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Showing papers on "Membrane published in 2016"


Journal ArticleDOI
TL;DR: The mouse I105N/human I104N mutation, which has been shown to prevent macrophage pyroptosis, attenuated both cell killing by p30 in a 293T transient overexpression system and membrane permeabilization in vitro, suggesting that the mutants are actually hypomorphs, but must be above certain concentration to exhibit activity.
Abstract: Gasdermin-D (GsdmD) is a critical mediator of innate immune defense because its cleavage by the inflammatory caspases 1, 4, 5, and 11 yields an N-terminal p30 fragment that induces pyroptosis, a death program important for the elimination of intracellular bacteria. Precisely how GsdmD p30 triggers pyroptosis has not been established. Here we show that human GsdmD p30 forms functional pores within membranes. When liberated from the corresponding C-terminal GsdmD p20 fragment in the presence of liposomes, GsdmD p30 localized to the lipid bilayer, whereas p20 remained in the aqueous environment. Within liposomes, p30 existed as higher-order oligomers and formed ring-like structures that were visualized by negative stain electron microscopy. These structures appeared within minutes of GsdmD cleavage and released Ca(2+) from preloaded liposomes. Consistent with GsdmD p30 favoring association with membranes, p30 was only detected in the membrane-containing fraction of immortalized macrophages after caspase-11 activation by lipopolysaccharide. We found that the mouse I105N/human I104N mutation, which has been shown to prevent macrophage pyroptosis, attenuated both cell killing by p30 in a 293T transient overexpression system and membrane permeabilization in vitro, suggesting that the mutants are actually hypomorphs, but must be above certain concentration to exhibit activity. Collectively, our data suggest that GsdmD p30 kills cells by forming pores that compromise the integrity of the cell membrane.

641 citations


Journal ArticleDOI
TL;DR: In this paper, a review of the advances since 2012 on high permeability polymeric membrane materials for CO2 separations is presented, which includes both polymeric membranes and polymer-inorganic hybrid membranes.
Abstract: Membrane processes have evolved as a competitive approach in CO2 separations compared with absorption and adsorption processes, due to their inherent attributes such as energy-saving and continuous operation. High permeability membrane materials are crucial to efficient membrane processes. Among existing membrane materials for CO2 separations, polymer-based materials have some intrinsic advantages such as good processability, low price and a readily available variety of materials. In recent years, enormous research effort has been devoted to the use of membrane technology for CO2 separations from diverse sources such as flue gas (mainly N2), natural gas (mainly CH4) and syngas (mainly H2). Polymer-based membrane materials occupy the vast majority of all the membrane materials. For large-scale CO2 separations, polymer-based membrane materials with high CO2 permeability and good CO2/gas selectivity are required. In 2012, we published a Perspective review in Energy & Environmental Science on high permeability polymeric membrane materials for CO2 separations. Since then, more rapid progress has been made and the research focus has changed significantly. This review summarises the advances since 2012 on high permeability polymer-based membrane materials for CO2 separations. The major features of this review are reflected in the following three aspects: (1) we cover polymer-based membrane materials instead of purely polymeric membrane materials, which encompass both polymeric membranes and polymer–inorganic hybrid membranes. (2) CO2 facilitated transport membrane materials are presented. (3) Biomimetism and bioinspired membrane concepts are incorporated. A number of representative examples of recent advances in high permeability polymer-based membrane materials is highlighted with some critical analysis, followed by a brief perspective on future research and development directions.

571 citations


Journal ArticleDOI
TL;DR: These are the latest ground-breaking studies in 2D-material membranes as nanosheet and laminar membranes, with a focus on starting materials, nanostructures, and transport properties.
Abstract: Two-dimensional (2D) materials of atomic thickness have emerged as nano-building blocks to develop high-performance separation membranes that feature unique nanopores and/or nanochannels. These 2D-material membranes exhibit extraordinary permeation properties, opening a new avenue to ultra-fast and highly selective membranes for water and gas separation. Summarized in this Minireview are the latest ground-breaking studies in 2D-material membranes as nanosheet and laminar membranes, with a focus on starting materials, nanostructures, and transport properties. Challenges and future directions of 2D-material membranes for wide implementation are discussed briefly.

