Reactivity and aging in hydroxy-iron(III) polymers, analogs of ferritin cores

✍ Scribed by Barbara A. Sommer; Dale W. Margerum; John Renner; Paul Saltman; Thomas G. Spiro

• Publisher: Elsevier Science
• Year: 1973
• Weight: 971 KB
• Volume: 2
• Category: Article
• ISSN: 0006-3061
• DOI: 10.1016/s0006-3061(00)80202-1

✦ Synopsis

The aging of hydrolytic polymers of ferric iron, analogs of the hydroxyiron cores of ferritiu, has been monitored via increases in light absorption, sedimentation velocity, and r&stance to attack by acid. Two concurrent, yet distinct aging proceses are observed, which can be associated with structural change and with growth via particle sceretion The acid decompoeition kinetics am first order in the number of polymerized iron(II1) ions in solution and first order in nitric acid concentration. Moreover the polymer particles shrink in proportion to the amount of acid consumed_ The kinetic evidence suggests that either the particles harden outward from the center, or that they are accessible to the solvent over much of their interior. The polymers can be annealed in solution, rapidly decreasing their reactivity.