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152. Towards High Performance Metal-Organic Framework-Microporous Polymer Mixed Matrix Membranes: Addressing Compatibility and Limiting Aging by Polymer Doping

Author

Sabetghadam, Anahid, primary, Liu, Xinlei, additional, Orsi, Angelica F., additional, Lozinska, Magdalena M., additional, Johnson, Timothy, additional, Jansen, Kaspar M. B., additional, Wright, Paul A., additional, Carta, Mariolino, additional, McKeown, Neil B., additional, Kapteijn, Freek, additional, and Gascon, Jorge, additional

Published
2018
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154. Platinum Nanoparticle Inclusion into a Carbonized Polymer of Intrinsic Microporosity: Electrochemical Characteristics of a Catalyst for Electroless Hydrogen Peroxide Production

Author

Adamik, Robert, primary, Hernández-Ibáñez, Naiara, additional, Iniesta, Jesus, additional, Edwards, Jennifer, additional, Howe, Alexander, additional, Armstrong, Robert, additional, Taylor, Stuart, additional, Roldan, Alberto, additional, Rong, Yuanyang, additional, Malpass-Evans, Richard, additional, Carta, Mariolino, additional, McKeown, Neil, additional, He, Daping, additional, and Marken, Frank, additional

Published
2018
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158. The synthesis, chain-packing simulation and long-term gas permeability of highly selective spirobifluorene-based polymers of intrinsic microporosity

Author

Bezzu, C. Grazia, primary, Carta, Mariolino, additional, Ferrari, Maria-Chiara, additional, Jansen, Johannes C., additional, Monteleone, Marcello, additional, Esposito, Elisa, additional, Fuoco, Alessio, additional, Hart, Kyle, additional, Liyana-Arachchi, T. P., additional, Colina, Coray M., additional, and McKeown, Neil B., additional

Published
2018
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161. Polymer ultrapermeability from the inefficient packing of 2D chains

Author

Rose, Ian, primary, Bezzu, C. Grazia, additional, Carta, Mariolino, additional, Comesaña-Gándara, Bibiana, additional, Lasseuguette, Elsa, additional, Ferrari, M. Chiara, additional, Bernardo, Paola, additional, Clarizia, Gabriele, additional, Fuoco, Alessio, additional, Jansen, Johannes C., additional, Hart, Kyle E., additional, Liyana-Arachchi, Thilanga P., additional, Colina, Coray M., additional, and McKeown, Neil B., additional

Published
2017
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166. High-Utilisation Nanoplatinum Catalyst (Pt@cPIM) Obtained via Vacuum Carbonisation in a Molecularly Rigid Polymer of Intrinsic Microporosity

Author

Rong, Yuanyang, primary, He, Daping, additional, Malpass-Evans, Richard, additional, Carta, Mariolino, additional, McKeown, Neil B., additional, Gromboni, Murilo F., additional, Mascaro, Lucia H., additional, Nelson, Geoffrey W., additional, Foord, John S., additional, Holdway, Philip, additional, Dale, Sara E. C., additional, Bending, Simon, additional, and Marken, Frank, additional

Published
2016
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167. Toward an Understanding of the Microstructure and Interfacial Properties of PIMs/ZIF-8 Mixed Matrix Membranes

Author

Benzaqui, Marvin, primary, Semino, Rocio, additional, Menguy, Nicolas, additional, Carn, Florent, additional, Kundu, Tanay, additional, Guigner, Jean-Michel, additional, McKeown, Neil B., additional, Msayib, Kadhum J., additional, Carta, Mariolino, additional, Malpass-Evans, Richard, additional, Le Guillouzer, Clément, additional, Clet, Guillaume, additional, Ramsahye, Naseem A., additional, Serre, Christian, additional, Maurin, Guillaume, additional, and Steunou, Nathalie, additional

Published
2016
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169. Correlating Gas Permeability and Young’s Modulus during the Physical Aging of Polymers of Intrinsic Microporosity Using Atomic Force Microscopy

Author

Longo, Mariagiulia, De Santo, Maria Penelope, Esposito, Elisa, Fuoco, Alessio, Monteleone, Marcello, Giorno, Lidietta, Comesaña-Gándara, Bibiana, Chen, Jie, Bezzu, C. Grazia, Carta, Mariolino, Rose, Ian, McKeown, Neil B., and Jansen, Johannes C.

