Nonadditivity of nanoparticle interactions.

Area of Science:

• Physical Chemistry
• Materials Science
• Nanotechnology

Background:

• Understanding inorganic nanoparticle (NP) interactions is crucial for self-organization and various physical, chemical, and biological phenomena.
• Quantitative descriptions of interparticle forces are hindered by challenges not present for microsize particles (μPs).

Purpose of the Study:

• Analyze the sources of difficulties in describing nanoscale interparticle forces.
• Propose a future research direction for understanding nanoparticle interactions.

Main Methods:

• Analysis of classical theories for colloidal interactions.
• Identification of heuristic rules for discriminating between additive and nonadditive nanoscale systems.
• Discussion of the role of discreteness, fluctuations, and multiscale collective effects.

Main Results:

• Nanoscale interactions are complicated by increased discreteness and fluctuations compared to microsize particles.
• Classical theories require modification to address the nonadditivity of various nanoscale interactions (electrostatic, van der Waals, hydrophobic).
• Heuristic rules are identified to help distinguish between additive and nonadditive nanoscale systems.

Conclusions:

• Future research should treat NPs as strongly correlated, reconfigurable systems requiring new experimental and theoretical tools.
• Atomic simulations are becoming more practical for studying NP interactions.
• Advancements in experimental tools and simulations will improve force fields and elucidate the electronic origins of classical interactions at the nanoscale.