Lattice-driven gating in a Cu-based zeolitic imidazolate framework for efficient high-temperature hydrogen isotope separation.

For the separation of hydrogen isotopes (H/D), traditional kinetic quantum sieving (KQS) takes advantage of the diffusion barriers created by the flexibility of organic linkers and the breathing frameworks in porous solids. While the phenomena have been observed typically below 77 K, in this study, we present that a copper-based zeolite imidazolate framework (Cu-ZIF-gis) can show KQS above 120 K. Since Cu-ZIF-gis has narrow channels with ca.

A Gate-Opening Control Strategy via Nitrate-Chloride Anion Exchange for Enhanced Hydrogen Isotope Separation in Metal-Organic Frameworks.

Efficient separation of hydrogen isotopes, especially deuterium (D), is pivotal for advancing industries such as nuclear fusion, semiconductor processing, and metabolic imaging. Current technologies, including cryogenic distillation and Girdler sulfide processes, suffer from significant limitations in selectivity and cost-effectiveness. Herein, we introduce a novel approach utilizing an imidazolium-based Metal-Organic Framework (MOF), JCM-1, designed to enhance D/H separation through temperature-dependent gate-opening controlled by ion exchange.

High-Entropy Zeolitic Imidazolate Frameworks for Dynamic Hydrogen Isotope Separation.

Entropy-driven strategy enables the systematic design of complex systems by using entropy as a quantifiable design parameter for the degree of mixing. In this study, we present mixed-linker zeolitic imidazolate frameworks (ZIFs), sod-ZIF-1 series, that features two types of six-membered rings (6MRs) with aperture sizes of 3.4 Å and 1.

Comprehensive Design and Experimental Protocol for Scalable and Temperature-Controllable Cryogenic Hydrogen Isotope Separation.

Hydrogen isotope separation is a complex task due to the nearly identical physical and thermodynamic properties of isotopes, such as deuterium and protium. Traditional methods, including cryogenic distillation, exhibit limitations such as low selectivity and high energy consumption. Recent advancements utilizing the quantum sieving effect in crystalline porous materials have shown promise under cryogenic conditions, but experimental approaches using larger, more practical sample sizes remain scarce.

Molecular Imprinting as a Tool for Exceptionally Selective Gas Separation in Nanoporous Polymers.

The alarming rise in atmospheric CO levels, primarily driven by fossil fuel combustion and industrial processes, has become a major contributor to global climate change. Effective CO capture technologies are urgently needed, particularly for the selective removal of CO from industrial gas streams, such as flue gas and biogas, which often contain impurities like N and CH. In this study, we report the design and synthesis of novel molecularly imprinted polymers (MIPs) using 4-vinylpyridine (4VP) and methacrylic acid (MAA) as functional monomers, and thiophene (Th) and formaldehyde (HC) as molecular templates.

Pore Structure Modulation in Kirigamic Zeolitic Imidazolate Framework.

Paper crafts, such as origami and kirigami, have become an interdisciplinary research theme transportable from art to science, and further to engineering. Kirigami-inspired architectural design strategies allow the establishment of three-dimensional (3D) mechanical linkages with unprecedented mechanical properties. Herein, we report a crystalline zeolitic imidazolate framework (ZIF), displaying folding mechanics based on a kirigami tessellation, originated from the double-corrugation surface (DCS) pattern.

High Hydrogen Storage in Trigonal Prismatic Monomer-Based Highly Porous Aromatic Frameworks.

Hydrogen storage is crucial in the shift toward a carbon-neutral society, where hydrogen serves as a pivotal renewable energy source. Utilizing porous materials can provide an efficient hydrogen storage solution, reducing tank pressures to manageable levels and circumventing the energy-intensive and costly current technological infrastructure. Herein, two highly porous aromatic frameworks (PAFs), C-PAF and Si-PAF, prepared through a Yamamoto C─C coupling reaction between trigonal prismatic monomers, are reported.

Small-pore hydridic frameworks store densely packed hydrogen.

Nanoporous materials have attracted great attention for gas storage, but achieving high volumetric storage capacity remains a challenge. Here, by using neutron powder diffraction, volumetric gas adsorption, inelastic neutron scattering and first-principles calculations, we investigate a magnesium borohydride framework that has small pores and a partially negatively charged non-flat interior for hydrogen and nitrogen uptake. Hydrogen and nitrogen occupy distinctly different adsorption sites in the pores, with very different limiting capacities of 2.

Establishing ZIF-8 as a reference material for hydrogen cryoadsorption: An interlaboratory study.