Abstract

The relationship, during physical aging, between the transport properties and Young’s modulus for films of polymers of intrinsic microporosity (PIM) was investigated using pure gas permeability and atomic force microscopy (AFM) in force spectroscopy mode. Excellent agreement of Young’s modulus measured for the archetypal PIM-1 with values obtained by other techniques in the literature, confirms the suitability of AFM force spectroscopy for the rapid and convenient assessment of mechanical properties. Results from different polymers including PIM-1 and five ultrapermeable benzotriptycene-based PIMs provide direct evidence that size selectivity is strongly correlated to Young’s modulus. In addition, film samples of one representative PIM (PIM-DTFM-BTrip) were subjected to both normal physical aging and to accelerated aging by thermal conditioning under vacuum for comparison. Accelerated aging resulted in a similar decrease in permeability and increase in Young’s modulus as normal aging, however, significant differences suggest that thermally induced accelerated aging occurs throughout the bulk of the polymer film whereas normal aging occurs predominantly at the surface of the film. For all PIMs, the increased in film rigidity upon aging led to an increase in gas size selectivity.

Published
2020
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170. Polymer of Intrinsic Microporosity (PIM‐7) Coating Affects Triphasic Palladium Electrocatalysis.

Author

Mahajan, Ankita, Bhattacharya, Swapan K., Rochat, Sébastien, Burrows, Andrew D., Fletcher, Philip J., Rong, Yuanyang, Dalton, Alan B., McKeown, Neil B., and Marken, Frank

Subjects
MICROPOROSITY, OXIDATION-reduction reaction, HYDROGEN evolution reactions, PALLADIUM, CARBON electrodes, POLYMERS, ELECTROPLATING, ELECTROCATALYSIS
Abstract

A film of the polymer of intrinsic microporosity PIM‐7 is coated onto a glassy carbon electrode and the resulting effects on electron transfer reactions are studied for three different types of processes: (i) aqueous solution based, (ii) solid state surface immobilised, and (iii) electrocatalytic processes on electrodeposited palladium. The effects on reactivity for hydroquinone oxidation in aqueous phosphate buffer are shown to be linked to microporosity causing a slightly lower rate of mass transport without detrimental effects on electron transfer and reaction kinetics. Next, water‐insoluble microcrystalline anthraquinone is immobilised directly into the PIM‐7 film and shown to give a chemically reversible reduction process, which is enhanced in the presence of PIM‐7, when compared to the case of anthraquinone immobilised directly onto bare glassy carbon. Electrodeposition of a film of nano‐palladium is demonstrated to give catalytically active electrodes for the reduction/oxidation of protons/hydrogen, the reduction of oxygen, and for the oxidation of formic acid and methanol. With the PIM‐7 film applied onto palladium, a mechanical stabilisation effect occurs. In addition, both the hydrogen insertion and the hydrogen evolution reactions as well as formic acid oxidation are enhanced. Effects are discussed in terms of PIM‐7 beneficially affecting the interfacial reaction under triphasic conditions. The microporous polymer acts as an interfacial "gas management" layer. [ABSTRACT FROM AUTHOR]

Published
2019
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171. Triphasic Nature of Polymers of Intrinsic Microporosity Induces Storage and Catalysis Effects in Hydrogen and Oxygen Reactivity at Electrode Surfaces.

Author

Madrid, Elena, Lowe, John P., Msayib, Kadhum J., McKeown, Neil B., Song, Qilei, Attard, Gary A., Düren, Tina, and Marken, Frank

Subjects
ELECTROCHEMICAL analysis, CHEMICAL reactions, OXIDATION-reduction reaction, ELECTRODES, OXYGEN reduction
Abstract

Hydrogen oxidation and oxygen reduction are two crucial energy conversion reactions, which are shown to be both strongly affected by the presence of intrinsically microporous polymer coatings on electrodes. Polymers of intrinsic microporosity (PIMs) are known to possess extremely high internal surface area and ability to bind gases under dry conditions. It is shown here that both, hydrogen‐ and oxygen gas binding into PIMs, also occurs under wet or "triphasic" conditions in aqueous electrolyte environments (when immersed in 0.01 M phosphate buffer at pH 7). For two known PIM materials (PIM‐1 and PIM‐PY), nanoparticles are formed by an anti‐solvent precipitation protocol and then cast as a film onto platinum or glassy carbon electrodes. Voltammetry experiments reveal evidence for hydrogen and oxygen binding. Both, PIM‐1 and PIM‐PY, locally store hydrogen or oxygen gas at the electrode surface and thereby significantly affect electrocatalytic reactivity. The onset of oxygen reduction on glassy carbon is shifted by 0.15 V in the positive direction. One for three: Due to their hydrophobic and molecularly rigid nature, intrinsically microporous polymers affect the conditions for gas|liquid electrolyte|solid electrode triphasic reactions. [ABSTRACT FROM AUTHOR]

