ZIF-8 Pellets as a Robust Material for Hydrogen Cryo-Adsorption Tanks

Advancements in chitosan-based nanocomposites with ZIF-8 nanoparticles: multifunctional platforms for wound healing applications

The integration of chitosan and zeolitic imidazolate framework-8 (ZIF-8) nanoparticles has demonstrated significant potential in enhancing wound healing through their multifunctional capabilities. This review explores recent developments in chitosan-based nanocomposites incorporating ZIF-8 nanoparticles, emphasizing their antibacterial properties, pH-responsive drug release, angiogenesis promotion, and mechanical stability. Applications span hydrogel scaffolds, electrospun nanofibers, and sprayable membranes, all tailored for addressing challenges such as bacterial resistance, delayed tissue regeneration, and chronic wound management. Key findings highlight the synergistic benefits of ZIF-8's bioactivity with chitosan's biocompatibility, yielding innovative therapeutic strategies for complex wound healing scenarios. The discussed advancements not only underline their clinical relevance but also set a foundation for future explorations in regenerative medicine.

Freeze Casting of Microporous Composite Beads Based on a Polymer of Intrinsic Microporosity for Gas Storage Applications

Polymers of intrinsic microporosity (PIMs) show potential for gas storage and separation applications. However, they are often produced in fine-scale particulate form which can lead to handling and fouling issues, for example when inserted inside storage tanks. We provide the first demonstration of a manufacturing technique to form millimeter scale PIM-based beads by freeze casting PIM-1 droplets. The PIM-based beads are shown to exhibit similar Brunauer-Emmett-Teller (BET) surface areas compared to its original particulate form and low pressure hydrogen isotherms (to 0.1 MPa) are presented to examine gas storage behavior. We also demonstrate the production of composite PIM-1 beads containing up to 80 wt % of activated carbon filler, which leads to improved surface area for gas storage and separation, generally following the rule of mixtures. The composite beads can store 1.6 wt % hydrogen at 0.1 MPa and 77 K and are predicted to have a maximum storage capacity of 8.1 wt %, with potential to meet the Department of Energy (DoE) targets for light duty fuel cell vehicles.

Solar Hydrogen Production and Storage in Solid Form: Prospects for Materials and Methods

Climatic changes are reaching alarming levels globally, seriously impacting the environment. To address this environmental crisis and achieve carbon neutrality, transitioning to hydrogen energy is crucial. Hydrogen is a clean energy source that produces no carbon emissions, making it essential in the technological era for meeting energy needs while reducing environmental pollution. Abundant in nature as water and hydrocarbons, hydrogen must be converted into a usable form for practical applications. Various techniques are employed to generate hydrogen from water, with solar hydrogen production-using solar light to split water-standing out as a cost-effective and environmentally friendly approach. However, the widespread adoption of hydrogen energy is challenged by transportation and storage issues, as it requires compressed and liquefied gas storage tanks. Solid hydrogen storage offers a promising solution, providing an effective and low-cost method for storing and releasing hydrogen. Solar hydrogen generation by water splitting is more efficient than other methods, as it uses self-generated power. Similarly, solid storage of hydrogen is also attractive in many ways, including efficiency and cost-effectiveness. This can be achieved through chemical adsorption in materials such as hydrides and other forms. These methods seem to be costly initially, but once the materials and methods are established, they will become more attractive considering rising fuel prices, depletion of fossil fuel resources, and advancements in science and technology. Solid oxide fuel cells (SOFCs) are highly efficient for converting hydrogen into electrical energy, producing clean electricity with no emissions. If proper materials and methods are established for solar hydrogen generation and solid hydrogen storage under ambient conditions, solar light used for hydrogen generation and utilization via solid oxide fuel cells (SOFCs) will be an efficient, safe, and cost-effective technique. With the ongoing development in materials for solar hydrogen generation and solid storage techniques, this method is expected to soon become more feasible and cost-effective. This review comprehensively consolidates research on solar hydrogen generation and solid hydrogen storage, focusing on global standards such as 6.5 wt% gravimetric capacity at temperatures between -40 and 60 °C. It summarizes various materials used for efficient hydrogen generation through water splitting and solid storage, and discusses current challenges in hydrogen generation and storage. This includes material selection, and the structural and chemical modifications needed for optimal performance and potential applications.

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.