559 citations


Journal ArticleDOI
TL;DR: It is demonstrated that the discotic nematic phase of graphene oxide (GO) can be shear aligned to form highly ordered, continuous, thin films of multi-layered GO on a support membrane by an industrially adaptable method to produce large-area membranes.
Abstract: Graphene-based membranes demonstrating ultrafast water transport, precise molecular sieving of gas and solvated molecules shows great promise as novel separation platforms; however, scale-up of these membranes to large-areas remains an unresolved problem. Here we demonstrate that the discotic nematic phase of graphene oxide (GO) can be shear aligned to form highly ordered, continuous, thin films of multi-layered GO on a support membrane by an industrially adaptable method to produce large-area membranes (13 × 14 cm(2)) in 90%) for charged and uncharged organic probe molecules with a hydrated radius above 5 A as well as modest (30-40%) retention of monovalent and divalent salts. The highly ordered graphene sheets in the plane of the membrane make organized channels and enhance the permeability (71 ± 5 l m(-2) hr(-1) bar(-1) for 150 ± 15 nm thick membranes).

548 citations


Journal ArticleDOI
TL;DR: The latest developments on understanding mass transport through graphene-based membranes, including perfect graphene lattice, nanoporous graphene and graphene oxide membranes are reviewed here in relation to their potential applications to enable researchers to better understand the mass-transport mechanism.
Abstract: Significant achievements have been made on the development of next-generation filtration and separation membranes using graphene materials, as graphene-based membranes can afford numerous novel mass-transport properties that are not possible in state-of-art commercial membranes, making them promising in areas such as membrane separation, water desalination, proton conductors, energy storage and conversion, etc. The latest developments on understanding mass transport through graphene-based membranes, including perfect graphene lattice, nanoporous graphene and graphene oxide membranes are reviewed here in relation to their potential applications. A summary and outlook is further provided on the opportunities and challenges in this arising field. The aspects discussed may enable researchers to better understand the mass-transport mechanism and to optimize the synthesis of graphene-based membranes toward large-scale production for a wide range of applications.

520 citations


Journal ArticleDOI
TL;DR: In this paper, a review of nanocomposite membranes that are made by incorporating nanoparticles (NPs) into polymeric membrane matrix by different methods like coating, blending, and deposition is presented.

475 citations


Journal ArticleDOI
TL;DR: In this article, a hybrid membrane made from protein amyloid fibrils and activated porous carbon is used to remove heavy metal ions and radioactive waste from water, and the performance of the membrane is enabled by the ability of the amyloids to selectively absorb heavy metal pollutants from solutions.
Abstract: Industrial development, energy production and mining have led to dramatically increased levels of environmental pollutants such as heavy metal ions, metal cyanides and nuclear waste. Current technologies for purifying contaminated waters are typically expensive and ion specific, and there is therefore a significant need for new approaches. Here, we report inexpensive hybrid membranes made from protein amyloid fibrils and activated porous carbon that can be used to remove heavy metal ions and radioactive waste from water. During filtration, the concentration of heavy metal ions drops by three to five orders of magnitude per passage and the process can be repeated numerous times. Notably, their efficiency remains unaltered when filtering several ions simultaneously. The performance of the membrane is enabled by the ability of the amyloids to selectively absorb heavy metal pollutants from solutions. We also show that our membranes can be used to recycle valuable heavy metal contaminants by thermally reducing ions trapped in saturated membranes, leading to the creation of elemental metal nanoparticles and films.

