The fertile physics of chemical gardens

Abstract

Many a child has enjoyed watching the gardens grow; many a physicist has puzzled over the transformation of self-organized, nonequilibrium patterns into permanent structures.

Camphor-Engine-Driven Micro-Boat Guides Evolution of Chemical Gardens

“…The perplexed hydrodynamics of growing chemical gardens was studied recently in detail by various groups 40 – 43 . Our group demonstrated recently that chemical gardens may be grown in water polymer solutions, and also under geometrical confinement within microliter droplets 44 – 46 .…”

Self-organization in precipitation reactions far from the equilibrium

“…Chemical gardens are the most iconic and oldest example of pattern formation through precipitation reactions ( 37 – 39 ). These lifelike landscapes consist of hollow, inorganic tubes with diameters of around 1 mm and lengths of several centimeters.…”

Pressure Controlled Chemical Gardens

“…[2][3][4] Chemical gardens consist of macroscopic and often colorful tubes that can reach lengths of several centimeters within seconds to minutes. The classic experiment is also a well-known classroom demonstration as it simply involves the placement of a metal salt grain into a basic sodium silicate solution.…”

“…With l denoting the time-dependent height of the precipitate structure and under the assumption that the tube is filled with a fluid of density ρ Zn , Eqs. (3,4) yield Especially during the early growth stage, the term l(ρ Si -ρ Zn ) is much smaller than ρ Si h 2 and can hence be neglected. The resulting simple inhomogeneous differential equation has the solution where C* and c 0 are positive constants.…”