Surfactant softening of plant leaf cuticle model wax--a Differential Scanning Calorimetry (DSC) and Quartz Crystal Microbalance with Dissipation (QCM-D) study

Anton Fagerström; Vitaly Kocherbitov; Peter Westbye; Karin Bergström; Thomas Arnebrant; Johan Engblom

doi:10.1016/j.jcis.2014.03.064

Surfactant softening of plant leaf cuticle model wax--a Differential Scanning Calorimetry (DSC) and Quartz Crystal Microbalance with Dissipation (QCM-D) study

J Colloid Interface Sci. 2014 Jul 15:426:22-30. doi: 10.1016/j.jcis.2014.03.064. Epub 2014 Apr 4.

Authors

Anton Fagerström¹, Vitaly Kocherbitov², Peter Westbye³, Karin Bergström⁴, Thomas Arnebrant⁵, Johan Engblom⁶

Affiliations

¹ Biomedical Science, Faculty of Health and Society, Malmö University, SE-205 06 Malmö, Sweden; Biofilms - Research Center for Biointerfaces, Malmö University, SE-205 06 Malmö, Sweden. Electronic address: anton.fagerstrom@mah.se.
² Biomedical Science, Faculty of Health and Society, Malmö University, SE-205 06 Malmö, Sweden; Biofilms - Research Center for Biointerfaces, Malmö University, SE-205 06 Malmö, Sweden. Electronic address: vitaly.kocherbitov@mah.se.
³ Agro Applications Europe, AkzoNobel Surface Chemistry AB, SE-444 30 Stenungsund, Sweden. Electronic address: peter.westbye@akzonobel.com.
⁴ Agro Applications Europe, AkzoNobel Surface Chemistry AB, SE-444 30 Stenungsund, Sweden. Electronic address: karin.bergstrom@akzonobel.com.
⁵ Biomedical Science, Faculty of Health and Society, Malmö University, SE-205 06 Malmö, Sweden; Biofilms - Research Center for Biointerfaces, Malmö University, SE-205 06 Malmö, Sweden. Electronic address: thomas.arnebrant@mah.se.
⁶ Biomedical Science, Faculty of Health and Society, Malmö University, SE-205 06 Malmö, Sweden; Biofilms - Research Center for Biointerfaces, Malmö University, SE-205 06 Malmö, Sweden. Electronic address: johan.engblom@mah.se.

PMID: 24863760
DOI: 10.1016/j.jcis.2014.03.064

Abstract

The aim was to quantify the softening effect that two surfactants (C10EO7 and C8G1.6) have on a plant leaf cuticle model wax. Effects on the thermotropic phase behavior and fluidity of the wax (C22H45OH/C32H66/H2O) were determined. The model wax is crystalline at ambient conditions, yet it is clearly softened by the surfactants. Both surfactants decreased the transition temperatures in the wax and the G″/G' ratio of the wax film increased in irreversible steps following surfactant exposure. C10EO7 has a stronger fluidizing effect than C8G1.6 due to stronger interaction with the hydrophobic waxes. Intracuticular waxes (IW) comprise both crystalline and amorphous domains and it has previously been proposed that the fluidizing effects of surfactants are due to interactions with the amorphous parts. New data suggests that this may be a simplification. Surfactants may also absorb in crevices between crystalline domains. This causes an irreversible effect and a softer cuticle wax.

Keywords: Crystalline domains; Differential Scanning Calorimetry (DSC); Fluidizing effect; Plant leaf cuticle; Quartz Crystal Microbalance with Dissipation (QCM-D); Surfactant softening; Wax film.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Calorimetry, Differential Scanning / methods*
Models, Biological
Plants / chemistry*
Quartz*
Rheology
Surface-Active Agents / chemistry*
Waxes*

Substances

Surface-Active Agents
Waxes
Quartz