Varying Pore Size Research Articles

Adenine-based metal–organic framework with 1 D narrow channel for molecular-sieving separation of n-butane and isobutane

Molecular-sieving separation of isomeric C4 paraffins, n-butane (n-C4H10) and isobutane (iso-C4H10), is highly desired but challenging because of their very close molecular sizes and physical properties. However, most of the MOF adsorbents often undergo framework flexibility or ligand rotation or swing, leading to the variation of pore size and the loss of the molecular-sieving effect. In this work, an adenine-based MOF with a suitable window size and rigid narrow 1D channel, namely IPM-101, was selected for n-C4H10/iso-C4H10 separation. Adsorption experiments demonstrate that IPM-101 can sensitively adsorb n-C4H10 in the low-pressure region (0–0.05 bar) and reach a saturation state at 0.1 bar while iso-C4H10 is excluded by the size-exclusion effect. Owing to the high porosity, IPM-101 exhibits a high n-C4H10 adsorption capacity (51.6 cm3 g−1) at 1 bar and 298 K. Density functional theory (DFT) calculations clearly reveal the molecular-sieving mechanism that n-C4H10 molecule can diffuse into the pore channel of IPM-101 easily but the diffusion of iso-C4H10 in IPM-101 is kinetically forbidden for its high diffusion energy barrier. The breakthrough experiments show that n-C4H10 and iso-C4H10 can be efficiently separated and iso-C4H10 with a purity of up to 99.9 % can be directly collected. The regeneration experiments show that IPM-101 has good cycling stability for n-C4H10 adsorption and n-C4H10/iso-C4H10 separation. Therefore, the high separation efficiency, excellent regeneration ability, and low cost indicate that IPM-101 has great application potential for practical n-C4H10/ iso-C4H10 separation in industry.

Mesoscopic framework in hierarchical Pt/Silicate-1 zeolite catalyst enables stable low-temperature CO conversion

Hierarchical porous zeolites often exhibit improved diffusion and enhanced catalytic performance compared to conventional microporous zeolites. Meanwhile, metal encapsulation in a zeolite framework becomes an efficient way to achieve a highly dispersed and stable metal loading for heterogeneous catalysts. Herein, we synthesize a hierarchical Silicate-1 (S-1) zeolite catalyst with three-dimensional mesoscopic channels, which achieves both improved diffusion and uniform encapsulation of Pt species. We find that the optimized zeolite possesses atom-precise mesoscopic channels (2 and 4 nm) formed during the controlled crystallization process, which enables a better catalytic performance (100% CO conversion at a low temperature of ∼60 °C for over 250 h) compared with other mesoscopic S-1 catalysts with varied pore sizes and also superior to micropore-only S-1 with an even smaller Pt size. This unique channel structure enables a balance between maximizing the effective encapsulation of Pt and prohibiting aggregation of Pt species, further broadening the scope of hierarchical porous zeolite catalysts.

Design, Fabrication and Characterization of Multi-Yolk@Shell NiCuFe2 O4 @mSiO2 Mesoporous Nanocomposite Spheres for the Synthesis of Pyrimido-Quinolines under Solvent-Free Conditions.

Multi-yolk@shell mesoporous silica spheres are becoming more and more attractive as high-performance catalysts because of their high surface areas, variable pore sizes, and low densities. In this work, a NiCuFe2 O4 magnetic core with a shell of mesoporous silica mesoporous has been prepared in an easy two-step procedure. The prepared multi-yolk@shell NiCuFe2 O4 @mSiO2 spheres were characterized by using FT-IR, XRD, VSM, EDX, BET, FE-SEM and HR-TEM techniques. These unique multi-yolk@shell NiCuFe2 O4 @mSiO2 spheres demonstrated high catalytic activity for the synthesis of pyrimidoquinolines. Also, this method exposes obvious benefits such as catalyst recyclability, easy reaction condition, simplicity of work up, high product yields and short reaction times.

From molecular sieving to gas effusion through nanoporous 2D graphenes: Comparison between analytical predictions and molecular simulations.

