Yield-stress fluids foams: flow patterns and controlled production in T-junction and flow-focusing devices. Issue 46 (10th November 2016)

• Record Type: Journal Article
• Authors: Laborie, Benoit; Rouyer, Florence; Angelescu, Dan E.; Lorenceau, Elise
• Is Part Of: Soft matter. Volume 12:Issue 46(2016)
• Page Start: 9355
• Page End: 9363
• Publication Date: 2016-11-10
• Subjects: Soft condensed matter -- Periodicals; 530.413
• DOI: 10.1039/c6sm02054b
• Languages: English
• ISSNs: 1744-683X

Abstract

Abstract : Yield stress fluid foams are formed in a continuous way using microfluidic flow-focusing and T-junction devices. Abstract : We study the formation of yield-stress fluid foams in millifluidic flow-focusing and T-junction devices. First, we provide a phase diagram for the unsteady operating regimes of bubble production when the gas pressure and the yield-stress fluid flow rate are imposed. Three regimes are identified: a co-flow of gas and yield-stress fluid, a transient production of bubble and a flow of yield-stress fluid only. Taking wall slip into account, we provide a model for the pressure at the onset of bubble formation. Then, we detail and compare two simple methods to ensure steady bubble production: regulation of the gas pressure or flow-rate. These techniques, which are easy to implement, thus open pathways for controlled production of dry yield-stress fluid foams as shown at the end of this article.