Controlled Pore Size Research Articles

Small biochar particles added to coarse sandy subsoil greatly increase water retention and affect hydraulic conductivity

AbstractSandy soils can benefit greatly from the addition of biochar, but the benefits depend on the properties of both the soil and the biochar. This study investigated the role of biochar particle size in controlling pore size distribution, hydraulic conductivity and water retention after careful mixing with coarse sandy subsoil. Intact commercial pellets of straw biochar (SB; approx. 8 × 5 mm) and ground pellets separated into 6 size fractions (median diameter 15, 33, 44, 81, 135 and 205 μm) were investigated at two concentrations (1.50 and 3.00 wt%). The results were compared with effects obtained with another feedstock (wood; WB) and another soil. Light microscopy and water retention measurements showed that smaller biochar particles settled into large existing soil pores, creating smaller interstitial pores to a much greater extent than larger particles. Accordingly, small particles (≤44 μm) had large enhancing effects on water retention and hydraulic conductivity in the medium suction range (pF1.7‐pF3.0), which were not found to a similar extent after the addition of larger particles (>81 μm). It was not possible to systematically distinguish the effects obtained with the three smallest particle fractions (SB15, WB18 and SB33). All effects measured were greatest at the highest biochar concentration level. In one soil, amendment with 3.00 wt% of SB15 decreased the fractional volume of drainable pores with an equivalent diameter of ≥60 μm from 31.3 vol% in the control to 19.1 vol%, while increasing the volume of pores in the 0.2–60 μm range that could potentially retain plant‐available water from 8.7 vol% to 20.1 vol%. Hydraulic conductivity at pF1.7 was increased by a factor of 10 (from 2.3 to 22.5 cm/day) and at pF3.0 by a factor of 14 (from 0.1*10−3 to 1.4*10−3 cm/day). Similar effects were observed in the other soil but at slightly different levels. The PDI version of the bimodal van Genuchten model was successfully fitted to measured water retention and log‐transformed hydraulic conductivity data (RMSE values in the interval 0.0011–0.0029 and 0.024–0.215, respectively). Dynamic simulation under variable field conditions including the hydraulic properties of biochar‐amended soil layers could be a useful method to investigate the effects on crop water supply, water and fertilizer utilization and yields.

Thermodynamic Window for Size-Controlled Pore Formation in Graphene for Large-Scale Molecular Sieves.

Nanopores in graphene monolayers are a promising option for molecular separation applications, such as desalination and carbon capture. Graphene's atomic thickness allows for an optimal balance between molecular selectivity and permeability, while its chemical stability and robust mechanical properties make it appealing for a wide range of commercial applications. However, scaling to large areas with controlled pore size distribution is an open challenge in ultrathin membranes. Here, using first-principles calculations, we identify a suitable thermodynamic window in a chemical vapor deposition system for directly growing graphene monolayers with a controlled pore size distribution. As an example, our calculations show that a postgrowth annealing step with a supersaturation range of 19.7-25 kJ/mol at 1000 K results in the creation of a controllable pore density at graphene grain boundaries, with pore sizes falling within the range of 5-8 Å. Such pores isolate hydrated Cl ions from water molecules, effectively desalinating seawater. Thus, it allows the design of targeted synthesis of large-scale 2D layers for membrane applications.

Injectable Bioactive Antioxidative One-Component Polycitrate Hydrogel with Anti-Inflammatory Effects for Osteoarthritis Alleviation and Cartilage Protection.

