On the measurement of the surface pressure in Langmuir films with finite shear elasticity

We investigate the use of the Wilhelmy plate method to measure the surface pressure in a solid-like Langmuir film under compression. Layers of the protein hydrophobin, which exhibits a high shear elastic modulus, are spread and compressed in a Langmuir trough. The resulting isotherms are classified...

Full description

Bibliographic Details
Main Authors: Aumaitre, E, Vella, D, Cicuta, P
Format: Journal article
Language:English
Published: 2011
_version_ 1826271740514271232
author Aumaitre, E
Vella, D
Cicuta, P
author_facet Aumaitre, E
Vella, D
Cicuta, P
author_sort Aumaitre, E
collection OXFORD
description We investigate the use of the Wilhelmy plate method to measure the surface pressure in a solid-like Langmuir film under compression. Layers of the protein hydrophobin, which exhibits a high shear elastic modulus, are spread and compressed in a Langmuir trough. The resulting isotherms are classified according to the surface pressure and distance between the barriers measured at the onset of buckling. We find that the surface pressure measured in the centre of the layer at the onset of buckling decays with increasing distance between the barriers (which can be tuned by varying the amount of material spread initially). However, unlike the case of particle rafts, the length scale of this decay is not controlled by the width of the trough but rather by the size of the Wilhelmy plate used. We use experiments and a computational model to suggest that this independence of trough width may be attributed to the localised nature of the effect of the trough walls. Our work highlights the potential pitfalls of using the Wilhelmy method to characterize layers with high shear rigidity and may lead to a better understanding of the use of the Wilhlemy plate to measure the surface stress tensor. © 2011 The Royal Society of Chemistry.
first_indexed 2024-03-06T22:01:28Z
format Journal article
id oxford-uuid:4ebd1624-657c-49c7-8a20-38762e467606
institution University of Oxford
language English
last_indexed 2024-03-06T22:01:28Z
publishDate 2011
record_format dspace
spelling oxford-uuid:4ebd1624-657c-49c7-8a20-38762e4676062022-03-26T16:02:56ZOn the measurement of the surface pressure in Langmuir films with finite shear elasticityJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:4ebd1624-657c-49c7-8a20-38762e467606EnglishSymplectic Elements at Oxford2011Aumaitre, EVella, DCicuta, PWe investigate the use of the Wilhelmy plate method to measure the surface pressure in a solid-like Langmuir film under compression. Layers of the protein hydrophobin, which exhibits a high shear elastic modulus, are spread and compressed in a Langmuir trough. The resulting isotherms are classified according to the surface pressure and distance between the barriers measured at the onset of buckling. We find that the surface pressure measured in the centre of the layer at the onset of buckling decays with increasing distance between the barriers (which can be tuned by varying the amount of material spread initially). However, unlike the case of particle rafts, the length scale of this decay is not controlled by the width of the trough but rather by the size of the Wilhelmy plate used. We use experiments and a computational model to suggest that this independence of trough width may be attributed to the localised nature of the effect of the trough walls. Our work highlights the potential pitfalls of using the Wilhelmy method to characterize layers with high shear rigidity and may lead to a better understanding of the use of the Wilhlemy plate to measure the surface stress tensor. © 2011 The Royal Society of Chemistry.
spellingShingle Aumaitre, E
Vella, D
Cicuta, P
On the measurement of the surface pressure in Langmuir films with finite shear elasticity
title On the measurement of the surface pressure in Langmuir films with finite shear elasticity
title_full On the measurement of the surface pressure in Langmuir films with finite shear elasticity
title_fullStr On the measurement of the surface pressure in Langmuir films with finite shear elasticity
title_full_unstemmed On the measurement of the surface pressure in Langmuir films with finite shear elasticity
title_short On the measurement of the surface pressure in Langmuir films with finite shear elasticity
title_sort on the measurement of the surface pressure in langmuir films with finite shear elasticity
work_keys_str_mv AT aumaitree onthemeasurementofthesurfacepressureinlangmuirfilmswithfiniteshearelasticity
AT vellad onthemeasurementofthesurfacepressureinlangmuirfilmswithfiniteshearelasticity
AT cicutap onthemeasurementofthesurfacepressureinlangmuirfilmswithfiniteshearelasticity