If you are interested in attending, please contact Jeremy Averyt (firstname.lastname at lasp.colorado.edu) to be added to the mailing list or for Zoom information.
LASP seminars are generally held every Thursday at 4:00 PM on Zoom and in person: https://lasp.colorado.edu/home/about/events/science-seminars/
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Abstract:
Polyaromatic hydrocarbons (PAHs) are found throughout the Universe. The ubiquity of these organic molecules means that they are of considerable interest in the context of cosmic dust, which typically travel at hypervelocities (> 1 km s-1) within our Solar System. However, studying such fast-moving micrometer-sized particles in laboratory-based experiments requires suitable synthetic mimics. Herein we use ball-milling to produce microparticles of anthracene, which is the simplest member of the PAH family. Size control can be achieved by varying the milling time in the presence of a suitable anionic commercial polymeric dispersant (Morwet D-425). These anthracene microparticles are then coated with a thin overlayer of polypyrrole (PPy), which is an air-stable organic conducting polymer. The uncoated and PPy-coated anthracene microparticles are characterized in terms of their particle size, surface morphology and chemical structure using optical microscopy, scanning electron microscopy, laser diffraction, aqueous electrophoresis, FT-IR spectroscopy, Raman microscopy and XPS. Finally, such microparticles can be accelerated up to hypervelocities using a Light Gas Gun. Moreover, studies of impact craters indicate carbon debris so they are expected to serve as the first synthetic mimic for PAH-based cosmic dust.
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The Physics Frontiers Centers (PFC) program supports university-based centers and institutes where the collective efforts of a larger group of individuals can enable transformational advances in the most promising research areas. The program is designed to foster major breakthroughs at the intellectual frontiers of physics by providing needed resources such as combinations of talents, skills, disciplines, and/or specialized infrastructure, not usually available to individual investigators or small groups, in an environment in which the collective efforts of the larger group can be shown to be seminal to promoting significant progress in the science and the education of students. PFCs also include creative, substantive activities aimed at enhancing education, broadening participation of traditionally underrepresented groups, and outreach to the scientific community and general public.