Osmotic contribution to the flow-driven tube formation of copper–phosphate and copper–silicate chemical gardens
Evelin Rauscher,Gábor Schuszter,Bíborka Bohner,Ágota Tóth,Dezső Horváth
Physical Chemistry Chemical Physics Pub Date : 01/23/2018 00:00:00 , DOI:10.1039/C7CP08282G
Abstract

We have produced hollow copper-containing precipitate tubes using a flow-injection technique, and characterized their linear and volume growth. It is shown that the ratio of the volume increase rate to that of pumping is constant independent of the chemical composition. It is also found that osmosis significantly contributes to the tube growth, since the inward flux of chemical species dominates during the precipitate pattern formation. The asymmetric hydrodynamic field coupled with the inherent concentration and pH gradients results in different particle morphology on the two sides of the precipitate membrane. While the tubes have a smooth outer surface, the inner walls are covered with nanoflowers for copper phosphate and with nanoballs for copper silicate.

Graphical abstract: Osmotic contribution to the flow-driven tube formation of copper–phosphate and copper–silicate chemical gardens