{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,7]],"date-time":"2026-07-07T05:16:22Z","timestamp":1783401382918,"version":"3.54.6"},"reference-count":46,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2020,4,3]],"date-time":"2020-04-03T00:00:00Z","timestamp":1585872000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Seventh Framework Programme","award":["608490"],"award-info":[{"award-number":["608490"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Membranes"],"abstract":"<jats:p>A detailed comparison of the gas permeability of four Polymers of Intrinsic Microporosity containing Tr\u00f6ger\u2019s base (TB-PIMs) is reported. In particular, we present the results of a systematic study of the differences between four related polymers, highlighting the importance of the role of methyl groups positioned at the bridgehead of ethanoanthracene (EA) and triptycene (Trip) components. The PIMs show BET surface areas between 845\u20131028 m2 g\u22121 and complete solubility in chloroform, which allowed for the casting of robust films that provided excellent permselectivities for O2\/N2, CO2\/N2, CO2\/CH4 and H2\/CH4 gas pairs so that some data surpass the 2008 Robeson upper bounds. Their interesting gas transport properties were mostly ascribed to a combination of high permeability and very strong size-selectivity of the polymers. Time lag measurements and determination of the gas diffusion coefficient of all polymers revealed that physical ageing strongly increased the size-selectivity, making them suitable for the preparation of thin film composite membranes.<\/jats:p>","DOI":"10.3390\/membranes10040062","type":"journal-article","created":{"date-parts":[[2020,4,6]],"date-time":"2020-04-06T05:05:13Z","timestamp":1586149513000},"page":"62","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":30,"title":["Effect of Bridgehead Methyl Substituents on the Gas Permeability of Tr\u00f6ger\u2019s-Base Derived Polymers of Intrinsic Microporosity"],"prefix":"10.3390","volume":"10","author":[{"given":"Richard","family":"Malpass-Evans","sequence":"first","affiliation":[{"name":"EaStCHEM, School of Chemistry, University of Edinburgh, Joseph Black Building, David Brewster Road, Edinburgh, Scotland EH9 3FJ, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ian","family":"Rose","sequence":"additional","affiliation":[{"name":"EaStCHEM, School of Chemistry, University of Edinburgh, Joseph Black Building, David Brewster Road, Edinburgh, Scotland EH9 3FJ, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8355-0141","authenticated-orcid":false,"given":"Alessio","family":"Fuoco","sequence":"additional","affiliation":[{"name":"Institute on Membrane Technology, CNR-ITM, Via P. Bucci 17\/C, 87036 Rende (CS), Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0370-6319","authenticated-orcid":false,"given":"Paola","family":"Bernardo","sequence":"additional","affiliation":[{"name":"Institute on Membrane Technology, CNR-ITM, Via P. Bucci 17\/C, 87036 Rende (CS), Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gabriele","family":"Clarizia","sequence":"additional","affiliation":[{"name":"Institute on Membrane Technology, CNR-ITM, Via P. Bucci 17\/C, 87036 Rende (CS), Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Neil B.","family":"McKeown","sequence":"additional","affiliation":[{"name":"EaStCHEM, School of Chemistry, University of Edinburgh, Joseph Black Building, David Brewster Road, Edinburgh, Scotland EH9 3FJ, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4538-6851","authenticated-orcid":false,"given":"Johannes C.","family":"Jansen","sequence":"additional","affiliation":[{"name":"Institute on Membrane Technology, CNR-ITM, Via P. Bucci 17\/C, 87036 Rende (CS), Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0718-6971","authenticated-orcid":false,"given":"Mariolino","family":"Carta","sequence":"additional","affiliation":[{"name":"Department of Chemistry, College of Science, Swansea University, Grove Building, Singleton Park, Swansea SA2 8PP, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2020,4,3]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"5694","DOI":"10.1039\/c2ra22580h","article-title":"Membrane processes for a sustainable industrial growth","volume":"3","author":"Buonomenna","year":"2013","journal-title":"RSC Adv."