• Home
  • Search Results
  • Citrate milling of oxides: from poly-dispersed micron scale to nearly mono-dispersed nanoscale.

Citrate milling of oxides: from poly-dispersed micron scale to nearly mono-dispersed nanoscale.

Physical chemistry chemical physics : PCCP (2013-03-02)
Parvez A Shaikh, Abhik Banerjee, Onkar Game, Yesappa Kolekar, Sangeeta Kale, Satishchandra Ogale
ABSTRACT

Complex (multivalent/mixed valent) oxides involving two or more cations (e.g. ABO3, AB2O4 and A2B2O7) exhibit the most fascinating range of physical and chemical properties amongst the family of materials systems. There is growing interest in nanoscale forms of such oxides which emanates from the novel changes in their properties with size. To obtain nanomaterials with a high degree of crystallinity it is desirable to first make crystalline oxide powders by high temperature processing and then mill them down to nanometer size. In this paper we show that simple citric acid treatment of BiFeO3 and Bi2O3 powders leads to the desired micron-scale to nanoscale transformation, yielding nearly monodispersed nanoparticles. Importantly, these are highly dispersible and stable in water. By performing similar experiments on Fe3O4 and Fe2O3 we have elucidated the possible mechanism, which hinges on valence-controlled dissolution and ripening phenomena.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Citric acid, ACS reagent, ≥99.5%
Sigma-Aldrich
Citric acid, 99%
Sigma-Aldrich
Citric acid, meets analytical specification of Ph. Eur., BP, USP, E330, anhydrous, 99.5-100.5% (based on anhydrous substance)
Supelco
Citric acid, Anhydrous, Pharmaceutical Secondary Standard; Certified Reference Material
Sigma-Aldrich
Citric acid, anhydrous, suitable for cell culture, suitable for plant cell culture
Sigma-Aldrich
Bismuth(III) oxide, ReagentPlus®, powder, 10 μm, 99.9% trace metals basis
Sigma-Aldrich
Bismuth(III) oxide, powder, 99.999% trace metals basis
Supelco
Citric acid, analytical standard
Sigma-Aldrich
Citric acid, BioUltra, anhydrous, ≥99.5% (T)
Sigma-Aldrich
Citric acid, ≥99.5%, FCC, FG
Sigma-Aldrich
Bismuth, powder, −100 mesh, 99% trace metals basis
Sigma-Aldrich
Bismuth, granular, ≥99.99% trace metals basis
Sigma-Aldrich
Bismuth, pieces, 1-12 mm, 99.999% trace metals basis
Sigma-Aldrich
Bismuth, powder, −100 mesh, ≥99.99% trace metals basis
Supelco
Citric acid, certified reference material, TraceCERT®
Sigma-Aldrich
Bismuth(III) oxide, nanopowder, 90-210 nm particle size, 99.8% trace metals basis
Sigma-Aldrich
Bismuth(III) oxide, purum, ≥98.0% (KT)
Sigma-Aldrich
Bismuth, shot, 4-30 mesh, 99.9% trace metals basis
Sigma-Aldrich
Bismuth, beads, 1-5 mm, 99.999% trace metals basis