Abstract by Emily Burrell
Chemistry and Biochemistry
Computational and Experimental Study of the Kinetics and Thermodynamics of New Particle Formation
The measured concentration of particles in the atmosphere is often higher than predicted by atmospheric models. To reconcile the difference between measured and modeled particle concentrations new mechanisms for particle formation need to be determined. The formation of particles has been modeled using classical nucleation theory (CNT). The first step in CNT is to form molecular clusters. In a second step, these clusters grow into particles through coagulation or condensation. Previous research has shown that for prototypical clusters such as the H2SO4-H2O and MSA-H2O systems that the rate of particle formation is enhanced by the inclusion of ppt concentrations of amines to the reaction mixture. We have investigated computationally and experimentally the ability of the formic acid-water (HCOOH-H2O) and hydroperoxy radical-water (HO2-H2O) complexes to serve as nucleating clusters for new particle formation in the absence and presence of trace amounts of amines. Our results show that the inclusion of amines stabilizes the HCOOH-H2O and HO2-H2O complexes and may serve as a mechanism for new particle formation in the atmosphere.