Magnetic resonance studies of chemical reactions in microemulsions

[摘要] The Belousov-Zhabotinsky (BZ) reaction is the preeminent oscillating chemical reaction for the study of pattern formation in reaction-diffusion systems. The dispersal of the reaction in a water-in-oil AOT microemulsion (BZ-AOT reaction) gives rise to an extended range of patterns, including dash waves, segmented spirals and, most notably, stationary Turing patterns that are thought to be significant to an understanding of the biological process of morphogenesis. To date, these patterns have only been observed in two-dimensions using optical microscopy. In this project, nuclear magnetic resonance (NMR) spectroscopy and imaging (MRI) techniques were used along with existing optical methods in order to identify redox indicators suitable for the visualisation of pattern formation in the BZ-AOT reaction using MRI. The location of the redox indicator in the microemulsion was found to be important with respect to its application as an indicator. Thus, the use of Ru(II)(bpy)3 as an MR contrast agent was ruled out as it was found to reside within the micellar interface. Manganese, however, proved to be a viable MR indicator. Oscillations were observed in the manganese-catalysed BZ-AOT reaction through changes in the NMR relaxation times of solvent water molecules. The ability of manganese to act as an MR contrast indicator has enabled pattern formation in the BZ-AOT reaction to be visualised using MRI for the first time. Further development of the technique may allow pattern formation to be visualised in three-dimensions.

[发布机构] University:University of Birmingham;Department:School of Chemistry

[关键词] Q Science;QD Chemistry