In this paper, we study the permeation of polyatomic gas molecules through 2D graphene membranes. Using equilibrium molecular dynamics simulations, we investigate the permeation of pure gas compounds (CH4, CO2, O2, N2, and H2) through nanoporous graphene membranes with varying pore sizes and geometries. Our simulations consider the recrossing mechanism, often neglected in previous studies, which has a significant effect on permeation for intermediate pore size to molecular diameter ratios. We find that the permeation process can be decoupled into two steps: the crossing process of gas molecules through the pore plane and the escaping process from the pore region to a neighboring adsorption site, which prevents recrossing. To account for these mechanisms, we use a permeance model expressed as the product of the permeance for the crossing process and the probability of molecule escape. This phenomenological model is extended to account for small polyatomic gas molecules and to describe permeation regimes ranging from molecular sieving to effusion. The proposed model captures the temperature dependence and provides insights into the key parameters of the gas/membrane interaction controlling the permeance of the system. This work lays the foundation for predicting gas permeance and exploring membrane separation factors in 2D materials such as graphene.

Fibrin-Dextran Hydrogels with Tunable Porosity and Mechanical Properties.

Hydrogels as scaffolds in tissue engineering have gained increasing attention in recent years. Natural hydrogels, e.g., collagen or fibrin, are limited by their weak mechanical properties and fast degradation, whereas synthetic hydrogels face issues with biocompatibility and biodegradation. Therefore, combining natural and synthetic polymers to design hydrogels with tunable mechanical stability and cell affinity for biomedical applications is of interest. By using fibrin with its excellent cell compatibility and dextran with controllable mechanical properties, a novel bio-based hydrogel can be formed. Here, we synthesized fibrin and dextran-methacrylate (MA)-based hydrogels with tailorable mechanical properties, controllable degradation, variable pore sizes, and ability to support cell proliferation. The hydrogels are formed through in situ gelation of fibrinogen and dextran-MA with thrombin and dithiothreitol. Swelling and nuclear magnetic resonance diffusometry measurements showed that the water uptake and mesh sizes of fabricated hydrogels decrease with increasing dextran-MA concentrations. Cell viability tests confirm that these hydrogels exhibit no cytotoxic effect.

In situ regulation of selectivity and permeability by electrically tuning pore size in trans-membrane ion process

Regulating ion transport behavior through pore size variation is greatly attractive for membrane to meet the need for precise separation, but fabricating nanofiltration (NF) membranes with tunable pore size remains a huge challenge. Herein, a NF membrane with electrically tunable pores was fabricated by intercalating polypyrrole into reduced graphene oxide interlayers. As the potential switches from reduction to oxidation, the membrane pore size shrinks by 11%, resulting in a 16.2% increase in salt rejection. The membrane pore size expands/contracts at redox potentials due to the polypyrrole volume swelling/shrinking caused by the insertion/desertion of cations, respectively. In terms of the inserted cation, Na+ and K+ induce larger pore-size stretching range for the membrane than Ca2+ due to greater binding energy and larger doping amount. Such an electrical response characteristic remained stable after multiple cycles and enabled application in ion selective separation; e.g., the Na+/Mg2+ separation factor in the reduced state is increased by 41% compared to that in the oxide state. This work provides electrically tunable nanochannels for high-precision separation applications such as valuable substance purification and resource recovery from wastewater.

Revitalizing Inert Materials: Grafting Self‐Oscillating, Stimuli‐Responsive Organometallic Polymers for Pulsating Systems

AbstractA major challenge in materials science is dynamically adjusting material properties using sensors and control systems. This contribution develops a new approach using a self‐oscillating copolymer to autonomously change material surface properties in response to environmental changes. A redox‐sensitive terpolymer of N‐isopropylacrylamide (NIPAM), dimethylacrylamide (DMAc), and an iron‐based comonomer ([(phen)2(phen‐5‐yl‐acrylamide)FeII](PF6)2) is synthesized via Reversible Addition‐Fragmentation Chain Transfer (RAFT) polymerization, catalyzing an oscillating redox reaction (Belousov‐Zhabotinsky, BZ). The terpolymer oscillates from soluble to insoluble around 35 °C based on the iron's oxidation state. A catechol unit is incorporated to enhance versatility, enabling grafting onto different surfaces. Optimal BZ reagent concentrations are explored for maximum oscillation amplitude and frequency. By selecting a working temperature between redox transition points, the copolymer's oscillation from coil to globular conformation is observed due to redox oscillations. The self‐oscillating copolymer is grafted onto an ultrafiltration membrane, where conformational changes cause variations in pore size, leading to rapid negative flux peaks that disrupt the flux and reduce membrane fouling during protein filtration. This study highlights self‐oscillating polymers' ability to impart dynamic properties to inert materials, paving the way for smart materials with self‐regulating properties to adapt to changing conditions.

