A study on the method of short-time approximation – Criteria for applicability

Casandra, Alvin; Ismadji, Suryadi; Noskov, Boris A.; Liggieri, Libero; Lin, Shi‐Yow

doi:10.1016/j.ijheatmasstransfer.2015.07.030

Cited by 9 publications

(9 citation statements)

References 45 publications

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“…The convective flow can affect the initial adsorption and bring estimation errors for dynamic adsorption analyses that are focused on diffusionlimited measurements to obtain diffusion coefficients [26]. Therefore, any measurements and adsorption-rate analysis at these very early initial times will always need careful treatments such as those outlined by Casandra et al [27]. Even if short-time adsorption measurements can be made, the size of the interface for dynamic adsorption measurements will also be an important factor in achieving high-sensitivity results.…”

Section: Dynamic Surface Tension Measurementsmentioning

confidence: 99%

“…Thus, kinetically two time regimes can be identified -an ultrafast Short-Time Adsorption Approximation (the initial approach of the surfactant to the interface in the absence of ''back diffusion") and a Long-Time Adsorption Approximation (the approach to equilibrium), where a balance between adsorption and desorption of the water-soluble surfactant eventually results in no net change, because the adsorbing flux of monomers to the surface is equal to its desorbing flux. Because of its widespread use in the determination of adsorption mechanisms and the estimation of surfactant diffusivity, Casandra et al [27] provided a very specific range of time intervals or surface pressures over which the short-time approximation at the air-water interface should be applied. In applying the Ward Tordai model, it is therefore necessary to adhere to these rules of limiting surface pressure (p max ) and dimensionless time (t ⁄ max ) as a function of their dimensionless surfactant concentration (C o /a), -the ratio between the bulk concentration and the surfactant activity.…”

Section: Dynamic Behavior: the Ward-tordai Diffusion Modelmentioning

confidence: 99%

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New sensitive micro-measurements of dynamic surface tension and diffusion coefficients: Validated and tested for the adsorption of 1-Octanol at a microscopic air-water interface and its dissolution into water

Kinoshita

Parra

2017

Journal of Colloid and Interface Science

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Currently available dynamic surface tension (DST) measurement methods, such as Wilhelmy plate, droplet- or bubble-based methods, still have various experimental limitations such as the large size of the interface, convection in the solution, or a certain "dead time" at initial measurement. These limitations create inconsistencies for the kinetic analysis of surfactant adsorption/desorption, especially significant for ionic surfactants. Here, the "micropipette interfacial area-expansion method" was introduced and validated as a new DST measurement having a high enough sensitivity to detect diffusion controlled molecular adsorption at the air-water interfaces. To validate the new technique, the diffusion coefficient of 1-Octanol in water was investigated with existing models: the Ward Tordai model for the long time adsorption regime (1-100s), and the Langmuir and Frumkin adsorption isotherm models for surface excess concentration. We found that the measured diffusion coefficient of 1-Octanol, 7.2±0.8×10cm/s, showed excellent agreement with the result from an alternative method, "single microdroplet catching method", to measure the diffusion coefficient from diffusion-controlled microdroplet dissolution, 7.3±0.1×10cm/s. These new techniques for determining adsorption and diffusion coefficients can apply for a range of surface active molecules, especially the less-characterized ionic surfactants, and biological compounds such as lipids, peptides, and proteins.

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Section: Dynamic Surface Tension Measurementsmentioning

confidence: 99%

Section: Dynamic Behavior: the Ward-tordai Diffusion Modelmentioning

confidence: 99%

New sensitive micro-measurements of dynamic surface tension and diffusion coefficients: Validated and tested for the adsorption of 1-Octanol at a microscopic air-water interface and its dissolution into water

Kinoshita

Parra

2017

Journal of Colloid and Interface Science

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“…Solutions of this equation for different geometries can be found in many publications [ 39 , 40 , 41 ]. Sketches illustrating the process of penetration through a flat and hollow cylindrical membrane are presented in Figure 1 a,b.…”

