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Polymers of Intrinsic Microporosity (PIMs) are recognized as promising polymers for active separation of organic pollutants. These highly porous and solution-processable polymers could be tailored to remove specific targets from an aqueous system. In this study, PIM-1 powder was modified to amidoxime PIM-1 powder and adsorption of charged dyes which are Methylene Blue (MB, cationic) and Methyl Orange (MO, anionic) from an aqueous system was explored to evaluate the influence of contact time, initial concentration, solution pH and temperature on the removal of dyes. The adsorption reached the equilibrium within three hours in a batch adsorption process for both dyes. Experimental adsorption capacity (qe, exp) of Amidoxime PIM-1 was found as 79.8 mg g−1 and 69.8 mg g−1 for MO and MB, respectively at pH 6 and 298 K. The Amidoxime PIM-1 was also able to remove a mixture of anionic and cationic dyes simultaneously from aqueous system. The removal ability is dependent on the solution pH and the selectivity can be tuned by shifting solution pH such as at low pH (pH 3) anionic dye adsorption is more favourable, while at high pH (pH 10) cationic dye adsorption is preferable. Equilibrium data acquired from batch adsorption experiments have been examined by four two-parameter (Langmuir, Freundlich, Temkin and Dubinin–Radushkevich), four three-parameter (Redlich–Peterson, Sips, Khan and Liu) isotherm models, and by kinetic models such as the pseudo-first-order, the pseudo-second-order, Elovich equation and intraparticle diffusion using non-linear regression technique. Combination of several errors analysis techniques was applied to find the best fitting isotherm and kinetic models. Liu isotherm was the best to define the experimental data and the maximum adsorption capacities (qm) were calculated as 86.7 mg g−1 and 81.3 mg g−1 for MO and MB, respectively at pH 6 and 298 K. Adsorption data have the best consistency with the pseudo-second-order kinetic model. Furthermore, thermodynamic parameters were determined and the experiments suggested that the adsorption of MB and MO onto Amidoxime PIM-1 is a physical, spontaneous and exothermic. [ABSTRACT FROM AUTHOR]