Chronic inflammation in osteoarthritis (OA) can destroy the cartilage extracellular matrix (ECM), causing cartilage damage and further exacerbating the inflammation. Effective regulation of the inflammatory microenvironment has important clinical significance for OA alleviation and cartilage protection. Polycitrate-based polymers have good antioxidant and anti-inflammatory abilities but cannot self-polymerize to form hydrogels. Herein, a one-component multifunctional polycitrate-based (PCCGA) hydrogel for OA alleviation and cartilage protection is reported. The PCCGA hydrogel is prepared using only the PCCGA polymer by self-polymerization and exhibits multifunctional properties such as injectability, adhesion, controllable pore size and elasticity, self-healing ability, and photoluminescence. Moreover, the PCCGA hydrogel exhibits good biocompatibility, biodegradability, antioxidation by scavenging intracellular reactive oxygen species, and anti-inflammatory ability by downregulating the expression of proinflammatory cytokines and promoting the proliferation and migration of stem cells. In vivo results from an OA rat model show that the PCCGA hydrogel can effectively alleviate OA and protect the cartilage by restoring uniform articular surface and cartilage ECM levels, as well as inhibiting cartilage resorption and matrix metalloproteinase-13 levels. These results indicate that the PCCGA hydrogel, as a novel bioactive material, is an effective strategy for OA treatment and has broad application prospects in inflammation-related biomedicine.

Preparation of Highly Porous Scaffolds with Controllable Pore Size from Microbial Polyesters

Microbial polyesters saw limited use in the field of tissue engineering, even though the biocompatibility of these polymers makes them ideal candidates for this role. The primary factor that hinders the proliferation of microbial polyesters in this market is that their processing with conventional techniques, such as electrospinning or 3D printing, is challenging. However, the full potential of these biopolymers could still be utilized by applying unconventional manufacturing methods, such as those based on the concept of salt leaching. An implementation of this concept facilitates the production of scaffolds that simultaneously have high porosity and excellent permeability. Moreover, the average pore size can also be varied in the range from 50 to 400 µm, which was reported to be optimal for the cultivation of eucaryotic cell cultures. By adjusting the pore size, the scaffold can be tailored to the eucaryotic cells the tissue consists of. Furthermore, we have developed an entirely new computational method for the approximation of the pore size distribution of the scaffolds. The method relies on 3D data reconstructed by the software of a digital optical microscope and also facilitates the modeling of the average pore size of scaffolds. Thus, besides the control of the pore size, our method enables its prediction as well.

Dragging 3D printing technique controls pore sizes of tissue engineered blood vessels to induce spontaneous cellular assembly

To date, several off-the-shelf products such as artificial blood vessel grafts have been reported and clinically tested for small diameter vessel (SDV) replacement. However, conventional artificial blood vessel grafts lack endothelium and, thus, are not ideal for SDV transplantation as they can cause thrombosis. In addition, a successful artificial blood vessel graft for SDV must have sufficient mechanical properties to withstand various external stresses. Here, we developed a spontaneous cellular assembly SDV (S-SDV) that develops without additional intervention. By improving the dragging 3D printing technique, SDV constructs with free-form, multilayers and controllable pore size can be fabricated at once. Then, The S-SDV filled in the natural polymer bioink containing human umbilical vein endothelial cells (HUVECs) and human aorta smooth muscle cells (HAoSMCs). The endothelium can be induced by migration and self-assembly of endothelial cells through pores of the SDV construct. The antiplatelet adhesion of the formed endothelium on the luminal surface was also confirmed. In addition, this S-SDV had sufficient mechanical properties (burst pressure, suture retention, leakage test) for transplantation. We believe that the S-SDV could address the challenges of conventional SDVs: notably, endothelial formation and mechanical properties. In particular, the S-SDV can be designed simply as a free-form structure with a desired pore size. Since endothelial formation through the pore is easy even in free-form constructs, it is expected to be useful for endothelial formation in vascular structures with branch or curve shapes, and in other tubular tissues such as the esophagus.

A simple and effective method to adjust the size of micropores on the inner surface of Polyvinylidene fluoride hollow fiber membranes

AbstractPore‐forming agents affect phase thermodynamics of solution‐case membranes, hence influencing the structure and properties of the membrane. Polyvinylidene fluoride (PVDF) membrane has many advantages, but more in‐depth research is needed regarding directional control of membrane pore size. To solve this problem, a simple and efficient method is proposed. By adjusting the percentage of polyvinylpyrrolidone (PVP) in the casting solution, pore diameter is controlled between 0.01 and 10 μm. The number density and diameter of the inner surface increased significantly with increasing PVP content. The relevance of this study lies in the modulation of the inner surface micropore size of PVDF hollow fiber membranes in a simple and efficient procedure.Highlights Adjusting the size of micropores on the inner surface. The size range of the inner surface is controlled between 0.01 and 10 μm. It is possible to regulate the pore structure by limiting PVP concentration. Significant increase in the number and size of pore on the inner surface. A simple method for regulating the size of micropores.

