Water-Soluble, Carboxyl-Modified Silicon Nanoparticles
S. Lee and W-J Cho
Korea Institute of Science and Technology, KR
silicon, nanoparticles, watersoluble
Since silicon has both the well-known chemistry and the industrial benefits of non-toxic and low cost, an interest in Si nanoparticles has rapidly increased. We will discuss a practical surface modification of Si nanoparticles prepared by ultrasound-induced solution synthesis. This speedy rout produces the silicon nanoparticles in the size range from 2 nm to 5 nm and the surface of Si nanoparticles are carboxylated by a simple and timesaving rout. Sodium silicide was sonicated with excess chloroacetonitrile in absolute glyme for 1 hour and then it was followed to hydrolyze the nitril groups. The carboxyl functional groups were directly attached at the nanoparticle surface with covalent bonds between C atoms of organic and Si atoms of the nanoparticle. This organic layer with polar terminated groups keeps Si nanoparticles to stably disperse in aqueous solutions. The carboxyl group of nanoparticles was characterized by FT-IR spectroscopy. The HRTEM images show that the carboxyl-modified Si nanoparticles have spherical shape, predominantly with diameters in the range of 2-4 nm. The photoluminescence of nanoparticles dispersed in water were excited by 325 nm, He-Cd laser. The emission maximum of PL spectrum for samples exhibited at 475 nm and the FWHM was approximately 130 nm.
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Nanotech 2005 Conference Program Abstract