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Porous organic polymers (POPs), a versatile class of materials that possess many tunable properties such as high chemical absorptivity and ionic conductivity, are emerging candidate electrode materials, permselective membranes, ionic conductors, interfacial stabilizers and functional precursors to synthesize advanced porous carbon. Based on their crystal structure features, the emerging POPs can be classified into two subclasses: amorphous POPs (hyper cross-linked polymers, polymers with intrinsic microporosity, conjugated microporous polymers, porous aromatic frameworks

For the first time, we demonstrate the utilization of covalent organic framework (COF) membranes for efficient ethylene/ethane separation.

Electrochemical CO

The construction of robust (quasi)-solid-state electrolyte (SSE) for flexible lithium-metal batteries is desirable but extremely challenging. Herein, a novel, flexible, and robust quasi-solid-state electrolyte (QSSE) with a "tree-trunk" design is reported for ultralong-life lithium-metal batteries (LMBs). An in-situ-grown metal-organic framework (MOF) layer covers the cellulose-based framework to form hierarchical ion-channels, enabling rapid ionic transfer kinetics and excellent durability. A conductivity of 1.36 × 10

Electrochemical CO2 reduction (CO2RR) using renewable energy sources represents a sustainable means of producing carbon-neutral fuels. Unfortunately, low energy efficiency, poor product selectivity, and rapid deactivation are among the most intractable challenges of CO2RR electrocatalysts. Here, we strategically propose a "two ships in a bottle" design for ternary Zn-Ag-O catalysts, where ZnO and Ag phases are twinned to constitute an individual ultrafine nanoparticle impregnated inside nanopores of an ultrahigh-surface-area carbon matrix. Bimetallic electron configurations are modulated by constructing a Zn-Ag-O interface, where the electron density reconfiguration arising from electron delocalization enhances the stabilization of the *COOH intermediate favorable for CO production, while promoting CO selectivity and suppressing HCOOH generation by altering the rate-limiting step toward a high thermodynamic barrier for forming HCOO*. Moreover, the pore-constriction mechanism restricts the bimetallic particles to nanosized dimensions with abundant Zn-Ag-O heterointerfaces and exposed active sites, meanwhile prohibiting detachment and agglomeration of nanoparticles during CO2RR for enhanced stability. The designed catalysts realize 60.9% energy efficiency and 94.1 ± 4.0% Faradaic efficiency toward CO, together with a remarkable stability over 6 days. Beyond providing a high-performance CO2RR electrocatalyst, this work presents a promising catalyst-design strategy for efficient energy conversion.

The implementation of mixed matrix membranes (MMMs) for sub-angstrom scale gas separations remains a grand challenge. Herein, a series of analogous mixed matrix membrane (AMMMs) were constructed via molecular-level hybridization by utilizing a reactive ionic liquid (RIL) as the continuous phase and graphene quantum dots (GQD) as nanofiller for sub-angstrom scale ethylene/ethane (0.416 nm/0.443 nm) separation. With a small number of GQDs (3.5 wt%) embedded in GQD/RIL AMMMs, ethylene permeability soared by 3.1-fold, and ethylene/ethane selectivity simultaneously boosted by nearly 60 % and reached up to 99.5, which outperformed most previously reported state-of-the-art membranes. Importantly, the interfacial pathway structure was visualized and their self-assembly mechanism was revealed, where the non-covalent interactions between RIL and GQDs induced the local arrangement of IL chains to self-assemble into plenty of compact and superfast interfacial pathways, contributing to the combination of superhigh permeability and selectivity.

Zinc-iodine redox flow batteries (ZIFBs) have emerged as promising energy storage systems due to their high-energy density. However, their practical use has been limited by their poor stability, low efficiency and high cost. In this work, we implemented a novel strategy to improve the performance and cyclability of ZIFBs, as well as decrease the chemical cost, by developing and utilizing ammonium-based electrolytes. An ammonium chloride supported zinc-iodine redox flow battery (AC-ZIFB) based on the ammonium iodide/triiodide redox couple was designed, and it achieved a high energy density of 137 Wh L -1 , Coulombic efficiency of ~99%, energy efficiency of ~80%, and a cycle-life of 2500 cycles at a 11-times lower chemical cost than conventional ZIFBs. Such improvements are mainly attributed to the multifunctional roles of cost-effective chemicals utilized in a new decoupled electrolyte design, which mitigates zinc dendrite formation, facilitates anodic and cathodic reaction kinetics and unlocks extra capacity with the primary aid of I 2 C l − formation. This straightforward, yet effective strategy, empowers the AC-ZIFB with excellent potential as a robust and practical redox flow battery and more broadly demonstrates a facile strategy of using multifunctional electrolyte chemistry to achieve a reliable, high-performance, and cost-competitive energy storage system.