461 citations


Journal ArticleDOI
TL;DR: This work presents supramolecular polymer assemblies resulting from self-assembly of mostly amphiphilic copolymers either as 3D compartments either as polymersomes, PICsomes, peptosomes, or as planar membranes as candidates in applications ranging from drug delivery systems, up to artificial organelles, or active surfaces.
Abstract: Biological membranes play an essential role in living organisms by providing stable and functional compartments, preserving cell architecture, whilst supporting signalling and selective transport that are mediated by a variety of proteins embedded in the membrane. However, mimicking cell membranes – to be applied in artificial systems – is very challenging because of the vast complexity of biological structures. In this respect a highly promising strategy to designing multifunctional hybrid materials/systems is to combine biological molecules with polymer membranes or to design membranes with intrinsic stimuli-responsive properties. Here we present supramolecular polymer assemblies resulting from self-assembly of mostly amphiphilic copolymers either as 3D compartments (polymersomes, PICsomes, peptosomes), or as planar membranes (free-standing films, solid-supported membranes, membrane-mimetic brushes). In a bioinspired strategy, such synthetic assemblies decorated with biomolecules by insertion/encapsulation/attachment, serve for development of multifunctional systems. In addition, when the assemblies are stimuli-responsive, their architecture and properties change in the presence of stimuli, and release a cargo or allow “on demand” a specific in situ reaction. Relevant examples are included for an overview of bioinspired polymer compartments with nanometre sizes and membranes as candidates in applications ranging from drug delivery systems, up to artificial organelles, or active surfaces. Both the advantages of using polymer supramolecular assemblies and their present limitations are included to serve as a basis for future improvements.

446 citations


Journal ArticleDOI
TL;DR: A thin-film nanocomposite (TFN) membrane containing graphene oxide (GO) nanosheets was prepared by the in-situ interfacial polymerization process as mentioned in this paper.

425 citations


Journal ArticleDOI
TL;DR: In this article, the authors reviewed the research and development of polymeric pervaporation membranes from the perspective of membrane fabrication procedures and materials, and showed that the membrane is one of the crucial factors in determining the overall efficiency of separation process.

411 citations


Journal ArticleDOI
TL;DR: The latest advances in the field of zeolitic membranes for gas separation are critically reviewed with special emphasis on new synthetic protocols in this paper, and various approaches to either limit defect formation or decrease their adverse effect by post-synthesis modification.

Journal ArticleDOI
TL;DR: In this article, the authors present details of recent research progress on CO2 separation membranes and membrane processes using ionic liquids (ILs) over the past few years, including supported ionic liquid membranes (SILMs), poly(ionic liquid) membranes (PILMs) and membrane absorption processes based on ILs.

Journal ArticleDOI
TL;DR: In this paper, the TiO2 nanoparticles were directly anchored on the surface of poly(vinylidene fluoride) (PVDF) membrane, making the intrinsic hydrophobic polymer membrane become hydrophilic, what's more, the mussel inspired method was modified by introducing a silane coupling agent KH550, the ability to bind nanoparticles was retained and the as-prepared membrane turn from a common hydrophic state to superhydrophilic state.

Journal ArticleDOI
TL;DR: It is demonstrated for the first time that a metal- organic framework can be grown on the covalent-organic framework (COF) membrane to fabricate COF-MOF composite membranes, which demonstrate higher separation selectivity of H2/CO2 gas mixtures than the individual COF and MOF membranes.
Abstract: The search for new types of membrane materials has been of continuous interest in both academia and industry, given their importance in a plethora of applications, particularly for energy-efficient separation technology. In this contribution, we demonstrate for the first time that a metal–organic framework (MOF) can be grown on the covalent-organic framework (COF) membrane to fabricate COF-MOF composite membranes. The resultant COF-MOF composite membranes demonstrate higher separation selectivity of H2/CO2 gas mixtures than the individual COF and MOF membranes. A sound proof for the synergy between two porous materials is the fact that the COF-MOF composite membranes surpass the Robeson upper bound of polymer membranes for mixture separation of a H2/CO2 gas pair and are among the best gas separation MOF membranes reported thus far.

Journal ArticleDOI
TL;DR: In this article, a composite material consisting of nanocrystals of metal-organic frameworks dispersed within a high-performance polyimide was proposed to reduce chain mobility of the polymer while simultaneously boosting membrane separation performance.
Abstract: The implementation of membrane-based separations in the petrochemical industry has the potential to reduce energy consumption significantly relative to conventional separation processes. Achieving this goal, however, requires the development of new membrane materials with greater selectivity, permeability and stability than available at present. Here, we report composite materials consisting of nanocrystals of metal-organic frameworks dispersed within a high-performance polyimide, which can exhibit enhanced selectivity for ethylene over ethane, greater ethylene permeability and improved membrane stability. Our results suggest that framework-polymer interactions reduce chain mobility of the polymer while simultaneously boosting membrane separation performance. The increased stability, or plasticization resistance, is expected to improve membrane utility under real process conditions for petrochemical separations and natural gas purification. Furthermore, this approach can be broadly applied to numerous polymers that encounter aggressive environments, potentially making gas separations possible that were previously inaccessible to membranes.


