Synthesis of Zerovalent Nanophase Metal Particles Stabilized with Poly(ethylene glycol)

• Published in: Langmuir Vol. 20; no. 16; pp. 6896 - 6903
• Main Authors: Khalil, Hanaa, Mahajan, Devinder, Rafailovich, Miriam, Gelfer, Mikhail, Pandya, Kaumudi
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 03.08.2004
• Subjects: MATERIALS SCIENCE; METALS; NANOSTRUCTURES; NATIONAL SYNCHROTRON LIGHT SOURCE; POLYETHYLENE GLYCOLS; STABILIZATION; SYNTHESIS
• ISSN: 0743-7463; 1520-5827
• DOI: 10.1021/la0497402

Concurrent sonolysis of iron pentacarbonyl and poly(ethylene glycol)-400 (PEG-400) in hexadecane solvent proceeds via zero-order kinetics and results in Fe nanoparticles encapsulated in PEG-400 (Fe−PEG). The transmission electron microscopy images show Fe−PEG consisting of <3 nm Fe particles that are evenly dispersed in the PEG matrix. Mössbauer and X-ray absorption fine structure/X-ray absorption near-edge structure data reveal an ordered PEG assembly that helps protect the zerovalent Fe core. The Fe nanoparticles in Fe−PEG are superparamagnetic with a magnetization value of 45 emu/g-Fe at 10 KOe. The rheology of the synthesized material shows an unusual increase in viscosity with temperature that is likely due to lower critical saturation temperature phase segregation over 40 °C. The low-temperature mobility of the PEG-400 moiety in Fe−PEG would allow facile ligation of the Fe0 core with biologically and chemically active groups.