The construction of safe and environmentally-benign solid-state electrolytes (SSEs) with intrinsic hydroxide ion-conduction for flexible zinc-air batteries is highly desirable yet extremely challenging. Herein, hierarchically nanostructured CCNF-PDIL SSEs with reinforced concrete architecture are constructed by nanoconfined polymerization of dual-cation ionic liquid (PDIL, concrete) within a robust three-dimensional porous cationic cellulose nanofiber matrix (CCNF, reinforcing steel), where plenty of penetrating ion-conductive channels are formed and undergo dynamic self-rearrangement under different hydrated levels. The CCNF-PDIL SSEs synchronously exhibit good flexibility, mechanical robustness, superhigh ion conductivity of 286.5 mS cm

With the rising level of atmospheric CO

Manufacturing advanced solid-state electrolytes (SSEs) for flexible rechargeable batteries becomes increasingly important but remains grand challenge. The sophisticated structure of robust animal dermis and good water-retention of plant cell in nature grant germane inspirations for designing high-performance SSEs. Herein, tough bioinspired SSEs with intrinsic hydroxide ion (OH

Summary Polysulfide retention and catalysis are currently among the most important factors toward solving much of the technical challenges of lithium-sulfur (Li-S) batteries. Taking advantage of the electronic structure specific to tantalum, we explore the application of amorphous tantalum oxide with oxygen vacancies embedded inside a microporous carbon matrix as an electrocatalyst for the Li-S system. Through a pore-constriction mechanism, the dimensions of tantalum oxide are controlled to be nanosized with abundant polysulfide-retaining and catalytically active sites. High cycle and rate performances were achieved at practically relevant sulfur loadings and electrolyte content. We believe our identification of tantalum as a new catalyst material for Li-S batteries will incite more investigation into the specific selection of transition metals based on their electronic structures. Meanwhile, the “ship in a bottle” strategy will enlighten the structure design for energy conversion and storage systems.

Simultaneously improving energy efficiency (EE) and material stability in electrochemical CO2 conversion remains an unsolved challenge. Among a series of ternary Sn-Ti-O electrocatalysts, 3D ordered mesoporous (3DOM) Sn0.3 Ti0.7 O2 achieves a trade-off between active-site exposure and structural stability, demonstrating up to 71.5 % half-cell EE over 200 hours, and a 94.5 % Faradaic efficiency for CO at an overpotential as low as 430 mV. DFT and X-ray absorption fine structure analyses reveal an electron density reconfiguration in the Sn-Ti-O system. A downshift of the orbital band center of Sn and a charge depletion of Ti collectively facilitate the dissociative adsorption of the desired intermediate COOH* for CO formation. It is also beneficial in maintaining a local alkaline environment to suppress H2 and formate formation, and in stabilizing oxygen atoms to prolong durability. These findings provide a new strategy in materials design for efficient CO2 conversion and beyond.

The notorious shuttling behaviors and sluggish conversion kinetics of the intermediate lithium polysulfides (LPS) are hindering the practical application of lithium sulfur (Li-S) batteries. Herein, an ultrafine, amorphous, and oxygen-deficient niobium pentoxide nanocluster embedded in microporous carbon nanospheres (A-Nb2O5-x@MCS) was developed as a multifunctional sulfur immobilizer and promoter toward superior shuttle inhibition and conversion catalyzation of LPS. The A-Nb2O5-x nanocluster implanted framework uniformizes sulfur distribution, exposes vast active interfaces, and offers a reduced ion/electron transportation pathway for expedited redox reaction. Moreover, the low crystallinity feature of A-Nb2O5-x manipulates the LPS chemical affinity, while the defect chemistry enhances the intrinsic conductivity and catalytic activity for rapid electrochemical conversions. Attributed to these superiorities, A-Nb2O5-x@MCS delivers good Li-S battery performances, that is, high areal capacity of 6.62 mAh cm-2 under high sulfur loading and low electrolyte/sulfur ratio, superb rate capability, and cyclability over 1200 cycles with an ultralow capacity fading rate of 0.024% per cycle. This work provides a synergistic regulation on crystallinity and oxygen deficiency toward rapid and durable sulfur electrochemistry, holding a great promise in developing practically viable Li-S batteries and enlightening material engineering in related energy storage and conversion areas.

