Foam formation in porous media is a topic of growing scientific and industrial interest due to its range of applications, from daily life consumer products to oil recovery. Despite the work done so far on foams flowing through complex structures, such as rigid porous media, this subject still needs to be fully elucidated. An additional complexity to the problem arises when the porous medium is deformable, a situation which has only been faced, to our knowledge, from a modelling point of view. In this work, the investigation of foam formation in deformable porous media is carried out by using commercial sponges as a deformable porous media system, with special emphasis on the effect of confinement on foam bubble size distribution. Foam is formed by wetting the sponge with an aqueous surfactant solution and then squeezing the sponge either between two glass cover slides or between a plastic net and a cover slide. Our experimental data reveal that the latter system allows the formation of drier foams (ie, with lower liquid fraction, f_L < 0.3), more similar to the ones obtained in dish‐washing applications. Moreover, the effect of sponge type, in terms of material and microstructure, on final foam is presented. Our results are of potential interest for the optimization of foams in complex structures, such as in deformable porous media.

中文翻译：

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通过可变形多孔介质形成泡沫的实验研究

多孔介质中的泡沫形成因其广泛的应用范围而引起了科学和工业的关注，从日常生活的消费产品到石油开采，其应用范围广泛。尽管到目前为止，泡沫在流经复杂结构（例如刚性多孔介质）的泡沫方面已做过工作，但仍然需要充分阐明这一主题。当多孔介质可变形时，问题的另一复杂性出现了，据我们所知，这种情况只是从建模的角度来看才面临。在这项工作中，通过使用商业海绵作为可变形多孔介质系统来研究可变形多孔介质中泡沫的形成，并特别强调了限制对泡沫气泡尺寸分布的影响。泡沫是通过用表面活性剂水溶液润湿海绵，然后在两个玻璃盖玻片之间或塑料网和盖玻片之间挤压海绵而形成的。我们的实验数据表明，后一种系统可以形成干燥的泡沫（即，较低的液体分数f_L  <0.3），与在洗碗应用中获得的相似。此外，在材料和微观结构方面，介绍了海绵类型对最终泡沫的影响。我们的结果对于优化复杂结构（例如可变形多孔介质）中的泡沫具有潜在的兴趣。