In situ high temperature 27Al NMR study of structure and dynamics in a calcium aluminosilicate glass and melt

Practical comparison of sensitivity and resolution between STMAS and MQMAS for 27Al

“…These values are identical whichever STMAS and MQMAS spectra were selected, and found to be d iso = 8.9 ± 0.3 ppm and P Q = 3.5 ± 0.3 MHz for [6] Al site of kaolin, and d iso = 71.5 ± 0.5 ppm and P Q = 6.8 ± 0.6 MHz for [4] Al site of glass. These values are reasonably consistent with those of the previous studies [16,17,19]. However, it should be noted that the P Q estimated for glass is just an average value of widely-distributed quadrupolar interaction.…”

“…Two inorganic materials of kaolin (Al 2 Si 2 O 5 (OH) 4 , quadrupolar products P Q = 3.6 MHz) [16] and glass (43.1CaO-12.5Al 2 O 3 -44.4SiO 2 , P Q = 7.2 MHz) [17] were chosen as models of useful inorganic compounds. Kaolin was purchased from Aldrich Chemical Company, Inc., while the glass was synthesized from a reagentgrade, well dried starting materials to have a composition of 43.1 mol% CaO, 12.5 mol% Al 2 O 3 , and 44.4 mol% SiO 2 (CAS glass).…”

Reconsideration on Al Coordination in CaO–SiO2–Al2O3–(R2O or RO) Glasses by Using High Field Solid-State 27Al NMR Spectroscopy

“…[7][8][9] The viscosity of CaO-SiO 2 -Al 2 O 3 -(R 2 O or RO) melts would be dependent on the amount of AlO 5 in these melts. In situ high temperature 27 Al MAS NMR for these glasses should provide useful information about the temperature dependences of Al coordination structure, which would be closely linked to some physical properties such as viscosity of the melt, as future work.…”

Molecular Dynamics Study of the Structural Properties of Calcium Aluminosilicate Slags with Varying Al2O3/SiO2 Ratios

“…This has been studied through various sorts of techniques e.g. Nuclear Magnetic Resonance (NMR), [1][2][3][4] XRay absorption spectroscopy (XAS), 5,6) neutron diffraction, 7,8) Raman scattering 9,10) and molecular dynamics (MD) simulation. [11][12][13][14] However, previous studies mainly paid their attention to CAS glasses or slags with a low silica mole fraction or a varying CaO proportion.…”