Transition-metal carbides (MXenes), multifunctional 2D materials, have caught the interest of researchers in the fabrication of high-performance nanocomposite membranes. However, several issues regarding MXenes still remain unresolved, including low ambient stability; facile restacking and agglomeration; and poor compatibility and processability. To address the aforementioned challenges, we proposed a facile, green, and cost-efficient approach for coating a stable layer of plant-derived polyphenol tannic acid (TA) on the surface of MXene (Ti

Although one of the most mature battery technologies, lithium-ion batteries still have many aspects that have not reached the desired requirements, such as energy density, current density, safety, environmental compatibility, and price. To solve these problems, all-solid-state lithium batteries (ASSLB) based on lithium metal anodes with high energy density and safety have been proposed and become a research hotpot in recent years. Due to the advanced electrochemical properties of 2D materials (2DM), they have been applied to mitigate some of the current problems of ASSLBs, such as high interface impedance and low electrolyte ionic conductivity. In this work, the background and fabrication method of 2DMs are reviewed initially. The improvement strategies of 2DMs are categorized based on their application in the three main components of ASSLBs: The anode, cathode, and electrolyte. Finally, to elucidate the mechanisms of 2DMs in ASSLBs, the role of in situ characterization, synchrotron X-ray techniques, and other advanced characterization are discussed.

Aqueous Zn-ion batteries are well regarded among a next-generation energy-storage technology due to their low cost and high safety. However, the unstable stripping/plating process leading to severe dendrite growth under high current density and low temperature impede their practical application. Herein, it is demonstrated that the addition of 2-propanol can regulate the outer solvation shell structure of Zn

A BN membrane with a distinct nanoconfinement effect toward efficient ethylene/ethane separation is presented. The horizontal and inclined self-assembly of 2D BN nanosheets endow the BN membrane with abundant percolating nanochannels, and these nanochannels are further decorated by reactive ionic liquids (RILs) to tailor their sizes as well as to achieve nanoconfinement effect. The noncovalent interactions between RIL and BN nanosheets favor the ordered alignment of the cations and anions of RIL within BN nanochannels, which contributes to a fast and selective ethylene transport. The resultant membranes exhibit an unprecedented separation performance with superhigh C2 H4 permeance of 138 GPU and C2 H4 /C2 H6 selectivity of 128 as well as remarkably improved long-term stability for 180 h, outperforming reported state-of-the-art membranes.

Electrochemical water splitting, which is economical and sustainable, has been considered as one of the most potential methods to produce large amounts of hydrogen with high purity. However, the de...

The escalating level of atmospheric CO2 is one of the most pressing environmental concerns of our age. The development of advanced materials for efficient CO2 capture and separation is a burgeoning field that has spurred great interest in materials science. Among the contenders in the arena of CO2 adsorption materials, porous carbons have emerged as particularly promising candidates owing to their unique properties suitable for CO2 capture under a wide range of conditions. This review systematically presents the primary design and synthesis strategies of porous carbons and seminal research that has inspired their advancements, with specific emphasis on uncovering their structure–performance relationship in CO2 capture. Moreover, the underlying mechanism of CO2 adsorption over porous carbons with a defined pore texture and surface chemistry is particularly discussed. Finally, the current challenges and future opportunities in developing porous carbons for practical CO2 capture are summarized. This review is intended to serve as a guideline for rational design of tailored porous carbon materials toward high-performance CO2 capture, benefiting both scientists and engineers active in this emerging and potentially world-changing discipline.

