Transient complex oscillations in a closed chemical system with coupled autocatalysis

Abstract

In this study, hydroquinone was introduced to the classic Belousov-Zhabotinsky (BZ) reaction to build up coupled autocatalytic feedbacks. Various complex dynamical behaviors including successive period-adding bifurcations, irregular oscillations, and frequency modulations were observed in the coupled reaction system. Not only the complexity of oscillations but also the time period during which complex oscillations persist were found to depend greatly on the initial concentration of hydroquinone, which was expected to manifest the coupling strength in the studied system. Dependence of the observed transient complex oscillations on concentrations of ferroin, sulfuric acid, bromate, and malonic acid was also characterized systematically. Numerical simulations with a modified BZ model via incorporating reactions involving hydroquinone and products of hydroquinone qualitatively reproduced the influence of hydroquinone seen in experiments.

Ternary Phase Diagram for the Belousov−Zhabotinsky Reaction-Induced Mechanical Oscillation of Intelligent PNIPAM Colloids

“…It is well-known that the BZ reaction can exhibit a variety of dynamic regimes, such as steady state, periodic oscillation, and chaos, in both open and closed systems, depending on reagent concentrations and a number of external factors such as temperature, speed of agitation, and flowing rate. ,215,− As shown by Yoshida and his co-workers, factors such as temperature and substrate concentrations not only turn on or off of the Hopf bifurcation, ,,, but also control the frequency and magnitude of the mechanical oscillation of the self-oscillating gel. ,,,, For the practical application of the self-oscillating microgels to colloidal crystal annealing, it is therefore important to identify the main ‘tuning knobs' for self-assembly and understand the interplay between the polymer system and the BZ reaction. In this study, we focused our attention on controlling the oscillation dynamics of colloids by varying the BZ substrate concentrations.…”

Identification of the best medium for experiments on chemical computation with Belousov–Zhabotinsky reaction and ferroin-loaded Dowex beads

“…Positive electric potential on the working electrode attracts the inhibitor species Br − from the solution near the working electrode. If Br − is not added to the initial solution, it takes several hours to form it from brominated malonic acid [32] and brominated 1,4-cyclohexandedione [33].…”

Nonlinear Phenomena in Light-Mediated Bromate−Hydroquinone−Benzoquinone Reactions

“…It has also been confirmed in our laboratory that mixing yellow Q and colorless H 2 Q together results in an immediate formation of black powder. Several chemical oscillators reported recently contain both H 2 Q and Q as intermediates. – Whether the formation of H 2 Q−Q complexes plays an important role in the kinetics of these chemical oscillations remains to be answered and could be critical in deciphering the mechanism of these chemical oscillators. In particular, these chemical oscillators have exhibited various interesting nonlinear behaviors which could not be interpreted based on the current mechanisms, such as the anomalous dispersion relationship in the ferroin−bromate−cyclohexanedione system …”