Designed patterns: flexible control of precipitation through electric currents.
Understanding and controlling precipitation patterns formed in reaction-diffusion processes is of fundamental importance with high potential for technical applications. Here we present a theory showing that precipitation resulting from reactions among charged agents can be controlled by an appropriately designed, time-dependent electric current. Examples of current dynamics yielding periodic bands of prescribed wavelength, as well as more complicated structures are given. The pattern control is demonstrated experimentally using the reaction-diffusion process 2AgNO3 + K2Cr2O7-->under Ag2Cr2O7 + 2KNO3.
Bena
I
I
Theoretical Physics Department, University of Geneva, CH-1211 Geneva 4, Switzerland.
Droz
M
M
Lagzi
I
I
Martens
K
K
Rácz
Z
Z
Volford
A
A