Structural investigation and specific heat measurements on borosilicate, uranium and rare earths loaded borosilicate glasses

Abstract

• Disposal of contaminated sodium in borosilicate glass matrix without evolution of hydrogen. • Increase glass transition temperature and decrease linear thermal expansion of doped glasses without altering Na/Si ratio (1.34) is demonstrated. • The intensity variation in the Raman spectra due to high B2O3 and low Na2O and absence of Q0 band due to low sodium oxide content are addressed. • Enthalpy increments and specific heat capacity of doped BSGs are compared well with pristine BSG. Enthalpy increment data were acquired for borosilicate and doped borosilicate glasses containing oxides of uranium and surrogates of plutonium (CeO 2 , Nd 2 O 3 and Gd 2 O 3 ) using isoperibol drop calorimetry. The specific heat of borosilicate glasses were derived from these data and compared with doped glasses. The specific heat of the pristine glass is nearly similar to that of BSGU and found to show a dissimilar trend for BSGUCe and BSGRE. Internal network connectivity of the base glasses was investigated using micro-Raman spectrometer and compared with the glass containing high and low concentration of modifier (Na 2 O) for better understanding of thermal stability of the glasses. The Raman spectra reveal changes in the network structure with varying concentration of Na 2 O.