Hydrogen storage by cryoadsorption on porous materials has the advantages of low material cost, safety, fast kinetics, and high cyclic stability. The further development of this technology requires reliable data on the H uptake of the adsorbents, however, even for activated carbons the values between different laboratories show sometimes large discrepancies. So far no reference material for hydrogen cryoadsorption is available.

Porous zeolitic imidazolate frameworks assembled with highly-flattened tetrahedral copper(II) centres and 2-nitroimidazolates.

Cu(II)-based zeolitic imidazolates (Cu-ZIFs), Cu-ZIF-gis and -rho, formulated as Cu(nIm) (nIm = 2-nitroimidazolate) have highly-flattened tetrahedral coordination geometry. Cu-ZIF-gis has 2.4 Å cylindrical pores that can adsorb H gas, and Cu-ZIF-rho has 19.

Heterometallic Gd-Dy Formate Frameworks for Enhanced Magnetocaloric Properties.

Lanthanide-based metal-organic frameworks (MOFs) have great potential as magnetic refrigerants under cryogenic conditions and are comparable to conventional alloys and magnetic nanoparticles. In particular, MOFs with Gd ions behave as excellent magnetic refrigerants because of their large spin ground states. However, the major drawback of Gd-based MOFs is that they are not affected by the ligand material owing to the excessively large spin-only magnetic moment; therefore, their application is limited to the cryogenic region in the magnetic cooling field.

Thermodynamic Separation of Hydrogen Isotopes Using Hofmann-Type Metal-Organic Frameworks with High-Density Open Metal Sites.

Hydrogen isotope separation with nanoporous materials is a very challenging yet promising approach. To overcome the limitation of the conventional isotope separation strategy, quantum sieving-based separation using nanoporous materials has been investigated recently. In this study, to see the thermodynamic deuterium separation phenomena attributed to the chemical affinity quantum sieving effect, we examine Hofmann-type metal-organic frameworks (MOFs), Co(pyz)[M(CN)] (pyz = pyrazine, M = Pd, Pt, and Ni), which have microporosity (4.

Design and fabrication of novel flexible sensor based on 2D Ni-MOF nanosheets as a preliminary step toward wearable sensor for onsite Ni (II) ions detection in biological and environmental samples.

Herein, for the first time, an innovative and sensitive flexible sensor for efficient potentiometric monitoring of Ni (II) ions has been designed and developed. The developed flexible sensor is constructed from highly porous activated flexible carbon cloth decorated with nitrogen and spherical porous carbon nanoparticles derived from low-cost cotton doped with polypyrrole nanoparticles via simple carbonization-activation process followed by dip-coating in membrane cocktail containing 2D Ni-MOF nanosheets as an electroactive material. The developed flexible sensor affords rapid, accurate and stable response for the Ni (II) ions monitoring at its trace level in the biological fluids including human saliva and sweat samples in addition to tap water as an environmental sample without any preconditioning steps over pH range of 2-8 with detection limit of 2.

Exploitation of 2D Cu-MOF nanosheets as a unique electroactive material for ultrasensitive Cu(II) ion estimation in various real samples.

Herein, hybrid carbon sensor has been developed with graphite sheets as a matrix, tricresyl phosphate (TCP) as a plasticizer and nanosheets of 2D Cu-MOF (metal-organic framework) as an electroactive material for the ultrasensitive Cu(II) ion detection in various real samples. Where, the present study proves the efficiency of 2D Cu-MOF as a promising sensing material for the development of Cu(II) ion selective carbon sensor. The developed 2D Cu-MOF nanosheets based sensor containing 2D Cu-MOF: TCP: graphite in the ratio of 2.

Hybrids of Pd Nanoparticles and Metal-Organic Frameworks for Enhanced Magnetism.

Nonmagnetic Pd exhibits ferromagnetism in the nanosize regime. Various stabilization agents, including surfactants, metal oxide supports, polymers, and porous materials (e.g.

Exploiting the Specific Isotope-Selective Adsorption of Metal-Organic Framework for Hydrogen Isotope Separation.

Adsorptive separation using narrow-micropore adsorbents has demonstrated the potential to separate hydrogen isotopes. In this work, we employed an isotope-responsive separation using cobalt formate. A D-responsive third sorption step was revealed, and consequently, a noticeable difference was observed in the uptakes of D and H.

Elucidation of Diffusivity of Hydrogen Isotopes in Flexible MOFs by Quasi-Elastic Neutron Scattering.

