POLY 506 |
| The Stöber process is the well-used synthesis route to monodisperse silica particles in the size range of 100-nm and greater, which involves the hydrolysis of tetraalkoxysilane precursor in an alcohol/ammonia solution under highly basic conditions. It is difficult to extend this chemistry to silica nanoparticles (particles with sizes below 100 nm) without sacrificing monodispersity, however. Such nanoparticles are of great interest in drug delivery, catalysis, and photonic materials synthesis. We report a new polymer-based synthesis route to silica-based nanoparticles with a high degree of monodispersity, based on the use of charged polyamine aggregates as templates. Contacting these polymer aggregates with silicic acid leads to the formation of silica/polymer composite nanoparticles, as characterized through scanning electron microscopy and dynamic light scattering. The synthesis route is carried out at room temperature, in water, and at relatively neutral pH conditions, resulting in a stable suspension of unaggregated NPs. We discuss the synthesis conditions that allows one to control tightly particle sizes in the sub-100-nm regime. |
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Nanoparticles and Microparticles: Synthesis and Applications
6:00 PM-8:00 PM, Tuesday, 12 September 2006 Moscone Center -- Hall D, Poster
Sci-Mix
Division of Polymer Chemistry |