Related Experiment Video
Updated: Jun 14, 2026

Liquid-cell Transmission Electron Microscopy for Tracking Self-assembly of Nanoparticles
Published on: October 16, 2017
Assembling nonspherical 2D binary nanoparticle superlattices by opposite electrical charges: the role of Coulomb
Zhaoyong Sun1, Zhiping Luo, Jiye Fang
1Department of Chemistry, State University of New York at Binghamton, Binghamton, New York 13902, USA.
Abstract:
High-quality approximately 16 nm c-In2O3 nanoctahedra and approximately 6 nm Pd spherical nanoparticles were synthesized via a high-temperature wet-chemical approach, and their electrophoretic mobilities in toluene were investigated, respectively. Opposite electrical charge-induced 2D binary nanoparticle superlattice patterns containing two such nanocomponents were prepared, for the first time. Three types of c-In2O3-skeleton-structure-contained assembly patterns were identified as well. It was further observed that the vertices of c-In2O3 nanoctahedra could have higher electrical charge density than that on edge or plane and the small Pd nanoparticles were "suspended" on the middle plane of the c-In2O3 nanoctahedra, apparently well above the substrate surface (support film) rather than sitting on it. The assembly structure study indicates that Coulomb forces resulted from the opposite electrical charges are the dominative driving forces to induce the formation of such nanoctahedra-nanospheres 2D binary nanoparticle superlattices.
Related Concept Videos
Coulomb's Law and The Principle of Superposition
The Principle of Superposition answers the question. Yes, Coulomb's Law applies to each pair of charges, and the net force on each charge is the vector sum of the...
Coulomb's Law
Newton's third law applies to the Coulomb force — the force on...
Comparison Between Electrical And Gravitational Forces
Since both are inverse square law forces, the distance gets canceled when the ratio of the two forces is considered. Instead, the ratio of the electrical and gravitational forces depends on...
Electric Field of Two Equal and Opposite Charges
A separation of the positive and negative charges can lead to a weak, remnant effect of the positive and negative charges. The expectation is that the more the distance between the positive and...
Ionic Crystal Structures
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
The Electrical Double Layer

