Angstrom Porosimety with quantum Herium

埃孔隙率与量子氦

基本信息

批准号：
05554018
负责人：
KANEKO Katsumi
金额：
$ 3.14万
依托单位：
Chiba University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Developmental Scientific Research (B)
财政年份：
1993
资助国家：
日本
起止时间：
1993 至 1994
项目状态：
已结题

项目摘要

A He atom is the smallest spherical monoatomic molecule and interacts nonspecifically with any solid surface. He adsorption at 4.2 K is an effective method for determination of Angstrom pore structures. The He adsorption at 4.2 K was applied to activiated carbon system. The adsorption isotherms were compared with N_2 adsorption isotherms using the theoretical adsorbed He density (0.202gml^<-1>) on the flat surface and the liquid N_2 density (0.807gml^<-1>) , respectively. The amount of He adsorption was much greater than that of N_2 in the low relative pressure region. This suggests better accessibility and accelerated bilayr adsorption of He. The He adsorption isotherm was analyzed by the Dubinin-Radushukevich plot and we developed the determination method of the Angstrom pore size distribution from the He adsorption isotherm using the Gaussian distribution function and the Dubinin-Stoeckli relation. This analysis was quite effective for determination of the Angstrom pore size distrib … More ution for activated carbon. It can show presence of the Angstrom pores which cannot be evaluated by N_2 adsorption method. However, the application of this approach is limited to activated carbon system. We developed a more general analysis using the potential profile and distribution of a He atom in the pore. We applied the Steele approach to He adsorption on the flat surface to the Angstrom pore analysis. The potential profile of a He atom with the pore was determined by calculation using the Lennard-Jones potential as a function of the pore width. This potential profile and statistical considerations lead to a possible population of He atoms in the pore. Hence, we can determine the micropore size distribution by the best fit procedure to the observed adsorption isotherm. It was shown that this molecular potential approach for He adsorption having a general applicability is a hopeful method for Angstrom pore characterization. Also the Grand Canonical Monte Calro (GCMC) computer simulation was applied to analyze the He adsorption isotherm. However, it will take more time to establish the development of the Angstrom pore size distribution-determination with the GCMC method. Less

A原子是最小的球形单子分子，并与任何固体表面相互作用。他在4.2 K处的吸附是确定Angstrom孔结构的有效方法。将HE在4.2 K处吸附到活性炭系统上。使用理论吸附的He密度（0.202gml^<-1>）和液体N_2密度（0.807gml^<-1>）将吸附等温线与N_2吸附等温线进行比较。在低相对压力区域中，HE添加的吸附量远大于N_2的吸附量。这表明更好的可访问性和加速性bilayr增加了HE。通过Dubinin-Radushukevich图对He添加等温线进行了分析，我们从HE添加了Gaussian分布函数和Dubinin-Stoeckli关系中开发了Angstrom孔径分布的确定方法。该分析对于确定Angstrom孔径分布非常有效……用于活性炭的UTION。它可以显示出无法通过N_2添加吸附方法评估的Angstrom孔的存在。但是，这种方法的应用仅限于活化的碳系统。我们使用HE原子在孔中的潜在特征和分布进行了更一般的分析。我们将Steele方法应用于在平坦表面上吸附到Angstrom孔分析上。通过使用Lennard-Jones电位计算来确定He原子与孔的潜在曲线作为孔隙宽度的函数。这种潜在的特征和统计考虑导致毛孔中可能的HE原子种群。因此，我们可以通过观察到的吸附等温线的最佳拟合程序来确定微孔尺寸分布。结果表明，具有一般适用性的He吸附的这种分子潜在方法是埃孔孔特征的希望方法。还应用了大规范的蒙特卡罗（GCMC）计算机模拟来分析HE吸附等温线。但是，使用GCMC方法建立Angstrom孔径分布确定的开发将需要更多时间。较少的