Synthetic methods to vary crystallite properties of TON zeolites and their consequences for Brønsted-acid catalyzed propene oligomerization

Brønsted acid zeolites catalyze light alkene oligomerization to higher molecular weight alkenes. Rates and selectivities of propene oligomerization in MFI zeolites are regulated by intrazeolite diffusional constraints imposed by heavier alkene products that become occluded within zeolitic micropores during reaction, and by active site properties that influence kinetic rate constants. Propene oligomerization rates and selectivity are also reported to vary with zeolite topology; however, evaluating the relative influences of kinetic and diffusional factors on oligomerization rate and selectivity and their dependence on zeolite framework topology is challenged by a dearth of synthesis methods to crystallize zeolite topologies with independently varied active site and crystallite properties. Herein, we use combinations of different structure directing agents to crystallize TON zeolites, which comprise medium-pore unidirectional straight channels, with varied crystallite sizes (0.9–5.4 μm) at similar H+-site density (∼0.3 H+/unit cell (u.c.)). Propene dimerization rates (per H+, 503 K) decrease systematically with increasing TON crystallite size over a wide range of propene pressures (16–607 kPa C3H6), reflecting the strong influence of intrazeolite diffusion limitations. The effective diffusivity of propene, estimated through the effectiveness factor formalism, systematically decreases (by ∼5×) with increasing propene pressure, indicating that the higher concentrations of heavier alkene products formed at higher propene pressures inhibit intrazeolite diffusion; however, this decrease is less severe compared to that for MFI samples of similar H+-site density. An analysis of product selectivity on zeolite topologies of independently varied pore size and dimensionality (TON, MFI, MOR) reveals that the smaller pore size of TON (∼5 Å diam.) leads to higher rate constants for propene dimerization, but also restricts the growth of larger oligomer products (e.g., ≥ C9), resulting in a lighter composition of occluded products that is also more weakly influenced by changes in propene pressure compared to those present in MFI (∼5–7 Å diam.). Together, these findings reveal the distinct roles of zeolite pore size and interconnectivity in governing kinetic factors and the composition of occluded products that regulate intrazeolite diffusion during propene oligomerization catalysis in medium-pore zeolites, and thereby rate and selectivity.

Effect of impactor velocity on low velocity impact behavior of Al/SiC monocoque interpenetrating composites

This study investigates the impact behavior and energy absorption characteristics of C4 composites under different initial energy conditions. The force-displacement responses were recorded using a conical impactor on an impact testing machine. Three configurations of C4 composites with varying pore sizes (10PPI, 20PPI, and 30PPI) were tested at three initial impact energies (208 J, 312 J, and 416 J). The force-displacement curves revealed that the 30PPI-C4 exhibited the highest force gradient and maximum force, followed by the 20PPI-C4 and 10PPI-C4. The maximum force increased with increasing impact energy for all configurations. Velocity attenuation during impact tests showed a correlation with deformation and collapse mechanisms of the C4 composite. Energy absorption analysis indicated that the 30PPI-C4 exhibited the highest energy absorption per unit mass, followed by the 20PPI-C4 and 10PPI-C4. Visual inspection revealed circular indentations and shear cracks on the top and bottom surfaces, with increasing damage area and depth of indentation at higher impact energies. The 30PPI-C4 demonstrated better resistance to indentation and failure, along with higher specific energy absorption. The refined grains in the 30PPI-C4 contributed to crack mitigation and energy absorption. The C4 composites with higher SiC volume percentages exhibited reduced damage area and higher stability during impact tests. The study concludes that the 30PPI-C4 composite with 18 vol% SiC foam shows superior impact resistance and energy absorption properties, making it a promising material for impact-related applications.

