Enhancing the yield of calcium carbonate precipitation by obstacles in laminar flow in a confined geometry

Abstract

Flow-driven precipitation experiments are performed in model porous media shaped within the confinement of a Hele-Shaw cell. Precipitation pattern formation and the yield of the reaction are investigated when borosilicate...

Alkaline vents recreated in two dimensions to study pH gradients, precipitation morphology, and molecule accumulation

“…In the field of chemobrionics, confined quasi-2D flow setups (Hele-Shaw flow cells) are commonly used to study precipitation reactions and the resulting pattern formation. The experiments mostly use radial injection of the fluid (10,41,42,(45)(46)(47) rather than injection from one side as in our setting. Although we used different injections and chemical compositions, Rocha et al (46) showed the formation of similar morphologies over the time of the experiment.…”

“…The resulting structures, often referred to as chemical gardens, can be seen as a simple example of self-organizing systems that exhibit all kinds of different morphologies under different chemical and physical conditions (37,38). Apart from precipitation and crystallization, structure growth is driven by fluid advection through either active injection (39)(40)(41)(42) or osmosis and convection (43,44). In the past years, they have also been increasingly studied in quasi-two-dimensional (2D) settings using microfluidic devices like Hele-Shaw flow cells (10,40,45,46).…”

Diffusion in liquid mixtures

“…In addition, sedimentation can in some cases trigger a local clogging in confined reactors. Such dynamics have been recently studied for applications in CO 2 sequestration techniques 67 , 68 , polymorph selection 69 , 70 , frontal polymerization 71 or new material synthesis, to name a few. The specificity of precipitation reactions is that the solid product undergoes sedimentation and always changes the density of the solution, which naturally induces buoyancy-driven flows on earth.…”

Non-equilibrium Composition of Mixed Metal Hydroxide Membranes Grown in Flow Systems

“…The resulting formation of a semi-permeable membrane around the dissolving seed initiates the development of a steep chemical gradient, which drives, by a combination of osmotic pressure and buoyant forces, the growth of hollow structures . These structures mimic hydrothermal vent chimneys in terms of their shapes and chemical gradients but more importantly also in terms of the product materials and porosities. − Starting from these chemical gardens, recent work has greatly increased the reproducibility and spectroscopic accessibility by introducing spatial confinement to quasi-two-dimensional Hele–Shaw cells − and microfluidic channels. − The latter approach allows for the creation of two co-flowing reactant streams that nucleate and sustain the growth of a linear precipitation membrane at their reactive interface.…”