Dr. Shuchi Vaishnav is a postdoctoral researcher based at Sheffield Hallam University. Her current research interest is in fundamental studies of amorphous solids and applying a range of spectroscopic  techniques including Raman spectroscopy, NMR, Neutron diffraction , High energy X-Ray Diffraction, SEM and DTA-DSC to  determine structure-property relationships  in glassy systems.  Her PhD focussed at looking  into anionic solubilities in high level radioactive waste glasses. She worked as a Nuclear Research Engineer at  EDF R&D , France before joining her PhD and has interned at various nuclear reactor facilities based in India and France working on irradiation assisted cracking of nuclear materials.

Shuchi Vaishnav

S. Vaishnav *1, M.J. Packard 2, N. Barrow 3, A.C. Hannon 4, M. C. Wilding1, S. Feller 2, P.A. Bingham1

1Materials and Engineering Research Institute, Sheffield Hallam University, Sheffield, United Kingdom
2Department of Physics, Coe College, Cedar Rapids, Iowa, United States
3Solid State NMR facility, Johnson Matthey, Reading, United Kingdom
4ISIS Neutron Facility, Rutherford Appleton Laboratory, Didcot, United Kingdom

Raman and 2D-MAS NMR (29Si; 23Na and 13C) spectroscopic techniques have been employed to study structural differences and carbonate retention within a very wide range of sodium silicate glasses, xNa2O.(100-x)SiO2 (x=20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70 mol%). The conventional glass forming region for an alkali silicate glass is typically below 50mol % alkali oxide. Therefore, beyond 45 mol % Na2O, the higher Na2O glasses were prepared using roller-quenching procedures. Spectroscopic evidence for the presence of dissolved carbonate was observed in the highly modified sodium silicate glasses. 13C MAS NMR and Raman spectroscopy enabled understanding of the local environment of carbonate anions in high-alkali glasses. These spectroscopic studies, in addition to Neutron Diffraction, Leco, thermal analysis and density measurements provide a deeper understanding of the impact of carbonate retention on the structure and physical properties of silicate glasses.

Keywords: Sodium, Silicate, Carbonate, Carbon dioxide, NMR, Raman

Figure: (Top) Raman and (bottom) 13C- MAS NMR spectra of xNa2O.(100-x)SiO2 (x= 60, 65, 70 mol%) glasses