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2D to 3D transition of nanoparticles assembled at the liquid interface

ORAL

Abstract

With in situ atomic force microscopy (AFM) imaging, the structure of nanoparticles assembled at the water-oil interface is clearly resolved with the nanometer in 3D. The increase in the surfactant concentration in the oil phase leads to the increase in the contact angle of the nanoparticles at the water-oil interface. Unlike the prediction by equilibrium theory, a 2D monolayer to a 3D multilayer transition of nanoparticles is observed at high surfactant concentrations, which is attributed to the co-existence of completed wetted and partially wetted nanoparticles at the water-oil interface. The contact angle change and structural transition of nanoparticles induced by the increase of surfactant concentration is further confirmed macroscopically by the phase-inversion of Pickering emulsions and anomalous compliance of liquid interface. Our study sheds light on the importance of both thermodynamics and kinetics on the assembly of nanomaterials at the liquid interface and also demonstrate the advantage of using in situ AFM to characterize the assembly of nanomaterials at the liquid interface.

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Presenters

  • Yu Chai

    Lawrence Berkeley National Laboratory

Authors

  • Yu Chai

    Lawrence Berkeley National Laboratory

  • Alysia Lukito

    Lawrence Berkeley National Laboratory

  • Jaffar Hasnain

    University of California, Berkeley

  • Anju Toor

    University of California, Berkeley

  • wenqian feng

    Lawrence Berkeley National Laboratory

  • Yufeng Jiang

    University of California, Berkeley, Lawrence Berkeley National Laboratory

  • Joe Forth

    Lawrence Berkeley National Laboratory

  • yunhui tang

    Lawrence Berkeley National Laboratory

  • honghao hou

    Lawrence Berkeley National Laboratory

  • teresa williams

    Lawrence Berkeley National Laboratory

  • ravi chandra

    Lawrence Berkeley National Laboratory

  • dong li

    Lawrence Berkeley National Laboratory

  • Phillip Geissler

    University of California, Berkeley

  • brett helms

    Lawrence Berkeley National Laboratory, The Molecular Foundry, Lawrence Berkeley National Laboratory

  • Thomas Russell

    Univ of Mass - Amherst, Polymer Science and Engineering, University of Massachusetts Amherst, Lawrence Berkeley National Laboratory, Polymer Science and Engineering Department, UMass

  • paul ashby

    Molecular Foundry, Lawrence Berkeley National Laboratory, Lawrence Berkeley National Laboratory