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Hydrogen uptake in complex multicomponent alloys, including high-entropy alloys (HEAs), governs both hydrogen storage capacity and resistance to hydrogen-induced degradation. We combine high-pressure experiments, density-functional theory (DFT), and a GRACE universal interatomic potential to investigate hydrogen absorption in Al0.3CoCrFeNi and Al CoCrFeNi HEAs. In Has a pressure-transmitting medium, the FCC Al0.3CoCrFeNi alloy forms hydrides at ambient temperature above 3 GPa, whereas the Al-rich B2 Al CoCrFeNi alloy shows no evidence of hydride formation even upon heating at pressures up to 50 GPa. Experiments and calculations show that aluminum suppresses hydrogen uptake by increasing solution energies and destabilizing interstitial sites. The universal potential, employed in the calculations and pretrained on large DFT databases, closely reproduces DFT energetics and demonstrates transferability from the dilute limit to the hydride-forming regime. Simulations further disentangle the roles of local ordering, volume changes, composition, and crystal structure. Overall, our results indicate that hydrogen solubility in Al-containing HEAs is governed primarily by composition, with Al-driven B2 ordering as a strong secondary effect.
Reactive extrusion has emerged as a continuous approach for conducting mechanochemical reactions on a large scale. However, the use of this method under industrial conditions is hindered by limited understanding. In this study, we unveil the black box of reactive extrusion by employing energy-dispersive X-ray diffraction (EDXRD) to collect time- and spatially resolved in situ data. Our findings demonstrate the EDXRD method’s applicability to a range of chemical transformations and conditions associated with reactive extrusion.
We report the scale-up of a batch solid synthesis of zeolitic imidazolate framework-8 (ZIF-8) for reactive extrusion. The crystalline product forms in the extruder directly under the mixture of solid 2-methylimidazole and basic zinc carbonate in the presence of a catalytic amount of liquid. Highly crystalline ZIF-8 with a Brunauer−Emmett−Teller (BET) surface area of 1816 m2 g−1 was quantitatively prepared at mild temperature using a catalytic amount of ethanol and a small excess of the linker. Extruded ZIF-8 is an affordable alternative to commercial Basolite Z1200 as a reference material for H2 cryoadsorption.
Mechanochemistry, a sustainable synthetic method that minimizes solvent use, has shown great promise in producing metal–organic framework (MOF)-based biocomposites through ball milling. While ball milling offers fast reaction times, biocompatible conditions, and access to previously unattainable biocomposites, it is a batch-type process typically limited to gram-scale production, which is insufficient to meet commercial capacity. We introduce a scalable approach for the continuous solid-state production of MOF-based biocomposites. Our study commences with model batch reactions to examine the encapsulation of various biomolecules into Zeolitic Imidazolate Framework-8 (ZIF-8) via hand mixing, establishing a foundation for upscaling. Subsequently, the process is scaled up using reactive extrusion, enabling continuous and reproducible kilogram-scale production of bovine serum albumin (BSA)@ZIF-8 with tunable protein loading. Furthermore, we achieve the one-step formation of shaped ZIF-8 extrudates encapsulating clinical therapeutic hyaluronic acid (HA). Upon release of HA from the composite, the molecular weight of HA is preserved, highlighting the industrial potential of reactive extrusion for the cost-effective and reliable manufacturing of biocomposites for drug-delivery applications.
Reactive extrusion of zif-8-based biocomposites: Scale-up enabled by in situ monitoring advances
(2025)
Mechanochemistry offers a solvent-free, sustainable alternative to conventional synthesis of metal-organic framework (MOF) biocomposites, which show great promise for drug delivery, biocatalysis, and biosensing. However, current approaches remain limited to batch-type, gram-scale syntheses that hinder industrial application.
Building on our previous work in in situ monitoring of extrusion reactions ‒ including real-time Raman spectroscopy and energy-dispersive X-ray diffraction (EDXRD),2 which revealed the formation mechanism of zeolitic imidazolate framework-8 (ZIF-8) and enabled process optimization, we developed a scalable solid-state method for producing MOF-based biocomposites via continuous reactive extrusion.
The process begins with rapid model reactions using hand-mixing,3 allowing encapsulation of diverse biomolecules into ZIF-8, including proteins, carbohydrates, and enzymes, thereby enabling fast screening and optimization of reaction conditions. We then translated the batch protocol to twin-screw extrusion, achieving continuous and scalable synthesis of biocomposites such as bovine serum albumin (BSA)@ZIF-8 with tunable protein content. The resulting materials were highly crystalline and porous, with protein loadings of up to 26 wt% and encapsulation efficiencies as high as 96%. The production rate reached 1.2 kg d⁻¹, surpassing previously reported continuous methods.
