Belousov–Zhabotinsky reaction

The Belousov–Zhabotinsky reaction (BZ reaction) is a class of oscillating chemical reactions, which serve as a classic example of non-equilibrium thermodynamics. The reaction is named after Boris Belousov and Anatol Zhabotinsky, who first discovered and studied the phenomenon.

History

The BZ reaction was first discovered by Boris Belousov in the 1950s. Belousov observed that in a mixture of certain chemicals, the concentration of reactants and products oscillated over time, rather than reaching a stable equilibrium. This was contrary to the expectations of classical chemical kinetics. Belousov's work was initially met with skepticism, but it was later confirmed and expanded upon by Anatol Zhabotinsky in the 1960s.

Mechanism

The BZ reaction typically involves the oxidation of an organic substrate, such as malonic acid, by bromate in the presence of a metal catalyst, such as cerium or ferroin. The reaction proceeds through a complex network of intermediate steps, leading to periodic changes in the concentration of various species. These oscillations can manifest as color changes, making the reaction visually striking.

Mathematical Modeling

The BZ reaction can be described by a set of nonlinear differential equations known as the Oregonator model, which is a simplified version of the more comprehensive Field-Körös-Noyes mechanism. These models capture the essential features of the oscillatory behavior and have been used to study pattern formation and chaotic dynamics.

Applications

The study of the BZ reaction has implications for various fields, including biochemistry, neuroscience, and materials science. It provides insights into the behavior of biological oscillators, such as the circadian rhythm, and has been used to develop chemical computing systems.

See Also

• Chemical oscillator
• Non-equilibrium thermodynamics
• Chaos theory
• Pattern formation
• Oregonator model