Impacts of the carbonyl group location of ester bond on interfacial properties of sugar-based surfactants: experimental and computational evidences.
Interfacial properties of surfactants are dependent on the conformation adopted by the hydrophilic headgroup or/and the hydrophobic tail at the boundary limit of two immiscible phases. Here, we demonstrate the impacts of the carbonyl group (-CO-) location of the ester bond of sugar-based surfactants by comparing some properties of two closely related esters, octyl glucuronate and glucose octanoate, at the air-water interface. The carbonyl group location influences the rate and extent of interfacial adsorption and the rheology properties of sugar esters at the air-water interface, which were evaluated by dynamic surface tension and complex surface viscoelastic measurements. Octyl glucuronate adsorbs the fastest at the air-water interface whereas glucose octanoate reduces the dynamic surface tension at the lowest value and exhibits the highest film viscoelasticity. Differences are attributed to molecular conformation constraints inducing relevant changes to the surface coverage kinetic capacity and the interaction strengths of the octyl sugar ester adsorbed films at the air-water interface. All of the results are supported by the minimum cross-sectional area values per molecule determined by both experimental and computational approaches.
Razafindralambo
Hary
H
Unite de Technologie des Industries Agro-Alimentaires, Centre de Biophysique Moleculaire Numerique, Faculte Universitaire des Sciences Agronomiques de Gembloux, 2 Passage des Deportes, B-5030 Gembloux, Belgium. razafindralambo.h@fsagx.ac.be
Blecker
Christophe
C
Mezdour
Samir
S
Deroanne
Claude
C
Crowet
Jean-Marc
JM
Brasseur
Robert
R
Lins
Laurence
L
Paquot
Michel
M
D000388:Air; D002236:Carbohydrate Conformation; D002241:Carbohydrates / Q000737:chemistry*; D003198:Computer Simulation; D004952:Esters / Q000737:chemistry*; D005947:Glucose / Q000737:chemistry; D005965:Glucuronates / Q000737:chemistry; D008958:Models, Molecular; D008970:Molecular Weight; D012212:Rheology; D013500:Surface Tension; D013501:Surface-Active Agents / Q000737:chemistry*; D013997:Time Factors; D055682:Viscoelastic Substances / Q000737:chemistry; D014867:Water / Q000737:chemistry
D002241:Carbohydrates; D004952:Esters; D005965:Glucuronates; D013501:Surface-Active Agents; D055682:Viscoelastic Substances; D014867:Water; D005947:Glucose