title: Surfactant softening of plant leaf cuticle model wax--a Differential Scanning Calorimetry (DSC) and Quartz Crystal Microbalance with Dissipation (QCM-D) study.
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.
authors.affiliation: 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.
authors.forename: Anton
authors.initials: A
authors.lastname: Fagerström
authors.affiliation: 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.
authors.forename: Vitaly
authors.initials: V
authors.lastname: Kocherbitov
authors.affiliation: Agro Applications Europe, AkzoNobel Surface Chemistry AB, SE-444 30 Stenungsund, Sweden. Electronic address: peter.westbye@akzonobel.com.
authors.forename: Peter
authors.initials: P
authors.lastname: Westbye
authors.affiliation: Agro Applications Europe, AkzoNobel Surface Chemistry AB, SE-444 30 Stenungsund, Sweden. Electronic address: karin.bergstrom@akzonobel.com.
authors.forename: Karin
authors.initials: K
authors.lastname: Bergström
authors.affiliation: 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.
authors.forename: Thomas
authors.initials: T
authors.lastname: Arnebrant
authors.affiliation: 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.
authors.forename: Johan
authors.initials: J
authors.lastname: Engblom
mesh_terms: D002152:Calorimetry, Differential Scanning / Q000379:methods*; D008954:Models, Biological; D010944:Plants / Q000737:chemistry*; D011791:Quartz; D012212:Rheology; D013501:Surface-Active Agents / Q000737:chemistry*; D014885:Waxes
chemical_list: D013501:Surface-Active Agents; D014885:Waxes; D011791:Quartz
keywords: Crystalline domains; Differential Scanning Calorimetry (DSC); Fluidizing effect; Plant leaf cuticle; Quartz Crystal Microbalance with Dissipation (QCM-D); Surfactant softening; Wax film