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"2780","DOI":"10.1021\/cr200035s","article-title":"Recent Development of Polymer Electrolyte Membranes for Fuel Cells","volume":"112","author":"Zhang","year":"2012","journal-title":"Chem. Rev."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"3302","DOI":"10.1039\/C7CS00071E","article-title":"Trends and challenges for microporous polymers","volume":"46","author":"Chaoui","year":"2017","journal-title":"Chem. Soc. Rev."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"289","DOI":"10.1038\/nmat4805","article-title":"Materials for next-generation molecularly selective synthetic membranes","volume":"16","author":"Koros","year":"2017","journal-title":"Nat. Mater."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"46","DOI":"10.1016\/j.ijggc.2013.04.012","article-title":"Current challenges in membrane separation of CO2 from natural gas: A review","volume":"17","author":"Adewole","year":"2013","journal-title":"Int. J. Greenh. Gas Control"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"2109","DOI":"10.1021\/ie071083w","article-title":"Natural Gas Processing with Membranes:\u2009 An Overview","volume":"47","author":"Baker","year":"2008","journal-title":"Ind. Eng. Chem. Res."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"4638","DOI":"10.1021\/ie8019032","article-title":"Membrane Gas Separation: A Review\/State of the Art","volume":"48","author":"Bernardo","year":"2009","journal-title":"Ind. Eng. Chem. Res."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"4729","DOI":"10.1016\/j.polymer.2013.05.075","article-title":"Energy-efficient polymeric gas separation membranes for a sustainable future: A review","volume":"54","author":"Sanders","year":"2013","journal-title":"Polymer"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"3298","DOI":"10.1021\/ma300213b","article-title":"Polymeric Gas Separation Membranes","volume":"45","author":"Yampolskii","year":"2012","journal-title":"Macromolecules"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"18","DOI":"10.1016\/j.memsci.2008.11.019","article-title":"Polymeric membranes for the hydrogen economy: Contemporary approaches and prospects for the future","volume":"327","author":"Shao","year":"2009","journal-title":"J. Membr. Sci."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"4078","DOI":"10.1021\/cr0501792","article-title":"Membranes for Hydrogen Separation","volume":"107","author":"Ockwig","year":"2007","journal-title":"Chem. Rev."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"27669","DOI":"10.1021\/acsami.6b08331","article-title":"Multifunctional Porous Organic Polymers: Tuning of Porosity, CO2, and H2 Storage and Visible-Light-Driven Photocatalysis","volume":"8","author":"Bandyopadhyay","year":"2016","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"7306","DOI":"10.1039\/C1EE02668B","article-title":"Advances in high permeability polymeric membrane materials for CO2 separations","volume":"5","author":"Du","year":"2012","journal-title":"Energy Environ. Sci."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"441","DOI":"10.1016\/j.memsci.2011.11.012","article-title":"Carbon dioxide capture with membranes at an IGCC power plant","volume":"389","author":"Merkel","year":"2012","journal-title":"J. Membr. Sci."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"5322","DOI":"10.1002\/anie.201402234","article-title":"Ending Aging in Super Glassy Polymer Membranes","volume":"53","author":"Lau","year":"2014","journal-title":"Angew. Chem. Int. Ed."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"6794","DOI":"10.1039\/C7TA01297G","article-title":"Perspectives on water-facilitated CO2 capture materials","volume":"5","author":"Wang","year":"2017","journal-title":"J. Mater. Chem. A"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"618","DOI":"10.1016\/j.cej.2017.06.082","article-title":"Cost-optimal CO2 capture ratio for membrane-based capture from different CO2 sources","volume":"327","author":"Roussanaly","year":"2017","journal-title":"Chem. Eng. J."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"12796","DOI":"10.1002\/chem.201803006","article-title":"Towards High Performance Metal\u2013Organic Framework\u2013Microporous Polymer Mixed Matrix Membranes: Addressing Compatibility and Limiting Aging by Polymer Doping","volume":"24","author":"Sabetghadam","year":"2018","journal-title":"Chem. A Eur. J."