Physisorption theory of surface area and porosity determination: A short review

In this work, it is shown that using the theoretical models could determine the surface area, porosity, and pore size of porous materials. Physisorption adsorption isothermal models of Langmuir, Brunauer-Emmett-Teller (BET), and Barrett-Joyner- Halenda (BJH) models were investigated. The Langmuir adsorption model describes the monolayer adsorption, while the BET adsorption model describes the multilayers adsorbate. In contrast, the pore size is determined by BJH adsorption model. Also, the six types of physisorption isotherms that were classified according to the international union of pure and applied chemistry (IUPAC) recommendations were presented and identified to determine the porosity type of materials.