MRI Study of Liesegang Patterns: Mass Transport and Banded Inorganic Phase Formation in Gel

A new non-optic method for the study of Liesegang patterns was tested. Liesegang patterns are periodically banded precipitates produced by the reaction–diffusion process, mostly occurring in geology. The Liesegang experiment (5.5 M NH4OH, gelatin matrix with 0.4 M MgSO4) was monitored using a 9.4 T magnetic resonance imaging (MRI) system, allowing the acquisition of sample images in any location and orientation without interfering with the process studied. The development of patterns in a gel matrix was observed for 7 days after starting the reaction. Qualitative data (T 2- and T 2*-weighted images) and quantitative T 2 maps were acquired. Preliminary experiments show that MRI is able to distinguish the regions between the precipitated bands and the structural changes in the gel matrix during the reaction. A damaged gel matrix was measured to reveal the effect of the initial reagent-gel contact area. MRI study of Liesegang patterns provides empirical data which can be used in theoretical model testing.