Size and surface effects of prussian blue nanoparticles protected by organic polymers

Takashi Uemura; Masaaki Ohba; Susumu Kitagawa

doi:10.1021/ic0488435

Size and surface effects of prussian blue nanoparticles protected by organic polymers

Inorg Chem. 2004 Nov 15;43(23):7339-45. doi: 10.1021/ic0488435.

Authors

Takashi Uemura¹, Masaaki Ohba, Susumu Kitagawa

Affiliation

¹ Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan.

PMID: 15530083
DOI: 10.1021/ic0488435

Abstract

Prussian blue (PB) nanoparticles protected by organic polymers such as poly(vinylpyrrolidone) (PVP) and poly(diallyldimethylammonium chloride) (PDDA) were prepared. Different experimental conditions (concentrations of Fe ions and feed ratios of Fe to the polymers) have been investigated to control the size of the PB nanoparticles. For example, the averaged dimensions of the PB nanoparticles were tuned from 12 to 27 nm by use of PVP in the different conditions. Addition of PDDA produced the PB nanoparticles with very small dimensions (5-8 nm) by an effective electrostatic interaction. We found that the surface environments of the PB nanoparticles affect the inherent properties of PB. The shifts of charge transfer (CT) absorptions from Fe(2+) to Fe(3+) in the PB nanoparticles resulted from the surface-protecting polymers. Especially, the PB nanoparticles with the PVP protection show high solubility in a variety of organic solvents and a solvent-dependent CT absorption. Measurement of the magnetic properties of the PB nanoparticles showed unprecedented size-dependency, surface effect, and superparamagnetic properties.