P. Chan et al., ORGANIC-INORGANIC NANOCOMPOSITES BASED ON IRON-CONTAINING CLUSTERS AND BIOMOLECULES, Australian Journal of Chemistry, 48(4), 1995, pp. 783-792
Biopolymers, such as the protein ferritin and the polysaccharides chon
droitin sulfate and chitosan, have been used to control the nucleation
and growth of nanoscale iron(III) hydroxide clusters. The biopolymers
can provide nucleation sites, that in some cases are spatially define
d by the shape of the polymer, and/or defined volumes within which cry
stal growth of the iron(III) hydroxide can proceed. The product inorga
nic clusters are bound to the organic polymers which both keep them in
solution and prevent aggregation. The morphology of the clusters (sph
eres or rods) and the uniformity of their dimensions are determined by
the biopolymer chosen. The temperature of formation is shown to have
an effect on the structure of the clusters, a higher temperature resul
ting in larger inorganic clusters with a higher degree of structural o
rder. Iron(III) hydroxide clusters in ferritin cages can be partially
transformed to iron sulfide by reaction with H2S gas while remaining i
n the protein cage.