A New Analysis of Foam Coalescence: From Isolated Films to Three-Dimensional Foams
A New Analysis of Foam Coalescence: From Isolated Films to Three-Dimensional Foams
复制标题
泡沫聚结的新分析：从隔离膜到三维泡沫
DOI：
--
复制
发表时间：
2000
期刊：
影响因子：
--
通讯作者：
A. Colin
中科院分区：
文献类型：
--
作者：
D. Monin;A. Espert;A. Colin
研究了直立三维肥皂泡沫的破裂。在垂直柱中产生具有受控尺寸和水含量的泡沫，并且随后通过电导率测量其在重力排水下的液体部分的演变。使用简单的模型来描述同时泡沫的几何形状和液体排水（脱水收缩），我们测量聚结事件在散装泡沫。各种表面活性剂的使用，表明两种机制的泡沫破坏。在一种情况下，皂膜的破裂是由液体排出导致的毛细管压力增加引起的：泡沫在柱的顶部破裂，其水平以恒定的速度下降。在另一种情况下，膜不受排水的影响，并且它们的破裂随机地分布在整个泡沫中，泡沫在空间中均匀地聚结。这两种机制解释与微观参数，单层弹性和分离的压力等温线的基础上。
The rupture of standing three-dimensional soap foams was examined. A foam of controlled size and water content was produced in a vertical column and the evolution of its liquid fraction under gravitational drainage was followed by electrical conductivity measurements. Using simple models to describe simultaneously foam geometry and liquid drainage (syneresis), we measured coalescence events in a bulk foam. Various surfactants were used, indicating two mechanisms for foam destruction. In one case, the rupture of soap films is induced by the increase of capillary pressure resulting from liquid drainage: foam breaks at the top of the column and its level goes down with a constant velocity. In the other case, films are not influenced by drainage and their breakage is randomly distributed throughout the foam, which coalesces homogeneously in space. These two mechanisms are interpreted with microscopic arguments, based on monolayer elasticity and disjoining pressure isotherms.