Tuning pore structure of polymer-derived carbon materials for supercapacitor electrode materials using microscopic phase separation engineering

Specific surface area and pore structure have critical impact on the performance of carbon-based supercapacitors. However, for carbon materials, the association between pore architecture and electrochemical performance remains unclear. In this study, sub-nano porous carbon materials with precisely controllable pore size were fabricated by a simple direct carbonization method using interpenetrating polymer networks (IPN), Besides, the correlation between pore architecture and electrochemical performance was explored by controlling the relative content of the two polymer phases to enhance or weaken the degree of microscopic phase separation so as to modulate the pore structure. C-IPN1 exhibited the highest Specific Surface Area (SSA) at 827 m2 g−1, where micropores contributed 95.8 % for the total SSA. Within the three-electrode device, C-IPN1 provided an excellent Specific Capacitance of 238.5 F g−1 at the current density of 0.5 A g−1, which had high cycle stability (100 % capacity retention for 10,000 cycles) and achieved 79.5 % capacitance retention for 20-fold increase in current density (0.5 A g-1 to 10 A g−1). Furthermore, assembled symmetrical supercapacitors achieved an energy density of 7.31 Wh Kg−1 at the power density of 62.5 W Kg−1. This could provide a new avenue for the development of high-performance carbon electrode materials for double layer capacitors, given its simple synthesis process and excellent performance.

Development by emulsion templating of a novel Tunisian clay-polyvinyl alcohol/extra-virgin olive oil scaffold with antibiofilm properties

A biobased porous scaffold with antibacterial and antioxidant properties was developed using the emulsion templating method. This technique represents a new route for the development of porous materials with controllable pore size. To take into account the environmental and economic aspects, polyvinyl alcohol (PVA) was chosen as the polymer matrix, raw Tunisian clay as the Pickering emulsion stabilizer, and extra virgin olive oil (EVOO) as the oil phase. PVA is often chosen for producing wound dressings that create a moist environment and consequently promote healing. Clay was used as a barrier against bacteria and as emulsifier due to its nanoscale and layered structure. In EVOO, the polyphenolic compounds have antioxidant activity and fatty acids have a plasticizer role. X-ray fluorescence, X-ray diffraction and Fourier transform infrared spectroscopy were used to analyze the raw clay. Then, the obtained films were structurally and chemically characterized, and their performance, antimicrobial activity against Pseudomonas aeruginosa, and antioxidant activity were evaluated. The emulsion characterization showed that clay addition influenced the emulsion type and increased the emulsion stability index to 98%, even after 3 months of storage. This was explained by the irreversible adsorption of clay platelets on the droplet surface that formed a rigid shell to prevent coalescence. The film characterization demonstrated that the oil: water ratio did not influence the surface porosity, although it affected the pore size uniformity and interconnection. Conversely, shortening the curing time improved the surface porosity. The resulting PVA-clay/EVOO scaffold displayed an exceptional performance, including high mechanical strength (∼2.1 MPa), interconnected porous structure with a size ranging from few µm to > 30 µm, and hydrophobic properties (∼90° ± 2). In addition, it showed antiadhesive and antibiofilm activities against P. aeruginosa. Therefore, this scaffold could be used for the early prevention of biofilm formation during wound healing and is a promising candidate for the controlled release of drugs and potentially for various applications in soft tissues.

