A Comparative Study of Different Amorphous and Paracrystalline Silica by NMR and SEM/EDS
来源期刊：Journal Of Wuhan University Of Technology Materials Science Edition2015年第5期
论文作者：贾援 王宝民 张婷婷
文章页码：900 - 907
摘 要：This work aimed to research the structure models of amorphous materials. Five amorphous and paracrystalline samples（natural or artificial） were investigated via 29Si/27 Al nuclear magnetic resonance（NMR） and field emission scanning electron microscopy/energy dispersive spectroscopy（FE-SEM/EDS）. The results of NMR showed the resonances of different specimens:-93.2 ppm,-101.8 ppm,-111.8 ppm for natural pozzolana opal shale（POS）. These peaks were assigned to the Q2（2OH）, Q3（OH）/Q4（1Al） and Q4 respectively. The results of 27 Al MAS NMR indicated that Al substituted for Si site in tetrahedral existing in the POS, while the Al/Si atomic ratio in opal was low（around 0.04）. For the alkali-silicate-hydrate gel, there were at least three resolved signals assigned to Q0 and Q1, respectively. For the fused silica glass powder, there were the primary signals centered about at the range from-107 to-137 ppm, which were assigned to Q4 units. In addition, the peaks at around-98 and-108 ppm were corresponding to Q3（1OH） and Q4 units existing in aerogel silica structure.
贾援，王宝民，张婷婷
School of Civil Engineering, Dalian University of Technology
摘 要：This work aimed to research the structure models of amorphous materials. Five amorphous and paracrystalline samples（natural or artificial） were investigated via 29Si/27 Al nuclear magnetic resonance（NMR） and field emission scanning electron microscopy/energy dispersive spectroscopy（FE-SEM/EDS）. The results of NMR showed the resonances of different specimens:-93.2 ppm,-101.8 ppm,-111.8 ppm for natural pozzolana opal shale（POS）. These peaks were assigned to the Q2（2OH）, Q3（OH）/Q4（1Al） and Q4 respectively. The results of 27 Al MAS NMR indicated that Al substituted for Si site in tetrahedral existing in the POS, while the Al/Si atomic ratio in opal was low（around 0.04）. For the alkali-silicate-hydrate gel, there were at least three resolved signals assigned to Q0 and Q1, respectively. For the fused silica glass powder, there were the primary signals centered about at the range from-107 to-137 ppm, which were assigned to Q4 units. In addition, the peaks at around-98 and-108 ppm were corresponding to Q3（1OH） and Q4 units existing in aerogel silica structure.
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