surface interaction.

As oxygen molecules sprint around the atmosphere, eventually they will end up in your blood stream. Somewhere along the way they have interacted with the surfaces of your lungs and passed into your blood stream. This is what Diego Troya, an associate professor of Chemistry at Virginia Tech, is interested in. His lab is trying to understand the interactions between gases and surfaces.

 As oxygen molecules sprint around the atmosphere, eventually they will end up in your blood stream. Somewhere along the way they have interacted with the surfaces of your lungs and passed into your blood stream. This is what Diego Troya, an associate professor of Chemistry at Virginia Tech, is interested in. His lab is trying to understand the interactions between gases and surfaces.

His lab is trying to carry out simulations of the molecular dynamics of collisions between the gases of the low-Earth orbit atmosphere and models of the polymers that are used as thermal blankets or protective paints on the spacecraft surface. These simulations will provide valuable information about the microscopic reaction mechanisms of erosion processes that cannot be determined from in-orbit or ground-based experiments.

His lab is also studying the adsorption of chemical-warfare agents on surfaces. Recent news has reported the use of substances like Sarin as a warfare agent. This gas is a nerve agent that deactivates the enzyme that controls muscle relaxation, and can be fatal in large concentrations.

Use of these subtances in the battlefield also results in contamination of equipment and other materials like sand that might inadvertently get shipped back to the United States. In the Troya lab, modeling work is used to find out how this agent sticks to common surfaces so that more efficient decontamination trategies can be developed. Because nerve agents like Sarin are extremely toxic, studies in a laboratory setting are challenging. Therefore, computational simulations can fill the experimental void and help to get a complete picture of the surface chemistry of this gas.

Because the lab is engaged in research of the interactions of gas moleculs with extended surfaces, Dr. Troya’s lab uses over a million CPU hours a year. In the spring of 2013, Troya’s lab started using BlueRidge, Virginia Tech Advanced Research Center’s new supercomputer, and his lab has benefitted tremendously from this resource. Blueridge provides the type of cutting-edge research equipment that provides results very quickly, and it has been an incredible gift for their laboratory. “BlueRidge is many times faster than the prior computer we used to operate. A lot of problems that we couldn’t tackle before Blueridge hav now become tractable,” said Prof. Troya.

Since the lab is using this state-of-the-art equipment, the researchers have to be properly trained to exploit its capabilities. In his laboratory, Dr. Troya is a hands-on adviser to his graduate students (Angela Edwards, Robert Chapleski, and Jacky Chan). He always tries to work with them individually, and it is not rare to find him sitting with them as they learn to write computer programs or analyze the result of the simulations.