To demonstrate industrial viability, we extended the approach to produce shaped ZIF-8 monoliths loaded with hyaluronic acid (HA) in a single-step extrusion. These monoliths maintained their structural integrity during washing and released HA without measurable degradation, as confirmed by size-exclusion chromatography.
This study establishes reactive extrusion as a robust platform for the scalable synthesis and shaping of MOF biocomposites, expanding the toolkit for drug delivery and biocatalytic applications.
Mechanochemistry offers a solvent-free, sustainable alternative to conventional synthesis of metal-organic framework (MOF) biocomposites, which hold great promise for applications in drug delivery, biocatalysis, and biosensing,[1] yet the field remains limited to batch-type, gram-scale processes that restrict industrial application. To overcome these limitations, we present a scalable solid-state method for producing MOF-based biocomposites via continuous reactive extrusion.
The process begins with rapid model reactions using hand-mixing[2] to encapsulate a variety of biomolecules into zeolitic imidazolate framework-8 (ZIF-8), including proteins, carbohydrates, and enzymes, thereby enabling rapid screening and optimization of reaction conditions. The mild synthesis conditions preserve the catalytic activity of glucose oxidase, confirming the suitability of the method to sensitive biomaterials. Building on this, we translated the batch protocol to twin-screw extrusion,[3] enabling continuous and scalable synthesis of biocomposites such as bovine serum albumin (BSA)@ZIF-8 with tunable protein content. The extrusion process yielded highly crystalline, porous materials with protein loadings of up to 26 wt% and encapsulation efficiencies as high as 96%. The production rate reached 1.2 kg d⁻¹, significantly exceeding previously reported continuous methods.[4]
To demonstrate the industrial viability of the method, we extended the approach to produce shaped ZIF-8 monoliths loaded with hyaluronic acid (HA) in a single-step extrusion. These monoliths retained their structural integrity during washing and released HA without measurable degradation, as confirmed by size-exclusion chromatography.
Our study opens new avenues for the industrial implementation of MOF biocomposites and establishes reactive extrusion as a robust platform for their scalable synthesis and shaping, expanding the toolkit for drug delivery and biocatalytical applications.
Mechanochemistry has emerged as a powerful approach for sustainable materials synthesis and processing, with significant potential to meet the UN Sustainable Development Goals. This presentation will highlight our recent advancements in understanding, monitoring, and scaling-up mechanochemical transformations, focusing on the balance between fundamental understanding of reaction mechanisms and its practical applications in energy storage and energy transfer materials.
Our research has made significant strides in elucidating the fundamental mechanisms of mechanochemical reactions. We have investigated delayed polymorphism under mechanochemical conditions, revealing new insights into the interplay between mechanical impact, thermal effects, and structural transformations in molecular crystals. By employing variable temperature ball milling, we have demonstrated unprecedented control over polymorphic forms in organic cocrystals, opening new avenues for tailoring material properties.
A central focus of our work has been the development and application of time-resolved in situ monitoring techniques for mechanochemical processes. Our research on real-time synchrotron X-ray diffraction has enabled unprecedented insights into reaction pathways and kinetics. Recently, we have successfully applied energy-dispersive X-ray diffraction for time-resolved in situ monitoring of reactive extrusion, marking a significant step towards ‘lighting up’ industrial-scale mechanochemistry.
Bridging fundamental understanding with practical applications, we have explored the mechanochemical synthesis of functional materials for energy storage and transfer, making process in the mechanochemical synthesis of highly proton-conductive metal phosphonates, demonstrating the potential of mechanochemistry to manufacture advanced materials for energy applications. Addressing the challenges of industrial scale-up, we have investigated the role of solvent polarity in mechanochemical reactions, providing valuable guidance for optimizing organic syntheses such as the Knoevenagel condensation. This work contributes to our broader efforts to develop more efficient and sustainable chemical manufacturing processes.
Looking to the future, we will discuss emerging directions in mechanochemistry, including the development of continuous flow processes and the integration of machine learning approaches for reaction prediction and optimization. As we anticipate the next decade of research, we envision mechanochemistry playing an increasingly crucial role in sustainable chemical manufacturing and materials processing, with far-reaching implications for addressing global energy and environmental challenges.
Mechanochemical Innovations for Sustainable Synthesis of Framework Materials and Industrial ScaleUp
Mechanochemistry has emerged as a powerful approach for sustainable materials synthesis and processing, with significant potential to meet the UN Sustainable Development Goals. This presentation will highlight our recent advancements in understanding, monitoring, and scaling-up mechanochemical synthesis of framework materials, focusing on the balance between fundamental understanding of reaction mechanisms and its practical applications in energy storage and energy transfer materials.
