Wierenga Peter A, Basheva Elka S, Denkov Nikolai D
Laboratory of Food Chemistry, Wageningen University, Wageningen, The Netherlands.
Langmuir. 2009 Jun 2;25(11):6035-9. doi: 10.1021/la901068w.
Many of the macroscopic properties of foams and emulsions are controlled by the mesoscopic properties of the thin films separating the bubbles or droplets. The properties of these films depend on contributions (1) from the adsorbed surface layers and (2) from the liquid that separates these adsorbed layers. To separate in the experimental studies the effects of these two contributions, we developed a new modified version of the capillary cell for foam film studies (originally developed by Scheludko and Exerowa (Scheludko, A.; Exerowa, D. Kolloid Z. 1959, 165, 148-151), which allows exchange of the film-forming liquid between the air-water surfaces. This modified cell allows one to distinguish between the role of the adsorbed species (e.g., proteins, particles, or long-chain synthetic polymers) and the species present in the film interior (e.g., particles, electrolytes, or surfactants). The film properties that can be studied in this way include film stability, rate of film thinning, and surface forces stabilizing the film. These properties are of significant interest in understanding and controlling the stability of dispersed systems. The experimental procedure and the capabilities of the modified cell are demonstrated in several examples.
泡沫和乳液的许多宏观性质由分隔气泡或液滴的薄膜的介观性质所控制。这些薄膜的性质取决于（1）来自吸附表面层的贡献以及（2）来自分隔这些吸附层的液体的贡献。为了在实验研究中区分这两种贡献的影响，我们开发了一种用于泡沫膜研究的新型改良版毛细管池（最初由Scheludko和Exerowa开发（Scheludko, A.; Exerowa, D. Kolloid Z. 1959, 165, 148 - 151）），它允许在气 - 水表面之间交换成膜液体。这种改良池能够区分吸附物质（例如蛋白质、颗粒或长链合成聚合物）的作用与薄膜内部存在的物质（例如颗粒、电解质或表面活性剂）的作用。通过这种方式可以研究的薄膜性质包括薄膜稳定性、薄膜变薄速率以及稳定薄膜的表面力。这些性质对于理解和控制分散体系的稳定性具有重要意义。在几个示例中展示了改良池的实验步骤和功能。
