Hot nano-particles in polar or paramagnetic liquids interact as monopoles

TL;DR

This paper demonstrates that heated or cooled nano-particles in polar or paramagnetic liquids behave as monopoles, interacting via electrostatic or magnetic-like forces, but do not respond to external fields.

Contribution

It reveals the monopole-like interactions of nano-particles in polar and paramagnetic liquids, extending the analogy with electrostatics and magnetostatics.

Findings

Nano-particles act as monopoles in polar liquids.

They interact via monopole-like forces.

Particles do not move under external fields.

Abstract

When neutral nano-particles are heated or cooled in a polar liquid, they will interact with each other as if they carry an electrostatic charge that is proportional to the temperature difference between the particle and the surrounding fluid. The same should hold for paramagnetic liquids, in which case the nano-particles should behave as magnetic monopoles. However, the analogy with electrostatics/magnetostatics is not complete: heated/cooled nano-particles do not move under the influence of an applied field. They should, however, interact as monopoles.