Two-fluid, hydrodynamic model for spherical electrolyte systems

TL;DR

This paper introduces a nonlocal, two-fluid hydrodynamic model for electrolytes that captures ionic plasmon effects, revealing significant nonlocal quenching and tunability, with implications for biological, chemical, and plasmonic applications.

Contribution

It develops a novel semi-classical, nonlocal hydrodynamic theory for ionic systems, bridging classical and quantum descriptions of electrolyte plasmonics.

Findings

Up to 90% nonlocal quenching observed in ionic systems.

Ionic plasmon effects are highly tunable via ion concentration, mass, and charge.

The model enables studying non-classical electrolyte effects relevant for catalysis and biological systems.

Abstract

Spatial interaction effects between charge carriers in ionic systems play a sizable role beyond a classical Maxwellian description. We develop a nonlocal, two-fluid, hydrodynamic theory of charges and study ionic plasmon effects, i. e. collective charge oscillations in electrolytes. Ionic spatial dispersion arises from both positive and negative charge dynamics with an impact in the (far-)infrared. Despite highly classical parameters, nonlocal quenching of up to 90% is observed for particle sizes spanning orders of magnitude. Notably, the ionic system is widely tunable via ion concentration, mass and charge, in contrast to solid metal nanoparticles. A nonlocal soft plasmonic theory for ions is relevant for biological and chemical systems bridging hard and soft matter theory and allowing the investigation of non-classical effects in electrolytes in full analogy to solid metal particles. The presented semi-classical approach allows studying plasmonic photo-catalysis introducing nonlocal aspects into electrolyte-metal interactions.