Understanding ice and water film formation on soil particles by combining DFT and Casimir-Lifshitz forces

TL;DR

This paper investigates how quantum electromagnetic forces influence the formation of thin ice and water films on soil particles, using first-principles calculations to improve understanding of environmental processes.

Contribution

It combines density functional theory with Casimir-Lifshitz force calculations to accurately model dispersion forces on soil particles, a novel approach in this context.

Findings

Moisture can form micron-sized water layers on calcite particles.

DFT-based dielectric functions improve modeling of dispersion forces.

Water layers significantly alter soil particle dielectric properties.

Abstract

Thin films of ice and water on soil particles play crucial roles in environmental and technological processes. Understanding the fundamental physical mechanisms underlying their formation is essential for advancing scientific knowledge and engineering practices. Herein, we focus on the role of the Casimir-Lifshitz force, also referred to as dispersion force, in the formation and behavior of thin films of ice and water on soil particles at 273.16 K, arising from quantum fluctuations of the electromagnetic field and depending on the dielectric properties of interacting materials. We employ the first-principles density functional theory (DFT) to compute the dielectric functions for two model materials, CaCO$_3$ and Al$_2$O$_3$, essential constituents in various soils. These dielectric functions are used with the Kramers-Kronig relationship and different extrapolations to calculate the frequency-dependent quantities required for determining forces and free energies. Moreover, we assess the accuracy of the optical data based on the DFT to model dispersion forces effectively, such as those between soil particles. Our findings reveal that moisture can accumulate into almost micron-sized water layers on the surface of calcite (soil) particles, significantly impacting the average dielectric properties of soil particles. This research highlights the relevance of DFT-based data for understanding thin film formation in soil particles and offers valuable insights for environmental and engineering applications.