Synthesis, characterization and assessment of hydrophilic oxidized carbon nanodiscs in bio-related applications

Oxidation of industrially prepared carbon nanodiscs using a simple, versatile, and reproducible approach based on the Staudenmaier method yields a new hydrophilic form of nanocarbon. As a result of the strong acid treatment, which also enables the separation of carbon nanodiscs from the mixed starting material, the graphene planes detach from the discs, while the surface of the carbon nanodiscs is decorated with various oxygen-containing functional polar groups. Thus, the completely insoluble carbon nanodiscs are converted to a hydrophilic derivative dispersable in many polar solvents, including water. The new carbon structure is expected to have a wide range of applications in several fields including bioapplications. To this end, the functionalized carbon nanodiscs exhibit very low cytotoxicity, while they achieve high drug loadings, enabling their application as an effective drug nanocarrier. Furthermore, the carbon disks were evaluated as supports in nanobiocatalytic applications, increasing significantly the stability of the systems, due to carbon disks' nano-sized dimensions

Engineered pH-Responsive Mesoporous Carbon Nanoparticles for Drug Delivery

In this work, two types of mesoporous carbon particles with different morphology, size and pore structure have been functionalized with a self-immolative polymer sensitive to changes in pH and tested as drug nanocarriers. It is shown that their textural properties allow significantly higher loading capacity compared to typical mesoporous silica nanoparticles. In vial release experiments of a model Ru dye at pH 7.4 and 5 confirm the pH-responsiveness of the hybrid systems, showing that only small amounts of the cargo are released at physiological pH, whereas at slightly acidic pH (e.g. that of lysosomes) self-immolation takes place and a significant amount of the cargo is released. Cytotoxicity studies using human osteosarcoma cells show that the hybrid nanocarriers are not cytotoxic by themselves but induce significant cell growth inhibition when loaded with a chemotherapeutic drug such as doxorubicin. In preparation of an in vivo application, in vial responsiveness of the hybrid system to short-term pH-triggering is confirmed. The consecutive in vivo study shows no substantial cargo release over a period of 96 hours under physiological pH conditions. Short-term exposure to acidic pH releases an experimental fluorescent cargo during and continuously after the triggering period over 72 hours

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 H2 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. The metal-organic framework ZIF-8 is an ideal material possessing high thermal, chemical, and mechanical stability that reduces degradation during handling and activation. Here, we distributed ZIF-8 pellets synthesized by extrusion to 9 laboratories equipped with 15 different experimental setups including gravimetric and volumetric analyzers. The gravimetric H2 uptake of the pellets was measured at 77 K and up to 100 bar showing a high reproducibility between the different laboratories, with a small relative standard deviation of 3–4 % between pressures of 10–100 bar. The effect of operating variables like the amount of sample or analysis temperature was evaluated, remarking the calibration of devices and other correction procedures as the most significant deviation sources. Overall, the reproducible hydrogen cryoadsorption measurements indicate the robustness of the ZIF-8 pellets, which we want to propose as a reference material.M. Maiwald, J. A. Villajos, R. Balderas and M. Hirscher acknowledge the EMPIR programme from the European Union's Horizon 2020 research and innovation programme for funding. F. Cuevas and F. Couturas acknowledge support from France 2030 program under project ANR-22-PEHY-0007. D. Cazorla and A. Berenguer-Murcia thank the support by PID2021-123079OB-I00 project funded by MCIN/AEI/10.13039/501100011033, and “ERDF A way of making Europe”. K. N. Heinselman, S. Shulda and P. A. Parilla acknowledge the support from the National Renewable Energy Laboratory, operated by Alliance for Sustainable Energy, LLC, for the U.S. Department of Energy (DOE) under Contract No. DE-AC36-08GO28308. Funding provided by U.S. Department of Energy Office of Energy Efficiency and Renewable Energy Hydrogen and Fuel Cell Technology Office through the HyMARC Energy Materials Network

Fundamentals of hydrogen storage in nanoporous materials

Physisorption of hydrogen in nanoporous materials offers an efficient and competitive alternative for hydrogen storage. At low temperatures (e.g. 77 K) and moderate pressures (below 100 bar) molecular H2 adsorbs reversibly, with very fast kinetics, at high density on the inner surfaces of materials such as zeolites, activated carbons and metal–organic frameworks (MOFs). This review, by experts of Task 40 ‘Energy Storage and Conversion based on Hydrogen’ of the Hydrogen Technology Collaboration Programme of the International Energy Agency, covers the fundamentals of H2 adsorption in nanoporous materials and assessment of their storage performance. The discussion includes recent work on H2 adsorption at both low temperature and high pressure, new findings on the assessment of the hydrogen storage performance of materials, the correlation of volumetric and gravimetric H2 storage capacities, usable capacity, and optimum operating temperature. The application of neutron scattering as an ideal tool for characterising H2 adsorption is summarised and state-of-the-art computational methods, such as machine learning, are considered for the discovery of new MOFs for H2 storage applications, as well as the modelling of flexible porous networks for optimised H2 delivery. The discussion focuses moreover on additional important issues, such as sustainable materials synthesis and improved reproducibility of experimental H2 adsorption isotherm data by interlaboratory exercises and reference materials

A microporous Cu2+ MOF based on a pyridyl isophthalic acid Schiff base ligand with high CO2 uptake

