Requier Alice, Guidolin Chiara, Rio Emmanuelle, Galvani Nicolò, Cohen-Addad Sylvie, Pitois Olivier, Salonen Anniina
Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405 Orsay, France.
Sorbonne Université, CNRS-UMR 7588, Institut des NanoSciences de Paris, 4 Place Jussieu, 75005 Paris, France.
Soft Matter. 2024 Jul 31;20(30):6023-6032. doi: 10.1039/d4sm00296b.
Foams coarsen because of pressure differences between bubbles of different sizes. We study the coarsening of quasi-2D foams made from model yield stress fluids: concentrated oil-in-water emulsions. We show that increasing the yield stress of the foamed emulsion continuous phase leads to both slower coarsening and irreversible structural change. The impact of the continuous phase rheology is stronger when the foamed emulsion is wetter or more confined. The bubble growth and organisation both become highly heterogeneous with an excess of small bubbles. We present a model that rationalises the impact of these three parameters by taking into account a resisting pressure required to displace the yield stress fluid around the bubbles.
由于不同尺寸气泡之间的压力差，泡沫会变得粗糙。我们研究了由模型屈服应力流体（即浓水包油乳液）制成的准二维泡沫的粗糙化过程。我们发现，增加泡沫乳液连续相的屈服应力会导致粗糙化速度变慢以及不可逆的结构变化。当泡沫乳液更湿润或受限程度更高时，连续相流变学的影响会更强。气泡的生长和组织都会变得高度不均匀，出现过多的小气泡。我们提出了一个模型，通过考虑在气泡周围驱替屈服应力流体所需的抵抗压力，来解释这三个参数的影响。
