Electrochemical Study on Redox Behavior of the multivalent Metal Ions in the glass Melts

玻璃熔体中多价金属离子氧化还原行为的电化学研究

• 批准号: 09450327
• 负责人: MAEKAWA Takashi
• 金额: $ 8.64万
• 依托单位: Ehime University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09450327/
• 关键词: Redox equilibria; Differential pulse voltammetry; Half-wave potential; Glass melt; Multivalent metal ion; Basicity; MAS-NMR; 微分パルスポルタンメトリー; 状態別分析

The Sn^<4+>-Sn^<2+> and Fe^<3+>-Fe^<2+> equilibrium in alkali borate and silicate melts was studied by means of differential pulse voltammetry. The half-wave potentials in Fe-containing glasses become negative with decrease of temperature and increase of alkali oxide when they exceed 20 mol%. When alkali oxide is less than about 20 mol%, the data can be fitted by two reduction peaks, i.e. the Fe^<3+>-containing complex and free Fe^<3+> to Fe^<2+>. The half-wave potentials of Sn^<4+>-Sn^<2+> equilibrium in borate melts shift to the negative with an increase in Na_2O content and a decrease in temperature. On the other hand, the half-wave potentials in the silicate melts shift to the positive with an increase in Na_2O content. There results can be interpreted in terms of complex formations of Sn^<4+> and Sn^<2+>, in which the coordination numbers of the oxide ion for both ions do not differ significantly and their equilibrium constants for complex formation depend largely on the alkali species.The ^<29>Si and ^<31>P nuclear magnetic resonance (NMR) chemical shifts and the Q_n distribution in ternary sodium phosphosilicate glasses were examined. When the P_2O_5 content increases at fixed mole fractions of SiO_2 equal to 0.1 and 0.05, the 6-coordinated silicon atoms appear. The presence of 6-coordinated silicon atoms is expected in glasses where the [P_2O_5]/[Na_2O] composition ratio is greater than unity. From the NMR spectra of 30Na_2O ・ 5SiO_2 ・ 65[(1-x)P_2O_5 ・ xB_2O_3] glasses, the distribution curves derived from the deconvolution of the spectra by component signal of each phosphate and borate species agree with those calculated using species with different [Na_2O] / [P_2O_5] ratios when P_2O_5 reacts with Na_2O and B_2O_3 preferably.

采用微分脉冲伏安法研究了碱金属硼酸盐和硅酸盐熔体中Sn^<4+>-Sn^<2+>和Fe^<3+>-Fe^<2+>的平衡。当含Fe玻璃超过20mol%时，随着温度的降低和碱金属氧化物的增加而变成负值。当碱金属氧化物小于约20mol%时，数据可以通过两次还原来拟合。峰，即含 Fe^<3+> 络合物和游离 Fe^<3+> 到 Fe^<2+> 的 Sn^<4+>-Sn^<2+> 平衡的半波电位。随着Na_2O含量的增加和温度的降低，硼酸盐熔体的半波电位向负值移动，而随着Na_2O含量的增加，硅酸盐熔体的半波电位向正值移动。根据 Sn^<4+> 和 Sn^<2+> 的络合物形成来解释，其中两种离子的氧化物离子的配位数没有显着差异，并且它们络合物形成的平衡常数很大程度上取决于碱物质研究了当P_2O_5含量以固定摩尔数增加时，三元磷硅酸钠玻璃中的^ 29 Si和^ 31 P核磁共振(NMR)化学位移和Q_n分布。当 SiO_2 分数等于 0.1 和 0.05 时，会出现 6 配位硅原子。根据 NMR 谱，预计玻璃中会出现 6 配位硅原子，其中 [P_2O_5]/[Na_2O] 组成比大于 1。 30Na_2O ・ 5SiO_2 ・ 65[(1-x)P_2O_5 ・xB_2O_3]玻璃中，当P_2O_5优选与Na_2O和B_2O_3反应时，通过每个磷酸盐和硼酸盐物种的分量信号对光谱进行解卷积而得到的分布曲线与使用具有不同[Na_2O]/[P_2O_5]比率的物种计算的分布曲线一致。

项目成果

Isamu YAMAGUCHI: "^Si MAS NMR Study of Porous Silica Glass Prepared from Sodium Boroshilicate Glasses" J.Ceram.Soc.Jpn.105・8. 700-702 (1997)

Isamu YAMAGUCHI：“^<29>由硼硅酸钠玻璃制备的多孔二氧化硅玻璃的Si MAS NMR研究”J.Ceram.Soc.Jpn.105・8(1997)。

H.Yamashita, K.Nozaki, K.Toshinari, T.Mima, T.Maekawa: "Synthesis of Spherical Porous Zirconia and Titania Particles in W/O Emulsion" J.Ceram.Soc.Jpn.106-12. 1184-1189 (1998)

H.Yamashita、K.Nozaki、K.Toshinari、T.Mima、T.Maekawa：“W/O 乳液中球形多孔氧化锆和二氧化钛颗粒的合成”J.Ceram.Soc.Jpn.106-12。

Makoto NAKASHIMA: "Electrochemical Study of Fe Ions in Alakali Borate Melts" J.Non-Cryst.Solids. 223. 133-140 (1998)

Makoto NAKASHIMA：“碱硼酸盐熔体中铁离子的电化学研究”J.Non-Cryst.Solids。

Hiroshi YAMASHITA: "Redox Equilibria of Tin Ions in Alakali Borate Melts" J.Ceram.Soc.Jpn.106・7. 724-726 (1998)

Hiroshi YAMASHITA：“Alakali 硼酸盐熔体中锡离子的氧化还原平衡”J.Ceram.Soc.Jpn.106・7 (1998)。

Hiroshi YAMASHITA: "Structural Studies of 30Na_2O・SiO_2・5[(1-x)P_2O_5・B_2O_3]Glasses by NMR, Raman and IR Spectroscopy" J.Non-Cryst.Solids. (in press). (1999)

Hiroshi YAMASHITA：“通过 NMR、拉曼和红外光谱对 30Na_2O·SiO_2·5[(1-x)P_2O_5·B_2O_3] 玻璃进行结构研究”J.Non-Cryst.Solids（出版中）。