通过FTIR、Raman、27 Al NMR、XRD、DSC等测试方法,研究了ZnO含量对Bi2O3-B2O3-ZnO-SiO2-Al2O3系统低熔点玻璃结构及热性能的影响。结果表明:当ZnO含量小于12wt%时,Zn^2+与自由氧结合形成[ZnO 4]四面体,增强网络结构,玻璃化转变温度增大...通过FTIR、Raman、27 Al NMR、XRD、DSC等测试方法,研究了ZnO含量对Bi2O3-B2O3-ZnO-SiO2-Al2O3系统低熔点玻璃结构及热性能的影响。结果表明:当ZnO含量小于12wt%时,Zn^2+与自由氧结合形成[ZnO 4]四面体,增强网络结构,玻璃化转变温度增大,热膨胀系数减小;当ZnO含量大于12wt%时,锌氧多面体由四配位[ZnO4]转变为六配位[ZnO6],破坏网络结构,玻璃化转变温度减小,热膨胀系数增大;ZnO含量的提高和热处理温度的升高对玻璃析晶能力没有明显的促进作用。展开更多
Poly(aluminum chloride)(PAC) solutions of different basicity were prepared from pure aluminum foil and hydrochloric acid. Aluminum species were investigated by 27Al NMR spectroscopy and the tridecameric polycation Al ...Poly(aluminum chloride)(PAC) solutions of different basicity were prepared from pure aluminum foil and hydrochloric acid. Aluminum species were investigated by 27Al NMR spectroscopy and the tridecameric polycation Al 13 was detected. With the increase of PAC′s basicity, the molar ratio of Al 13 to Al m in PAC increases. The jar tests with kaolin water and water from Huangpu River at the same PACs dosage showed that the more basicity and content of Al 13, the more effective the coagulation effect on water with middle-high turbidity, while only less effect of the basicity was observed on water with low turbidity.展开更多
文摘通过FTIR、Raman、27 Al NMR、XRD、DSC等测试方法,研究了ZnO含量对Bi2O3-B2O3-ZnO-SiO2-Al2O3系统低熔点玻璃结构及热性能的影响。结果表明:当ZnO含量小于12wt%时,Zn^2+与自由氧结合形成[ZnO 4]四面体,增强网络结构,玻璃化转变温度增大,热膨胀系数减小;当ZnO含量大于12wt%时,锌氧多面体由四配位[ZnO4]转变为六配位[ZnO6],破坏网络结构,玻璃化转变温度减小,热膨胀系数增大;ZnO含量的提高和热处理温度的升高对玻璃析晶能力没有明显的促进作用。
文摘Poly(aluminum chloride)(PAC) solutions of different basicity were prepared from pure aluminum foil and hydrochloric acid. Aluminum species were investigated by 27Al NMR spectroscopy and the tridecameric polycation Al 13 was detected. With the increase of PAC′s basicity, the molar ratio of Al 13 to Al m in PAC increases. The jar tests with kaolin water and water from Huangpu River at the same PACs dosage showed that the more basicity and content of Al 13, the more effective the coagulation effect on water with middle-high turbidity, while only less effect of the basicity was observed on water with low turbidity.
