A surface rheological study of non-ionic surfactants at the water-air interface and the stability of the corresponding thin foam films

摘要: Abstract The dilational elasticities ɛ and viscosities η of the two non-ionic surfactants n -dodecyl-β- d -maltoside (β-C 12 G 2 ) tetraethylene-glycol-monodecylether (C 10 E 4 were studied as a function frequency ν surfactant concentration c . To have access to large range different oscillating drop tensiometers used. first is based on evaluating profile allows study rheology in from 0.005 0.2 Hz, while second measuring capillary pressure, thus extending up 100 Hz. concentrations investigated been chosen similar, or even equal, those for which disjoining pressure Π versus thickness h curves respective foam films known. results are discussed light stability focussing observation that cannot be explained solely by magnitude surface forces. Indeed, correlation between visco-elasticity films, was suggested basis low data previous study, here confirmed extended higher frequency.