Portable and flexible energy devices demand lightweight and highly efficient catalytic materials for use in energy devices. An efficient water splitting electrocatalyst is considered an ideal future energy source. Well‐aligned high‐surface‐area electrospun polymers of intrinsic microporosity (PIM‐1)‐based nitrogen‐doped carbon nanofibers were prepared as a free‐standing flexible electrode. A non‐noble‐metal catalyst NiOOH/Ni(OH)2 was precisely deposited over flexible free‐standing carbon nanofibers by using atomic layer deposition (ALD). The morphology, high surface area, nitrogen doping, and Ni states synergistically showed a low onset potential (ηHER=−40 and ηOER=290 mV vs. reversible hydrogen electrode), small overpotential at η10 [oxygen evolution reaction (OER)=390.5 mV and hydrogen evolution reaction (HER)=−147 mV], excellent kinetics (Tafel slopes for OER=50 mV dec−1 and HER=41 mV dec−1), and high stability (>16 h) towards water splitting in an alkaline medium (0.1 m KOH). The performance was comparable with that of state‐of‐the‐art noble‐metal catalysts (e.g., Ir/C, Ru/C for OER, and Pt/C for HER). Post‐catalytic characterization with X‐ray photoelectron spectroscopy (XPS) and Raman spectroscopy further proved the durability of the electrode. This study provides insight into the design of 1D‐aligned N‐doped PIM‐1 electrospun carbon nanofibers as a flexible and free‐standing NiOOH/Ni(OH)2 decorated electrode as a highly stable nanocatalyst for water splitting in an alkaline medium. A simple and controlled synthesis of flexible, free‐standing, binder‐free, atomically deposited NiOOH/Ni(OH)2 on well‐aligned N‐doped PIM‐CF and its application towards overall water splitting (i.e., hydrogen evolution reaction and oxygen evolution reaction) in an alkaline medium. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Bead-free and uniform PIM-2 fibers were produced by electrospinning. • Self-standing electrospun PIM-2 fibrous membranes show high surface area. • Fibrous membranes demonstrate significantly high hydrophobicity with a water contact angle of 155 ± 6°. • Fibrous membranes of PIM-2 were employed in effective organic/oil removal. • PIM-2 fibrous membranes show high organic and oil uptake. Abstract Polymers of intrinsic microporosity (PIMs) are increasingly recognized as a potential membrane material for adsorption and separation applications due to their permanent porosity and solution processability. PIM-2 can be produced using commercially available 5,5′,6,6′-Tetrahydroxy-3,3,3′,3′-tetramethyl-1,1′-spirobisindane and decafluorobiphenyl monomers in the powder form. It possesses considerable amount of fluorine in the polymer backbone and this feature could provide significant hydrophobicity to polymer. This research aims to investigate the fabrication of self-standing PIM-2 fibrous membranes by electrospinning method to introduce a useful material for adsorption applications. Electrospinning was performed using tetrachloroethane as a solvent and bead-free, uniform fibers were produced as confirmed by SEM imaging. Average fiber diameter was calculated as 5.5 ± 1.5 μm for a self-standing fibrous membrane of PIM-2. Structural characterization was conducted using FT-IR, NMR and XPS spectroscopies showing the purity of pristine powder and fibrous membrane of PIM-2. Thermal stability of PIM-2 fibrous membrane was investigated using TGA and it shows no discernible weight loss below 450 °C. The porosity of fibrous membrane was investigated by N 2 adsorption/desorption measurements that indicates significant microporosity with ∼600 m2 g−1 BET surface area. In addition, the hydrophobicity of PIM-2 was tested by water contact angle measurements, showing 155 ± 6° WCA, indicating superhydrophobicity owing to rough surface and high fluorine content. Consequently, the combination of straightforward synthesis, solution processability, high thermal stability, high surface area, and superhydrophobicity makes PIM-2 a promising candidate for adsorption applications. Therefore, it was successfully employed in organic and oil adsorption. Fibrous membranes of PIM-2 has shown up to 2200 ± 100% and 1900 ± 100% weight gain after in contact with silicon oil and DMSO respectively. In addition, dense membrane of PIM-2 was prepared by solvent casting method and the uptake ability was compared with fibrous membrane showing that fibrous form is more convenient for liquid adsorption applications. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • PIM-1 was modified by hydroxylamine to amidoxime PIM-1. • Electrospun amidoxime functionalized PIM-1 fibrous membrane was employed in uranyl adsorption. • Fibrous membranes were successfully used in column adsorption processes. • Uranyl adsorption capacity has increased up to 20 times by modification compared to parent PIM-1. Abstract The Polymers of Intrinsic Microporosity (PIM-1) is considered as one of the most promising polymer candidates for adsorption applications owing to its high surface area and the ability to tailor the functionality for the targeted species. This study reports a facile method for the preparation of amidoxime functionalized PIM-1 fibrous membrane (AF-PIM-FM) by electrospinning technique and its practical use for the extraction of U(VI) ions from aqueous systems via column sorption under continuous flow. Fibrous membrane form of amidoxime functionalized PIM-1 (AF-PIM-FM) was prepared by electrospinning method owing to its excellent processability in dimethylformamide. Bead-free and uniform fibers were obtained as confirmed by SEM imaging and average fiber diameter was 1.69 ± 0.34 μm for AF-PIM-FM. In addition, electrospun PIM-1 fibrous membrane (PIM-FM) was prepared as a control group. Structural and thermal characterization of powder and membrane forms of the materials were performed using FT-IR, 1H NMR, XPS, Elemental analyses, TGA, and DSC. The porosity of the samples was measured by N 2 sorption isotherms confirming amidoxime PIM-1 still maintain their porosity after functionalization. Amidoxime functionality along with membrane structure makes AF-PIM-FM a promising material for uranyl adsorption. First, a comparison between powder and membrane form of amidoxime functionalized PIM-1 was investigated using batch adsorption process. Although membrane form has shown slightly lower adsorption performance in the batch adsorption process, the advantage of using the membrane in column adsorption processes makes membrane form more feasible for real applications. In addition, amidoxime modification enhanced the uranium adsorption ability of PIM-FM up to 20 times. The effect of initial concentration and pH were investigated along with regeneration of the adsorbents. AF-PIM-FM was successfully used for five adsorption-desorption cycles without having any damage on the fibrous structure. [ABSTRACT FROM AUTHOR]

