Understanding Oxidation Reactions of Complex Organic and Biological Materials

虽然钻石被称为“永恒”，但所有有机和生物材料都会随着时间的推移而退化。任何碳基材料在氧气环境中都会经历一个缓慢的向二氧化碳的热力学过程。然而，当系统中引入自由基时，一种称为自氧化的自传播链式反应迅速加速了氧与材料的结合。这种氧化过程和随后的反应的可观察到的影响是众所周知的：塑料变黄，油变酸，烤面包，橡胶变脆，颜色变白，等等。

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.