Mn, N co-doped carbon nanospheres for efficient capture of uranium (VI) via capacitive deionization

Heteroatom doping, involving the introduction of atoms with distinct electronegativity into carbon materials, has emerged as an effective approach to optimize their charge distribution. In this study, we designed a strategy to synthesize in-situ Mn, N co-doped carbon nanospheres (Mn-NC) through the polycondensation of 2,6-diaminopyridine and formaldehyde in synchronization with Mn2+ chelation to form Mn-polytriazine precursor, followed by calcination to form carbonaceous solid. Then Mn-NC was fabricated into a capacitive deionization (CDI) electrode for the selective removal of uranium ions (U (VI)), which is commonly found in radioactive water. Interestingly, Mn-NC exhibited good selectivity for UO22+ capture with a demonstrated adsorption capacity of approximately 194 mg/g @1.8 V. The systematic analysis of the adsorption mechanism of UO22+ revealed that N dopants within Mn-NC can coordinate with the U (VI) ions, thereby facilitating the removal process. Our study presents a straightforward and convenient strategy for removing UO22+ ions by harnessing the coordination effect, eliminating the requirement for pore size control.

Piperazine-impregnated silica aerogel for direct air capture of CO2 for prevention of urea formation

Direct air capture (DAC) of CO2 using solid sorbents is a promising negative emission technology to reduce global greenhouse gas emissions. Despite many advantages of alkyl-amine-based adsorbents, degradation caused by urea formation under a dry CO2 regeneration remains a challenge. Herein, we hypothesized that certain nitrogen-containing heterocyclic compounds can contribute toward suppressing urea formation by the ring structure and thus, selected piperazine (PZ) as a representative chemical. PZ was wet-impregnated onto a silica aerogel (PZ/silica) with controlled pore size and volume. The synthesized sorbents exhibited high CO2 sorption uptake and kinetics. In a cyclic test via temperature swing adsorption (adsorption: calibrated 200 ppm CO2; desorption: dry CO2), PZ/silica exhibited stable and high adsorption capacities (average 1.3 mmol/g over 24 cycles). The suppression of urea formation in PZ/silica under extended dry CO2 regeneration was demonstrated using an in-situ diffuse reflectance infrared Fourier transform spectroscopy, thereby proving the above hypothesis. PZ/silica showed good anti-oxidation performance of CO2 capture, 1.6 mmol CO2/g, after 12 h oxidation under 21% O2 balanced with N2. Besides, PZ/silica maintained a CO2 adsorption uptake of 0.79 mmol/g after the preliminary adsorption of H2O. This study proposes a novel way to synthesize DAC solid adsorbents using N-containing heterocyclic compounds.

Porous Structure and Fractal Dimensions of Activated Carbon Prepared from Waste Coffee Grounds.

The present work reports the results of a systematic study on the evolution of the morphological properties of porous carbons derived from coffee waste using a one-pot potassium-hydroxide-assisted process at temperatures in the range of 400-900 °C. Raw materials and obtained carbons were studied by TG, DTG, SEM and nitrogen adsorption porosimetry. The decomposition temperature ranges for hemicellulose, cellulose and lignin as the main component of the feedstock have been established. It is shown that the proposed method for the thermochemical treatment of coffee waste makes it possible to obtain activated carbon with a controllable pore size distribution and a high specific surface area (up to 1050 m2/g). A comparative study of the evolution of the distribution of pore size, pore area and pore volume has been carried out based on the BJH and NL-DFT (slit-like pores approximation) methods. The fractal dimension of the obtained carbons has been calculated by Frenkel-Halsey-Hill method for single-layer and multilayer adsorptions.

Nano-structuring metal organic frameworks on semiconductor nanowire arrays for highly sensitive and selective chemical sensing

