Exotic dynamics of bimolecular reaction-diffusion fronts in immiscible systems.

Dynamics of bimolecular A+B & RARR;C reaction-diffusion (RD) fronts have been well characterized in miscible systems. We study here their properties when reactants A and B are initially dissolved in two immiscible solvents put in contact. Neglecting any convective effects, we show that bimolecular RD fronts developing in such immiscible systems upon transfer from the reactants from one phase to the other can change directions up to four times, contrary to miscible systems where only two changes of direction are possible. Further, the conditions for which two local maxima in the reaction rate can exist are identified.& COPY; 2023 Published by Elsevier Ltd.