Feb 10, 2025
Cover Page at Physical Chemistry Chemical Physics
A pattern of a gel-like coacervate forms by the injection of a biopolymer into a surfactant solution in a model porous medium
Our graphics contribution related to the article “Flow-driven pattern formation during coacervation of xanthan gum with a cationic surfactant” by Yorgos Stergiou, Alexandros Perrakis, Anne De Wit and Karin Schwarzenberger was selected for the front cover page of the RSC scientific journal Physical Chemistry Chemical Physics.
http://xlink.rsc.org/?DOI=D4CP01055H
https://pubs.rsc.org/en/journals/journalissues/cp
The work experimentally demonstrates that the coacervation of a biopolymer can trigger a hydrodynamic instability when a coacervate is formed upon injection of a xanthan gum dispersion into a cationic surfactant (C14TAB) solution. The local increase of the viscosity due to the coacervate formation induces a viscous fingering instability. Three characteristic displacement regimes were observed: a viscous fingering dominated regime, a buoyancy-controlled “volcano” regime and a “fan”-like regime determined by the coacervate membrane dynamics. The dependence of the spatial properties of the viscous fingering pattern on the Péclet and Rayleigh numbers was investigated.