Colloidal fingering in miscible liquids

An Observation of Nanoparticle‐Assisted Fingering Instability

“…Similar fingering instability is also reported for polystyrene particles (200 and 600 nm). [11] In the present proceeding, by studying the (in)stability without nanoparticle (e.g., ethanolic dye + water) as well as without solute (e.g., aqueous polystyrene + water), we confirm that the both components (i.e., nanoparticle, and suspending liquid that should not be same to the bottom liquid) must be present in the system for observing nanoparticle-assisted fingering. We also show that the proposed mechanism of colloidal fingering (i.e., double massdiffusive convection) in ref.…”

“…[8,9] Recently, we have shown the nanoparticle-assisted fingering under buoyancy force when a less dense phase of nanofluid overlies a denser liquid in an isothermal situation. [10,11] Here, we have utilized lipid and polystyrene to demonstrate the liposomal-as well as polystyrene-assisted fingers. [11] In the case of liposomal fingers, first colloidal suspension of liposome (size 500 nm) is formed by diffusive mixing of ethanolic lipid and water phases.…”

“…[10,11] Here, we have utilized lipid and polystyrene to demonstrate the liposomal-as well as polystyrene-assisted fingers. [11] In the case of liposomal fingers, first colloidal suspension of liposome (size 500 nm) is formed by diffusive mixing of ethanolic lipid and water phases. The interdiffusion between two liquids results in the aggregation of lipids into bilayer membranes that grow and close-up to form liposomes, [12,13] which start moving downward in the form of finger-like patterns.…”

“…We also show that the proposed mechanism of colloidal fingering (i.e., double massdiffusive convection) in ref. [11] only works for nanoparticles but not microparticles.…”

“…To observe the nanoparticle-assisted fingering, a thin-chamber setup (see Figure 1A is employed), [11] which is prepared by two glass slides (backplate -glass slide of thickness 1 mm, front plate -coverslip of thickness 0.17 mm) was separated by a silicone spacer (2 mm thickness). The plates were glued to the silicone sheet using Araldite.…”