Phase Diagram of Precipitation Morphologies in the Cu 2+ −PO 4 3- System

We have experimentally investigated the phase diagram of spatiotemporal pattern formation in the precipitation reaction of copper sulfate and sodium phosphate. The system exhibits an unusual variety of both vertically and horizontally growing structures. Quantitative measurements have been used to analyze the transition between the two patterns. The driving forces for the pattern formation have been identified as osmosis, buoyant forces, flow rate, and the mechanical properties of the membrane.