Fourier-transform infrared spectroscopy analysis of mechanochemical transformation kinetics of sodium carbonate to bicarbonate

Abstract

During mechanical activation, qualitative changes that can produce various phenomena occur in the material. In this study, anhydrous sodium carbonate was mechanically activated for 2, 7, 14, and 28 minutes in a vibro mill at a frequency of 3000 oscillations per minute. After activation, four series of activated samples were stored in the air at room conditions for 31 days (relaxation period). To monitor the kinetics of the transformation process of activated sodium carbonate samples, i.e. the mechanism of sodium bicarbonate formation during relaxation, Fourier-transform infrared (FTIR) spectroscopy analysis was used. FTIR testing was performed as a function of relaxation time for all four series of samples, with characteristic groups observed: CO32-, HCO3- and OH-. The obtained results provided kinetics parameters for the transformation of sodium carbonate into sodium bicarbonate due to the chemisorption of moisture and carbon dioxide from the atmosphere.