A series of functional block copolymers (COPs) was synthesized through the ring-opening polymerization of e-caprolactone (CL) and γ-(carbamic acid benzyl ester)-e-caprolactone (CABCL) monomers at different ratios, and then the effects of the COP additives on the hydrolytic and oxidative degradation and mechanical properties of PCL/COP samples were studied. From characterization using DSC, POM, AFM, WAXD, SAXS, etc., it was demonstrated that the content and distribution of pendant side chains in the COPs can alter the nucleation of macromolecular chains, and then modulate the lamellar thickness and crystallinity of the PCL/COP samples. Such variations of the macromolecular structures result in distinct changes in the mechanical properties during degradation. These results provide useful guidance for the development of ideal materials for biodegradable polymer stents with tunable degradation rates and the desirable evolution of the mechanical properties.

For ethylene/ethane separation, fabrication of facilitated transport membranes (FTMs) with properties of high ethylene permeability, selectivity, long-term stability and economic feasibility remains a great challenge. In this study, a series of deep eutectic solvents (DESs) containing NO3- as anion were designed, synthesized and characterized for the first time. Then, novel DES-FTMs were fabricated successfully through the incorporation of the transport carrier (AgNO3) into as-synthesized DESs. The investigation of structure-performance relationships of FTMs suggested that the hydrogen bond acceptors (HBAs), hydrogen bond donors (HBDs) and their molar ratios greatly manipulated separation performance of FTM, which was also greatly affected by the carrier concentration. The right combinations of HBAs, HBDs and carrier concentration could significantly enhance the ethylene/ethane selectivity up to 125. The operating conditions of the separation process were optimized, confirming ethylene/ethane selectivity increased with the decrease of the transmembrane pressure and operating temperature. The synergetic regulation of hydrogen bond and coordination interactions between DES and carrier could tune the interactions between the silver cation and its counter anion, which efficiently promoted the disassociation of carrier and increased carrier activity, leading to high ethylene permeability and ethylene/ethane selectivity. The Bronsted acidic property of HBAs endowed the FTMs with good stability. The low cost and facile availability of the DESs and carrier rendered FTMs with good economic feasibility. This study may reveal the definite potentiality of DES-FTMs in ethylene/ethane separation.

Electrochemical CO

Mn and N codoped carbon materials are proposed as one of the most promising catalysts for the oxygen reduction reaction (ORR) but still confront a lot of challenges to replace Pt. Herein, a novel gas-phase migration strategy is developed for the scale synthesis of atomically dispersed Mn and N codoped carbon materials (g-SA-Mn) as highly effective ORR catalysts. Porous zeolitic imidazolate frameworks serve as the appropriate support for the trapping and anchoring of Mn-containing gaseous species and the synchronous high-temperature pyrolysis process results in the generation of atomically dispersed Mn-N

Microporous framework membranes such as metal-organic framework (MOF) membranes and covalent organic framework (COF) membranes are constructed by the controlled growth of small building blocks with large porosity and permanent well-defined micropore structures, which can overcome the ubiquitous tradeoff between membrane permeability and selectivity; they hold great promise for the enormous challenging separations in energy and environment fields. Therefore, microporous framework membranes are endowed with great expectations as next-generation membranes, and have evolved into a booming research field. Numerous novel membrane materials, versatile manipulation strategies of membrane structures, and fascinating applications have erupted in the last five years. First, this review summarizes and categorizes the microporous framework membranes with pore sizes lower than 2 nm based on their chemistry: inorganic microporous framework membranes, organic-inorganic microporous framework membranes, and organic microporous framework membranes, where the chemistry, fabrications, and differences among these membranes have been highlighted. Special attention is paid to the membrane structures and their corresponding modifications, including pore architecture, intercrystalline grain boundary, as well as their diverse control strategies. Then, the separation mechanisms of membranes are covered, such as diffusion-selectivity separation, adsorption-selectivity separation, and synergetic adsorption-diffusion-selectivity separation. Meanwhile, intricate membrane design to realize synergistic separation and some emerging mechanisms are highlighted. Finally, the applications of microporous framework membranes for precise gas separation, liquid molecule separation, and ion sieving are summarized. The remaining challenges and future perspectives in this field are discussed. This timely review may provide genuine guidance on the manipulation of membrane structures and inspire creative designs of novel membranes, promoting the sustainable development and steadily increasing prosperity of this field.

