A Study on Surfactant Adsorption Kinetics: The Role of the Data of Equation of State γ(Γ) for C14E8

✍ Scribed by Shi-Yow Lin; Ya-Chi Lee; Ming-Jian Shao; Ching-Tien Hsu

• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 122 KB
• Volume: 244
• Category: Article
• ISSN: 0021-9797
• DOI: 10.1006/jcis.2001.7933

✦ Synopsis

The adsorption kinetics of C 14 E 8 at the air-water interface was investigated. A new approach to the determination of the adsorption isotherm and the evaluation of model parameters is proposed in this work. Besides the equilibrium surface tension γ (C), a second set of equilibrium data [equation of state γ ( )] was measured and used to determine the adsorption isotherm and model parameters. Dynamic surface tension γ (t) for the adsorption of C 14 E 8 onto a freshly created interface was measured and used to determine the controlling mechanism and diffusivity. The data of the equation of state play an important role in this study. No data for C 14 E 8 are available for γ (C) > 62 mN/m because an extremely long time is needed for solutions at very dilute concentrations to reach their equilibrium tensions. Equilibrium data, γ (C) and γ ( ), indicate that the adsorption of C 14 E 8 is anti-cooperative. The adsorption of C 14 E 8 onto a fresh interface is found to be diffusion-controlled. A diffusivity of 7.6 × 10 -6 cm 2 /s results from the best fit between the entire relaxation data of γ (t) and the model predictions.