Kinetic-quantum-sieving-assisted H :D separation in flexible porous materials is more effective than the currently used energy-intensive cryogenic distillation and girdle-sulfide processes for isotope separation. It is believed that material flexibility results in a pore-breathing phenomenon under the influence of external stimuli, which helps in adjusting the pore size and gives rise to the optimum quantum-sieving phenomenon at each stage of gas separation. However, only a few studies have investigated kinetic-quantum-sieving-assisted isotope separation using flexible porous materials.

Specific Isotope-Responsive Breathing Transition in Flexible Metal-Organic Frameworks.

An isotope-selective responsive system based on molecular recognition in porous materials has potential for the storage and purification of isotopic mixtures but is considered unachievable because of the almost identical physicochemical properties of the isotopes. Herein, a unique isotope-responsive breathing transition of the flexible metal-organic framework (MOF), MIL-53(Al), which can selectively recognize and respond to only D molecules through a secondary breathing transition, is reported. This novel phenomenon is examined using neutron diffraction experiments under the same conditions for H and D sorption experiments.

Rumor Propagation is Amplified by Echo Chambers in Social Media.

Spreading rumors on the Internet has become increasingly pervasive due to the proliferation of online social media. This paper investigates how rumors are amplified by a group of users who share similar interests or views, dubbed as an echo chamber. To this end, we identify and analyze 'rumor' echo chambers, each of which is a group of users who have participated in propagating common rumors.

Exploiting Dynamic Opening of Apertures in a Partially Fluorinated MOF for Enhancing H Desorption Temperature and Isotope Separation.

Deuterium has been recognized as an irreplaceable element in industrial and scientific research. However, hydrogen isotope separation still remains a huge challenge due to the identical physicochemical properties of the isotopes. In this paper, a partially fluorinated metal-organic framework (MOF) with copper, a so-called FMOFCu, was investigated to determine the separation efficiency and capacity of the framework for deuterium extraction from a hydrogen isotope mixture.

Coordinated Molecule-Modulated Magnetic Phase with Metamagnetism in Metal-Organic Frameworks.

Most well-known metal-organic frameworks (MOFs) possessing the magnetic NiO(CO) chains, called Ni-MOF-74, have been investigated with regard to magnetic properties at open-metal sites. We present the modulation of their magnetic phase and metamagnetism via imidazole molecule coordination.

Hydrogen Isotope Separation in Confined Nanospaces: Carbons, Zeolites, Metal-Organic Frameworks, and Covalent Organic Frameworks.

One of the greatest challenges of modern separation technology is separating isotope mixtures in high purity. The separation of hydrogen isotopes can create immense economic value by producing valuable deuterium (D) and tritium (T), which are irreplaceable for various industrial and scientific applications. However, current separation methods suffer from low separation efficiency owing to the similar chemical properties of isotopes; thus, high-purity isotopes are not easily achieved.

Selective Hydrogen Isotope Separation via Breathing Transition in MIL-53(Al).

Breathing of MIL-53(Al), a flexible metal-organic framework (MOF), leads to dynamic changes as narrow pore (np) transitions to large pore (lp). During the flexible and reversible transition, the pore apertures are continuously adjusted, thus providing the tremendous opportunity to separate mixtures of similar-sized and similar-shaped molecules that require precise pore tuning. Herein, for the first time, we report a strategy for effectively separating hydrogen isotopes through the dynamic pore change during the breathing of MIL-53(Al), a representative of flexible MOFs.

Exploiting Diffusion Barrier and Chemical Affinity of Metal-Organic Frameworks for Efficient Hydrogen Isotope Separation.

Deuterium plays a pivotal role in industrial and scientific research, and is irreplaceable for various applications such as isotope tracing, neutron moderation, and neutron scattering. In addition, deuterium is a key energy source for fusion reactions. Thus, the isolation of deuterium from a physico-chemically almost identical isotopic mixture is a seminal challenge in modern separation technology.

"Job-Sharing" Storage of Hydrogen in Ru/Li₂O Nanocomposites.

A "job-sharing" hydrogen storage mechanism is proposed and experimentally investigated in Ru/Li2O nanocomposites in which H(+) is accommodated on the Li2O side, while H(-) or e(-) is stored on the side of Ru. Thermal desorption-mass spectroscopy results show that after loading with D2, Ru/Li2O exhibits an extra desorption peak, which is in contrast to Ru nanoparticles or ball-milled Li2O alone, indicating a synergistic hydrogen storage effect due to the presence of both phases. By varying the ratio of the two phases, it is shown that the effect increases monotonically with the area of the heterojunctions, indicating interface related hydrogen storage.