am8b03688_si_006.mp4 (1.58 MB)
Nanoparticle Immobilization for Controllable Experiments in Liquid-Cell Transmission Electron Microscopy
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posted on 2018-06-08, 00:00 authored by Alex W. Robertson, Guomin Zhu, B. Layla Mehdi, Robert M. J. Jacobs, James De Yoreo, Nigel D. BrowningWe
demonstrate that silanization can control the adhesion of nanostructures
to the SiN windows compatible with liquid-cell transmission electron
microscopy (LC-TEM). Formation of an (3-aminopropyl)triethoxysilane
(APTES) self-assembled monolayer on a SiN window, producing a surface
decorated with amino groups, permits strong adhesion of Au nanoparticles
to the window. Many of these nanoparticles remain static, undergoing
minimal translation or rotation during LC-TEM up to high electron
beam current densities due to the strong interaction between the APTES
amino group and Au. We then use this technique to perform a direct
comparative LC-TEM study on the behavior of ligand and nonligand-coated
Au nanoparticles in a Au growth solution. While the ligand coated
nanoparticles remain consistent even under high electron beam current
densities, the naked nanoparticles acted as sites for secondary Au
nucleation. These nucleated particles decorated the parent nanoparticle
surface, forming consecutive monolayer assemblies of ∼2 nm
diameter nanoparticles, which sinter into the parent particle when
the electron beam was shut off. This method for facile immobilization
of nanostructures for LC-TEM study will permit more sophisticated
and controlled in situ experiments into the properties of solid–liquid
interfaces in the future.