Stanisław Staszic State University of Applied Sciences in Piła, Podchorążych Street 10, 64-920 Piła, Poland.
Carbon Materials Application in Electrochemistry and Environmental Protection Research Group, Faculty of Chemistry, Nicolaus Copernicus University in Toruń, Gagarin Street 7, 87-100 Toruń, Poland.
Molecules. 2021 Mar 10;26(6):1509. doi: 10.3390/molecules26061509.
The finite pore volume Guggenheim-Anderson-de Boer (fpv-GAB) adsorption isotherm model has been considered as a simple tool which not only enables us to analyze the shape of isotherms theoretically, but also provides information about pore diameter. The proposed methodology is based on the geometrical considerations and the division of the adsorption space into two parts: the monolayer and the multilayer space. The ratio of the volumes of these two spaces is unambiguously related to the pore diameter. This ratio can be simply determined from the N adsorption isotherm by its fitting with the use of fpv-GAB model. The volume ratio is equal to the ratio of the adsorption capacities in the monolayer and the multilayer-two of the best-fit parameters. The suggested approach has been verified using a series of isotherms simulated inside ideal carbon nanotubes. The adsorption data for some real adsorbents has also been used during tests. The studies performed have proven that diameters estimated with the use of the proposed method are comparable with the geometrical sizes or diameters published by others and based on the application of more sophisticated methods. For pores wider than 3 nm, the relative error does not exceed a few percent. The approach based on the fpv-GAB model reflects well the differences in pore sizes for the series of materials. Therefore, it can be treated as a convenient tool to compare various samples.
有限孔体积 Guggenheim-Anderson-de Boer（fpv-GAB）吸附等温线模型被认为是一种简单的工具，它不仅使我们能够从理论上分析等温线的形状，还提供有关孔径的信息。所提出的方法基于几何考虑，并将吸附空间分为两部分：单层和多层空间。这两个空间的体积比与孔径有明确的关系。可以通过使用 fpv-GAB 模型拟合 N 吸附等温线，从其简单确定该比值。该比值等于单层和多层吸附容量之比，这是两个最佳拟合参数之一。该方法已通过在理想碳纳米管内模拟的一系列等温线进行了验证。在测试过程中还使用了一些实际吸附剂的吸附数据。所进行的研究证明，使用所提出的方法估计的直径与其他人基于更复杂方法的应用所公布的几何尺寸或直径相当。对于孔径大于 3nm 的情况，相对误差不超过百分之几。基于 fpv-GAB 模型的方法很好地反映了一系列材料中孔径的差异。因此，它可以作为一种方便的工具来比较各种样品。