All-solid-state lithium ion batteries (ASSLBs) are considered next-generation devices for energy storage due to their advantages in safety and potentially high energy density. As the key component in ASSLBs, solid-state electrolytes (SSEs) with non-flammability and good adaptability to lithium metal anodes have attracted extensive attention in recent years. Among the current SSEs, composite solid-state electrolytes (CSSEs) with multiple phases have greater flexibility to customize and combine the advantages of single-phase electrolytes, which have been widely investigated recently and regarded as promising candidates for commercial ASSLBs. Based on existing investigations, herein, we present a comprehensive overview of the recent developments in CSSEs. Initially, we introduce the historical development from solid-state ionic conductors to CSSEs, and then summarize the fundamentals including mechanisms of lithium ion transport, key evaluation parameters, design principles, and key materials. Four main types of advanced structures for CSSEs are classified and highlighted according to the recent progress. Moreover, advanced characterization and computational simulation techniques including machine learning are reviewed for the first time, and the main challenges and perspectives of CSSEs are also provided for their future development.

Cellular membranes provide ideal archetypes for molecule or ion separations with sub-angstrom scale precision, which are featured with both extremely high permeability and selectivity due to the well-defined membrane protein channels. However, the development of bioinspired membranes with artificial channels for sub-angstrom scale ethylene/ethane (0.416 nm / 0.443 nm) separation remains an uncharted territory and a significant challenge. Herein, a bioinspired nano-ordered liquid membrane is constructed by a facile ion/molecule self-assembly strategy for highly efficient ethylene/ethane separation, which mimics the structure of cellular membrane elegantly and possesses plenty of three-dimensional (3D) nanochannels. The elaborate regulation of non-covalent interactions by optimizing the ion/molecule compositions within membrane confers the nano-ordered liquid structure with interpenetrating and bi-continuous apolar domains and polar domains, which results in the formation of regular carrier wires and enormous 3D interconnected ethylene transport nanochannels. By virtue of these 3D nanochannels, the bioinspired nano-ordered liquid membrane manifests simultaneously super-high selectivity, excellent permeance and long-term stability, which exceeds previously reported ethylene/ethane separation membranes. This methodology in this work for construction of bioinspired membrane with tunable 3D nanochannels through ion/molecule self-assembly will enlighten the design and development of high-performance separation membranes for angstrom/sub-angstrom scale ion or molecule separations.

Efficient olefin/paraffin separation is a grand challenge because of their similar molecular sizes and physical properties, and is also a priority in the modern chemical industry. Membrane separation technology has been demonstrated as a promising technology owing to its low energy consumption, mild operation conditions, tunability of membrane materials, as well as the integration of physical and chemical mechanisms. In this work, inspired by the physical mechanism of mass transport in channel proteins and the chemical mechanism of mass transport in carrier proteins, recent progress in channel‐based and carrier‐based membranes toward olefin/paraffin separations is summarized. Further, channel‐based membranes are categorized into membranes with network structures and with framework structures according to the morphology of channels. The separation mechanisms, separation performance, and membrane stability in channel‐based and carrier‐based membranes are elaborated. Future perspectives toward membrane‐based olefin/paraffin separation are proposed., Recent progress in channel‐based and carrier‐based membranes toward olefin/paraffin separations is summarized. Further, channel‐based membranes are categorized into membranes with network structures and with framework structures according to the morphology of channels. The separation mechanisms, separation performance, and membrane stability in channel‐based and carrier‐based membranes are elaborated. Future perspectives toward membrane‐based olefin/paraffin separation are proposed.

