The known unknowns about nanoparticles: from their formation in combustion to the health effects

The process of combustion is the dominant pathway through which mankind continuously injects particulate matter into the atmosphere at the present time. Modern engines are a major source of these combustion-generated nanoparticles since the current emissions regulations are mass-based and do not address the presence of nanoparticles. Given that such great quantities of carbonaceous nanoparticles are being introduced into the atmosphere by combustion source, the question naturally arises as to their environmental fate. However, the prediction of particle formation remains one of the most challenging subjects in combustion science.  Much of the work on soot formation has been driven by the need for predictive models of soot formation and oxidation arising from the principles of thermodynamics and reaction kinetics. In this talk I will review the work done on the chemistry of formation of nanoparticles in high temperature regimes, present new results from my group showing that the current models for particle formation need to be revised, and will end with open questions and information needed from the experimental groups working in this field.

The talk will also highlight our recent results on the interactions of carbonaceous nanomaterials with biological systems to assess their health effects. The computational method used to study these phenomena provide a connection between the various time scales in the high molecular mass compound growth problem, together with an unprecedented opportunity for the understanding of the atomistic interactions between actual carbonaceous nanoparticles produced in combustion processes and biomolecular structures representative of those at the cellular scale and in the lung.