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"281","DOI":"10.1039\/C8EE02897D","article-title":"Simultaneous production of biomethane and food grade CO2 from biogas: An industrial case study","volume":"12","author":"Esposito","year":"2019","journal-title":"Energy Environ. Sci."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"63","DOI":"10.1039\/b9py00319c","article-title":"Highly permeable polymers for gas separation membranes","volume":"1","author":"Budd","year":"2010","journal-title":"Polym. Chem."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"165","DOI":"10.1016\/0376-7388(91)80060-J","article-title":"Correlation of separation factor versus permeability for polymeric membranes","volume":"62","author":"Robeson","year":"1991","journal-title":"J. Membr. Sci."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"375","DOI":"10.1021\/ma9814548","article-title":"Basis of Permeability\/Selectivity Tradeoff Relations in Polymeric Gas Separation Membranes","volume":"32","author":"Freeman","year":"1999","journal-title":"Macromolecules"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"390","DOI":"10.1016\/j.memsci.2008.04.030","article-title":"The upper bound revisited","volume":"320","author":"Robeson","year":"2008","journal-title":"J. Membr. Sci."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"947","DOI":"10.1021\/acsmacrolett.5b00512","article-title":"Fine-Tuned Intrinsically Ultramicroporous Polymers Redefine the Permeability\/Selectivity Upper Bounds of Membrane-Based Air and Hydrogen Separations","volume":"4","author":"Swaidan","year":"2015","journal-title":"ACS Macro Lett."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"2733","DOI":"10.1039\/C9EE01384A","article-title":"Redefining the Robeson upper bounds for CO2\/CH4 and CO2\/N2 separations using a series of ultrapermeable benzotriptycene-based polymers of intrinsic microporosity","volume":"12","author":"Chen","year":"2019","journal-title":"Energy Environ. Sci."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"230","DOI":"10.1039\/b311764b","article-title":"Polymers of intrinsic microporosity (PIMs): Robust, solution-processable, organic nanoporous materials","volume":"2","author":"Budd","year":"2004","journal-title":"Chem. Commun. (Cambridge, UK)"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"8320","DOI":"10.1021\/ma501925j","article-title":"Gas Permeability of Hexaphenylbenzene file Based Polymers of Intrinsic Microporosity","volume":"47","author":"Carta","year":"2014","journal-title":"Macromolecules"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"5930","DOI":"10.1002\/adma.201202393","article-title":"A Spirobifluorene-Based Polymer of Intrinsic Microporosity with Improved Performance for Gas Separation","volume":"24","author":"Bezzu","year":"2012","journal-title":"Adv. Mater."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"3526","DOI":"10.1002\/adma.201305783","article-title":"Triptycene Induced Enhancement of Membrane Gas Selectivity for Microporous Tr\u00f6ger\u2019s Base Polymers","volume":"26","author":"Carta","year":"2014","journal-title":"Adv. Mater."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"36475","DOI":"10.1021\/acsami.8b13634","article-title":"Temperature Dependence of Gas Permeation and Diffusion in Triptycene-Based Ultrapermeable Polymers of Intrinsic Microporosity","volume":"10","author":"Fuoco","year":"2018","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"5267","DOI":"10.1039\/C4PY00609G","article-title":"The synthesis of microporous polymers using Troger\u2019s base formation","volume":"5","author":"Carta","year":"2014","journal-title":"Polym. Chem."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"5255","DOI":"10.1039\/C4PY00607K","article-title":"Synthesis of cardo-polymers using Troger\u2019s base formation","volume":"5","author":"Carta","year":"2014","journal-title":"Polym. Chem."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"5661","DOI":"10.1039\/C8TA00509E","article-title":"A highly rigid and gas selective methanopentacene-based polymer of intrinsic microporosity derived from Tr\u00f6ger\u2019s base polymerization","volume":"6","author":"Williams","year":"2018","journal-title":"J. Mater. Chem. A"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"912","DOI":"10.1021\/acsmacrolett.5b00439","article-title":"Highly permeable benzotriptycene-based polymer of intrinsic microporosity","volume":"4","author":"Rose","year":"2015","journal-title":"ACS Macro Lett."