In situ characterization of food and plastic waste carbonized under pressure

This seminar connects carbonization conditions with the structure and function of carbon made from discarded plastics and food-derived sugars. Commodity plastics are carbonized under autogenic pressure in sealed quartz capillaries; sugars undergo neutral and alkaline hydrothermal processing in water and ionic liquids. Time-resolved WAXS, SAXS and Raman measurements, supported by ex situ XPS, track organic networks as they become carbonaceous solids. SAXS identifies emerging porosity and density variation, WAXS follows short-range aromatic stacking, and Raman D and G bands measure evolving sp2 domains and defects. XPS distinguishes oxygen-rich hydrothermal chars from plastic-derived carbons with lower oxygen-to-carbon ratios and stronger graphitization signatures. The combined observations relate precursor chemistry to intramolecular rearrangement, intermolecular crosslinking, pore formation and aromatic ordering under pressure.