| Abstract
| - Nanometer-sized silver and copper metal particles can be synthesized by chemical reductionof Ag+ and Cu2+ ions dissolved in the water core of a water in supercritical fluid carbondioxide microemulsion. Sodium cyanoborohydride and N,N,N‘,N‘-tetramethyl-p-phenylenediamine are effective reducing agents for synthesizing these metal nanoparticles in themicroemulsion. Formation of the metal nanoparticles was monitored spectroscopically usinga high-pressure fiber-optic reactor equipped with a CCD array UV−vis spectrometer. Silverand copper nanoparticles synthesized in the microemulsion showed characteristic surfaceplasmon resonance absorption bands centered at 400 and 557 nm, respectively. Diffusionand distribution of the oxidized form of the reducing agent between the micellar core andsupercritical CO2 appeared to be the rate-determining step for the formation of the silvernanoparticles in this system.
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