The research focus of chemical engineering student and Schmitt Fellow Andrew Paluch is developing general computational and theoretical methods that will enable us to predict the solubility limit of species such as drug molecules and pollutants in different solvents.
“This is important for several reasons," Paluch explains. "In drug development research, companies are interested in discovering new molecules with a desired biological activity. How ‘available’ these molecules are to the body is determined by how soluble they are in biological fluids, and the methods we are developing will help companies determine this early in the drug discovery process. To make these drug molecules commercially, large amounts of solvents are required. Our methods can be used to help companies choose environmentally friendly solvents when they design production processes. These same techniques can be applied to many other situations. For example, as part of the Notre Dame Sustainable Energy Initiative, we are applying our methods to study how pollutants formed during the combustion of fossil fuels might be removed from exhaust streams by dissolving them selectively in special liquids.
“Working under the direction of my adviser, Prof. Edward Maginn, the main tools we use are statistical mechanics and molecular-level computer simulations. The key here is to view the process at the atomistic level. If, for example, we are interested in how a particular molecule dissolves in water, we can examine the atomistic-level interactions between this molecule and water with our simulation methods. We then apply statistical mechanical analysis to the results of the simulations to determine the properties that would be observed in the laboratory (i.e. the solubility). The challenge that we encounter is that it quickly becomes computationally exhaustive to create distributions of all of the relevant configurations of interest. To this end, we are developing novel simulation methodologies to tackle this specific problem.
“While the solubility of a molecule in a given solvent may be determined experimentally, time and expense constraints limit the number of systems that can be examined. The hope is that by providing reliable computational tools that can quickly assess the solubility of a compound in a range of solvents, we can substantially speed up the way in which solvents are selected in the areas of drug discovery and pollution control. Moreover, by taking a molecular-level view, we can gain a deeper fundamental understanding of the solvation process. For instance, why do two molecules that ‘look’ similar have such different solubilities in water? Our approach allows us to interrogate this process at its most fundamental level and therefore develop an understanding of the underlying physics.”
Andrew explains that when he began to investigate graduate schools, “I knew very well the type of research that I would like to perform. I was introduced to molecular simulations as an undergraduate, and I was hooked. I was fortunate to have very good guidance in selecting schools based on the research interests of faculty.
“Ultimately, I choose to come to Notre Dame as a result of a great visit with my adviser. Compared to other schools that I visited, I felt very comfortable interacting and talking with the faculty in the Chemical and Biomolecular Engineering department here. This level of comfort has continued and has allowed me to be extremely productive in my work.”
And productive he has been. Andrew has already published four first-author peer-reviewed papers and has several more in preparation. He has given nine conference paper presentations and been awarded fellowships to present his research at the UCLA Institute of Pure and Applied Mathematics workshop on Navigating Chemical Compound Space for Materials and Bio Design and a Gordon Research Conference on Computer Aided Drug Design. In 2009 he received an NSF fellowship to participate in the National Institute for Nanoengineering summer school at Sandia National Laboratories.