Section: Theorymentioning

confidence: 99%

“…The analysis of the mass flux dependency of the penetrant through the membrane is often made using the so-called short-time approximation method. It is based on the solution of the diffusion Equation (6) with the use of Laplace transform [ 39 , 40 , 41 , 42 ]. For short times it is possible to present the solution for mass flux density in the form:

…”

Section: Theorymentioning

confidence: 99%

Application of Ion Mobility Spectrometry for Permeability Studies of Organic Substances through Polymeric Materials

2020

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Drift tube ion mobility spectrometers (DT IMS) allow the concentration of different organic compounds to be measured. This gives the opportunity to use these detectors in measuring the penetration of various substances through polymer membranes. Permeation measurements of two substances (2-heptanone and dimethyl methylphosphonate (DMMP)) through a cylindrical silicone rubber membrane were carried out. The membrane separated the aqueous solution from the air. The analyte was introduced into water, and then its concentration in air on the opposite side of the membrane was recorded. Based on the dynamics of detector signal changes, the diffusion coefficients for both tested substances were determined. Determination of permeability coefficients was based on precise quantitative measurements, which took into account the non-linearity of the detector characteristics and the effect of water on detection sensitivity. The analysis of measurement results was based on a mathematical description of diffusion process.

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“…One of the biggest challenges of interfacial tension measurements is how to measure a precise dynamic surface tension change in such short times that are associated with molecular diffusion to the surface [ 134 ]. Until now, only a few techniques have been successful and achieved reliable data that could be analysed in terms of theoretical models.…”

Section: Equilibrium and Dynamic Surface Tension: Adsorption Of Somentioning

confidence: 99%

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

Kinoshita

Utoft

2019

Micromachines

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This review presents a series of measurements of the surface and interfacial tensions we have been able to make using the micropipette technique. These include: equilibrium tensions at the air-water surface and oil-water interface, as well as equilibrium and dynamic adsorption of water-soluble surfactants and water-insoluble and lipids. At its essence, the micropipette technique is one of capillary-action, glass-wetting, and applied pressure. A micropipette, as a parallel or tapered shaft, is mounted horizontally in a microchamber and viewed in an inverted microscope. When filled with air or oil, and inserted into an aqueous-filled chamber, the position of the surface or interface meniscus is controlled by applied micropipette pressure. The position and hence radius of curvature of the meniscus can be moved in a controlled fashion from dimensions associated with the capillary tip (~5–10 μm), to back down the micropipette that can taper out to 450 μm. All measurements are therefore actually made at the microscale. Following the Young–Laplace equation and geometry of the capillary, the surface or interfacial tension value is simply obtained from the radius of the meniscus in the tapered pipette and the applied pressure to keep it there. Motivated by Franklin’s early experiments that demonstrated molecularity and monolayer formation, we also give a brief potted-historical perspective that includes fundamental surfactancy driven by margarine, the first use of a micropipette to circuitously measure bilayer membrane tensions and free energies of formation, and its basis for revolutionising the study and applications of membrane ion-channels in Droplet Interface Bilayers. Finally, we give five examples of where our measurements have had an impact on applications in micro-surfaces and microfluidics, including gas microbubbles for ultrasound contrast; interfacial tensions for micro-oil droplets in oil recovery; surface tensions and tensions-in-the surface for natural and synthetic lung surfactants; interfacial tension in nanoprecipitation; and micro-surface tensions in microfluidics.

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A study on the method of short-time approximation – Criteria for applicability

Cited by 9 publications

References 45 publications

New sensitive micro-measurements of dynamic surface tension and diffusion coefficients: Validated and tested for the adsorption of 1-Octanol at a microscopic air-water interface and its dissolution into water

New sensitive micro-measurements of dynamic surface tension and diffusion coefficients: Validated and tested for the adsorption of 1-Octanol at a microscopic air-water interface and its dissolution into water

Application of Ion Mobility Spectrometry for Permeability Studies of Organic Substances through Polymeric Materials

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

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