Published
2019
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177. pH-induced reversal of ionic diode polarity in 300nm thin membranes based on a polymer of intrinsic microporosity

Author

Rong, Yuanyang, primary, Song, Qilei, additional, Mathwig, Klaus, additional, Madrid, Elena, additional, He, Daping, additional, Niemann, Ralf G., additional, Cameron, Petra J., additional, Dale, Sara E.C., additional, Bending, Simon, additional, Carta, Mariolino, additional, Malpass-Evans, Richard, additional, McKeown, Neil B., additional, and Marken, Frank, additional

Published
2016
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183. Intrinsically Microporous Polymer Retains Porosity in Vacuum Thermolysis to Electroactive Heterocarbon

Author

Rong, Yuanyang, primary, He, Daping, additional, Sanchez-Fernandez, Adrian, additional, Evans, Craig, additional, Edler, Karen J., additional, Malpass-Evans, Richard, additional, Carta, Mariolino, additional, McKeown, Neil B., additional, Clarke, Tomos J., additional, Taylor, Stuart H., additional, Wain, Andrew J., additional, Mitchels, John M., additional, and Marken, Frank, additional

Published
2015
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186. Ultrathin Composite Polymeric Membranes for CO2/N2 Separation with Minimum Thickness and High CO2 Permeance.

Author

BENito, Javier, Sánchez ‐ Laínez, Javier, Zornoza, Beatriz, Martín, Santiago, Carta, Mariolino, Malpass ‐ Evans, Richard, Téllez, Carlos, McKeown, Neil B., Coronas, Joaquín, and Gascón, Ignacio

Subjects
THIN films, POLYMERIC membranes, MICROPOROSITY, SEPARATION of gases, SEDIMENTATION & deposition
Abstract

The use of ultrathin films as selective layers in composite membranes offers significant advantages in gas separation for increasing productivity while reducing the membrane size and energy costs. In this contribution, composite membranes have been obtained by the successive deposition of approximately 1 nm thick monolayers of a polymer of intrinsic microporosity (PIM) on top of dense membranes of the ultra-permeable poly[1-(trimethylsilyl)-1-propyne] (PTMSP). The ultrathin PIM films (30 nm in thickness) demonstrate CO2 permeance up to seven times higher than dense PIM membranes using only 0.04 % of the mass of PIM without a significant decrease in CO2/N2 selectivity. [ABSTRACT FROM AUTHOR]

Published
2017
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187. Highly stable fullerene-based porous molecular crystals with open metal sites

Author

Bezzu, C., Burt, Luke, McMonagle, Charlie, Moggach, Stephen, Kariuki, Benson, Allan, David, Warren, Mark, and McKeown, Neil

Abstract

The synthesis of conventional porous crystals involves building a framework using reversible chemical bond formation, which can result in hydrolytic instability. In contrast, porous molecular crystals assemble using only weak intermolecular interactions, which generally do not provide the same environmental stability. Here, we report that the simple co-crystallization of a phthalocyanine derivative and a fullerene (C60or C70) forms porous molecular crystals with environmental stability towards high temperature and hot aqueous base or acid. Moreover, by using diamond anvil cells and synchrotron single-crystal measurements, stability towards extreme pressure (>4 GPa) is demonstrated, with the stabilizing fullerene held between two phthalocyanines and the hold tightening at high pressure. Access to open metal centres within the porous molecular co-crystal is demonstrated by in situ crystallographic analysis of the chemisorption of pyridine, oxygen and carbon monoxide. This suggests strategies for the formation of highly stable and potentially functional porous materials using only weak van der Waals intermolecular interactions. Porous molecular crystals are easy to fabricate but thought to have limited stability as they are bound by non-covalent interactions. Here, a porous crystal composed of C60and phthalocyanine is demonstrated with stability to heat, acid, base and high pressures.

Published
2019
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190. Polymers of Intrinsic Microporosity

Author

McKeown, Neil B.

Subjects
Article Subject
Abstract

This paper focuses on polymers that demonstrate microporosity without possessing a network of covalent bonds—the so-called polymers of intrinsic microporosity (PIM). PIMs combine solution processability and microporosity with structural diversity and have proven utility for making membranes and sensors. After a historical account of the development of PIMs, their synthesis is described along with a comprehensive review of the PIMs that have been prepared to date. The important methods of characterising intrinsic microporosity, such as gas absorption, are outlined and structure-property relationships explained. Finally, the applications of PIMs as sensors and membranes for gas and vapour separations, organic nanofiltration, and pervaporation are described.