Understanding the Impedance of Mesoporous Oxides: Reliable Determination of the Material-Specific Conductivity.

The unique architecture of ordered mesoporous oxides makes them a promising class of materials for various electrochemical applications, such as gas sensing or energy storage and conversion. The high accessibility of the internal surface allows tailoring of their electrochemical properties, e.g., by adjusting the pore size or surface functionalization, resulting in superior device performance compared to nanoparticles or disordered mesoporous counterparts. However, optimization of the mesoporous architecture requires reliable electrochemical characterization of the system. Unfortunately, the interplay between nanocrystalline grains, grain boundaries, and the open pore framework hinders a simple estimation of material-specific transport quantities by using impedance spectroscopy. Here, we use a 3D electric network model to elucidate the impact of the pore structure on the electrical transport properties of mesoporous thin films. It is demonstrated that the impedance response is dominated only by the geometric current constriction effect arising from the regular pore network. Estimating the effective conductivity from the total resistance and the electrode geometry, thus, differs by more than 1 order of magnitude from the material-specific conductivity of the solid mesoporous framework. A detailed analysis of computed impedances for varying pore size allows for the correlation of the effective conductivity with the material-specific conductivity. We derive an empirical expression that accounts for the porous structure of the thin films and allows a reliable determination of the material-specific conductivity with an error of less than 8%.

Applications of Metal-Organic Frameworks in Methane Storage

Metal-organic frameworks (MOFs) are a type of porous materials that are receiving a lot of attention for their application potential in gas storage and separation. Methane storage, in particular, is an active area of research due to its significance as a vital component of natural gas, which is used for heating, transportation, and electricity generation. MOFs offer a promising solution to the challenge of efficiently storing and transporting methane because of their enormous surface area and variable pore sizes, which can facilitate efficient and reversible methane adsorption. The development of MOFs for methane storage has the potential to revolutionize the energy industry by enabling more efficient and cost-effective storage and transportation of natural gas, thereby reducing greenhouse gas emissions and promoting the use of cleaner energy sources. New MOF materials are being created and characterized as part of this field's research., and the study of their adsorption properties uses both experimental and computational techniques as well as the understanding the underlying mechanisms that govern methane adsorption in these materials. Key areas of investigation include measuring methane uptake and selectivity, as well as studying the thermodynamics and kinetics of the adsorption process.

Catalytic membrane with multiscale iron-based catalysts anchored on 2D/2D hybrid g-C3N4/layered clay for pollutant removal

The catalytic membrane, which combines the physical barrier and peroxymonosulfate (PMS)/visible light (Vis)-induced catalytic oxidation functionalities while minimizing biofouling, exhibits great promise as a material for the removal of persistent organic pollutants from wastewater. In this study, three catalytic membranes composed of 2D/2D hybrid g-C3N4/kaolinite with nitrogen vacancies and modified with different iron species (γ-FeOOH nanosheets, Fe2O3 quantum dots, and Fe single atoms) were prepared via vacuum filtration. Evaluation of the catalytic performance demonstrated that γ-FeOOH nanosheets-modified sample exhibited a relatively higher water flux (258.13 L m-2 h-1). In contrast, Fe single atom-modified sample achieved improved bisphenol A removal efficiency (97.39%) under the PMS/Vis synergetic system. Interestingly, the Fe2O3 quantum dots-modified sample exhibited the highest rate constant based on the retention time. Furthermore, the Fe single atom-modified sample showed consistent removal of bisphenol A, reaching nearly 100% during continuous-flow operation for 180 min, while maintaining a flux of approximately 200 L m-2 h-1. Quenching experiments suggested that •O2−, 1O2, and h+ were the most important oxidizing species involved in the reaction of the three membranes. Statistical analysis indicated that variations in the average pore size of the membranes were key factors influencing the catalytic activity. Overall, this study offers an in-depth insight into the systematic and quantitative assessment of 2D/2D hybrid g-C3N4/layered clay-based catalytic membranes for wastewater treatment.

