The Heat Capacity and Thermodynamic Properties of the Iron Oxides and Their Relation to the Mineral Core of the Iron Storage Protein Ferritin
The iron oxides are a group of materials with geological, biological, and technological importance. A thermodynamic understanding of these materials is important because it provides information about their relative stabilities, chemical reactivity, and transformations. This study provides the heat c...
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| Format: | Others |
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BYU ScholarsArchive
2010
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| Online Access: | https://scholarsarchive.byu.edu/etd/2435 https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=3434&context=etd |
| Summary: | The iron oxides are a group of materials with geological, biological, and technological importance. A thermodynamic understanding of these materials is important because it provides information about their relative stabilities, chemical reactivity, and transformations. This study provides the heat capacity of a nanocrystalline magnetite (Fe3O4) sample, bulk hematite (α-Fe2O3), nanocrystalline hematite, akaganéite (β-FeOOH), and lepidocrocite (γ-FeOOH) at temperatures as low as 0.5 K. These measurements were fit to theoretical functions at temperatures lower than 15 K, and the respective thermophysical properties of these materials are discussed. Also the molar entropies of bulk hematite and hydrous nanocrystalline hematite as well as hydrous akaganéite are given. Finally, a ferritin protein powder was prepared for heat capacity measurements by reconstituting the iron core in the presence of an imidazole buffer. This method allowed the introduction of almost 3000 iron atoms into each protein. Heat capacity measurements of apoferritin and the reconstituted ferritin sample are anticipated in the near future with plans to compare the heat capacity of the mineral core to that of other nanocrystalline iron oxides and oxyhydroxides. |
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