Accurate stacking engineering of MOF nanosheets as membranes for precise H sieving.

Two-dimensional (2D) metal-organic framework (MOF) nanosheet membranes hold promise for exact molecular transfer due to their structural diversity and well-defined in-plane nanochannels. However, achieving precise regulation of stacking modes between neighboring nanosheets in membrane applications and understanding its influence on separation performance remains unrevealed and challenging. Here, we propose a strategy for accurately controlling the stacking modes of MOF nanosheets via linker polarity regulation.

Enhanced Propylene/Propane Separation via Aniline-Decorated ZIF-8 Membrane: Lattice Rigidity Adjustment and Adsorption Site Introduction.

Metal-organic framework (MOF)-based membranes excel in molecular separation, attracting significant research interest. The crystallographic microstructure and selective adsorption capacity of MOFs closely correlate with their gas separation performance. Here, aniline was added to the ZIF-8 synthesis in varying concentrations.

Tuning the Stacking Modes of Ultrathin Two-Dimensional Metal-Organic Framework Nanosheet Membranes for Highly Efficient Hydrogen Separation.

Two-dimensional (2D) metal-organic framework (MOF) membranes are considered potential gas separation membranes of the next generation due to their structural diversity and geometrical functionality. However, achieving a rational structure design for a 2D MOF membrane and understanding the impact of MOF nanosheet stacking modes on membrane separation performance remain challenging tasks. Here, we report a novel kind of 2D MOF membrane based on [Cu Br(IN) ] (IN=isonicotinato) nanosheets and propose that synergetic stacking modes of nanosheets have a significant influence on gas separation performance.

3-Methoxythiophene-Based Indophenine Reaction Generating an Isomeric Dynamic Equilibrium System.

A 3-methoxythiophene-based indophenine reaction with -(2-hexyldecyl)isatin in the presence of concentrated sulfuric acid produces an indophenine cis-trans isomeric dynamic equilibrium system, which is dominated by the (Z,E,Z) configuration with a trace of the (Z,Z,Z) configuration.

Preparation of Carbon Dots from PET Waste by One-step Hydrothermal Method and its Application in Light Blocking Films and LEDs.

An environmentally friendly PET-based Carbon Dots (PET-CDs) with excellent fluorescence properties were prepared with waste PET bottle, pyromellitic acid and ammonia water as raw materials by one-step hydrothermal method. The preparation mechanism of PET-CDs was as follows: PET first underwent ammonolysis reaction to produce terephthalic acid diamide and ethylene glycol, and then dehydrated and carbonized with pyromellitic acid to form PET-CDs. The as-prepared PET-CDs exhibit excitation-independent emission properties in the range from 340 to 440 nm, and the fluorescence quantum yield is as high as 87.

Solvothermal preparation of nitrogen-doped carbon dots with PET waste as precursor and their application in LEDs and water detection.

Developing novel, alternative ways to recycle PET waste, which has an important influence on reduction of landfilling and CO emissions, has always been a research hot spot for industry and academy. In this work, PET waste was adopted as precursor for the preparation of nitrogen-doped Carbon Dots (NCDs). Firstly, PET oligomers were obtained by alcoholysis of PET waste with ethylene glycol.

Ultrathin and Ultrastrong Kevlar Aramid Nanofiber Membranes for Highly Stable Osmotic Energy Conversion.

An ion-selective membrane can directly convert the osmotic energy to electricity through reverse electrodialysis. However, developing an advanced membrane that simultaneously possesses high power density, excellent mechanical strength, and convenient large-scale production for practical osmotic energy conversion, remains challenging. Here, the fabrication of ultrathin and ultrastrong Kevlar aramid nanofiber (KANF) membranes with interconnected three-dimensional (3D) nanofluidic channels via a simple blade coating method is reported.

Supported MXene/GO Composite Membranes with Suppressed Swelling for Metal Ion Sieving.

Novel two-dimensional (2D) membranes have been utilized in water purification or seawater desalination due to their highly designable structure. However, they usually suffer from swelling problems when immersed in solution, which limits their further applications. In this study, 2D cross-linked MXene/GO composite membranes supported on porous polyamide substrates are proposed to improve the antiswelling property and enhance the ion-sieving performance.

A Lamellar MXene (Ti C T )/PSS Composite Membrane for Fast and Selective Lithium-Ion Separation.

A two-dimensional (2D) laminar membrane with Li selective transport channels is obtained by stacking MXene nanosheets with the introduction of poly(sodium 4-styrene sulfonate) (PSS) with active sulfonate sites, which exhibits excellent Li selectivity from ionic mixture solutions of Na , K , and Mg . The Li permeation rate through the MXene@PSS composite membrane is as high as 0.08 mol m  h , while the Li /Mg , Li /Na , and Li /K selectivities are 28, 15.

Flexible Polypropylene-Supported ZIF-8 Membranes for Highly Efficient Propene/Propane Separation.

