This proposal seeks funding to acquire an integrating nephelometer and a scanning mobility particle sizer (SMPS) to characterize nanoparticles in the Nanoparticle Research Laboratory at Seattle University. The integrating nephelometer measures an optical property of particles, and the SMPS provides accurate particle size distribution measurements. The initial investigation with this equipment will study the optical properties and size distribution of black carbon particles coated with an inorganic material. Recent theoretical evidence and modeling studies of the earth's climate show that these coated particles have a considerable net warming effect on the climate. Data generated by this study will enable a quantitative comparison between the experiments and current theories. The integrating nephelometer is an indispensable measurement technique for studying the light scattering ability of atmospheric particles. The SMPS is of equal importance because the scattering and absorption cross-sections depend on particle size. Additionally, the SMPS will ensure the stability of the particle generation source during the optical measurements. The integrating nephelometer and SMPS are versatile pieces of equipment that will support many additional nanoparticle studies in the future. Acquiring the integrating nephelometer and SMPS will facilitate collaboration between researchers at Seattle University and Portland State University. Through this collaboration, the light extinction of coated black carbon particles will be studied using Portland State University's Cavity Ring Down (CRD) instrument. This combined effort will allow for the quantitative measurements of both key optical properties (scattering and absorption) of coated soot particles. This study will significantly impact the current understanding of how these particles affect climate change.
Broader Impacts Experimental measurements of coated nanoparticles will directly benefit the global climate modeling community by providing accurate data for climate models. The experimental results of this study will be shared with the scientific community through publications and conference presentations. Seattle University is a predominantly undergraduate institution, so access to these instruments will greatly enhance undergraduate research and instruction. Undergraduates will be intimately involved with the proposed research and will be encouraged to publish and present their findings at conferences. The equipment will be used in the laboratory sections of three courses offered in three different academic departments at Seattle University. The university has a substantial enrollment of female and underrepresented racial groups; training with this advanced scientific instrumentation will benefit their preparation for graduate school or future employment. The equipment will also be used for the Seattle University "Science Splash!," which is a summer program providing underrepresented, middle school girls an opportunity to conduct scientific research.