A new Cu2+ complex that was isolated from the initial use of 5-((pyridin-4-ylmethylene) amino) isophthalic acid (PEIPH2) in 3d metal-organic framework (MOF) chemistry is reported. Complex [Cu-3(PEIP)(2)(5-NH2-mBDC)(DMF)].7DMF8 denoted as Cu-PEIP.7DMF was isolated from the reaction of Cu(NO3)(2).2.5H(2)O with PEIPH2 in N, N-dimethylformamide (DMF) at 100 degrees C and contains both the PEIP2-ligand and its 5-NH2-mBDC(2)-fragment. After the structure and properties of Cu-PEIP were known an analogous complex was prepared by a rational synthetic method that involved the reaction of Cu(NO3)(2).2.5H(2)O, 5-((pyridin-4-ylmethyl) amino) isophthalic acid (PIPH2 - the reduced analogue of PEIPH2) and 5-NH2-mBDCH(2) in DMF at 100 degrees C. Cu-PEIP comprises two paddle-wheel [Cu-2(COO)(4)] units and exhibits a 3D-framework with a unique trinodal underlying network and point symbol (4.52)(4)(4(2).5(4).6(4).8(3).9(2))(2)(5(2).8(4)). This network consists of pillared kgm-a layers containing a hexagonal shaped cavity with a relatively large diameter of similar to 8-9 angstrom surrounded by six trigonal shaped ones with a smaller diameter of similar to 4-5 angstrom and thus resembles the structure of HKUST-1. Gas sorption studies revealed that Cu-PEIP exhibits a 1785 m(2) g(-1) BET area as well as high CO2 sorption capacity (4.75 mmol g(-1) at 273 K) and CO2/CH4 selectivity (8.5 at zero coverage and 273 K)

Synthesis of Poly(ethylene furanoate) Based Nanocomposites by In Situ Polymerization with Enhanced Antibacterial Properties for Food Packaging Applications

Poly(ethylene 2,5-furandicarboxylate) (PEF)-based nanocomposites containing Ce–bioglass, ZnO, and ZrO2 nanoparticles were synthesized via in situ polymerization, targeting food packaging applications. The nanocomposites were thoroughly characterized, combining a range of techniques. The successful polymerization was confirmed using attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy, and the molecular weight values were determined indirectly by applying intrinsic viscosity measurements. The nanocomposites’ structure was investigated by depth profiling using time-of-flight secondary ion mass spectrometry (ToF-SIMS), while color measurements showed a low-to-moderate increase in the color concentration of all the nanocomposites compared to neat PEF. The thermal properties and crystallinity behavior of the synthesized materials were also examined. The neat PEF and PEF-based nanocomposites show a crystalline fraction of 0–5%, and annealed samples of both PEF and PEF-based nanocomposites exhibit a crystallinity above 20%. Furthermore, scanning electron microscopy (SEM) micrographs revealed that active agent nanoparticles are well dispersed in the PEF matrix. Contact angle measurements showed that incorporating nanoparticles into the PEF matrix significantly reduces the wetting angle due to increased roughness and introduction of the polar -OH groups. Antimicrobial studies indicated a significant increase in inhibition of bacterial strains of about 9–22% for Gram-positive bacterial strains and 5–16% for Gram-negative bacterial strains in PEF nanocomposite films, respectively. Finally, nanoindentation tests showed that the ZnO-based nanocomposite exhibits improved hardness and elastic modulus values compared to neat PEF

Heterometallic In(III)–Pd(II) Porous Metal–Organic Framework with Square-Octahedron Topology Displaying High CO₂ Uptake and Selectivity toward CH₄ and N₂

The targeted synthesis of metal–organic frameworks (MOFs) with open metal sites, following reticular chemistry rules, provides a straightforward methodology toward the development of advanced porous materials especially for gas storage/separation applications. Using a palladated tetracarboxylate metalloligand as a 4-connected node, we succeeded in synthesizing the first heterobimetallic In­(III)/Pd­(II)-based MOF with square-octahedron (<b>soc</b>) topology. The new MOF, formulated as [In₃O­(<b>L</b>)_1.5(H₂O)₂Cl]·n­(solv) (<b>1</b>), features the oxo-centered trinuclear clusters, [In₃(μ₃-O)­(−COO)₆], acting as trigonal-prismatic 6-connected nodes that linked together with the metalloligand <i>trans</i>-[PdCl₂(PDC)₂] (<b>L</b>^<b>4–</b>) (PDC: pyridine-3,5-dicarboxylate) to form a 3D network. After successful activation of <b>1</b> using supercritical CO₂, high-resolution microporous analysis revealed the presence of small micropores (5.8 Å) with BET area of 795 m² g^–1 and total pore volume of 0.35 cm³ g^–1. The activated solid shows high gravimetric (92.3 cm³ g^–1) and volumetric (120.9 cm³ cm^–3) CO₂ uptake at 273 K and 1 bar as well as high CO₂/CH₄ (15.4 for a 50:50 molar mixture) and CO₂/N₂ (131.7 for a 10:90 molar mixture) selectivity, with moderate <i>Q</i>_st⁰ for CO₂ (29.8 kJ mol^–1). Slight modifications of the synthesis conditions led to the formation of a different MOF with an anionic framework, having a chemical formula [Me₂NH₂]­[In­(<b>L</b>)]·<i>n</i>(solv) (<b>2</b>). This MOF is constructed from pseudotetrahedral, mononuclear [In­(−COO)₄] nodes bridged by four <b>L</b>^<b>4–</b> linkers, resulting in a 3D network with <b>PtS</b> topology