I&EC 151 |
| Several approaches for controlling the physical and chemical properties of nanomaterials synthesized using wet-chemical methods are currently under investigation. We have been investigating the effect of precursor molecule on the properties of cobalt nanoparticles synthesized wet-chemically. As precursors, two organometallic cobalt complexes were used: alkyne-bridged dicobalthexacarbonyl and the well known dicobalt octacarbonyl. Both precursors were thermally decomposed under identical reaction conditions using oleic acid as a surfactant. We have observed variation in properties such as size, crystal structure and oxidative stability of cobalt nanoparticles synthesized using the two precursors when reactions were carried out under identical conditions and the two different precursors decomposed within 15-20 minutes of the reaction. This lead us to question what exactly is responsible for controlling the properties of Co nanoparticle formed? Role of surfactants, precursor per say and reaction conditions can be ruled out. We have, therefore, carried out a systematic investigation of the decomposition pathway of the two precusors using FT-IR and UV-Vis spectroscopy. These investigations reveal different intermediates/decomposition products leading to the formation of Co nanoparticles and these are likley to be playing an important role as surface impurities on the cobalt nuclei formed controlling the physical and chemical properties of the final Co nanoparticles obtained. We will present details of these systematic investigations. |
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In Situ Spectroscopic Monitoring in Process Development and Production, Sponsored by Novel Chemistry with Industrial Applications Sub-Division
8:30 AM-12:00 PM, Wednesday, 13 September 2006 Moscone Center -- Room 252/254, Oral
Division of Industrial & Engineering Chemistry |