RAMAN-STUDY OF SULFURIC-ACID AT LOW-TEMPERATURES

A Raman spectroscopic study has been carried out for aqueous sulfuric acid of various concentrations at room temperature and in the glassy s tate. Temperature dependence of the Raman spectra was also investigate d from 44 to -40 degrees C. Anomalous T-g (glass transition temperatur e) behavior of the aqueous sulfuric acid solution at similar to 86 wt % H2SO4 is interpreted in terms of ionic species involved in Raman spe ctral changes. It is shown that ionization of sulfuric acid increases exponentially with decreasing temperature. Complete ionization was att ained up to similar to 50 wt % H2SO4 concentration in glassy aqueous H 2SO4 solution.