The restricted mass transfer inside the anode pore channel affects the electroactive biofilms formation, community composition and the power production in microbial electrochemical systems

Porous anodes improve system performance in microbial electrochemical systems by increasing the specific surface area for electroactive bacteria. In this study, multilayer anodes with different pore diameters were constructed to assess the impact of pore size and depth on anode performance. This layered structure makes detecting electroactive biofilms more accessible layer by layer, which is the first study to examine electroactive biofilms' molecular biology and electrochemical properties at different depths in pores with varied pore sizes. The millimeter-scale pores inside the bioanode have a limited effect in increasing power. The larger the pore diameter, the higher the maximum power density (Pmax) obtained. The Pmax of anodes with 4 mm pore (1.91 ± 0.15 W m−2) was 1.4 times higher than that of the non-perforated (1.37 ± 0.07 W m−2) and 0.5 mm pore anodes (1.39 ± 0.04 W m−2). Electricigens can colonize into pore channels for at least 10 mm with a pore diameter ≥3 mm and current densities >0.05 A m−2. However, in the pores channel with 0.5 mm diameter, electricigens can only colonize to a depth of 2 mm. The biofilm thickness, electricity output, metabolic activity, and biocommunity changed with pore depth and were restricted by the limited mass transfer. The Geobacter sp. was the dominant species in inter-pore biofilms, with 43.8 %–78.6 % in abundance and decreased in quantity as pore depth increased. The inter-pore biofilms on the outer layer contributed a current density of 0.17 ± 0.003 A m−2, while that of the inner layer was only 0.02 ± 0.01 A m−2. Further studies found that the pore edge mass transfer effect can contribute up to 75 % of the current. The mass transfer process at the pore edge region could be a multidirectional mass transfer rather than a pore channel mass transfer.

A simulation and data informed approach to porosity partitioning

Information about pore shape and geometry form one of the significant inputs in determining the effective elastic properties of porous rocks. The size and structure of the pores determine the amount of fluid contents which in turn determine their bulk response. Conventionally, effective medium models have been used to study the macroscopic properties of these rocks. These models often use a fixed set of microscopic variables (like the shape parameter) to describe their bulk behavior. Barring the specification of the elastic properties of the starting host material, their original formulations often lack the provision to integrate any experimental data, later. In the context of carbonates, the rocks exhibit a large variation in pore shapes and sizes, hindering the development of rock physics models. Therefore, they eventually require calibration. This is an important issue as the size of the pores here range from nanoscale to meter scale due the presence of primary and secondary porosity systems. In this paper we develop a method that can integrate the pore shape information into differential effective medium models using simple statistical and machine learning algorithms. Avoiding the use of conceptual values for the interparticle and vug type pores, our technique facilitates a data-based inference of the shape parameters from both the image data and forward model simulations. Micro-tomography images were used to extract the pore shape information for relatively larger pores such as the vugs. The information about the interparticle pores was deduced using a simulation-based approach from well-logs. Both of these were used to specify the properties of the new inclusions, hence aiding in data informed porosity partitioning. Finally, we outline a simple regression-based scheme using a first order polynomial model that can be used to calibrate any general rock physics model.

Variations in pore size and contact angle distributions control rhizosphere rewetting

Rhizosphere wettability decreases upon severe drying leading to periods of prolonged low water content around roots after precipitation or irrigation. These observations were explained by the temporal hydrophobic character of mucilage, while structural alterations of the pore space caused by mucilage, such as pore clogging, remained mostly unexplored. In this study, time-series neutron radiography and a pore network model were used to assess the impact of pore geometry and wettability on water flow following the addition of mucilage in a sand substrate. To do so, we monitored the capillary rise of ethanol and water separately for mucilage contents, ranging from 0.0 to 2.0 mg g−1. A pore network model was developed to analyze the impact of alterations in pore geometry and wettability. Results are compared with analytical solutions of the Lucas-Washburn equation. Rewetting dynamics were explained by a combination of a decrease in effective pore throat size and a global decrease in wettability. The local distribution of wettability, however, appeared of minor importance as dynamics of water imbibition could be matched by a uniform effective contact angle. For 0.1 mg g−1 mucilage content increased wettability was predicted for both approaches: the analytical solution and the pore network model fit. At larger contents, a decrease in wettability occurred which was accompanied by a decrease in derived effective pore and pore throat size. On a minute scale, rewetting appeared to steadily progress at all mucilage contents with accelerated rewetting observed at 0.6 mg g−1 likely related to an increased wetting front length. This study highlights the importance of mucilage on pore geometry in combination with wettability modifications in the rhizosphere. Aside from rhizosphere rewetting, the presented approach provides an opportunity to investigate further wettability-related processes in other soil environments on various spatial scales.

