Wrap-bake-peel process for nanostructural transformation from beta-FeOOH nanorods to biocompatible iron oxide nanocapsules.
The thermal treatment of nanostructured materials to improve their properties generally results in undesirable aggregation and sintering. Here, we report on a novel wrap-bake-peel process, which involves silica coating, heat treatment and finally the removal of the silica layer, to transform the phases and structures of nanostructured materials while preserving their nanostructural characteristics. We demonstrate, as a proof-of-concept, the fabrication of water-dispersible and biocompatible hollow iron oxide nanocapsules by applying this wrap-bake-peel process to spindle-shaped akagenite (beta-FeOOH) nanoparticles. Depending on the heat treatment conditions, hollow nanocapsules of either haematite or magnetite were produced. The synthesized water-dispersible magnetite nanocapsules were successfully used not only as a drug-delivery vehicle, but also as a T2 magnetic resonance imaging contrast agent. The current process is generally applicable, and was used to transform heterostructured FePt nanoparticles to high-temperature face-centred-tetragonal-phase FePt alloy nanocrystals.
Piao
Yuanzhe
Y
National Creative Research Initiative Center for Oxide Nanocrystalline Materials and School of Chemical and Biological Engineering, Seoul National University, Seoul 151-744, South Korea.
Kim
Jaeyun
J
Na
Hyon Bin
HB
Kim
Dokyoon
D
Baek
Ji Seon
JS
Ko
Mi Kyeong
MK
Lee
Jung Hee
JH
Shokouhimehr
Mohammadreza
M
Hyeon
Taeghwan
T
D001672:Biocompatible Materials / Q000737:chemistry*; D005290:Ferric Compounds / Q000737:chemistry*; D052203:Ferrosoferric Oxide / Q000737:chemistry; D049329:Nanostructures / Q000032:analysis* / Q000648:ultrastructure*
D001672:Biocompatible Materials; D005290:Ferric Compounds; C000499:ferric oxide; C021024:ferric hydroxide; D052203:Ferrosoferric Oxide