Chemiresistive sensing of gas molecules has been widely investigated for application in medical diagnostics and environmental monitoring, showing high sensitivity and low limits of detection toward various volatile organic compounds. While metal oxide semiconductors offer numerous advantages, such as ease of fabrication, high sensitivity, and fast response times, they often suffer of high insufficient selectivity. Here, we report the engineering of a low-temperature sensing platform consisting of nanostructured zeolitic imidazolate framework (ZIF-8) metal organic frameworks (MOFs) over InP semiconducting nanowire (NW) arrays. These devices were fabricated via top-down etching of InP NW arrays, aerosol deposition of flame-made ZnO nanoparticles, and their chemical vapor conversion to ZIF-8. The presence of ZIF-8 significantly enhances the device sensitivity over that of the pristine InP NW arrays by providing a high density of adsorption sites and faster reduction kinetics. Our optimal sensors can detect NO2 in a large concentration range from 0.1 to 8 ppm, in addition to showing relatively higher responses toward various gas molecules, including CO2, methanol, ethanol, acetone, and propane, in comparison with pristine InP NW sensors. Given the large family of MOFs with controllable pore size and chemical composition, our findings provide a flexible approach for engineering the selectivity of highly sensitive and miniaturized gas sensors for integration in miniaturized devices.

Study on the Supercooling Characteristics of Freezing Soil Based On Nucleation Theory

AbstractThe clarification of freezing in a soil‐water system is critical for assessing the formation of a freezing zone and liquid water flow. The supercooling phenomenon of soil pore solutions has been found during the freezing process, but the mechanism remains poorly understood. In this study, we propose a free energy function of soil‐water systems based on the Classical Nucleation Theory. The analytical solution of the critical nucleation problem of saline soil‐water system is obtained by combining the initial freezing temperature model and Pitzer activity coefficients model in electrolyte solutions. Then, the freezing‐thawing experiments of saline soil with various salt contents were conducted for verifying the analytical solution. The derived boundary nucleation rate is the quantitative solution of the critical condition for the supercooling. The findings suggested that the theory results agreed well with the experiment results. For the salt‐free soil‐water system, the critical maximum radius of supercooling was 7.15 nm. We compared eight classical ice‐water interfacial tension models, and the “Reinhardt & Doye” and “DeMott & Rogers” models showed excellent performance when using the new free energy theoretical framework to predict the crystallization nucleation rate of soil‐water systems. A positive correlation between the boundary nucleation rate and soil‐water potential is detected. According to the influencing factors, the boundary nucleation rate of soil‐water system can be divided into three zones: salt nature control zone (R > 100 μm), salt‐pore mixed control zone (100 μm > R > 100 nm), and pore size control zone (R < 100 nm).

Exploring potassium trifluoroacetate as a novel electrolyte for enhancing energy density of biomass-derived carbon-based supercapacitors and improving electrolyte-electrode adaptability

Improving the energy density by expanding the operating voltage of electrolytes and enhancing the charge storage capacity of electrode materials is crucial for the development of supercapacitors. This work proposes a potassium trifluoroacetate (CF3COOK, CFK) electrolyte for improving the energy density of supercapacitors without sacrificing the high power density and long-cycle performance while developing honeycomb-like interconnected hierarchical porous carbons (HIHPCs) with controlled pore size distribution, large specific surface area (3028 m2 g−1), interconnected pore structure, and high electrical conductivity (2.01 S cm−1) from waste biomass to match the proposed CFK electrolyte for harvesting high charge storage capability. The prepared HIHPCs exhibit excellent electrochemical performance in the proposed CFK electrolyte, achieving a high specific capacitance of up to 409 F g−1 over a wide operating voltage window of −1.0 to 0.9 V, with high coulomb efficiency, low internal resistance, good rate capability, and perfect electrochemical stability. Symmetric supercapacitors constructed using the obtained HIHPCs and the proposed CFK electrolyte can operate stably at 1.9 V and deliver high specific energy of 24.8 Wh kg−1 at 237.8 W kg−1 with good cycling stability. The effectiveness of the proposed CFK electrolyte as an ideal electrolyte with extended electrochemical stability windows to significantly improve the energy density of aqueous supercapacitors was verified. This work presents a promising approach for developing high-performance aqueous supercapacitors with potential applications in renewable energy systems.

Analysis and Refinement of Host-Guest Interactions in Metal-Organic Frameworks.

