The elasticity of soap bubbles containing wormlike micelles.
The elasticity of soap bubbles containing wormlike micelles.
复制标题
含有蠕虫状胶束的肥皂泡的弹性。
作者：
E. Sabadini;R. F. S. Ungarato;P. B. Miranda
肥皂泡破裂的慢动作成像通常显示液膜边缘以恒定速度（称为泰勒-库利克速度）收缩。在这里，我们研究了由阳离子表面活性剂（十六烷基三甲基溴化铵 - CTAB）和水杨酸钠的简单溶液形成的肥皂泡。水杨酸盐离子与 CTAB 的相互作用导致蠕虫状胶束 (WLM) 的形成，从而使气泡的液膜产生粘弹性行为。我们证明这些弹性气泡破裂的速度比泰勒-库利克极限高出 30 倍，而该极限从未被超越。这是因为在气泡膨胀过程中，纠缠的 WLM 链会拉伸，储存弹性能。然后，在气泡破裂过程中释放出额外的能量，产生薄膜收缩的额外驱动力（除了表面张力之外）。这种弹性气泡破裂的新机制可能对工业应用中粘弹性喷雾的破裂产生重要影响。
Slow-motion imaging of the rupture of soap bubbles generally shows the edges of liquid films retracting at a constant speed (known as the Taylor-Culick velocity). Here we investigate soap bubbles formed from simple solutions of a cationic surfactant (cetyltrimethylammonium bromide - CTAB) and sodium salicylate. The interaction of salicylate ions with CTAB leads to the formation of wormlike micelles (WLM), which yield a viscoelastic behavior to the liquid film of the bubble. We demonstrate that these elastic bubbles collapse at a velocity up to 30 times higher than the Taylor-Culick limit, which has never been surpassed. This is because during the bubble inflation, the entangled WLM chains stretch, storing elastic energy. This extra energy is then released during the rupture of the bubble, yielding an additional driving force for film retraction (besides surface tension). This new mechanism for the bursting of elastic bubbles may have important implications to the breakup of viscoelastic sprays in industrial applications.