Abstract
Abstract Upon the precipitation of iron(III) hydroxide (Fe(OH)3) and magnetite in the presence of poly(vinyl alcohol) (PVA) at R < 3, PVA is bound to the precipitates in very high yields, where R = [PVA polymer residue]/[Fe ion]. The thermal decomposition of the Fe(OH)3–PVA composite at R = 1.0 by heating at ca. 700 °C in nitrogen for 10 min or more affords almost pure iron metal particles of ca. 200 Å in diameter; almost no residues originating from the PVA remain. Before formation of the metallic iron, magnetite particles are produced as its precursor in the 250—650 °C temperature range, where the particle size increases with increasing temperature from ca. 80 up to ca. 350 Å in diameter, although these iron and magnetite products are not uniform, but are agglomerate or sintered particles. In these processes, the initially bound PVA effectively functions as a reducing agent during its own decomposition.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have