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"303","DOI":"10.1126\/science.1228032","article-title":"An Efficient Polymer Molecular Sieve for Membrane Gas Separations","volume":"339","author":"Carta","year":"2013","journal-title":"Science"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"17","DOI":"10.1016\/j.memsci.2018.10.001","article-title":"Thin film composite membranes based on a polymer of intrinsic microporosity derived from Tr\u00f6ger\u2019s base: A combined experimental and computational investigation of the role of residual casting solvent","volume":"569","author":"Bernardo","year":"2019","journal-title":"J. Membr. Sci."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"100","DOI":"10.1016\/j.memsci.2019.05.014","article-title":"Permeation, sorption, and diffusion of CO2-CH4 mixtures in polymers of intrinsic microporosity: The effect of intrachain rigidity on plasticization resistance","volume":"584","author":"Genduso","year":"2019","journal-title":"J. Membr. Sci."},{"key":"ref_38","unstructured":"Crank, J. (1975). The Mathematics of Diffusion, Oxford University Press. [2nd ed.]."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"39","DOI":"10.1016\/j.memsci.2018.04.029","article-title":"A novel time lag method for the analysis of mixed gas diffusion in polymeric membranes by on-line mass spectrometry: Method development and validation","volume":"561","author":"Fraga","year":"2018","journal-title":"J. Membr. Sci."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"4014","DOI":"10.1002\/cssc.201701139","article-title":"Ultrathin Composite Polymeric Membranes for CO2\/N2 Separation with Minimum Thickness and High CO2 Permeance","volume":"10","author":"Benito","year":"2017","journal-title":"ChemSusChem"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"7900","DOI":"10.1021\/ma501469m","article-title":"Molecular Modeling and Gas Permeation Properties of a Polymer of Intrinsic Microporosity Composed of Ethanoanthracene and Troger\u2019s Base Units","volume":"47","author":"Tocci","year":"2014","journal-title":"Macromolecules"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"2193","DOI":"10.1021\/ja01129a013","article-title":"Mechanisms of Elimination Reactions. V. Preparation and Elimination Reactions of cis- and trans-11,12-Dichloro-9,10-dihydro-9,10-ethanoanthracene1,2, 3","volume":"74","author":"Cristol","year":"1952","journal-title":"J. Am. Chem. Soc."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"258","DOI":"10.1021\/ja00183a039","article-title":"Formation of benzoxathiete under mild conditions and its valence tautomerism in solution to monothio-o-benzoquinone: An experimental and quantum chemical study","volume":"111","author":"Naghipur","year":"1989","journal-title":"J. Am. Chem. Soc."},{"key":"ref_44","first-page":"522","article-title":"Gas sorption in polymers of intrinsic microporosity: The difference between solubility coefficients determined via time-lag and direct sorption experiments","volume":"570\u2013571","author":"Mason","year":"2019","journal-title":"J. Membr. Sci."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"20121","DOI":"10.1039\/C9TA07159H","article-title":"The origin of size-selective gas transport through polymers of intrinsic microporosity","volume":"7","author":"Fuoco","year":"2019","journal-title":"J. Mater. Chem. A"},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"66","DOI":"10.1016\/0950-4214(90)80030-O","article-title":"Correlation aspects of the selective gas permeabilities of polymeric materials and membranes","volume":"4","author":"Teplyakov","year":"1990","journal-title":"Gas Sep. Purif."}],"container-title":["Membranes"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2077-0375\/10\/4\/62\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T09:15:08Z","timestamp":1760174108000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2077-0375\/10\/4\/62"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,4,3]]},"references-count":46,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2020,4]]}},"alternative-id":["membranes10040062"],"URL":"https:\/\/doi.org\/10.3390\/membranes10040062","relation":{},"ISSN":["2077-0375"],"issn-type":[{"value":"2077-0375","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,4,3]]}}}