Understanding Oxidation Reactions of Complex Organic and Biological Materials

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While a diamond is said to be « forever », all organic and biological materials endure degradation over time. Any carbon-based material in an oxygen environment undergoes a slow thermodynamic march towards carbon dioxide. When, however, free radicals are introduced in a system, a self-propagating chain reaction called autoxidation rapidly accelerates the incorporation of oxygen into the material. The observable effects of this oxidation process and subsequent reactions are well known: yellowing of plastics, rancidity of oils, burnt toast, brittle rubber, and bleached colours, to name a few. Our research goals are to improve the understanding of oxidation reactions in biological and organic systems. While research in this area has been active for decades, the ideas proposed here illustrate that more basic science research is needed to understand and ultimately, redirect oxidation chemistry. In particular, a high-throughput oxygen uptake apparatus is being developed to accelerate discoveries in this field of research. This setup will be used to study hundreds of oxidizing samples in parallel over days, without the need to add oxidants to accelerated the degradation process. With this data, we hope to demonstrate an unrecognized mechanism that cause antioxidants to behave as radical initiators. We also propose a method to prevent this unrecognized radical initiation reaction. With these mechanisms, we can answer more precisely why an open bottle of wine, full of antioxidants, oxidizes so quickly. Or why butylated hydroxytoluene (BHT) is widely used as a food additive while a "better" antioxidant such as vitamin E is ineffective and even detrimental for long-term storage. Additionally, a rather ambitious and innovative technique called “Melt-React-Trap” is proposed. Ultimately, this technique will yield a "spectroscopic movie" with sub-millisecond time-resolution that can be studied using precise spectroscopic tools such as Raman or infrared spectroscopy to identify reaction intermediates. The Melt-React-Trap technique will give us an unprecedented ability to study oxidation reactions in biological and organic materials. We also expect this technique to, some day, become a major tool in to study heterogeneous reaction mechanisms.