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Published on: January 31, 2020
Chemical activity induces dynamical force with global structure in a reaction-diffusion-convection system
Hitoshi Mahara1, Koichi Okada, Atsushi Nomura
1Nanotechnology Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba 305-8565, Japan.
Summary
Local chemical activity in the Belousov-Zhabotinsky reaction creates a rotating global structure. This phenomenon, influenced by bromomalonic acid, reveals complex pattern formation in chemical systems.
Area of Science:
- Chemical kinetics and reaction-diffusion systems
- Complex pattern formation
- Nonlinear dynamics
Background:
- The Belousov-Zhabotinsky (BZ) reaction is a classic example of an excitable chemical system exhibiting complex spatiotemporal patterns.
- Understanding pattern selection and emergent global structures in reaction-diffusion systems is crucial for various scientific fields.
- Previous studies have explored spiral waves in BZ reactions, but the induction of global rotating structures remains an area of interest.
Purpose of the Study:
- To investigate the emergence of a rotating global structure induced by local chemical activity in a thin solution layer of the Belousov-Zhabotinsky reaction.
- To analyze the relationship between chemical spiral waves and large-scale structural phenomena like surface flow and global tilt.
- To identify key factors, such as specific chemical components, that drive the formation of these hierarchical patterns.
Main Methods:
- Utilized a thin solution layer of the excitable Belousov-Zhabotinsky reaction coupled with diffusion.
- Observed and analyzed chemical spiral waves with a wavelength of approximately 1 mm.
- Scanned conditions for hierarchical pattern selection and investigated the role of bromomalonic acid.
- Examined the interplay between reaction-diffusion dynamics and surface-tension-driven effects.
Main Results:
- A rotating global structure was successfully induced by the dynamical force of local chemical activity.
- Chemical spiral waves were associated with a global unidirectional surface flow and a global tilt across the Petri dish.
- Bromomalonic acid was identified as a critical component for inducing the rotating global structure.
- Hierarchical patterns with different scales emerged from the interaction between reaction-diffusion and surface-tension effects.
Conclusions:
- Local chemical activity in the BZ reaction can drive large-scale, rotating global structures.
- The formation of these structures involves a complex interplay between chemical reactions, diffusion, and surface tension.
- Bromomalonic acid plays a pivotal role in the induction and characteristics of the observed global rotating structure.
- This study demonstrates a mechanism for hierarchical pattern formation in chemical systems with implications for understanding complex emergent behaviors.
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