ConspectusMetal-organic frameworks (MOFs) are a class of hybrid porous materials characterized by their periodic assembly using metal ions and organic ligands through coordination bonds. Their high crystallinity, extensive surface area, and adjustable pore sizes make them promising candidates for a wide array of applications. These include gas adsorption and separation, substrate binding, and catalysis, of relevance to tackling pressing global issues such as climate change, energy challenges, and pollution. In comparison to traditional porous materials such as zeolites and activated carbons, the design flexibility of organic ligands in MOFs, coupled with their orderly arrangement with associated metal centers, allows for the precise engineering of uniform pore environments. This unique feature enables a rich variety of interactions between the MOF host and adsorbed gas molecules, which are fundamental to understanding the observed uptake capacity and selectivity for target gas molecules and thus the overall performance of the material.In this Account, a data set for three-dimensional MOFs has been constructed based upon the structural analysis of host-guest interactions using the largest experimental database, the Cambridge Structural Database (CSD). A full screening was performed on structures with guest molecules of H2, C2H2, CO2, and SO2, and the relationship between the primary binding site, the isosteric heats of adsorption (Qst), and the adsorption uptake was extracted and established. We review the methodologies to refine host-guest interactions based primarily on our studies on the host-guest chemistry of MOFs. The methods include ligand functionalization, variation of metal centers, formation of defects, addition of single atom sites, and control of pore size and structure. In situ structural and dynamic investigations using diffraction and spectroscopic techniques are powerful tools to visualize the details of host-guest interactions upon the above modifications, affording key insights into functional performance at a molecular level. Finally, we give an outlook of future research priorities in the study of host-guest chemistry in MOF materials. We hope this Account will encourage the rational development and improvement of future MOF-based sorbents for applications in challenging gas adsorption, separations, and catalysis.

Emerging Pristine MOF-Based Heterostructured Nanoarchitectures: Advances in Structure Evolution, Controlled Synthesis, and Future Perspectives.

Metal-organic frameworks (MOFs) can be customized through modular assembly to achieve a wide range of potential applications, based on their desired functionality. However, most of the initially reported MOFs are limited to microporous systems and are not sufficiently stable, which restricts their popularization. Heterogeneity is introduced into a simple MOF framework to create MOF-based heterostructures with fascinating properties and interesting functions. Heterogeneity can be introduced into the MOFs via postsynthetic/ligand exchange. Although the ligand exchange has shown potential, it is difficult to precisely control the degree of exchange or position. Among the various synthesis strategies, hierarchical assembly is particularly attractive for constructing MOF-based heterostructures, as it can achieve precise regulation of MOF-based heterostructured nanostructures. The hierarchical assembly significantly expands the compositional diversity of MOF-based heterostructures, which has high elasticity for lattice matching during the epitaxial growth of MOFs. This review focuses on the synthetic evolution mechanism of hierarchical assemblies of MOF-based nanoarchitectures. Subsequently, the precise control of pore structure, pore size, and morphology of MOF-based nanoarchitectures by hierarchical assembly is emphasized. Finally, possible solutions to address the challenges associated with heterogeneous interfaces are presented, and potential opportunities for innovative applications are proposed.

SiO2 Modification of Silicon Carbide Membrane via an Interfacial In Situ Sol-Gel Process for Improved Filtration Performance.

Silicon carbide (SiC) membrane has emerged as a promising class of inorganic ceramic membranes with many advantageous attributes and has been used for a variety of industrial microfiltration (MF) processes. The state-of-the-art industrial manufacturing of SiC membranes based on the particle sintering method can only achieve an average pore size that ranges from 40 nm to a few micrometers, which is still unsatisfactory for ultrafiltration (UF) applications. Thus, the pore size control of SiC membranes remains a focus of continuing study. Herein, we provide an in situ sol-gel modification strategy to tailor the pore size of SiC membranes by a superficial deposition of SiO2 onto the membrane surface and membrane pore channels. Our in situ sol-gel modification method is simple and effective. Furthermore, the physical characteristics and the filtration performance of the membrane can easily be controlled by the in situ reaction time. With an optimal in situ reaction time of 30 min, the average pore size of the membrane can be reduced from macropores (400 nm) to mesopores (below 20 nm), and the retention ability for 20 nm fluorescent PS microspheres can be improved from 5% to 93%; the resultant SiC/SiO2 composite membranes are imparted with water permeance of 77 L·m-2·h-1·bar-1, improved anti-protein-fouling properties, excellent performance, and anti-acid stabilities. Therefore, modified SiC/SiO2 membranes based on the in situ sol-gel process have great potential as UF membranes for a variety of industrial processes.

