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Producing metal oxide nanoparticles by the sonochemical, microwave and RAPET techniques.
Bar-Ilan University, Ramat-Gan 52900, Israel
Department of Chemistry and Kanbar Laboratory for Nanomaterials
Bar-Ilan University Center for Advanced Materials & Nanotechnology
Bar-Ilan University, Ramat-Gan, 52900, Israel
In the last few years we have employed three techniques for the fabrication of metal oxides nanoparticles. These methods are: Sonochemistry, Microwave dielectric heating, and RAPET (Reaction under Autogenic Pressure at Elevated Temperatures).
An introduction to these three methods will be presented in my presentation and examples will be given.
In the sonochemical method we will emphasize the difference in the products obtained from a precursor which is volatile solute (transition metal carbonyls) and a precursor that is a nonvolatile solute. The first precursor will yield an amorphous product because of the fast cooling rates obtained upon the collapse of the bubble whereas the latter yields a nanocrystalline product.
The Microwave reactions were conducted in a domestic microwave oven that underwent a modification to include a distillation column. We will present the antimicrobial effect of a metal oxide strongly dependent on the particle size. The mechanism of the bacteria killing will be discussed. Another example of doping one metal oxide in another for example doping MnO in ZnO is made easy by the use of microwave radiation.
For the RAPET section we will present results in which transition metal oxides encapsulated in a carbon shell are being produced. The precursors for these reactions are the corresponding alkoxides. The same RAPET reaction under identical conditions was also carried out between the poles of a strong magnetic field (10T). In certain cases the magnetic field has no effect on the products while for others a dramatic change is observed.
Presentation: Oral at E-MRS Fall Meeting 2007, Cost D30 Meeting, by Aharon Gedanken
See On-line Journal of E-MRS Fall Meeting 2007
Submitted: 2007-09-13 23:28 Revised: 2009-06-07 00:44