Growth and form of a self-constructing tube network.

When a small amount of liquid is quickly injected into another liquid with similar density, the fluid jet usually does not propagate very far. However, when the two solutions chemically react to form a flexible membrane at their interface, then structures that are long and branching can form. Here, we describe the tube networks produced when a small amount of AlCl solution is quickly injected into a NaOH solution.

Growing a Chemical Garden at the Air-Fluid Interface.

Here we grow chemical gardens using a novel, quasi two-dimensional, experimental configuration. Buoyant calcium chloride solution is pumped onto the surface of sodium silicate solution. The solutions react to form a precipitation structure on the surface.

Spontaneous formation of complex structures made from elastic membranes in an aluminum-hydroxide-carbonate system.

A popular playground for studying chemo-hydrodynamic patterns and instabilities is chemical gardens, also known as silicate gardens. In these systems, complex structures spontaneously form, driven by buoyant forces and either osmotic or mechanical pumps. Here, we report on systems that differ somewhat from classical chemical gardens in that the membranes are much more deformable and soluble.

Cyclic growth of hierarchical structures in the aluminum-silicate system.

Background: Biological structures grow spontaneously from a seed, using materials supplied by the environment. These structures are hierarchical, with the 'building blocks' on each level constructed from those on the lower level. To understand and model the processes that occur on many levels, and later construct them, is a difficult task.

The dynamics of open precipitation tubes.

When a flowing fluid is channeled by chemical or physical precipitation, then tubular structures form. These patterns are common in nature, however, there have been few quantitative studies of their formation. Here, we report measurements of the radius, length, and internal pressure, as functions of time and flow rate, for precipitation tubes growing in chemical gardens.

Emergence of complex behavior in chemical cells: the system AlCl₃-NaOH.

Chemical cells that spontaneously form in simple inorganic systems are presented. The cells are surrounded by semipermeable membranes that allow water and some ions to diffuse through. These cells exhibit dynamical behaviors that are typically associated with biological entities.

Chemical precipitation structures formed by drops impacting on a deep pool.

The experiments described here are at the intersection of two dynamical systems with long pedigrees for forming interesting patterns: liquid droplet impacts and precipitation membranes. Drops of calcium chloride solution have been allowed to impact on a deep pool of sodium silicate solution. The precipitation structures produced by this method, and how these structures subsequently evolve, have been observed.

Precipitation pattern formation in the copper(II) oxalate system with gravity flow and axial symmetry.

Chemical systems that are far from thermodynamic equilibrium may form complex temporal and spatiotemporal structures. In our paper, we present unusual precipitation patterns that have been observed in the system of Cu(II)-oxalate. Starting with a pellet of copper sulfate immersed in or by pumping copper sulfate solution into a horizontal layer of sodium oxalate solution, we have observed the formation of a precipitate ring and an array of radially oriented thin fingers.

Pressure oscillations in a chemical garden.

When soluble metal salts are placed in a silicate solution, chemical gardens grow. These gardens are treelike structures formed of long thin hollow tubes. The growth is driven by the increase in internal pressure from osmosis.

Oscillations of a chemical garden.

When soluble metal salts are placed in a silicate solution, chemical gardens grow. These gardens are treelike structures formed of long, thin, hollow tubes. Here we study one particular case: a calcium nitrate pellet in a solution of sodium trisilicate.