Archimedean Spirals Form at Low Flow Rates in Confined Chemical Gardens
Luís A. M. Rocha, Lewis Thorne, Jasper J. Wong, Julyan H. E. Cartwright, Silvana S. S. Cardoso
Abstract
We describe and study the formation of confined chemical garden patterns. At low flow rates of injection of cobalt chloride solution into a Hele-Shaw cell filled with sodium silicate, the precipitate forms with a thin filament wrapping around an expanding "candy floss" structure. The result is the formation of an Archimedean spiral structure. We model the growth of the structure mathematically. We estimate the effective density of the precipitate and calculate the membrane permeability. We set the results within the context of recent experimental and modeling work on confined chemical garden filaments.
Topics & Concepts
Permeability (electromagnetism)Protein filamentFlow (mathematics)Hexagonal crystal systemContext (archaeology)Sodium silicateMembraneVolumetric flow rateMaterials scienceChemical physicsChemical engineeringChemistryMineralogyMechanicsCrystallographyPhysicsGeologyComposite materialEngineeringPaleontologyBiochemistryNonlinear Dynamics and Pattern FormationSlime Mold and Myxomycetes ResearchOrigins and Evolution of Life