Journal ArticleDOI
TL;DR: This review summarizes the antifouling mechanisms of zwitterionic materials inspired by cell membranes as well as the popular approaches to incorporate them onto membrane surfaces to form a comprehensive knowledge about the principles and methods of modifying membrane surfaces with zwatterionic materials.

Journal ArticleDOI
TL;DR: Li10GeP2S12 (LGPS) is incorporated into polyethylene oxide (PEO) matrix to fabricate composite solid polymer electrolyte (SPE) membranes.

Journal ArticleDOI
Bo Jiang1, Lantao Wu1, Lihong Yu2, Xinping Qiu1, Jingyu Xi1 
TL;DR: In this paper, a series of commercial Nafion membranes (equivalent weight of 1100 grams −1 ) with thickness of 50μm, 88μm and 125μm were selected to investigate the thickness impact on the performance of vanadium redox flow battery (VRFB).

Journal ArticleDOI
26 Oct 2016-Polymer
TL;DR: In this article, a review article describes research on different methods for manufacturing polymeric NF membranes, including the composite structure, monomeric and polymeric reactants employed to endow specific characteristics, and additives used to influence the reaction.

Journal ArticleDOI
28 Apr 2016-Nature
TL;DR: Hydrocarbon fuel-cell membranes with surface nanocrack coatings operated at intermediate temperatures show improved electrochemical performance, and coated reverse-electrodialysis membranes show enhanced ionic selectivity with low bulk resistance.
Abstract: The regulation of water content in polymeric membranes is important in a number of applications, such as reverse electrodialysis and proton-exchange fuel-cell membranes. External thermal and water management systems add both mass and size to systems, and so intrinsic mechanisms of retaining water and maintaining ionic transport in such membranes are particularly important for applications where small system size is important. For example, in proton-exchange membrane fuel cells, where water retention in the membrane is crucial for efficient transport of hydrated ions, by operating the cells at higher temperatures without external humidification, the membrane is self-humidified with water generated by electrochemical reactions. Here we report an alternative solution that does not rely on external regulation of water supply or high temperatures. Water content in hydrocarbon polymer membranes is regulated through nanometre-scale cracks ('nanocracks') in a hydrophobic surface coating. These cracks work as nanoscale valves to retard water desorption and to maintain ion conductivity in the membrane on dehumidification. Hydrocarbon fuel-cell membranes with surface nanocrack coatings operated at intermediate temperatures show improved electrochemical performance, and coated reverse-electrodialysis membranes show enhanced ionic selectivity with low bulk resistance.

Journal ArticleDOI
TL;DR: In this paper, the authors reviewed recent advances in different polymer-based reverse osmosis (RO) and forward osmotic (FO) desalination membranes in terms of materials and strategies developed for improving properties and performances.

Journal ArticleDOI
TL;DR: Solvated reduced graphene oxide membranes show high rejections to small molecules with charges the same as that of S-rGO coatings or neutral molecules larger than 3.4 nm, while retaining their high permeances to organic solvents.
Abstract: Solvated reduced graphene oxide (S-rGO) membranes are stable in organic solvents, and strong acidic, alkaline, or oxidative media. They show high rejections to small molecules with charges the same as that of S-rGO coatings or neutral molecules larger than 3.4 nm, while retaining their high permeances to organic solvents.

