University of illinois Urbana-Champaign

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Nanoparticles and Microspheres

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Created 11/09/2000

These images of optical micrographs and corresponding schematics show the effects of nonadsorbing, mutually repulsive nanoparticle additions to mutually attractive microspheres. (i) In the absence of nanoparticles or at low nanoparticle concentrations, the attractive microspheres flocculate to form a 3-D gel or percolated network. (ii) At modest nanoparticle concentrations, nanoparticles form a protective "halo" configuration around the microspheres preventing flocculation. (iii) At higher nanoparticle concentrations, microspheres once again aggregate. The attractions between microspheres, however, are weaker than case (i) and prevent formation of a spanning 3-D gel. The data (left) was acquired by the fluoresence microscope, while the schematics (right) were created in Maya.


  • Osamu Sakurada , Materials Science, Engineering
  • Valeria Tohver , Materials Science, Engineering
  • A. Lewis , Material Sciences, Engineering
  • Paul V. Braun , Materials Science, Engineering
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