Our research projects all contain some aspect or application of aerosol science. Currently we are conducting experiments to probe the microstructure and composition of nanodroplets, and to measure nucleation rates in supersonic nozzles. Models of multicomponent condensation in supersonic flows complement the experimental work. Our group is also active in developing biological and biomedical applications of aerosol science.
Even in the liquid state, the composition of multicomponent nanometer-sized droplets is highly non-uniform despite their small size and the relatively short diffusion times. Surface enrichment in aerosols affects the heterogeneous chemistry of aerosol particles as well as nucleation, growth and evaporation kinetics. Our research group uses small angle neutron scattering (SANS) and tunable laser diode absorption spectroscopy (TDLAS) to probe the structure and composition of nanodroplets in order to develop a better understanding of how molecules segregate within aerosol droplets.
Nucleation and Condensation
In most industrial applications and in the atmosphere, more than one condensible species is present, and the rates of new particle formation and growth may be severely under predicted if interactions between the species are ignored. In our group we use a continuous flow supersonic nozzle apparatus to explore nucleation, condensation, and aerosol evolution at supersaturations and expansion rates that are comparable to those found in turbomachinery, jet exhausts, and steam turbines. By conducting small angle neutron scattering and pressure trace experiments, nucleation rates can be measured that are 6 – 8 orders of magnitude higher than in any other type of equipment.
Our research group also collaborates actively with colleagues on bio-related aerosol problems. Our current research focuses on developing aerosol based delivery systems for tissue therapy.