Correlation effects during liquid infiltration into hydrophobic nanoporous mediums

TL;DR

This paper investigates how correlation effects influence liquid infiltration into hydrophobic nanoporous materials, proposing a mechanism for energy absorption and explaining experimental observations through percolation theory and interface energy considerations.

Contribution

It introduces a novel mechanism linking correlation effects and percolation properties to energy absorption during liquid infiltration into hydrophobic nanoporous media.

Findings

Energy absorption during infiltration depends on porosity and pore connectivity.

Filling can result in either positive or negative thermal effects.

The model explains all discussed experimental data.

Abstract

Correlation effects arising during liquid infiltration into hydrophobic porous medium are considered. On the basis of these effects a mechanism of energy absorption at filling porous medium by nonwetting liquid is suggested. In accordance with this mechanism, the absorption of mechanical energy is a result expenditure of energy for the formation of menisci in the pores on the shell of the infinite cluster and expenditure of energy for the formation of liquid-porous medium interface in the pores belonging to the infinite cluster of filled pores. It was found that in dependences on the porosity and, consequently, in dependences on the number of filled pores neighbors, the thermal effect of filling can be either positive or negative and the cycle of infiltration-defiltration can be closed with full outflow of liquid. It can occur under certain relation between percolation properties of porous medium and the energy characteristics of the liquid-porous medium interface and the liquid-gas interface. It is shown that a consecutive account of these correlation effects and percolation properties of the pores space during infiltration allow to describe all experimental data under discussion.