A central focus of our work has been the development and application of time-resolved in situ monitoring techniques for mechanochemical processes. Our research on real-time synchrotron X-ray diffraction has enabled unprecedented insights into reaction pathways and kinetics. Recently, we have successfully applied energy-dispersive X-ray diffraction for time-resolved in situ monitoring of reactive extrusion, marking a significant step towards ‘lighting up’ industrial-scale mechanochemistry.
Bridging fundamental understanding with practical applications, we have explored the mechanochemical synthesis of functional materials for energy storage and transfer, making process in the mechanochemical synthesis of highly proton-conductive metal phosphonates, demonstrating the potential of mechanochemistry to manufacture advanced materials for energy applications.
Metal-organic framework-based biocomposites (MOF-biocomposites) are promising materials for biosensing, biocatalysis, and delivery of biopharmaceuticals. One of the most studied MOFs for bioapplications is ZIF-8 (zeolitic imidazolate framework 8) due to its high surface area, high thermal and chemical stability, and low cytotoxicity. The conventional synthesis of ZIF-8-biocomposites called biomimetic mineralization includes mixing selected biomolecules 2-methylimidazole, and soluble Zn2+ source in water.[3] Despite the high efficiency of the method, it does not allow for large-scale production and is restricted to hydrophilic biomolecules. Aimed at developing a scalable and versatile approach, we adapted our recently-reported ZIF-8 reactive extrusion for biocomposite production.
We selected bovine serum albumin (BSA) as an inexpensive model biomacromolecule for the preparation of biocomposites. The synthesis of BSA@ZIF-8 was performed using a twin-screw extruder ZE 12 HMI (Three-Tec Gmbh) at a mild temperature of 40 °C. Automatic volumetric feeder ZD 12B (Three-Tec GmbH) was used to supply the reagent mixture consisting of 2-methylimidazole, zinc source, and BSA. To initiate the reaction, a catalytic amount of EtOH was added using a peristaltic pump BT-L (Lead Fluid, China). Powder X-Ray diffraction (PXRD), thermogravimetric analysis (TGA), FTIR, and N2 adsorption were used to characterize the extrudates.
Highly crystalline and pure BSA@ZIF-8 with different BSA loadings was isolated after washing the extrudate with EtOH and sodium dodecyl sulfate. The EtOH feeding rate was optimized by following the protein encapsulation efficiency at a BSA mass fraction of 10%. A continuous extruder operation under optimized conditions showed good reproducibility and capability of producing biocomposites on the kilograms scale. These results provide highly valuable information for cheap and large-scale production of ZIF-8-based biocomposites. Due to the lack of restrictions on molecule size and solubility, our proof-of-concept study may significantly expand the selection of biomolecules for immobilization in ZIF-8, making the method applicable to various functional applications
Metal-organic framework-based biocomposites (MOF-biocomposites) hold significant promise for applications in biosensing, biocatalysis, and delivery of biopharmaceuticals. One of the most studied MOFs for bioapplications is ZIF-8 (zeolitic imidazolate framework 8) due to its high surface area, high thermal and chemical stability, and low cytotoxicity. The conventional synthesis method for ZIF-8-biocomposites, known as biomimetic mineralization, involves mixing specific biomolecules, 2-methylimidazole, and a soluble Zn2+ source in water. While this method is highly efficient, it has limitations in terms of scalability and is restricted to hydrophilic biomolecules. Aimed at developing a scalable and versatile approach, we adapted our recently reported ZIF-8 reactive extrusion for biocomposite production.
For the preparation of biocomposites, bovine serum albumin (BSA) was selected as an inexpensive model biomacromolecule. The synthesis of BSA@ZIF-8 was carried out using a twin-screw extruder at a mild temperature of 40 °C, employing a catalytic amount of EtOH following our previously explored procedure[4]. Comprehensive characterization using powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), FTIR, N2 adsorption, confocal laser scanning microscopy (CLSM), and Bradford assay allowed us to optimize reaction conditions and quantify the amount of encapsulated BSA.
After thoroughly washing the extrudate with ethanol to eliminate surface-adsorbed BSA molecules, we obtained highly crystalline and pure BSA@ZIF-8 with varying BSA loadings. Notably, achieving a maximum BSA encapsulation of 26wt% was possible with 40wt% BSA in the reagent mixture. With 5wt% BSA, we reached a high encapsulation efficiency of 96%, a critical aspect for the cost-effective production of biocomposites involving expensive biomolecules. A continuous extruder operation under optimized conditions demonstrated consistent product quality, enabling the production of biocomposites on a 1.2 kd d-1 scale with a space-time yield of approximately 30000 kg m−3 d−1. These findings offer valuable insights into the cost-effective and large-scale production of ZIF-8-based biocomposites. Moreover, due to its solid-state nature, this reaction is independent of the hydrophilic or hydrophobic properties of biomolecules, providing flexibility and advantages over solvent-based processes.