Reverse microemulsion-mediated synthesis of silica-coated gold and silver nanoparticles.
A reverse microemulsion method is reported for preparing monodispersed silica-coated gold (or silver) nanoparticles without the use of a silane coupling agent or polymer as the surface primer. This method enables a fine control of the silica shell thickness with nanometer precision. As compared to the Stöber method reported for direct silica coating, which can only coat large gold particles ( approximately 50 nm in diameter) at low concentrations (<1.5 x 10(10) particles/mL), this new approach is capable of coating gold particles of a wide range of sizes (from 10 to 50 nm) at a much higher concentration ( approximately 1.5 x 10(13) particles/mL). Moreover, it enables straightforward surface functionalization via co-condensation between tetraethyl orthosilicate and another silane with the desired functional groups. The functional groups introduced by this method are readily accessible and thus useful for various applications.
Han
Yu
Y
Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, The Nanos, Singapore 138669.
Jiang
Jiang
J
Lee
Su Seong
SS
Ying
Jackie Y
JY
D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D012821:Silanes / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*
D012821:Silanes; D012834:Silver; D006046:Gold; D012822:Silicon Dioxide