Polymers of Intrinsic Microporosity (PIM-1) is a promising material for adsorption and separation applications. While PIM-1 displays high affinity for neutral species, it shows lack of interaction with charged molecules in an aqueous system due to non-polar nature of it. Functionalization of PIM-1 provides an advantage of tailoring the interaction ability as well as the adsorption performance of PIM-1 towards target pollutants. In this study, electrospun Polymer of Intrinsic Microporosity (PIM-1) fibrous membrane (PIM-FM) was reacted with borane dimethyl sulfide complex to obtain amine modified PIM-1 fibrous membrane (AM-PIM-FM). Furthermore, PIM-1 film, which is referred as PIM-1 dense membrane (PIM-DM), was also modified under the same conditions as a control material. Structural analyses have confirmed that nitrile groups of PIM-1 have been fully converted to amine group as a result of the reduction reaction. Average fiber diameter of parent PIM-1 fibers was found 2.3 ± 0.3 μm, and it remained almost the same after the amine modification. In addition, no physical damage has been observed on fiber structure based on the SEM analysis. Both amine modified PIM-1 dense and fibrous membranes became insoluble in common organic solvents. Before the modification, water contact angle of PIM-FM was 138 ± 2° which also remained almost the same after the modification, showing water contact angle of 131 ± 8°. The insolubility along with amine functionality make membranes promising materials for adsorption of anionic dyes from wastewater. Here, dye (i.e. Methyl Orange) removal ability of AM-PIM-FM from an aqueous system was investigated and compared with parent PIM-1 (PIM-FM) as well as dense membrane form (AM-PIM-DM). AM-PIM-FM shows extremely higher adsorption capacity than that of PIM-FM and AM-PIM-DM. The maximum adsorption capacity of AM-PIM-FM was found 312.5 mg g −1 for Methyl Orange. Langmuir isotherm model was found more favorable for the adsorption. AM-PIM-FM was employed effectively in continuous adsorption/desorption studies for several times without having any damage on fiber morphology using batch adsorption process. Furthermore, AM-PIM-FM was successfully used as a molecular filter for the removal of methyl orange from an aqueous system. The results indicate that AM-PIM-FM could be a promising adsorbent for removal of anionic molecules from an aqueous system. [ABSTRACT FROM AUTHOR]

Polymers of intrinsic microporosity (PIMs) are among the most promising candidates for the development of novel polymeric gas separation membranes for processes such as carbon capture and storage, natural gas treatment and biogas upgrading. As one of the approaches to optimize their performance, PIMs are functionalized by CO 2 -philic groups to improve the CO 2 separation by the enhancement of specific noncovalent interactions. In this work, we show the preparation of amine-PIM from the archetypal PIM-1, using borane dimethyl sulphide complexes in order to control the degree of conversion. The PIM-1 to amine-PIM-1 conversion was characterized by ATR-IR and NMR analysis. The influence of the amine moiety on the gas transport behaviour was investigated by two complementary techniques: gas permeation measurements by the time lag method and analysis of the sorption kinetics and the equilibrium sorption isotherms by the gravimetric method. Both techniques show that permeability decreases with increasing degree of conversion. The trends in the indirectly calculated solubility confirm those of direct analysis, although quantitative comparison of the two shows fundamental differences. A pressure and temperature study on a fully converted sample indicates that the solution-diffusion model should be expressed in concentration dependent transport parameters to be correct. The experimental work was supported by quantum mechanics studies and by molecular dynamics simulations to confirm the selective non-covalent interaction of CO 2 with the amino groups. [ABSTRACT FROM AUTHOR]

This research aims to investigate the possibility of electrospun fibers from Polymers of Intrinsic Microporosity (PIM-1) as an alternative adsorbent for aniline removal from both air and aqueous solution. Adsorption properties of electrospun PIM-1 fibers were compared with powder and film form of PIM-1. While electrospun PIM-1 nanofibrous mat can adsorb 871 mg g −1 aniline from air, it can also adsorb 78 ± 5.4 mg g −1 aniline from aqueous environment when 50 mg L −1 aniline solution is used. The experimental maximum adsorption capacity of electrospun PIM-1 fibers was found as ( q e ) 138 mg g −1 . Langmuir and Freundlich isotherm models have been studied and Langmuir model found more appropriate for aniline adsorption on electrospun PIM-1 fibers. The study reveals that self-standing electrospun fibrous mat of PIM-1 has shown potential to be used as an efficient adsorbent material for the adsorption of VOCs from air and aqueous system thanks to its fast kinetic and high adsorption capacity. [ABSTRACT FROM AUTHOR]

