Magnetic interactions between nanoscale domains in liquids
Abstract
Although external magnetic fields (eMFs) may influence effective interactions between nanoscale particles in liquids, their effects remain poorly understood. In this work, we introduce a simplified model of a solvated nanoparticle that consists of localized magnetic domains at its surface to represent groups of paramagnetic ions, forming nanodomains whose effective magnetic dipole moments are at least one order of magnitude greater than the individual ions. We use classical density functional theory to estimate the effective interactions between these localized magnetic nanoparticles (LMNPs) solvated in a diamagnetic solvent. Our findings indicate that, unlike individual ions, magnetic dipole interactions of nanodomains in the LMNP model can indeed compete with the electrostatic, van der Waals, and hydration interactions. Depending on the direction of eMF, the effective interactions between two LMNPs become more attractive or repulsive at relatively short separations on the order of 1 nm or less. This indicates that the interactions driven by an eMF play a critical role in aggregation for nanoparticles with magnetic nanodomains. The effective interactions between LMNPs show oscillatory behaviors that originate from the solvent correlations, which are not affected significantly in the presence of eMFs.
Article Details
Journal Info
The Journal of Chemical Physics
American Institute of Physics
Authors (9)
Mohammadhasan Dinpajooh
Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory 1 , Richland, Washington 99352,
Giovanna Ricchiuti
Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory 1 , Richland, Washington 99352,
Andrew J. Ritchhart
Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory 1 , Richland, Washington 99352,
Tao E. Li
Department of Physics and Astronomy, University of Delaware 1 , Newark, Delaware 19716,
Elias Nakouzi
Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory 1 , Richland, Washington 99352,
Sebastian T. Mergelsberg
Pacific Northwest National Laboratory 2 , P.O. Box 999, Richland, Washington 99354,
Venkateshkumar Prabhakaran
Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory 1 , Richland, Washington 99352,
Jaehun Chun
Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory 1 , Richland, Washington 99352,
Maria L. Sushko
Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory 1 , Richland, Washington 99352,