Performance Evaluation of Ceramic Membrane Based Process for Microalgal Biomass Harvesting: Analyzing the Effect of Membrane Pore Sizes, Process Optimization and Fouling Behavior

Microalgal biofuel emerges as a potential resource of renewable energy in view of global energy demand and increasing greenhouse gases. However, substantial challenges of efficient up-concentrating of biomass act as a bottleneck in large scale production of biofuel. The study is aimed towards unravelling the obstacles encountered during dewatering of biomass from mixed-microalgae consortia using ceramic membrane based process with varying pore sizes in the microfiltration (MF) and ultrafiltration (UF) range. For clay and alumina based MF membrane, 1.2 µm pore size (average) and for alumina supported nano-alumina coated UF membrane, ∼0.01 µm pore size (average) was used. The effect of various recirculation parameters was studied for process optimization. Resistance-in-series model was employed for analyzing fouling behavior of the membranes. MF membrane was observed to have better harvesting efficiency than the UF counterpart in terms of productivity (124.41). Optimum permeate flux of microalgal suspension was found to be 315.29 L.m−2.h−1 for MF membrane. Regeneration of membranes by air assisted backpulsing process showed up to 97.71% of flux recovery for MF membrane. Volume reduction factor/ membrane area (371) was found to be considerably high compared to various reported studies. The study highlighted efficient harvesting of microalgae using indigenously developed ceramic MF membrane integrated filtration towards cost-effective production of biofuel.

A novel device for swift and efficient CD44 protein digestion of pipette tips in human serum

For molecular diagnostics in modern biomedical research, electrospray ionisation mass spectrometry (ESI-MS) based on proteome profiling is important. Now a days, sample preparation such as proteolysis and protein extraction remain incredibly challenging and inefficient. Recent sample-preparation methods based on micro tips show promising results toward the aim “a proteome in an hour”. Proteolysis at the tip, is still infrequently observed and does not represent the processing of complex bio-samples. In this study, we outline a unique technique for detecting and extracting human serum CD44 biomarkers by ligand–protein interactions. This method employs macropores silica particles (MPSP) or (MOSF) modified with hyaluronic acid (HA). In order to assist in the profile of the human serum proteome, we limitations of immunoassays for rapid and multimodal proteolysis. For effective in situ proteolysis, in micropipette tips, MPSP were designed as nanoreactors with variable pore size and surface chemistry. In MS-based bottom-up proteome analysis, the device as-built demonstrated favourable sensitivity (LOD of 0.304 ± 0.007 ng/mL and LOQ of 0.973 ± 0.054 ng/mL), selectivity, durability (at −20 °C for 2 months), reuse (at least 10 times), and minimal memory impact. In addition, we examined into specific surface chemistries of nanoparticles for the absorption of proteins in serum and profiled the HA-binding serum proteome, setting a new preliminary benchmark for future databases. Our study not only helped establish a new platform for extracting/detection of CD44 and identifying the HA-binding proteome, but it also offered design recommendations for ligand affinity-based techniques for the antibody-free study of serum biomarkers with a view towards diagnostic applications.

