Effects of radial injection and solution thickness on the dynamics of confined A plus B -> C chemical fronts
The spatio-temporal dynamics of an A + B -> C front subjected to radial advection is investigated experimentally in a thin solution layer confined between two horizontal plates by radially injecting a solution of potassium thiocyanate (A) into a solution of iron(iii) nitrate (B). The total amount...
Elmentve itt :
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| Dokumentumtípus: | Cikk |
| Megjelent: |
2020
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| Sorozat: | PHYSICAL CHEMISTRY CHEMICAL PHYSICS
22 No. 18 |
| doi: | 10.1039/c9cp06370f |
| mtmt: | 31410168 |
| Online Access: | http://publicatio.bibl.u-szeged.hu/19434 |
| Tartalmi kivonat: | The spatio-temporal dynamics of an A + B -> C front subjected to radial advection is investigated experimentally in a thin solution layer confined between two horizontal plates by radially injecting a solution of potassium thiocyanate (A) into a solution of iron(iii) nitrate (B). The total amount and spatial distribution of the product FeSCN2+ (C) are measured for various flow rates Q and solution thicknesses h. The long-time evolution of the total amount of product, n(C), is compared to a scaling obtained theoretically from a one-dimensional reaction-diffusion-advection model with passive advection along the radial coordinate r. We show that, in the experiments, n(C) is significantly affected when varying either Q or h but scales as n(C) similar to Q(-1/2)V where V is the volume of injected reactant A provided the solution thickness h between the two confining plates is sufficiently small, in agreement with the theoretical prediction. Our experimental results also evidence that the temporal evolution of the width of the product zone, W-C, follows a power law, the exponent of which varies with both Q and h, in disagreement with the one-dimensional model that predicts W-C similar to t(1/2). We show that this experimental observation can be rationalized by taking into account the non-uniform profile of the velocity field of the injected reactant within the cell gap. |
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| Terjedelem/Fizikai jellemzők: | 10278-10285 |
| ISSN: | 1463-9076 |