Ames Laboratory; Physics and Astronomy; Materials Science and Engineering
Ames Laboratory, Materials Science and Engineering, Physics and Astronomy
Advanced Materials Interfaces
It is shown that magnetite nanoparticles (MagNPs) grafted with polyethylene glycol (PEG) self‐assemble and short‐range‐order as 2D films at surfaces of aqueous suspensions by manipulating salt concentrations. Synchrotron X‐ray reflectivity and grazing‐incidence small angle X‐ray scattering studies reveal that K2CO3 induces the migration of the PEG‐MagNPs to the liquid/vapor interface to form a Gibbs layer of monoparticle in thickness. As the salt concentration and/or nanoparticle concentration increase, the surface‐adsorbed nanoparticles become more organized. And further increase in salt concentration leads to the growth of an additional incomplete nanoparticle layer contiguous to the first one at the vapor/liquid interface that remains intact.
Department of Energy Subject Categories
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 77 NANOSCIENCE AND NANOTECHNOLOGY