Periodic band formation of Fe(OH)3 precipitate through reaction–diffusion–reaction processes

This paper reports a new class of periodic banding Fe(OH) 3 precipitate through reaction–diffusion–reaction (RDR) processes in agarose gel sandwiched between two metal rods (Ti and Fe) with cyclic alternating voltages. In the RDR processes, electrochemical reactions at to generate reactant ions, diffusion ions influenced by electric field gel, form precipitates were coupled bands cathode side. The morphologies, spatial Fe distribution, microscopic morphologies investigated visual inspection, Kα intensity distribution measurements, scanning electron microscopy observations. strongly depended on applied voltages, periods for voltage alternation, cycle number ( N C ), length column. Periodic resembling Liesegang most clearly observed high reproducibility 50 mm columns under voltages 1 V 4 h, respectively. formed this system was generally given — C1 + 1, where is first band emerges. These contained significant amounts atoms that almost uniformly distributed supporting formation gelatinous bands.