In this study, the Polymer of Intrinsic Microporosity (PIM-1) was systematically hydrolyzed in the presence of sodium hydroxide by varying the concentration of base, washing procedure and the time of the reaction. The chemical structure analyses confirmed that PIM-1 could be hydrolyzed by 65% up to 99% conversion depending on the synthesis procedure. The hydrolyzed PIM-1 samples have shown improved solubility which facilitates the fabrication of hydrolyzed PIM-1 ultrafine fibers by electrospinning technique. Extensive optimization studies were performed for the electrospinning of uniform and bead-free fibers from hydrolyzed PIM-1 with different degree of hydrolysis (65%, 86%, 94% and 99%). The electrospun hydrolysed PIM-1 fibrous samples have average fiber diameters (AFD) ranging from 0.58 ± 0.15 μm to 1.21 ± 0.15 μm, depending on the polymer concentration and applied electrospinning parameters. After electrospinning, self-standing hydrolyzed PIM-1 fibrous membranes were obtained which is useful as a filtering material for the adsorption of organic dyes from wastewater. Here, the capability of hydrolyzed PIM-1 electrospun fibrous membranes for the removal of dyes from aqueous solutions was investigated by using a batch adsorption process. The maximum adsorption capacity of fully hydrolyzed PIM-1 fibers was found 157 ± 16 mg g − 1 for Methylene Blue and 4 mg g − 1 for Congo red when the adsorption was conducted by 20 mg L − 1 dye solution without using any dilution. Moreover, maximum dye adsorption was also studied by using concentrated Methylene Blue solutions showing up to 272 mg g − 1 adsorption maximum. In addition, the self-standing fibrous hydrolyzed PIM-1 membrane was employed to separate Methylene Blue from an aqueous system by filtration without the necessity of additional driving force. The results indicate that hydrolyzed PIM-1 electrospun nanofibrous membranes can be a promising filtering material for wastewater treatment [ABSTRACT FROM AUTHOR]

Nitrile groups in the polymer of intrinsic microporosity PIM-1 were modified by base-catalysed hydrolysis, by reaction with ethanolamine and diethanolamine, and by reduction to amine, and the products investigated for their ability to take up a range of dyes from aqueous or ethanolic solution. Hydrolysed products exhibited selectivity for cationic over anionic species, while other products showed the reverse selectivity. At low pH, amine-PIM-1 adsorbed more than its own weight of the anionic dyes Orange II and Acid Red I from aqueous solution. It was demonstrated that adsorbed Orange II can be removed with basic ethanol. Mixtures of oppositely charged dyes undergo precipitation, but selective adsorption of one dye leads to dissolution of the other from the precipitate. Thermal treatment of the chemically modified polymers at 300 °C for 48 h in an inert atmosphere led to structural changes that reduced the dye adsorption capacity. On the basis of a combination of thermogravimetric and elemental analysis with ATR-IR and NMR spectroscopy, feasible structures are suggested for the thermally-treated polymers. [ABSTRACT FROM AUTHOR]

[Display omitted] • Electrospun fibrous membranes of PIMs demonstrate promising performance in water treatment applications. • Electrospun PIMs exhibit a great potential in air filtration applications. • Carbon nanofibers produced from electrospun PIMs show unique advantages in electrochemical applications. • Widespread use of electrospun PIMs in various applications will be possible in the future. Polymers of Intrinsic Microporosity (PIMs) are increasingly recognized as membrane materials for molecular separation applications due to their unique structural and functional properties. Development of electrospun PIMs further improved the practical use of PIM polymers. PIM nanofibers produced by electrospinning could be an effective membrane material to handle various environmental concerns owing to their high surface area, high hydrophobicity and high adsorption abilities. In addition, highly selective electrospun PIMs could be produced by simple modification methods to obtain specific interactions with desired species. Versatility of electrospun PIMs provides a unique advantage of producing various novel fibrous membranes by electrospinning method for a range of potential applications. Therefore, this review aims to discuss the recent progress of electrospun PIMs, their properties and future directions in various applications. [ABSTRACT FROM AUTHOR]

