Voltammetry in silicate and borosilicate melts

With the aid of square-wave-voltammetry, redox equilibria of various multivalent elements were studied in a soda-lime-silicate and a borosilicate glass melt in the temperature range of 600 to 1300 degrees C. The peaks in the current-potential curves could be attributed to certain redox couples. The peak potentials measured dependend linearly on temperature proving that both standard enthalpy and standard entropy possess constant values within the temperature range studied. The peak potentials measured in the silicate and the borosilicate melt were in fairly good agreement. A systematic shift caused by the higher alkali content of the borosilicate glass could not be observed.