Synthesis of zerovalent nanophase metal particles stabilized with poly(ethylene glycol)

Hanaa Khalil; Devinder Mahajan; Miriam Rafailovich; Mikhail Gelfer; Kaumudi Pandya

doi:10.1021/la0497402

Synthesis of zerovalent nanophase metal particles stabilized with poly(ethylene glycol)

Langmuir. 2004 Aug 3;20(16):6896-903. doi: 10.1021/la0497402.

Authors

Hanaa Khalil¹, Devinder Mahajan, Miriam Rafailovich, Mikhail Gelfer, Kaumudi Pandya

Affiliation

¹ Energy Sciences and Technology Department, Brookhaven National Laboratory, Upton, New York 11973-5000, USA.

PMID: 15274601
DOI: 10.1021/la0497402

Abstract

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 degrees 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.