eprintid: 12925 rev_number: 2 eprint_status: archive userid: 1 dir: disk0/00/01/29/25 datestamp: 2023-11-10 03:27:29 lastmod: 2023-11-10 03:27:29 status_changed: 2023-11-10 01:49:53 type: article metadata_visibility: show creators_name: Mukhtar, A. creators_name: Mellon, N. creators_name: Saqib, S. creators_name: Lee, S.-P. creators_name: Bustam, M.A. title: Extension of BET theory to CO2 adsorption isotherms for ultra-microporosity of covalent organic polymers ispublished: pub keywords: Adsorption; Adsorption isotherms; Argon; Carbon dioxide; Cryogenics; Desorption; Microporosity; Microporous materials; Nitrogen; Specific surface area, Argon adsorption; CO2 adsorption; Cryogenic conditions; Cryogenic temperatures; Desorption isotherms; Linear region; N2 adsorption; Surface area, Organic polymers note: cited By 32 abstract: Usually, nitrogen and argon adsorption�desorption isotherms are used at their respective boiling points for the determination of specific surface area via the BET theory of microporous materials. However, for ultra-micropores, where nitrogen and argon cannot access at cryogenic temperatures, the CO2 adsorption�desorption isotherms have been considered as alternative options for the determination of specific surface area by extending BET theory, but the surface area determined by using CO2 adsorption�desorption isotherms is not significant due to strong CO2-CO2 interactions. In this study, the microporous covalent organic polymers are subjected to nitrogen and CO2 adsorption�desorption isotherms and the results showed that a clear linear region is available in isotherms, which confirms the presence of ultra-micropores. The surface area determined by the CO2 adsorption�desorption isotherms is higher than the surface area determined by N2 adsorption�desorption isotherms. These results indicate that the microporous covalent organic polymers contain ultra-micropores where only CO2 can reach, while nitrogen and argon cannot access at cryogenic conditions because their kinetic diameter is larger than CO2. © 2020, Springer Nature Switzerland AG. date: 2020 publisher: Springer Nature official_url: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85096140500&doi=10.1007%2fs42452-020-2968-9&partnerID=40&md5=f808294fa5ef668716429abfa6b9a5cc id_number: 10.1007/s42452-020-2968-9 full_text_status: none publication: SN Applied Sciences volume: 2 number: 7 refereed: TRUE issn: 25233971 citation: Mukhtar, A. and Mellon, N. and Saqib, S. and Lee, S.-P. and Bustam, M.A. (2020) Extension of BET theory to CO2 adsorption isotherms for ultra-microporosity of covalent organic polymers. SN Applied Sciences, 2 (7). ISSN 25233971