Folding Langmuir Monolayers

TL;DR

This paper introduces a novel theoretical framework for understanding reversible collapse in Langmuir monolayers, linking folding phenomena to Griffith crack formation, supported by microscopy and rheology experiments.

Contribution

It presents a new analogy-based description of monolayer collapse, connecting in-plane rheology with reversible folding behavior.

Findings

Reversible folding in Langmuir monolayers can be modeled using Griffith crack analogy.

Experimental evidence shows correlation between monolayer rheology and folding behavior.

The model explains the maximum pressure limit before collapse in surfactant monolayers.

Abstract

The maximum pressure a two-dimensional surfactant monolayer is able to withstand is limited by the collapse instability towards formation of three-dimensional material. We propose a new description for reversible collapse based on a mathematical analogy between the formation of folds in surfactant monolayers and the formation of Griffith Cracks in solid plates under stress. The description, which is tested in a combined microscopy and rheology study of the collapse of a single-phase Langmuir monolayer of 2-hydroxy-tetracosanoic acid (2-OH TCA), provides a connection between the in-plane rheology of LM's and reversible folding.