Measurement of Dynamic Interfacial Properties in an Overflowing Cylinder by Ellipsometry

Rates of Mass Transfer and Adsorption of Hexadecyltrimethylammonium Bromide at an Expanding Air–Water Interface

“…The design of the overflowing cylinder has been described in detail in previous publications (7)(8)(9). For the new experimental data reported in this paper, a stainless steel cylinder with an 8-cm internal diameter and a volume flow rate of 8 cm 3 s…”

“…The simplicity and convenience of the OFC do, however, come at a price. The surface expansion rate is determined by Marangoni effects, independent of the bulk flow rate through the cylinder (7). Consequently, for a given bulk concentration, the adsorption kinetics can only be studied at a single surface concentration, which is determined autonomously by the OFC.…”

Mixtures of n-dodecyl-β-d-maltoside and hexaoxyethylene dodecyl ether — Surface properties, bulk properties, foam films, and foams

“…The OFC sets up a steadystate expanding surface characterised by a constant surface expansion rate, θ, that is set autonomously by the surface properties of the surfactant and independent of the flow rate in the cylinder (within certain limits) [19]. The adsorbed amount on the surface of the OFC can be measured directly by neutron reflection or ellipsometry: the coefficient of ellipticity is an approximately linear function of the surface excess [20].…”

Ellipsometry and Infrared Reflection Absorption Spectroscopy of Adsorbed Layers of Soluble Surfactants at the Air–Water Interface

“…Ellipsometry, with differential refractometry, allows a more direct measurement of of an adsorbed layer at the air-water interface than using the Gibbs adsorption isotherm. Bain and co-workers used ellipsometry to study the adsorption dynamics of surfactants at a flowing liquid surface (26,29,31). By using either tension or neutron reflection data to calibrate the ellipticity in terms of surface excess, they demonstrated that ellipsometry is a rapid and sensitive technique for studying surfactant adsorption at the air-water interface.…”

“…The radiotracer technique is one of the earliest methods which can probe surface density directly (23)(24)(25). Recently, neutron reflection (26,27), second harmonic generation (28), ellipsometry (28)(29)(30)(31), and infrared reflection absorption spectroscopy (IRRAS) (18,21) have also been used for determining the surface density of soluble monolayers. Comparisons of the strengths and weaknesses of several of these techniques in determining surface coverage, molecular orientation, and hydrocarbon chain conformational state have been given in Ref.…”