Brian C Peebles

The Ohio State University, Columbus, OH, United States

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Publications (2)10.52 Total impact

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    ABSTRACT: Ozonation of two commercial carbon blacks (CBs), Printex 90 (P90) and Flammruss 101 (F101), was carried out and changes in their morphology, physical properties, and cytotoxicity were examined. The hypothesis examined was that different methods of manufacture of CBs influence their chemical reactivity and toxicological properties. Structural changes were examined by X-ray photoelectron spectroscopy, infrared spectroscopy, Raman spectroscopy, and electron paramagnetic resonance spectroscopy (EPR). Introduction of surface oxygen functionality upon ozonation led to changes in surface charge, aggregation characteristics, and free radical content of the CBs. However, these changes in surface functionality did not alter the cytotoxicity and release of inflammation markers upon exposure of the CBs to murine macrophages. Interaction of macrophages with F101 resulted in higher levels of inflammatory markers than P90, and the only structural correlation was with the higher persistent radical concentration on the F101.
    Environmental Science & Technology 11/2011; 45(24):10668-75. · 5.26 Impact Factor
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    ABSTRACT: The chemical and biological properties of iron-loaded manufactured carbon nanoparticles (Flammruss 101) were contrasted with those of an iron-loaded synthetic carbon particle. X-ray photoelectron spectroscopy was used to characterize the iron on the carbon particles. Production of hydroxyl free radicals via the Fenton reaction was monitored by electron paramagnetic resonance spectroscopy. The iron-loaded synthetic carbon particles produced a positive Fenton response, whereas the iron-loaded manufactured carbon particles did not. The source of the Fenton activity of the synthetic carbon particles is proposed to be a soluble iron compound that was formed during the synthesis of the particle. A likely candidate for the soluble iron species is Fe2F5, which was synthesized and its properties were examined. Higher toxicity of Fe2F5 toward murine macrophages compared with other simple iron salts was attributed to soluble iron that was stabilized by the fluoride ligand. The cytotoxicity of manufactured carbon particles toward murine macrophages decreased or remained unaltered upon impregnation with iron compounds.
    Environmental Science & Technology 09/2010; 44(17):6887-92. · 5.26 Impact Factor
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    ABSTRACT: Manufactured nanomaterials have become ubiquitous in science, industry, and medicine. Although electron microscopy and surface probe techniques have improved understanding of the physicochemical properties of nanomaterials, much less is known about what makes nanomaterials toxic. Particulate matter less than 2.5 micrometers in diameter is easily inhaled and taken deep into the lungs. The toxicity of inhaled particulate matter is related to its size and surface chemistry. Permissible exposure limits to micrometer-size particulate matter in the workplace are in place, but current limits do not specifically address the role of surface chemistry and the potentially higher toxicity of nanomaterials. The size, agglomeration characteristics, and surface chemistry of several manufactured nanoparticles including carbon, titania, and aluminosilicates are being studied and manipulated to explore the causes of their toxicity. Inflammatory response and cytotoxicity following exposure of human and murine macrophages to nanoparticles are being employed as indicators of particle toxicity. The results are expected to lead to more effective standards for nanomaterial exposure in the workplace and pathways to toxicity mitigation.
    41st American Chemical Society Central Regional Meeting; 05/2009