Diffusive Dynamics of Nanoparticles in Arrays of Nanoposts

Journal Article · Tue Jan 01 04:00:00 EST 2013 · ACS Nano

DOI:https://doi.org/10.1021/nn4007303· OSTI ID:1086640

He, Kai ^[1]; Korasani, Firoozeh ^[1]; Thomas, Darrell Keith ^[2]; Retterer, Scott T ^[2]; Conrad, Jacinta ^[1]; Krishnamoorti, Ramanan ^[1]

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1. University of Houston, Houston
2. ORNL

The diffusive dynamics of dilute dispersions of nanoparticles of diameter 200 400 nm were studied in microfabricated arrays of nanoposts using differential dynamic microscopy and single particle tracking. Posts of diameter 500 nm and height 10 m were spaced by 1.2 10 m on a square lattice. As the spacing between posts was decreased, the dynamics of the nanoparticles slowed. Moreover, the dynamics at all length scales were best represented by a stretched exponential rather than a simple exponential. Both the relative diffusivity and the stretching exponent decreased linearly with increased confinement and, equivalently, with decreased void volume. The slowing of the overall diffusive dynamics and the broadening distribution of nanoparticle displacements with increased confinement are consistent with the onset of cooperative dynamics.

• Research Organization: Oak Ridge National Laboratory (ORNL); Center for Nanophase Materials Sciences
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1086640
• Journal Information: ACS Nano, Journal Name: ACS Nano Journal Issue: 6 Vol. 7; ISSN 1936-0851
• Country of Publication: United States
• Language: English