Synthesis of nitrogen-doped carbon fibers (CF) has been proved to be one of the most promising oxygen reduction reaction (ORR) catalysts which can replace the state-of-art Pt catalyst for non-noble metal-free light-weight devices. Polymers of Intrinsic Microporosity (PIM-1) is soluble in common organic solvents and can be tailored by functionalization owing to nitrile groups in the backbone. PIM-1 was functionalized to amide (hydrolyzed PIM-1), amine and amidoxime groups. The modified PIM-1s were electrospun into ultrafine fibers and pyrolyzed to obtain CF. The present article investigates the influence of different functional groups on the properties of PIM-1 based CF and their nitrogen-doping. Particularly, their ORR performance has been evaluated. Interestingly, CF from hydrolyzed PIM-1 have the highest pore volume with small pore size among the CF based on PIM-1, amine and amidoxime PIM-1. The amount of nitrogen-doping in these CF shows the trend according to the functional groups as PIM-1 > amine > amidoxime > amide. Among all these PIM-1 based CF; CF from hydrolyzed PIM-1 has the highest percentage of pyridinic and graphitic nitrogen, furthermore, electrocatalysis revealed that ORR processed through four-electron with the onset potential 985 mV vs. reversible hydrogen electrode (RHE) which is comparable with the standard Pt/C catalysts. Image 1 • Electrospinning of amide, amine and amidoxime based PIM-1 fibers. • Synthesis and characterization of N-doped carbon fibers from electrospun fibers. • Influence of functional groups in the fibers towards oxygen reduction reaction. • Position of nitrogen and conductivity of fibers are crucial towards ORR catalysis. [ABSTRACT FROM AUTHOR]

This manuscript describes the gas separation performance of PIM-2, a partially fluorinated linear copolymer synthesized from 5,5′,6,6′-tetrahydroxy-3,3,3′,3′-tetramethylspirobisindane (TTSBI) and decafluorobiphenyl (DFBP). As one of the early members of the family of polymers of intrinsic microporosity, it had never been tested as a gas separation membrane because of insufficient mechanical resistance. This has been solved only recently, allowing the preparation of robust self-standing films. Molecular modelling studies demonstrated a high fractional free volume (34%) and an elevated surface area (642 m2 g−1), and the latter is in good agreement with experimental BET results. Pure gas permeabilities measured on a fixed-volume time-lag instrument at 1 bar compare well with the results of mixed separation tests on a variable volume setup from 1-6 bar(a). Molecular modelling and independent sorption measurements on a gravimetric sorption balance both show strong dual-mode sorption behaviour, especially for CO 2 and to a lesser extent for CH 4. Temperature-dependent pure gas permeation measurements show typical Arrhenius behaviour, with a clear increase in the activation energy for diffusion with the increasing molecular size of the gas, indicating high size-selectivity. This is in agreement with the highly rigid PIM structure, determined by AFM force spectroscopy measurements. The dual-mode behaviour results in a moderate pressure dependence of the CO 2 permeability and the CO 2 /N 2 and CO 2 /CH 4 selectivity, all slightly decreasing with increasing pressure. The presence of humidity in the gas stream has a remarkable small effect on the membrane performance, which is probably due to the high fluorine content and the consequently low water vapour solubility in the polymer, as confirmed by gravimetric sorption measurements. The manuscript describes an extensive study on the structure-property relationships in PIM-2. Image 1 • Fluorinated PIM-2 forms robust self-standing membranes. • CO 2 /N 2 and CO 2 /CH 4 mixed gas separation data lie close to the 2008 upper bound. • Separation performance is hardly affected by the presence of humidity in the feed gas. • Water sorption is very low due to the hydrophobic nature of the fluoropolymer. • MD simulations show how halogen bond networks enhance the energetic diffusion selectivity. [ABSTRACT FROM AUTHOR]

