石墨烯类粉体比表面积的氮气吸附法测量条件与不确定度评定

Measurement Conditions and Uncertainty Evaluation of Specific Surface Area of Graphene Powder by Nitrogen Adsorption Method

采用氮气吸附静态容量法(氮气吸附法),以氧化还原石墨烯/金属氧化物粉体为研究对象,利用ASAP 2460型比表面积和孔隙度分析仪测量了其比表面积,确定了测量比表面积的理想测试条件,并对测量不确定度进行评定。结果表明:氮气吸附法测量石墨烯类粉体比表面积的理想样品用量为0.20.4 g。比表面积不确定度的评定仅考虑测量重复性、天平称量样品质量及标样引入的标准不确定度,在置信水平p为95%,自由度V_(rel)为32时,采用氮气吸附法物理吸附仪测量石墨样品比表面积的扩展不确定度为14.55 m^(2)·g^(-1)。

Specific surface area of redox graphene/metal oxide powder was measured by ASAP 2460 specific surface area and porosity analyzer using nitrogen adsorption static capacity method(nitrogen adsorption method). The ideal test conditions were determined, and the measurement uncertainty was evaluated. The results show that the ideal sample amount for measuring the specific surface area of graphene powder by nitrogen adsorption method is 0.2~0.4 g. The uncertainty evaluation of specific surface area only considers the standard uncertainty introduced by measurement repeatability, the weight of sample weighed by the balance and the standard sample. When the confidence level p is 95% and the degree of freedom V_(rel) is 32, the expanded uncertainty of specific surface area of graphite sample measured by nitrogen adsorption method physical adsorption instrument is 14.55 m^(2) ·g^(-1).