Abstract:
Hypothesis Nonaqueous foams are found in a variety of applications, many of which contain volatile components that need to be removed during processing. Sparging air bubbles into the liquid can be used to aid in their removal, but the resulting foam can be stabilized or destabilized by several different mechanisms, the relative importance of which are not yet fully understood. Investigating the dynamics of thin film drainage, four competing mechanisms can be observed, such as solvent evaporation, film viscosification, and thermal and solutocapillary Marangoni flows. Experiments Experimental studies with isolated bubbles and/or bulk foams are needed to strengthen the fundamental knowledge of these systems. This paper presents interferometric measurements of the dynamic evolution of a film formed by a bubble rising to an air-liquid interface to shed light on this situation. Two different solvents with different degrees of volatility were investigated to reveal both qualitative and quantitative details on thin film drainage mechanisms in polymer-volatile mixtures. Findings Using interferometry, we found evidence that solvent evaporation and film viscosification both strongly influence the stability of interface. These findings were corroborated by comparison with bulk foam measurements, revealing a strong correlation between these two systems.
摘要:
假说非水泡沫存在于各种应用中,其中许多含有挥发性成分,需要在加工过程中去除。将气泡喷入液体可用于帮助去除气泡,但是产生的泡沫可以通过几种不同的机制稳定或不稳定,其相对重要性尚未完全理解。研究薄膜排水的动力学,可以观察到四种竞争机制,如溶剂蒸发,薄膜增粘,以及热和可溶毛细管Marangoni流动。实验需要使用孤立的气泡和/或散装泡沫进行实验研究,以加强这些系统的基本知识。本文介绍了由气泡上升到气液界面形成的薄膜的动态演化的干涉测量,以阐明这种情况。研究了两种具有不同挥发度的不同溶剂,以揭示聚合物挥发性混合物中薄膜排水机理的定性和定量细节。使用干涉测量法的发现,我们发现有证据表明,溶剂蒸发和膜增粘都强烈影响界面的稳定性。通过与散装泡沫测量进行比较,这些发现得到了证实,揭示了这两个系统之间的强相关性。