US EPA

4455300 

Journal Article 

Temporal viscosity modulations driven by a pH sensitive polymer coupled to a pH-changing chemical reaction 

Escala, DM; Muñuzuri, AP; De Wit, A; Carballido-Landeira, J 

2017 

1 

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

19 

19 

11914-11919 

English 

28440385 

10.1039/c7cp00426e 

WOS:000401640600020 

The Formaldehyde-Sulfite (FS) and the Formaldehyde-Sulfite-Gluconolactone (FSG) systems are examples of complex chemical reactions accompanied by well-controlled variations in pH. While the FS system exhibits a clock behavior, in the FSG reaction, this mechanism is coupled with the hydrolysis of the gluconolactone which gives the possibility to show large temporal oscillations of pH in an open reactor. In this work, we show how these reactive systems, due to their organic nature, can be coupled with pH sensitive polymers, particularly with polyacrylic acid (PAA) to trigger temporal changes of viscosity. We characterize this coupled reactive system showing the effects of changes in the initial concentrations of the polymer and in the chemical reagents on the induction time, the magnitude of the pH variations and the temporal modifications of the viscosity.