Metal-organic framework (MOF) membranes have enormous potential in separation applications. There are several MOF membranes grown on polymer substrates aimed for scale-up, but their brittleness hampers any industrial application. Herein, intergrown continuous polypropylene (PP)-supported ZIF-8 membranes have been successfully synthesized via fast current-driven synthesis (FCDS) within 1 h.

Balancing the Grain Boundary Structure and the Framework Flexibility through Bimetallic Metal-Organic Framework (MOF) Membranes for Gas Separation.

Separation is one of the most energy-intensive processes in the chemical industry, and membrane-based separation technology helps to reduce the energy consumption dramatically. Supported metal-organic framework (MOF) layers hold great promise as a molecular sieve membrane, yet only a few MOF membranes showed the expected separation performance. The main reasons include e.

Antibiotics Separation with MXene Membranes Based on Regularly Stacked High-Aspect-Ratio Nanosheets.

The uncontrolled release of antibiotics and pharmaceuticals into the environment is a worldwide increasing problem. Thus, highly efficient treatment technologies for wastewater are urgently needed. In this work, seven kinds of typical antibiotics (including water and alcohol soluble ones) are successfully separated from the corresponding aqueous and ethanolic solutions using highly regular laminated membranes.

Oppositely Charged Ti C T MXene Membranes with 2D Nanofluidic Channels for Osmotic Energy Harvesting.

Membrane-based reverse electrodialysis (RED) is considered as the most promising technique to harvest osmotic energy. However, the traditional membranes are limited by high internal resistance and low efficiency, resulting in undesirable power densities. Herein, we report the combination of oppositely charged Ti C T MXene membranes (MXMs) with confined 2D nanofluidic channels as high-performance osmotic power generators.

Self-Crosslinked MXene (TiCT) Membranes with Good Antiswelling Property for Monovalent Metal Ion Exclusion.

A 2D membrane-based separation technique has been increasingly applied to solve the problem of fresh water shortage via ion rejection. However, these 2D membranes often suffer from a notorious swelling problem when immersed in solution, resulting in poor rejection for the monovalent metal ion. The design of the antiswelling 2D lamellar membranes has been proved to be a big challenge for highly efficient desalination.

Paralyzed membrane: Current-driven synthesis of a metal-organic framework with sharpened propene/propane separation.

Metal-organic framework (MOF) membranes show great promise for propene/propane separation, yet a sharp molecular sieving has not been achieved due to their inherent linker mobility. Here, zeolitic imidazolate framework ZIF-8-type membranes with suppressed linker mobility are prepared by a fast current-driven synthesis (FCDS) strategy within 20 min, showing sharpened molecular sieving for propene/propane separation with a separation factor above 300. During membrane synthesis, the direct current promotes the metal ions and ligands to assemble into inborn-distorted and stiffer frameworks with ZIF-8_Cm (a newly discovered polymorph of ZIF-8) accounting for 60 to 70% of the membrane composition.

Ultra-Tuning of the Aperture Size in Stiffened ZIF-8_Cm Frameworks with Mixed-Linker Strategy for Enhanced CO /CH Separation.

ZIF-8 membrane has the potential for CO /CH separation based on size exclusion. But if traditionally prepared by solvothermal methods, it shows only negligible selectivity due to the linker mobility. Here, ≈500 nm-thin hybrid ZIF-7 -8 membranes with suppressed linker mobility and narrowed window aperture are prepared by a fast current-driven synthesis (FCDS) within 20 min.

Water Transport with Ultralow Friction through Partially Exfoliated g-C N Nanosheet Membranes with Self-Supporting Spacers.

Two-dimensional (2D) graphitic carbon nitride (g-C N ) nanosheets show brilliant application potential in numerous fields. Herein, a membrane with artificial nanopores and self-supporting spacers was fabricated by assembly of 2D g-C N nanosheets in a stack with elaborate structures. In water purification the g-C N membrane shows a better separation performance than commercial membranes.

A Two-Dimensional Lamellar Membrane: MXene Nanosheet Stacks.

Two-dimensional (2D) materials are promising candidates for advanced water purification membranes. A new kind of lamellar membrane is based on a stack of 2D MXene nanosheets. Starting from compact Ti AlC , delaminated nanosheets of the composition Ti C T with the functional groups T (O, OH, and/or F) can be produced by etching and ultrasonication and stapled on a porous support by vacuum filtration.

A Dual-Phase Ceramic Membrane with Extremely High H2 Permeation Flux Prepared by Autoseparation of a Ceramic Precursor.

A novel concept for the preparation of multiphase composite ceramics based on demixing of a single ceramic precursor has been developed and used for the synthesis of a dual-phase H2 -permeable ceramic membrane. The precursor BaCe0.5 Fe0.

Enhanced stability of Zr-doped Ba(CeTb)O(3-δ)-Ni cermet membrane for hydrogen separation.

A mixed protonic and electronic conductor material BaCe(0.85)Tb(0.05)Zr(0.