High-pressure spectroscopic study of hydrous and anhydrous Cs-exchanged natrolites
Data(s) |
01/01/2012
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Resumo |
Structural phase transitions in hydrous Cs-exchanged natrolite (Cs-NAT-hyd) and anhydrous Cs-exchanged natrolite (Cs-NAT-anh) have been investigated as a function of pressure and temperature using micro-Raman scattering and synchrotron infrared (IR) spectroscopy with pure water as the penetrating pressure medium. The spectroscopic results indicate that Cs-NAT-hyd undergoes a reversible phase transition around 4.72 GPa accompanied by the discontinuous frequency shifts of the breathing vibrational modes of the four-ring and helical eight-ring units of the natrolite framework. On the other hand, we observe that Cs-NAT-anh becomes rehydrated at 0.76 GPa after heating to 100 °C and then transforms into two distinctive phases at 2.24 and 3.41 GPa after temperature treatments at 165 and 180 °C, respectively. Both of these high-pressure phases are characterized by the absence of the helical eight-ring breathing modes, which suggests the collapse of the natrolite channel and formation of dense high-pressure polymorphs. Together with the fact that these high-pressure phases are recoverable to ambient conditions, our results imply a novel means for radionuclide storage utilizing pressure and a porous material.<br /> |
Identificador | |
Idioma(s) |
eng |
Publicador |
American Chemical Society |
Relação |
http://dro.deakin.edu.au/eserv/DU:30047834/liu-highpressurespectroscopic-2012.pdf http://dx.doi.org/10.1021/jp206678e |
Direitos |
2012, American Chemical Society |
Tipo |
Journal Article |