Thermodynamics of interface in the freezing of colloidal suspensions: from macroscale to the microscale

TL;DR

This paper explores the thermodynamics of the water/ice interface during freezing of colloidal suspensions, clarifying the mechanisms behind ice lensing from macroscale to microscale and challenging previous assumptions.

Contribution

It introduces a thermodynamic framework for the water/ice interface that explains ice lensing based on pore ice growth and critical curvature, differing from prior fracture-based models.

Findings

Ice lensing initiated by pore ice growth, not fracture.

Critical curvature undercooling determines ice lensing.

Porous structure packing influences ice lensing behavior.

Abstract

A long controversy of ice lensing exists in the research of frost heave. By elucidating the mechanical and thermodynamics equilibria at the interface, we present the thermodynamics of the water/ice interface from macroscale to microscale for the freezing of colloidal suspensions. The application of the Clapeyron equation is confirmed both at macroscale to microscale via curvature effect. The thermodynamics at the interface indicates the initial of ice lensing/banding from the growth of pore ice, determined by the critical curvature undercooling instead of the critical fracture of frozen fringe. It is also proposed that the packing status of the porous structure in the particle layer ahead of the water/ice interface determines the ice lensing behaviors. The results presented here are different scenarios from previous investigations of freezing colloidal suspensions, and may shed light on the researches of this area.