Journal ArticleDOI
TL;DR: This work establishes an atomic-level understanding of the effects of additional NPG layers, layer separation, and pore alignment on desalination performance, providing useful guidelines for the design of multilayer NPG membranes.
Abstract: While single-layer nanoporous graphene (NPG) has shown promise as a reverse osmosis (RO) desalination membrane, multilayer graphene membranes can be synthesized more economically than the single-layer material. In this work, we build upon the knowledge gained to date toward single-layer graphene to explore how multilayer NPG might serve as a RO membrane in water desalination using classical molecular dynamic simulations. We show that, while multilayer NPG exhibits similarly promising desalination properties to single-layer membranes, their separation performance can be designed by manipulating various configurational variables in the multilayer case. This work establishes an atomic-level understanding of the effects of additional NPG layers, layer separation, and pore alignment on desalination performance, providing useful guidelines for the design of multilayer NPG membranes.

Journal ArticleDOI
TL;DR: In this paper, a polyethersulfone (PES)-based mixed matrix nanofiltration membrane was developed by blending with partially reduced graphene oxide (rGO)/TiO 2 nanocomposite.

Journal ArticleDOI
TL;DR: A judicious assessment of the CO2 separation efficiency of different membranes is provided, and breakthroughs and key challenges in this field are highlighted.
Abstract: During the past decade, significant advances in ionic liquid-based materials for the development of CO2 separation membranes have been accomplished. This review presents a perspective on different strategies that use ionic liquid-based materials as a unique tuneable platform to design task-specific advanced materials for CO2 separation membranes. Based on compilation and analysis of the data hitherto reported, we provide a judicious assessment of the CO2 separation efficiency of different membranes, and highlight breakthroughs and key challenges in this field. In particular, configurations such as supported ionic liquid membranes, polymer/ionic liquid composite membranes, gelled ionic liquid membranes and poly(ionic liquid)-based membranes are detailed, discussed and evaluated in terms of their efficiency, which is attributed to their chemical and structural features. Finally, an integrated perspective on technology, economy and sustainability is provided.

Journal ArticleDOI
TL;DR: In this paper, a thorough investigation was carried out to understand the underlying phenomena in the membrane formation kinetics during the thermally induced phase separation (TIPS) process, which can be tailored to control the mechanical properties, pore size distribution, and flux of the prepared membranes.

Journal ArticleDOI
TL;DR: In this article, a novel graphene oxide/TiO2-polyvinylidene fluoride hybrid ultrafiltration membrane has been successfully developed via the phase inversion technique by supplementing with GO and TiO2 nanocomposites.

Journal ArticleDOI
Zhenggong Wang1, Dong Wang1, Shenxiang Zhang1, Liang Hu1, Jian Jin1 
TL;DR: The overall separation performance of the designed MOF/PI mixed matrix membranes surpasses the state-of-the-art 2008 Robeson upper bound for the H2 /CH4 and H1 /N2 gas pairs and approaches the 2008 upper bound.
Abstract: High-performance metal-organic framework (MOF)/polyimide (PI) mixed matrix membranes (MMMs) are fabricated by a facile strategy by designing the MOF/PI matrix interface via poly dopamine coating. The overall separation performance of the designed MMMs surpasses the state-of-the-art 2008 Robeson upper bound for the H2 /CH4 and H2 /N2 gas pairs and approaches the 2008 upper bound for the O2 /N2 gas pair.

Journal ArticleDOI
TL;DR: The structure-function relationship for a family of antimicrobial peptides from the skin of Australian tree frogs is discussed and compared with that of peptide toxins from bee and Australian scorpion venoms, and cell-penetrating peptides (CPPs), which translocate through the membrane without compromising its integrity, are discussed.
Abstract: ConspectusThe structure–function relationship for a family of antimicrobial peptides (AMPs) from the skin of Australian tree frogs is discussed and compared with that of peptide toxins from bee and Australian scorpion venoms. Although these membrane-active peptides induce a similar cellular fate by disrupting the lipid bilayer integrity, their lytic activity is achieved via different modes of action, which are investigated in relation to amino acid sequence, secondary structure, and membrane lipid composition. In order to better understand what structural features govern the interaction between peptides and lipid membranes, cell-penetrating peptides (CPPs), which translocate through the membrane without compromising its integrity, are also discussed.AMPs possess membrane lytic activities that are naturally designed to target the cellular membrane of pathogens or competitors. They are extremely diverse in amino acid composition and often show specificity against a particular strain of microbe. Since our an...