Nano@ micro: General method for entrapment of nanocrystals in sol− gel-derived composite hydrophobic silica spheres Academic Article uri icon


  • A general method for entrapment of hydrophobically coated nanocrystals in micrometer and submicrometer composite silica spheres, nano@ micro, was developed. The method employs two starting solutions hydrophobic solvent containing the sol− gel precursor, a polymer, and the nanocrystals, and an emulsifying hydrophilic phase which catalyzes the sol− gel process. The use of a hydrophobic polymer, polystyrene, serves to encapsulate the nanocrystals inside the spheres while maintaining many of their original properties. The obtained nano@ micro spheres were characterized structurally by transmission electron microscopy and scanning electron microscopy, chemically by energy dispersive X-ray spectroscopy, and optically by ensemble and single-particle fluorescence spectroscopy. It is possible to control the size of the microspheres from the 100 nm scale to the micrometer …

publication date

  • January 1, 2005