Hannah Hayes / Chemistry & Biochemistry / Faculty Mentor: Peter Kroll
The pyrolysis of a polymer-derived porous SiCO gel was investigated through thermogravimetric analysis. Despite using “ultra-pure” (99.999%) Ar, N2, or He, a substantial apparent mass gain was observed of 4 percentage points at temperatures above 700 and below 900 °C. Chemical analysis and FT-IR characterization of the pyrolyzed material attribute the effect to oxidation. When additional gas purification steps were used, we reduce or even eliminate the mass gain. This identifies the “inert” gas used during pyrolysis as the source of oxidation. As the porous SiCO gel decomposes, it becomes hypersensitive and reacts almost quantitatively with trace impurities in the gas stream. The material presented here can serve as a probe to test the inert environment used in thermal experiments. Moreover, similar porous silicon oxycarbide precursors may also experience oxidation that may have gone unnoticed.
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