The Effects of Different Concentrations of Nanoclay in Polyvinyl Alcohol (PVA) nanofibres- Polyester Bilayer on Morphological Structure, Mechanical Properties, and Filtration of Direct Red Dye

Nanofibres produced by electrospinning have high porosity, low basis weight, high surface area, and controllable pore size, which can be applied in various applications such as solar cells, supercapacitors, tissue engineering and regenerative medicine, wound dressing, chemical and gas sensing and photocatalysis. However, nanofibres have poor filtration properties, particularly in textile wastewater due to the poor colour adsorption by the fibres. Hence, the study aimed to improve the filtration properties of the nanofibres by developing a bi-layer membrane of polyvinyl alcohol (PVA) nanofibres-polyester woven with different concentrations of nanoclay. In this study, the nanoclay was added to polyvinyl alcohol (PVA) solution, which was electrospun using electrospinning to make PVA/nanoclay with polyester bi-layer. The analysis shows that the addition of nanoclay resulted in good adsorption of direct red dyes since direct dyes are often used in textile industry, indicating an improvement in the filtration properties. The tensile strength and Young’s modulus of samples decreased with an increase in the nanoclay concentration due to the fibre becoming stiffer in the bi-layer sample.

One-pot construction of gemcitabine loaded zeolitic imidazole framework for the treatment of lung cancer and its apoptosis induction

The zeolitic imidazole framework (ZIF) is a novel metal-organic framework with distinctive properties, including crystalline form, controllable pore size, wide surface area and biocompatibility. ZIF-L is a good candidate for biological applications due to its outstanding thermal and chemical stabilities. The current study aimed to develop gemcitabine (GEM) encapsulated ZIF-L in a single pot and assess its anticancer efficacy against lung cancer. The GEM@ZIF-L nanoparticles were studied using microscopic and spectroscopic measurements. The outcomes of cell counting kit-8 (CCK-8) demonstrated that two lung cancer cells were significantly cytotoxic to the IC50 values GEM@ZIF-L in A549 and H1299 cells were 9.12 ± 1.28 µg/mL, 5.47 ± 2.90 µg/mL, respectively. A dose-dependent decrease of lung cancer cells (A549 and H1299) was found using GEM@ZIF-L. Additionally, remarkably induced apoptosis was observed in GEM@ZIF-L, validated by fluorescence staining techniques (including acridine orange and ethidium bromide) (AO-EB and nuclear DAPI staining). The mode of cell death was examined by flow cytometry (dual staining Annexin V-FITC/PI) methods. Further, the ELISA analysis confirmed that GEM@ZIF-L induced apoptosis through caspase activation. The multifunctional GEM@ZIF-L nanoparticles may be suitable for biological applications, as the current work demonstrates.

Construction of Crystalline Porous Frameworks (COF/MOF) with Multi‐components or by Multi‐reactions

AbstractCovalent organic frameworks (COFs) and metal organic frameworks (MOFs) are crystalline porous materials with ordered framework structures. To create diverse framework structures, linkers with different geometries and sizes have been developed over the past decades. However, for more advanced applications, there is a need for continuous pore size control and property development. Researchers are exploring new synthesis methods, building blocks, and processing/fabrication protocols to meet these demands. Multi‐component or multiple ligands synthesis has been widely used in the construction of MOF structures, and this synthetic strategy has recently been adopted for COF synthesis and extended to versatile linker designing strategies. This review focuses on the recent development of the multi‐component or multi‐reaction strategy for COF synthesis, its application in new MOF synthetic strategies, and ligand development.