EXPERIMENTAL-STUDY OF A TERNARY A-]C REACTION-DIFFUSION SYSTEM WITH APROPAGATING REACTION FRONT - SCALING EXPONENTS(2B)

We study experimentally the A + 2B --> C reaction-diffusion process wi th initially separated reagents in a capillary using an inorganic chem ical reaction. We measure and compare with theory the dynamic quantiti es that characterize tl-ie kinetic behavior of the system: the global reaction rate R(t), the location of the reaction center x(f)(t), the f ront's width w(t), and the local production rate R(x(f), t). We demons trate the nonclassical phenomena of reactant segregation and depletion -zone formation for this reaction-diffusion profess. The experimental results are in good agreement with theory and simulation and quite dif ferent from the exponents for the elementary binary A + B --> C reacti on. The time exponents are 0.27 for the width, -0.48 for the global re action rate, and -0.75 for the local reaction rate, compared to theore tical values of 0.25, -0.5, and -0.75, respectively.