US EPA

2457324 

Journal Article 

pH oscillations and bistability in the methylene glycol-sulfite-gluconolactone reaction 

Kovacs, K; Mcilwaine, RE; Scott, SK; Taylor, AF 

2007 

1 

Physical Chemistry Chemical Physics
ISSN: 1463-9076
EISSN: 1463-9084 

9 

28 

3711-3716 

17622405 

10.1039/b704407k 

WOS:000247933800004 

http://dx.doi.org/10.1039/b704407k
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The Methylene Glycol-Sulfite-Gluconolactone (MGSG) reaction is the first example of an organic-based pH oscillator. This reaction is of particular interest as it displays large amplitude oscillations in hydroxide ion accompanied by small amplitude (10(-3) V) oscillations in potential, indicating that it is not driven by redox processes. We investigate the reaction in a batch (closed) and flow (open) reactor and examine the role of the aging of the gluconolactone stock solution. The system is found to display oscillations and bistability for a wide range of flow rates and initial compositions. The experimental results are reproduced in numerical simulations in an extended model of the reaction in which the decay of the stock solution is incorporated. Finally, we analyse the features of the reaction that make it a suitable basis for the development of novel pH oscillators.