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The size and shape control in the nanomaterial research is a riveting area of interest. New methods have been developed by the researchers to synthesize the metal nanoparticles with uniform size and shape distribution. Most of the methods for the preparation of the copper and silver nanoparticles involve the reduction of M(I) precursor to M(0) nanoparticles. In my work I have fabricated the copper and silver nanoparticles by the thermal decomposition in organic media. This method is quite similar to the CVD method, where the precursor decomposes and undergoes reduction at high temperatures to give the self-assembly of the nanoparticles. In order to get the monodispersed nanoparticles, I have used the surfactants to stabilize the nanoparticles from aggregation.
I have employed (hfac)Cu(PMe3) and (hfac)Ag(PMe3) as precursors in various solvents to generate the metal nanoparticles. Variety of surfactants have been used in order to get the nanoaprticles of the desired shape and size distribution. Some factors like concentration, reaction time , reaction temperature and precursor to surfactant mole ratio are modified in order to generate 6 nm copper nanoparticles and 20 nm ~ 40 nm spherical silver particles.
I have also made a trial to use binary surfactant system (oleic acid and oleylamine). These two surfactants combine to give new surfactant which contains the amide linkage leads to form micelle by hydrogen bonding to adjacent amide surfactant molecules results in the formation of self-assembly of the cubic as well as the spherical particles.
The characterization of the formed metal nanostructures have been carried out by transmission electron microscope to analyze the morphology. The energy dispersive spectroscopy and powder X-ray diffraction to confirm the composition were used of the synthesized metal nanocrystals.
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