Configurational temperature of charge-stabilized colloidal monolayers

TL;DR

This paper introduces experimental measurements of configurational temperature in colloidal monolayers, validating pair potentials and revealing insights into colloidal attractions caused by confinement.

Contribution

It presents the first experimental measurement of configurational temperature and a hierarchy of hyperconfigurational temperatures for colloidal systems.

Findings

Hyperconfigurational temperatures match thermodynamic temperature.

Thermodynamic self-consistency checks validate colloidal pair potentials.

Insights into like-charge attractions due to geometric confinement.

Abstract

Recent theoretical advances show that the temperature of a system in equilibriumcan be measured from static snapshots of its constituents' instantaneous configurations, withoutregard to their dynamics. We report the first measurements of the configurational temperature in an experimental system. In particular, we introduce a hierarchy of hyperconfigurational temperature definitions, which we use to analyze monolayers of charge-stabilized colloidal spheres. Equality of the hyperconfigurational and bulk thermodynamic temperatures provides previously lacking thermodynamic self-consistency checks for the measured colloidal pair potentials, and thereby casts new light on anomalous like-charge colloidal attractions induced by geometric confinement.