On April 8, 2016, The Graduate School hosted Graduate Student Day, the annual celebration,
competition, and award ceremony honoring USC graduate students. The day consisted
of 73 oral presentations, 64 poster presentations, 19 3-Minute Thesis/Dissertation
presentations, 11 Graduate Civic Scholar poster presentations, 3 creative presentations,
and an exhibit hosted by 2 art students. There were 39 faculty and staff from graduate
programs across campus who served as presentation judges.
Liang Yuan, of Professor Chuanbing Tang's group, won the Oral Research Presentation Competition.
The title of his oral research presentation was: "Next-Generation Plant Oil-Derived Polymers and Composites: Emerging Chemistry and Applications."
The summary of his oral research presentation:
Renewable resources may serve as an alternative choice for the industrial applications of polymeric materials, although there are many challenges to make them competitive with petroleum counterparts. We demonstrate the scalable preparation of monomers and recyclable polymer materials originating from plant oils via a robust transformation strategy. Specifically, the triglycerides were converted into mono-hydroxyl group functionalized fatty derivatives via a mild base-catalyzed amidation process. Polymers from plant oil-derived (meth)acrylic monomers exhibited properties from tacky to plastics depending on their chemical structure of the monomer. The monomer and polymer preparation was demonstrated in 3 lbs scale aiming at industrial production. Bio-plastic from the nanocomposites of soybean oil polymers with cellulose nano-crystals (CNCs) maintain high mechanical strength up to 200 °C. Thermally recyclable bio-elastomers with high resilience (over 90%) were constructed from soy-based tacky polymers. These studies were the leading research as the 2nd generation of renewable polymers from plant oils.
Audrey Duke, of Professor Donna Chen's group, won the Poster Research Presentation Competition.
The title of her poster research presentation was: "Model Pt-Re Systems for Methanol Oxidation: Ambient Pressure XPS and Reactor Studies."
The summary of her poster research presentation:
Methanol oxidation was performed over model Pt-Re catalysts to investigate the role
of Re in improving the activity of Pt, specifically by studying the effect of Re oxidation
states and Pt-Re interactions. Samples were prepared in vacuum using physical vapor
deposition to create Re films on either a Pt(111) single crystal or a polycrystalline
Pt foil. Pt-Re alloy
surfaces were prepared by annealing Re films to 1000 K for 5 minutes in vacuum. Methanol
oxidation experiments were performed from 300 K to 550 K on clean Pt(111), Re films
grown on Pt(111), and Pt-Re alloy surfaces under
200 mTorr O2 + 100 mTorr MeOH in an ambient pressure XPS (AP-XPS) system. The Re films oxidized
more readily than the alloys, but unlike the more stable alloys, oxidized Re films
became volatile at temperatures above 450 K and sublimed from the Pt surface. Furthermore,
the Pt-Re alloy surfaces showed lower atomic carbon levels compared to pure Pt surfaces
under the same conditions. Mass spectrometry showed that the main products on all
surfaces were CO2 and H2O; however, on only the pure Pt surface, selectivity shifted to CO and H2 as temperature increased. This selectivity change was suppressed on surfaces containing
Re. Methanol oxidation experiments were also conducted on a Pt foil, Re films grown
on a Pt foil, and Pt-Re alloy surfaces in a micro flow reactor coupled to an ultra-high
vacuum chamber for sample preparation and XPS analysis. Reactor experiments carried
out from 333 K to 463 K under 2% MeOH + 4% O2, balance He showed the alloy to have 10-20% lower activity than the Pt foil at all
temperatures over short time periods; however, over extended periods of time, the
Pt foil deactivates due to an accumulation of surface carbon while the alloy maintains
high activity.