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Hoffman Estates High School ESRP 2016

Homogeneous Mixing and Phase Separation During Self-Assembly of Bi-Dispersed Iron Oxide Nanoparticle Films


  • Students:
    • Harpreet Auby
    • Jill Prigge
    • Allison Schrader
    • Miraj Shah
    • Dillon Vadgama
    • Matt Vlasaty
  • Teachers:
    • Wayne Oras
  • Mentors:
    • Yu-Sheng Chen (University of Chicago, ChemMatCARS)
    • Sean Griesemer (University of Chicago, ChemMatCARS)
    • Binhua Lin (University of Chicago, ChemMatCARS)

Advanced Photon Source Sector 15: ChemMatCARS

Nanoparticle films have applications in sensors, transistors, photovoltaic cells, and filtration devices. Discovering a proper method of assembling nanoparticle films will lead to a series of innovations in the fields of material science and nanotechnology. Here, we propose to investigate the spontaneous self-assembly of bi-dispersed iron oxide nanoparticle films. Using liquid x-ray scattering at Sector 15-ID-C as well as transmission electron microscopy, we seek to understand how the size and number ratios of the constituent particles guide their arrangement on the water interface. Although 10:15 nm nanoparticle films appear to be homogeneously mixed because of polydispersities of the constituent particles being too high, there are still microscale phase separations within their own segregated domains. Therefore, we conclude that iron oxide nanoparticle films tend to display some degree of phase separation and never mix homogeneously regardless of the size ratios of nanoparticles. A decrease in the size ratio between nanoparticles results in a decrease in the domain size and a more prominently mixed film.

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