abstract
The influence of 1-ethyl-3-methylimidazolium chloride, 1-butyl-3-methylimidazolium chloride, 1-butyl-1-methylpyrrolidinium chloride, 1-ethyl-3-methylimidazolium tetrafluoroborate and 3-(2-hydroxyethyl)-1-methylimidazolium tetrafluoroborate ionic liquids (ILs) on the morphology and structure of CaCO3 has been investigated in an ethanolic medium by using calcium chloride and ammonium carbonate as the calcium and carbon sources, respectively. Syntheses were carried out at 9 degrees C and room temp. at different IL concentrations and CO32/Ca2+ molar ratios. No polymorph selectivity was detected, and calcite was the sole crystalline form obtained under all the considered reactions conditions. In the case of the BF4-based ILs, anion decomposition occurred, which led to the formation of fluorite. Low temperature reduced the precipitation rate. With the ILs employed, the morphology of CaCO3 has been finely tailored: calcite microcubes, microframes and microboxes with potential application in drug delivery, as well as nanocubes and nanocorn-like objects were produced with Cl-based ILs; with BF4-based ILs, hierarchically structured materials, in which calcite coexists with fluorite, and complex and intricate shapes were produced, such as nanostructured microspheres, nanostructured calla-lily-like and ice-cream-ball-like micro-objects.
keywords
INORGANIC MATERIALS; NANOPARTICLES; EFFICACY
subject category
Chemistry
authors
Fernandes, M; Paz, FAA; Bermudez, VD
our authors
Filipe Alexandre Almeida Paz
Principal Researcheracknowledgements
This work was financially supported by the Fundacao para a Ciencia e a Tecnologia (FCT) (contract PTDC/CTM-BPC/112774/2009). M. F. thanks the FCT for a grant (SFRH/BD/38530/2007).