Image of the Week - 03 February 2004

Nanoparticle Organization on Microsphere Surfaces

This image depicts highly charged polystyrene nanoparticles adsorbed onto oppositely charged silica microspheres (~1 micron in diameter). At low nanoparticle/microsphere volume fractions, the nanoparticle species can serve as bridges between microspheres, inducing their flocculation. Above a critical nanoparticle volume fraction, they can induce charge reversal of the microsphere surfaces promoting stability. This image was acquired with the ESEM after solvent exchange between water and ethanol followed by hexamethyldisilazane and subsequent drying.

Image Courtesy: James F. Gilchrist, Angel T. Chan, and Jennifer A. Lewis, Materials Science and Engineering

Contact: jfg1@uiuc.edu