Coating of gold-decorated silica nanoparticles with polyethylene glycol (PEG) was carried out in the aerosol phase. The process involves first functionalizing the nanoparticles at ∼225 ° C with a bifunctional reactant, 2-mercaptoethanol (ME), for which one end is a thiol that attaches to the gold surface and the other end is a terminal hydroxyl group, and then introducing ethylene oxide (EO), which reacts at ∼440 ° C with the hydroxyl group via a ring-opening polymerization to grow PEG. The morphology, elemental composition and surface chemistry of the PEGylated nanoparticles were characterized by means of transmission electron microscopy, energy dispersive x-ray spectroscopy in scanning transmission electron microscopy, x-ray photoelectron microscopy and Fourier transform infrared spectroscopy. The increase in mobility diameter of the nanoparticles due to PEG growth was measured on-line by tandem differential mobility analysis. The PEG coating thickness was found to increase wit...
Pingyan Lei and Steven L Girshick
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Pingyan Lei and Steven L Girshick
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