Published
2012
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197. Molecular Modeling and Gas Permeation Properties of a Polymer of Intrinsic Microporosity Composed of Ethanoanthracene and Tröger’s Base Units

Author

Tocci, Elena, primary, De Lorenzo, Luana, additional, Bernardo, Paola, additional, Clarizia, Gabriele, additional, Bazzarelli, Fabio, additional, Mckeown, Neil B., additional, Carta, Mariolino, additional, Malpass-Evans, Richard, additional, Friess, Karel, additional, Pilnáček, Kryštof, additional, Lanč, Marek, additional, Yampolskii, Yuri. P., additional, Strarannikova, Ludmila, additional, Shantarovich, Viktor, additional, Mauri, Michele, additional, and Jansen, Johannes C., additional

Published
2014
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198. Redox reactivity at silver microparticle-glassy carbon contacts under a coating of polymer of intrinsic microporosity (PIM).

Author

He, Daping, Rauwel, Erwan, Malpass-Evans, Richard, Carta, Mariolino, McKeown, Neil, Gorle, Demudu, Anbu Kulandainathan, M., and Marken, Frank

Subjects
SILVER nanoparticles, OXIDATION-reduction reaction, REACTIVITY (Chemistry), CARBON electrodes, OXIDATION
Abstract

Silver microparticles (ca. 1 μm average size clustered into cage-like aggregates of 10-20 μm diameter) are shown to adhere to a glassy carbon electrode surface to give voltammetric current responses, which are considerably enhanced/stabilised when applying a coating with a molecularly rigid polymer of intrinsic microporosity (PIM-EA-TB). In preliminary voltammetric experiments characteristic Ag(0/I) surface oxidation and back-reduction processes are observed in aqueous phosphate buffer (associated with silver phosphate layer formation on the silver surface). In contrast to the oxidation, which is dominated by a nucleation process causing a sharp well-defined current signal, for the back-reduction stochastic current responses are observed possibly associated with density fluctuations in the surrounding liquid phase ('Brownian activation') as an essential part of the mechanism of conversion of surface-oxidised silver back to silver metal. [ABSTRACT FROM AUTHOR]

Published
2017
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199. High-Utilisation Nanoplatinum Catalyst (Pt@cPIM) Obtained via Vacuum Carbonisation in a Molecularly Rigid Polymer of Intrinsic Microporosity.

Author

Rong, Yuanyang, He, Daping, Malpass-Evans, Richard, Carta, Mariolino, McKeown, Neil, Gromboni, Murilo, Mascaro, Lucia, Nelson, Geoffrey, Foord, John, Holdway, Philip, Dale, Sara, Bending, Simon, and Marken, Frank

Abstract

Polymers of intrinsic microporosity (PIM or here PIM-EA-TB) offer a highly rigid host environment into which hexachloroplatinate(IV) anions are readily adsorbed and vacuum carbonised (at 500 °C) to form active embedded platinum nanoparticles. This process is characterised by electron and optical microscopy, atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and electrochemical methods, which reveal that the PIM microporosity facilitates the assembly of nanoparticles of typically 1.0 to 2.5-nm diameter. It is demonstrated that the resulting carbonised 'Pt@cPIM' from drop-cast films of ca. 550-nm average thickness, when prepared on tin-doped indium oxide (ITO), contain not only fully encapsulated but also fully active platinum nanoparticles in an electrically conducting hetero-carbon host. Alternatively, for thinner films (50-250 nm) prepared by spin coating, the particles become more exposed due to additional loss of the carbon host. In contrast to catalyst materials prepared by vacuum-thermolysed hexachloroplatinate(IV) precursor, the platinum nanoparticles within Pt@cPIM retain high surface area, electrochemical activity and high catalyst efficiency due to the molecular rigidity of the host. Data are presented for oxygen reduction, methanol oxidation and glucose oxidation, and in all cases, the high catalyst surface area is linked to excellent catalyst utilisation. Robust transparent platinum-coated electrodes are obtained with reactivity equivalent to bare platinum but with only 1 μg Pt cm (i.e. ~100% active Pt nanoparticle surface is maintained in the carbonised microporous host). [ABSTRACT FROM AUTHOR]

Published
2017
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