Adsorption of ionic surfactants at microscopic air-water interfaces using the micropipette interfacial area-expansion method: Measurement of the diffusion coefficient and renormalization of the mean ionic activity for SDS

Measuring the impact of channel length on liquid flow through an ideal Plateau border and node system

“…The increase in surfactant concentration, G, at the interface results in a decrease in the surface tension that is well described by theory and experiment alike. 10,12,17,26,40,45 Fig. 7c shows the theoretical relationship using the Frumkin isotherm adsorption model with model parameters for pure SDS solution as described by Kinoshita et al 17 At the CMC, the formation of micelles in the bulk liquid and the subsequent reduction in the energy barrier limiting surfactant desorption tends to reduce further compression of the interface.…”

“…10,12,17,26,40,45 Fig. 7c shows the theoretical relationship using the Frumkin isotherm adsorption model with model parameters for pure SDS solution as described by Kinoshita et al 17 At the CMC, the formation of micelles in the bulk liquid and the subsequent reduction in the energy barrier limiting surfactant desorption tends to reduce further compression of the interface. 5 This would imply that around this point, any differences in the interfacial structures caused by PB length dependence should have become less pronounced.…”

Micro-Surface and -Interfacial Tensions Measured Using the Micropipette Technique: Applications in Ultrasound-Microbubbles, Oil-Recovery, Lung-Surfactants, Nanoprecipitation, and Microfluidics

“…In order to improve the time-lag, any need for micropipette movement was eliminated by fixing the micropipette a priori at a position that represented the expected meniscus diameter for a clean air-water surface (i.e., ~72 mN/m tension). This surface was then ready for the initial adsorption and therefore setting a diameter for time zero [7,8]. Figure 10 shows schematic images of the Micropipette Interfacial Area-expansion Method as used in this technique and a description of the sequence of events.…”

“…So here, by utilising a micropipette technique, we provide direct measures of surface and interfacial tensions at the same scales as microfluidic, lab-on-chip, and other devices. The goal is to provide the readership with a comprehensive review of many of the surface and interfacial tension measurements we have been able to make using the micropipette technique, including equilibrium measurements of the clean air-water surface and oil-water interface [6], as well as equilibrium and dynamic adsorption of water-soluble surfactants [7,8] and water-insoluble lipids [9,10] that required the development of a new technique, the Micropipette Interfacial Area-Expansion Method (MIAM) [7]. We also give examples of where our measurements and those of others [11] have had a direct impact on at least five applications.…”

Surface rheological measurements of isolated food foam systems

“…7(c) and 7(d)]. As surface tension varies inversely with the surfactant concentration at the air-liquid interface, 32 this would suggest that less surfactant at the interface caused an increase in the apparent surface viscosity. This counterintuitive result is explained when one considers that the range of apparent surface viscosity values calculated here was in the range 10 −10 g/s < μs < 10 −8 g/s, while the surface shear viscosity of pure water is approximately 1.2 × 10 −5 g/s.…”