Simultaneously improving energy efficiency (EE) and material stability in electrochemical CO

The notorious shuttling behaviors and sluggish conversion kinetics of the intermediate lithium polysulfides (LPS) are hindering the practical application of lithium sulfur (Li-S) batteries. Herein, an ultrafine, amorphous, and oxygen-deficient niobium pentoxide nanocluster embedded in microporous carbon nanospheres (A-Nb

Water electrolysis represents a promising technology for the production of hydrogen fuels. High-performance and stable non-noble electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) are urgently desired to improve the efficiency of water splitting for large-scale hydrogen production. Herein, a flowerlike heterojunction catalyst composed of N-doped carbon films and Mo2C nanoparticles strongly coupled with ultrasmall Ni or FeNi alloy (Ni-Mo2C/CF or FeNi-Mo2C/CF) is in-situ synthesized for efficient water splitting. The as-prepared samples with unique architecture and composition combine the synergistic effects of both geometric design and electronic modification, possessing plenty of active sites, robust heterostructures, abundant channels for rapid mass transport and electron/ion transfer, and the improved conductivity for high-efficiency charge exchange during electrocatalytic process. The optimized Ni-Mo2C/CF for HER and FeNi-Mo2C/CF for OER achieve overpotentials of 81 and 228 mV to reach 10 mA cm−2, respectively, in 1.0 M KOH. Furthermore, the FeNi-Mo2C/CF(+)//Ni-Mo2C/CF(−) alkaline water electrolyzer demonstrates a low cell voltage of 1.53 V at 10 mA cm−2, outperforming most ever-reported water electrolyzer cells, and impressive stability over 24 h at 50 mA cm−2. This work provides a facile and effective method to construct high-performance and non-precious metal electrocatalysts for commercial water splitting.

Herein, high performance polyethersulfone (PES) membranes were fabricated by introducing a series of imidazole-based deep eutectic solvents (DESs) as functional additives, which could tailor membrane structure due to the synergetic effect between DES components in phase inversion process. The addition of those DESs to the casting solutions all improved membrane porous structure, which contributed to a remarkably enhanced permeability and a high selectivity of the resultant membranes. Especially, the PES membrane with tetrabutylammonium chloride/imidazole as additive had a maximum water flux of 781 L/(m2 h), which was about 6.45 times that of the additive-free membrane, and a high BSA rejection of 97.7% at 2 bar. Moreover, the antifouling performance as well as thermal and mechanical properties of the prepared membranes was investigated. Overall, this work indicates the promise of imidazole-based DESs as alternative pore-forming additives for the fabrication of ultrafiltration membranes with superior performance.

In this work, a superhydrophilic Ti foam was designed and fabricated by applying a novel one-step hydrothermal approach to achieve highly efficient oil in water emulsion separation. Attributed to the synergistic effect of the surface roughness constructed by hierarchical flower-like TiO2 nanostructures and the surface hydrophilicity induced by titanium oxy-fluoride groups, the as-prepared Ti foam exhibited superhydrophilicity and underwater superoleophobicity. The formation of flower-like TiO2 nanostructures was studied and a possible “partial replacement” fluorinated process was proposed. Oil in water emulsion separation test showed that the superhydrophilic Ti foam could handle with various emulsions only under gravity with high separation efficiency over 99%. The separation efficiency remained high even after 20 times of reusing, demonstrating good reusability. More importantly, the superhydrophilic Ti foam could still maintain its wettability after immersed corrosive solutions for 48 h or stored under ambient atmosphere for three months, indicating excellent anti-corrosion property and long-term storage stability. We envision the methodology for the construction of a superhydrophilic surface by a simple and low-cost hydrothermal process will shed light on the Ti-based material design and also pave the way for applications in other fields such as liquid manipulation, fluidic devices and bioadhesion control.

In this work, a novel strategy was reported for improving SO2 capture through multiple-site interactions of N-imidazole derivative. The tris (2-(1-H-imidazole-1-y1)ethyl) amine (TIA) was designed, synthesised and mixed with water to form the mixed absorbents for SO2 absorption. The physical properties were determined and the mixed absorbents exhibited low densities and viscosities, which are beneficial to the mass and heat transfer. The SO2 absorption reached equilibrium rapidly within 60 s and as high as 2.09 mol SO2 per mol TIA could be absorbed at low SO2 concentration (

Deep eutectic solvents (DESs) have been seen as promising absorbents for SO2 capture in recent years. In this work, a series of DESs based on imidazole derivatives were synthesized to investigate the low pressure SO2 absorption. The physical properties were determined, and the DESs exhibited low viscosities and high stability. Effects of composition, operating temperature and pressure, and water content on SO2 absorption capacity were investigated. It was demonstrated that the 1-butyl-3-methylimidazolium chloride (BmimCl):4-methylimidazole (4CH3-Im) (1:2) could absorb 1.42 and 0.189 gSO2/gDES at 101.3 and 1 kPa SO2 partial pressure, respectively, which were higher than most reports to date under this condition. The absorbed SO2 could be released easily under mild condition, and there was no change in absorption performance after 5 cycles. Furthermore, the absorption mechanism studied by FTIR and NMR indicated that the high SO2 absorption capacity originated from the synergistic interaction of BmimCl and 4...

