Surface Equation of State of Nonionic C_mE_n Surfactants

Abstract

The surface equation of state (γ vs Γ/Γref), based on the experimental data from rapid expansion of a pendant bubble, has been used on studying the adsorption kinetics for C12E6 (Pan et al.

The effect of alkane tail length of C E8 surfactants on transport to the silicone oil–water interface

“…For the surfactants considered here, the Generalized Frumkin isotherm is chosen because it has been shown to agree quantitatively with dynamic surface tension studies at the air-water interface involving C 10 E 8 [8,12], C 12 E 8 [9,12,28], and C 14 E 8 [10][11][12]. The isotherm has four unknown parameters and is given by…”

“…We attempted to fit the simpler Langmuir isotherm for this analysis, however, we found it to be insufficient to capture the shape of both equilibrium and dynamic data. This isotherm is often fit by allowing all four parameters to vary [9,11,12,29]. A multi-parameter fit can lead to multiple best-fit solutions that depend on the initial guess, often resulting in very different parameter values.…”

“…Alternatively, the molecular diffusion coefficient can be assumed and diffusion-limited dynamic surface tension data can be used as further input to the multi-parameter isotherm fit. Previous studies have demonstrated the complexity of determining correct isotherm parameters by solely fitting equilibrium data [10,12,34]. This has led to the development of numerous experimental techniques designed to probe the isotherm in more detail, e.g.…”

“…Silicone oil is used in microfluidic studies and is available in different viscosities. This series of surfactants has been extensively studied at the air-water interface [8][9][10][11][12]. We anticipate that the parameters obtained from this study will be of use to those modeling surfactant mediated events in applications such as microfluidics, emulsification and de-emulsification processes.…”

“…Even though dynamic surface tension studies have been conducted at the oil-water interface [4][5][6][7][8][9][10][11][12][13][14][15], the number of possible oil-water/surfactant combinations is immense. Therefore, researchers interested in surfactant induced phenomena, e.g.…”