The Silicate Garden Reaction in Microgravity: A Fluid Interfacial Instability

Formation of Chemical Gardens

“…Unfortunately they provide few details of their experiments. Subsequently Jones and Walter (26,39) flew a further experiment, in which they found that the reaction occurred an order of magnitude slower than on ground, due to the absence of free convection. The absence of buoyancydriven flow led to novel structures, as apart from the tubes seen on Earth, they found also evidence for spherical membranes and fingers, structures typical of Laplacian growth mechanisms such as viscous fingering.…”

“…The precipitation of different materials on the inner and outer tube surfaces must give a strong compositional gradient across the thickness of the tube wall (26). Moreover, this gradual deposition of material on the walls leads to the tubes becoming stiffer over time.…”

Tubular precipitation structures: materials synthesis under non-equilibrium conditions

“…In addition, the physico-chemical description of the growth process has attracted renewed interest as exemplified by the study of Cartwright et al [36], who studied concentration changes in the solution surrounding the tubes using Mach-Zehnder interferometry. The first microgravity study on silica gardens was carried out by Jones & Walter [37,38]. Their experiments produced samples that were qualitatively similar to precipitation structures formed on the Earth.…”

Tube Formation in Reverse Silica Gardens

“…35 Tube growth was also investigated under microgravity conditions. [36][37][38] The qualitative description of tube growth in silica gardens involves the formation of a semipermeable, colloidal membrane around the dissolving seed crystal. 39 As the concentration of the metal salt ion increases, a buildup of osmotic pressure occurs and the inflow of water across the membrane causes it to breach.…”