Facilitated transport membranes (FTMs) for olefin/paraffin separations have failed to achieve commercial success due to the instability of carriers although great efforts have been made. In this work, ultra-stable and cost-efficient protic ionic liquid based FTMs (PIL-FTMs) were firstly prepared by utilizing the Bronsted acidic property of PILs to stabilize the carrier. The gas solubility in the carrier/PILs was measured and the separation performances of PIL-FTMs were evaluated systemically. The results indicated that the structure of PILs affected the C2H4 permeability and the presence of ether group and hydroxyl group in PILs significantly enhanced the C2H4/C2H6 selectivity. The carrier concentration led to structural variation of PIL-FTMs, thus manipulating the gas separation performances of PIL-FTMs. The increase of transmembrane pressure decreased C2H4 permeability and C2H4/C2H6 selectivity, indicating a typical feature of FTMs. The increase of temperature increased the C2H4 permeability but decreased C2H4/C2H6 selectivity. The separation performances of PIL-FTMs were much higher than other results in the literature. Furthermore, the PIL-FTMs exhibited excellent stability during the long-term experiments carried out for six months. Finally, the investigation of separation mechanism revealed that the hydrogen-bonding and coordinative interactions between PILs and carrier accounted for the high separation efficiency of PIL-FTMs. In all, the excellent long-term stability, outstanding separation performances and economic feasibility of PIL-FTMs could play an important role in moving these membranes toward industrial application.

With the aim of removing and recycling oil and organic solvent from water, a facile and low-cost crosslinking polymerization method was first applied on surface modification of cotton fabrics for water/oil separation. Micro-nano hierarchical rough structure was constructed by triethylenetetramine (TETA) and trimesoyl chloride (TMC) that formed a polymeric layer on the surface of the fabric and anchored Al2O3 nanoparticles firmly between the fabric surface and the polymer layer. Superhydrophobic property was further obtained through self-assembly grafting of hydrophobic groups on the rough surface. The as-prepared cotton fabric exhibited superoleophilicity in atmosphere and superhydrophobicity both in atmosphere and under oil with the water contact angle of 153° and 152° respectively. Water/oil separation test showed that the as-prepared cotton fabric can handle with various oil-water mixtures with a high separation efficiency over 99%. More importantly, the separation efficiency remained above 98% over 20 cycles of reusing without losing its superhydrophobicity which demonstrated excellent reusability in oil/water separation process. Moreover, the as-prepared cotton fabric possessed good contamination resistance ability and self-cleaning property. Simulation washing process test showed the superhydrophobic cotton fabric maintained high value of water contact angle above 150° after 100 times washing, indicating great stability and durability. In summary, this work provides a brand-new way to surface modification of cotton fabric and makes it a promising candidate material for oil/water separation.

Protic ionic liquids (PILs) were utilized for the fabrication of composite membranes containing silver salt as the C2H4 transport carrier to perform C2H4/C2H6 separation for the first time. The intrinsic nanostructures of PILs were adopted to construct fast and selective C2H4 transport nanochannels. The investigation of structure–performance relationships of composite membranes suggested that transport nanochannels (polar domains of PILs) could be tuned by the sizes of cations, which greatly manipulated activity of the carrier and determined the separation performances of membranes. The role of different carriers in the facilitated transport was studied, which revealed that the PILs were good solvents for dissolution and activation of the carrier due to their hydrogen bond networks and waterlike properties. The operating conditions of separation process were investigated systemically and optimized, confirming C2H4/C2H6 selectivity was enhanced with the increase of silver salt concentration, the flow rate ...