Application of radio analytical tracer technique to study the performance of industrial grade ion exchange resin exposed to UV radiations

Abstract

Abstract The thermodynamics and kinetics of bromide ion-isotopic exchange reactions performed by using fresh and UV radiation degraded industrial grade anion exchange resin Duolite A-638 resins were studied by application of radio analytical tracer technique. The reaction rate k in min−1 for the fresh resin decreases sharply with decrease in wavelength of UV radiations. Thus for 0.200 M labeled bromide ion solution maintained at a constant temperature of 30.0 °C, the k value for fresh resin (0.367 min−1), decreases to 0.335 min−1 for λ384 UV radiation degraded resin, which further decreases to 0.273 min−1 for λ284 UV radiation degraded resin. Under identical experimental conditions, the thermodynamic parameters like energy of activation (−1.65 kJ/mol), enthalpy of activation (−4.24 kJ/mol), free energy of activation (64.85 kJ/mol), and entropy of activation (−0.229 kJ/K/mol) calculated for the fresh resin increases to −1.61 kJ/mol, −4.19 kJ/mol, 64.92 kJ/mol, and −0.228 kJ/K/mol respectively for λ384 UV radiation degraded resin; which further increases to −1.60 kJ/mol, −4.18 kJ/mol, 65.17 kJ/mol, and −0.228 kJ/K/mol respectively for λ284 UV radiation degraded resin. Increase in thermodynamic parameters calculated here for the fresh and degraded resins suggests that decrease in wavelength of UV radiations has catastrophic effect on the resin making the bromide ion-isotopic exchange reactions thermodynamically less feasible. The impact of UV radiation on resin degradation was supported by their characterization study using Fourier-transform infrared spectroscopy (FTIR) and Scanning Electron Microscopy (SEM) techniques.