Polymers of Intrinsic Microporosity (PIMs) are ultra-permeable macromolecules, which can be cast as a dense membrane and exploited in a wide spectrum of applications, particularly for gas separation owing to their extremely large inner surface area, free volume and high gas permeability. While they are mostly intended to serve as membranes for gas separation, in recent years, they have been also employed in water treatment applications owing to their solution processability, which enables the production of fibrous membranes by electrospinning. The fibrous form provides an increase in sorption performance, water permeability and flux for their application in water treatment. However, owing to the low conductivity of PIM-1 solutions in 1,1,2,2-tetrachloroethane (TeCA) that is the ideal solvent for the electrospinning of PIM-1 solutions, a higher polymer concentration is required to produce bead-free fibers. Furthermore, the electrospinning of highly concentrated PIM-1 solutions leads to the formation of microfibers. To tackle these problems, we herein incorporated an ammonium salt (i.e., tetraethylammonium bromide, TEAB) to increase the conductivity of PIM-1 solutions and study the impact of solution conductivity on the electrospinning of PIM-1 solutions. In parallel to the conductivity study, the influence of relative humidity on the electrospinning and morphology of PIM-1 fibers was explored. The addition of TEAB significantly increased the solution conductivity and drastically enhanced the electrospinnability of PIM-1. The electrospinning of PIM-1 solutions (10% (w/v)) in the presence 7.5 wt% TEAB (with respect to PIM-1) led to bead-free fibers, while at the same concentration, electrosprayed beads and droplet splashing were observed in the absence of TEAB. On the other hand, increasing humidity did not influence the electrospinnability of PIM-1 and the fiber texture, however, less fibers were formed in a given time at very high humidity conditions (~80%). Overall, the experimental findings revealed that the addition of the salt drastically enhanced the electrospinnability of PIM-1 solutions owing to the enhanced conductivity and could lead to the formation of very thin PIM-1 fibers with 160 nm in diameter while no significant effect of relative humidity on the electrospinnability of PIM-1 solutions was observed. The influence of solution conductivity and relative humidity on the electrospinning of PIM-1 was studied, and the experimental findings revealed that higher solution conductivity significantly improved the electrospinnability of PIM-1 solutions, while relative humidity had no drastic influence on the electrospinnability of PIM-1. Image 1 • The conductivity of PIM-1 solutions was significantly increased by salt addition. • Higher salt content drastically improved the electrospinnability of PIM-1 solutions. • Very thin PIM-1 fibers with 160 nm in diameter could be produced by salt addition. • Increasing relative humidity did not influence the electrospinnability of PIM-1. • Less fibers were formed at very high humidity conditions (~80%) in a given time. [ABSTRACT FROM AUTHOR]

In this study, thermally crosslinked hydrolyzed polymers of intrinsic microporosity (HPIM)/polybenzoxazine electrospun nanofibrous membranes (NFMs) are successfully produced. The nanofibers having 800 ± 260 to 670 ± 150 nm average fiber diameters from HPIM and blends of HPIM/ benzoxazine (BA‐a) ranging from HPIM:(BA‐a) weight ratio of 9:1 to 2:1 w/w are produced by electrospinning. Self‐standing HPIM/(BA‐a) NFMs are thermally step‐wise cured resulting in crosslinked HPIM/Poly(BA‐a) NFMs. Structural characterization of as‐electrospun HPIM/(BA‐a) and crosslinked HPIM/Poly(BA‐a) NFM is conducted by FT‐IR spectroscopy to trace the ring opening and crosslinking reactions. Elemental analysis and XPS studies show an increase in carbon content and reduction in nitrogen content due to the crosslinking reaction. Decomposition temperature (Td) of HPIM NFM increases from 218 to 270 °C with the crosslinking based on the DSC. DMA analysis shows that the mechanical strength of the NFMs has increased significantly with crosslinking. Young's moduli of HPIM NFM is increased from 16 ± 7 to 67 ± 1 MPa for crosslinked HPIM/Poly(BA‐a)%33 NFM. Similarly, higher storage modulus is observed for HPIM/Poly(BA‐a) NFMs compared to HPIM NFM. The crosslinked HPIM/Poly(BA‐a) NFMs keep their fibrous morphology after solvent treatment in dimethylformamide revealing their structural stability compared to pristine HPIM NFM. Electrospun hydrolyzed polymers of intrinsic microporosity (HPIM) nanofibrous membranes (NFMs) are successfully crosslinked with benzoxazine monomer (BA‐a) to improve mechanical, thermal, and structural properties of the HPIM NFM. [ABSTRACT FROM AUTHOR]

Nitrile groups in the polymer ofintrinsic microporosity PIM-1were reduced to primary amines using borane complexes. In adsorptionexperiments, the novel amine–PIM-1 showed higher CO2uptake and higher CO2/N2sorption selectivitythan the parent polymer, with very evident dual-mode sorption behavior.In gas permeation with six light gases, the individual contributionsof solubility and diffusion to the overall permeability was determinedvia time-lag analysis. The high CO2affinity drasticallyrestricts diffusion at low pressures and lowers CO2permeabilitycompared to the parent PIM-1. Furthermore, the size-sieving propertiesof the polymer are increased, which can be attributed to a higherstiffness of the system arising from hydrogen bonding of the aminegroups. Thus, for the H2/CO2gas pair, whereasPIM-1 favors CO2, amine–PIM-1 shows permselectivitytoward H2, breaking the Robeson 2008 upper bound. [ABSTRACT FROM AUTHOR]