The effect of Cs2O additions on HLW wasteform glasses

Probing alkali coordination environments in alkali borate glasses by multinuclear magnetic resonance

“…Alkali borate glasses have been extensively studied due to their potential importance as fast ion conductors [1][2][3][4] and alkali borosilicates as model systems for highly durable nuclear wasteforms [5,6]. One of the most valuable techniques for probing short-range structure in glasses is NMR spectroscopy [7][8][9][10].…”

Effect of BaO addition on the structural aspects and thermophysical properties of sodium borosilicate glasses

“…Extensive studies have been reported on the structural aspects of borosilicate glasses using techniques like 29 Si, 11 B, 17 O magic angle spinning nuclear magnetic resonance (MAS NMR), Raman and IR spectroscopy [3][4][5][6][7][8][9][10][11]. Based on these studies, the existence of structural units like trigonally coordinated boron (BO 3 ), tetrahedrally coordinated boron (BO 4 ), silicon atoms with 3 and 4 bridging oxygen atoms, (Q 3 and Q 4 : where Q n represents silicon structural units having n-number of bridging oxygen atoms), Q n units with Si-O-B linkages etc., have been well established [3][4][5][6][7][8][9][10][11]. The addition of network modifiers (alkali/alkaline earth metal oxides) to borosilicate and borate glasses results in the initial conversion of BO 3 to BO 4 structural units.…”

Structural studies on boroaluminosilicate glasses

“…Deconvolution of this peak assuming a Guassian line shape resulted in two peaks around À102 ppm and À91 ppm. Based on the previous 29 Si MAS NMR studies of borosilicate and boroaluminosilicate glasses [11][12][13][14][15], the peaks around À102 and À91 ppm can be attributed to the Q 4 and Q 3 structural units of silicon (i.e. silicon structural units having 4 and 3 bridging oxygen atoms, respectively).…”

“…The patterns are almost same except that the intensity of peaks around 3500 cm À1 and 1600 cm À1 are significantly higher for Cu 2+ exchanged sample compared to the unexchanged sample and this has been attributed to the water molecules incorporated into the glass during the room temperature ion exchange process. The peaks around 1050 and 460 cm À1 have been attributed to the stretching and bending vibrations of Si-O-Si/Si-O-B linkages [5,9,13] present in the glass. Photoluminescence measurements were carried out on the samples to check whether any Cu + ions are formed in the glass after ion exchange.…”

“…Similarly Bi 2 O 3 incorporation at the expense of PbO in PbO-B 2 O 3 -SiO 2 glasses results in the increase of thermal expansion coefficient, deformation and flow temperatures [10]. Addition of network modifiers (alkali/ alkaline earth metal oxides) to borosilicate glasses [11][12][13][14] results in the initial conversion of BO 3 to BO 4 structural units. With further increase in modifier concentration, BO 4 structural units in the glass are replaced by BO À 3 structural units (planar BO 3 structural units with one nonbridging oxygen atoms).…”