Core C: Materials Core

材料核心提供了特征良好的超级基金相关粒子和替代品的样本，旨在测试特定的研究假设，供6个研究项目研究。该核心的构建是为了协助研究与过渡金属颗粒物质(PM)相关的环境持久性自由基(EPFR)对健康和环境的影响。我们的研究人员发现，EPFR是由芳香族氯代苯、氯化苯酚和其他类型的苯酚与金属氧化物进行化学吸附，然后进行电子转移，还原金属形成EPFR形成的。这些EPFR可以在环境中持续存在，并具有生物活性。在燃烧和热处理系统中浓度较高时，它们还会自我反应形成新的污染物，如多氯二苯并对二恶英和二苯并呋喃。由于细颗粒和超细颗粒具有较高的表面积与体积比，并且由于不满意的价态而增加了反应性，因此它们可能特别容易形成EPFR。CORE开发了设备和技术来合成：i)包覆一层过渡金属(如氧化铜和氧化铁)的二氧化硅微粒；ii)含有相同过渡金属纳米区的二氧化硅微粒和超微粒；iii)纯铜和氧化铁的超微粒；iv)任何这些微粒与相关的环境持久性自由基(EPFR)；以及v)适当的对照样品。该核心还建立了利用电子顺磁表征受污染的超级基金土壤和EPFR危险物质热处理设备的颗粒排放的现场样品的能力 使用GC-MS和其他标准实验室技术的共振(EPR)光谱和分子前体。核心已经制定了系统的方法来接收样品请求，建立保管链，并在真空下储存颗粒，使其在使用前不会降解。核心主任有在过去5年中与每个项目负责人成功合作的记录，导致出版了多份出版物。

The Materials Core provides samples of well-characterized Superfund-related particles and surrogates designed to test specific research hypotheses for study by the 6 research projects. The Core was constructed to assist in the study of the health and environmental effects of environmentally persistent free radicals (EPFRs) associated with transition metal-containing particulate matter (PM). Our researchers have discovered EPFRs are formed by chemisorption of aromatic chlorinated benzenes, chlorinated phenols, and other types of phenols to metal oxides, followed by electron transfer that reduces the metal and forms the EPFR. These EPFRs can persist in the environment and are biologically active. At high concentrations in combustion and thermal processing systems, they also self-react to form new pollutants such as polychlorinated dibenzo-p-dioxins and dibenzofurans. Because fine particles and ultrafine particles have high surface-to-volume ratios and increased reactivity due to unsatisfied valences, they may be particularly prone to EPFR formation. The Core has developed facilities and techniques to synthesize: i) fine and ultrafine particles of silica coated with a monolayer of transition metals such as copper oxide and iron oxide; ii) fine and ultrafine silica particles containing size-controlled nanodomains of the same transition metals; iii) ultrafine particles of pure copper and iron oxides; iv) any of these particles with associated environmentally persistent free radicals (EPFRs); and v) appropriate control samples. The Core has also established the capabilities to characterize field samples from contaminated Superfund soils and particulate emissions of devices for thermal treatment of hazardous substances for EPFRs using electron paramagnetic resonance (EPR) spectroscopy and molecular precursors using GC-MS and other standard laboratory techniques. The Core has developed systematic approaches for receiving sample requests, establishing chain of custody, and storing particles under vacuum where they will not degrade prior to use. The Core Director has a record of successful collaborations with each of the Project Leaders over the past 5 years, leading to multiple publications.