Structural, spectral, and dynamical behaviors of biodegradable choline-based ionic liquids (CBILs) confined inside neutral and charged mxene nanopores for supercapacitor applications

This study explores the potential of using biodegradable choline-based ionic liquids (CBILs) as a more sustainable and eco-friendly alternative to classical ILs in the field of electrolyte media for energy storage devices. While previous studies have focused on electrostatic and capacitance properties, it is important to also consider dynamics and structural behavior when choosing adjustable electrolytes and electrodes. In this regard, molecular dynamics simulations were used to study the structural, spectral, and dynamical behaviors of two CBILs ([Ch][Sa] and [Ch][β-Ala]) inside MXene nanopores with varying pore size and surface charge density. As the pore size decreases, the number of hydrogen bonds in the first layer decreases from 0.447 to 0.122 and 0.154–0.063 in [Ch][Sa] and [Ch][β-Ala], respectively. Also, the presence of an aromatic ring benefits packing efficiency, causing [Sa]- to have a parallel orientation relative to MXene surface. Applying a fixed charge (1.8–7.2 μC/cm2) on MXene electrodes results in the formation of an electric double layer (EDL). At higher surface charge densities, there is slower dynamics and lower structural correlations between anions and cations. Moreover, Infrared (IR) spectra show blue and red shifts for the O-H bond in choline and carbonyl C-O stretching vibrational modes in anions, respectively, due to the interaction of anions with the MXene surface in the first layer reducing their interaction with cations. The results of our research may potentially lead to the creation of novel energy storage devices that are eco-friendly, utilizing MXene electrodes and CBILs as electrolytes.

Survival of Zirconium-Based Metal-Organic Framework Crystallinity at Extreme Pressures.

Recent research on metal-organic frameworks (MOFs) has shown a shift from considering only the crystalline high-porosity phases to exploring their amorphous counterparts. Applying pressure to a crystalline MOF is a common method of amorphization, as MOFs contain large void spaces that can collapse, reducing the accessible surface area. This can be either a desired change or indeed an unwanted side effect of the application of pressure. In either case, understanding the MOF's pressure response is extremely important. Three such MOFs with varying pore sizes (UiO-66, MOF-808, and NU-1000) were investigated using in situ high-pressure X-ray diffraction and Raman spectroscopy. Partial crystallinity was observed in all three MOFs above 10 GPa, along with some recovery of crystallinity on return to ambient conditions if the frameworks were not compressed above thresholds of 13.3, 14.2, and 12.3 GPa for UiO-66, MOF-808, and NU-1000, respectively. This threshold was marked by an unexpected increase in one or more lattice parameters with pressure in all MOFs. Comparison of compressibility between MOFs suggests penetration of the pressure-transmitting oil into MOF-808 and NU-1000. The survival of some crystallinity above 10 GPa in all of these MOFs despite their differing pore sizes and extents of oil penetration demonstrates the importance of high-pressure characterization of known structures.

3D Porous Scaffold-Based High-Throughput Platform for Cancer Drug Screening.

Natural polymer-based porous scaffolds have been investigated to serve as three-dimensional (3D) tumor models for drug screening owing to their structural properties with better resemblance to human tumor microenvironments than two-dimensional (2D) cell cultures. In this study, a 3D chitosan-hyaluronic acid (CHA) composite porous scaffold with tunable pore size (60, 120 and 180 µm) was produced by freeze-drying and fabricated into a 96-array platform for high-throughput screening (HTS) of cancer therapeutics. We adopted a self-designed rapid dispensing system to handle the highly viscous CHA polymer mixture and achieved a fast and cost-effective large-batch production of the 3D HTS platform. In addition, the adjustable pore size of the scaffold can accommodate cancer cells from different sources to better mimic the in vivo malignancy. Three human glioblastoma multiforme (GBM) cell lines were tested on the scaffolds to reveal the influence of pore size on cell growth kinetics, tumor spheroid morphology, gene expression and dose-dependent drug response. Our results showed that the three GBM cell lines showed different trends of drug resistance on CHA scaffolds of varying pore size, which reflects the intertumoral heterogeneity across patients in clinical practice. Our results also demonstrated the necessity to have a tunable 3D porous scaffold for adapting the heterogeneous tumor to generate the optimal HTS outcomes. It was also found that CHA scaffolds can produce a uniform cellular response (CV < 0.15) and a wide drug screening window (Z' > 0.5) on par with commercialized tissue culture plates, and therefore, can serve as a qualified HTS platform. This CHA scaffold-based HTS platform may provide an improved alternative to traditional 2D-cell-based HTS for future cancer study and novel drug discovery.