Using classical methods to start quantum mechanical calculations for microporosity and mesoporosity
| Autor: | James B. Condon |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Surface (mathematics)
Materials science General Chemical Engineering Thermodynamics 02 engineering and technology Surfaces and Interfaces General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Least squares 0104 chemical sciences Adsorption Gas pressure Range (statistics) 0210 nano-technology Porosity Quantum Physical quantity |
| Zdroj: | Adsorption. 26:1291-1299 |
| ISSN: | 1572-8757 0929-5607 |
| DOI: | 10.1007/s10450-020-00267-8 |
| Popis: | One primary measurement of open porosity uses physical adsorption isotherm, amount adsorbed versus gas pressure. Classical treatments, including the BET, cannot fit the isotherm for its full range, therefore standard curves have been created from non-porous materials for comparison. This classical method yields three output parameters, two surface areas, pore and external, relative to the standard. The third output is moles of material needed to fill the pores. A modern treatment using quantum mechanics and thermodynamics, call χ/ESW, yields seven physical quantities. However, the calculation requires a non-linear least squares routine, with initial parameters to find a minimum. In this paper the possibility of using the answers from the classical method as a first approximation is explored, with no need for a standard since χ/ESW treatment is used as a self-standard. Within limits, this works well for microporosity but mesoporosity presents some problems with one of the parameters. |
| Databáze: | OpenAIRE |
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