氧化钨物理特征的测量

DETERMINATION OF PHYSICAL CHARACTERIZATION OF TUNGSTEN OXIDES

对铵钨青铜 (ATB)、氢钨青铜 (HTB)、紫色氧化钨 (TVO)和蓝色氧化钨 (TBO)四种氧化钨粉的氮气吸附 /脱附等温线数据的分析 ,可以得出其表面积、微孔体积、微孔分布、中孔体积、平均孔径和分数维数。吸附 /脱附等温线数据的分析表明 ,TVO粉末具有最大的中孔体积 ,最小的微孔体积 ,最窄的孔径分布 ,最小的分数维数和最大的平均孔径 ,其有利于氢还原制取超细钨粉 ,而不利于掺杂工艺。HTB粉末具有最大的微孔体积、最宽的孔径分布、最高的分数维数和最小的平均孔径 ,对于掺杂工艺来说是有利的。ATB和TBO的上述参数界于TVO和HTB之间。结果表明 ,利用吸附 /脱附等温线来研究氧化物的物理特征是一个很好的方法 ;在氧化钨用于氢还原工艺和掺杂工艺之前必须研究其物理特征。

The physical characterization of surface area, micropore volume, micropore size distribution, mesopore volume, average pore diameter and fractal dimensions of four tungsten oxides of ATB (ammonium tungsten bronze,(NH 4) 0.5 WO 3), HTB (hydrogen tungsten bronze,H 0.33 WO 3), TVO (violet tungsten oxide,W 18 O 49 ) and TBO (tungsten blue oxide,WO 3+WO 2.9 ) were evaluated from analysis of nitrogen adsorption desorption isotherm data. The results suggested that in this study TVO with the largest mesopore volume, the smallest micropore volume, the narrowest micropore size distribution, the lowest fractal dimension value and the biggest average pore diameter was advantageous for hydrogen reduction during fine tungsten powder production process and disadvantageous for doping process; HTB with the largest micropore volume, the widest micropore size distribution, the highest fractal dimension value and the smallest average pore diameter was favorable for doping process, and characterization properties of ATB and TBO in this investigation were just between TVO′s and HTB′s. Results showed that it was a preferable method to investigate the physical characterization of oxides by using adsorption desorption isotherms in this study and the physical characterization of tungsten oxides should be taken into account before they were used in reduction or doping process.