AAAR 37th Annual Conference October 14 - October 18, 2019 Oregon Convention Center Portland, Oregon, USA
Abstract View
Optical Monitoring of Aerosol Thermal Processing
JAMES RADNEY, Christopher Zangmeister, National Institute of Standards and Technology
Abstract Number: 471 Working Group: Nanoparticles and Materials Synthesis
Abstract The thermal processing (e.g. chemical reduction, particle dehydration, thermal decomposition, etc.) of nanoparticles using furnace reactors has seen significant use due to the simplicity and scalability of the process. The ability to control temperature and reaction conditions enables a wide array of chemical and thermal process to occur, enabling the development of new nanomaterials. A major challenge is the measurement of aerosol chemical reactions in real-time, in-situ. Here we introduce and demonstrate a new in-situ method that measures aerosol mass and spectroscopic changes as a function of reaction temperature. Two systems were investigated: the evolution of CuO from CuSO4∙5H2O and the reduction of graphene oxide to graphene in a furnace reactor. The physical properties of the particles (size and mass) were characterized utilizing a combination of multiple differential mobility analyzers (DMAs) and an aerosol particle mass analyzer (APM) while spectroscopic (extinction and absorption) changes were probed using 2-λ cavity ring-down and photoacoustic spectroscopies, respectively. This combination of optical measurements allows for determination of the absorption Ångström exponent and co-albedo at 2-λ which can be used as proxies for particle color.