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The coalification process significantly influences the composition of coal material and the development of pore size, ultimately affecting the adsorption capacity of coal seams and the extraction of coalbed methane. This project aimed to assess the pore structure and gas adsorption capacity of coal samples from nine key sedimentary basins in China. The N 2 test results revealed that during the initial stage of coalification, micropore, transition pore, and mesopore dominate in order of magnitude. In the subsequent coalification stages, the development of mesopore is most significant during the second jump, while the transition pore becomes more prominent in the third jump. Additionally, the findings from nuclear magnetic resonance tests indicate that the proportion of adsorbed pore demonstrates a decreasing-then-increasing trend throughout the coalification process. The first and second coalification jumps primarily contribute to the development of adsorption pore and seepage pore, whereas the third jump mainly focuses on adsorption pore development. The gas adsorption capacity is influenced by various factors such as pore structure, material composition, and chemical structure. During the first coalification jump, gas adsorption mainly occurs in the adsorption pore. In the second jump, medium gas adsorption capacity is achieved due to the combined effects of enhanced adsorption pore development and reduced moisture and ash content. Finally, the third coalification jump exhibits highly developed adsorption pores, the lowest moisture and ash levels, and a sufficient aromatic structure in the chemical composition, resulting in high adsorption capacity. These findings contribute to a deeper understanding of the variations in coalbed methane enrichment across different basins in China, with coalification playing a crucial controlling role. • Three key stages in coal pore evolution identified. • Pore size distribution during coal thermal evolution in key basins studied. • Gas adsorption capacity of coal during coalification jumps studied. [ABSTRACT FROM AUTHOR]

Silicon carbide (SiC) ceramic membranes are highly sought-after for their exceptional properties including high temperature resistance, corrosion resistance, good hydrophilicity, high flux, and high mechanical strength. However, achieving stable regulation of high solid content SiC slurries for membrane preparation remains a significant challenge. This study presents a novel approach to stabilize the dispersion of high solid content SiC slurries by controlling parameters such as solid content, pH, ball milling time and spray coating parameters. Furthermore, the impact of different milling durations on SiC particle size and membrane performance is systematically investigated, establishing, for the first time, a direct correlation between milling time and particle size. The investigations reveal that prolonged ball milling, specifically 18 h, results in a notable reduction in membrane pore size by approximately 40 %, accompanied by a remarkable enhancement in retention performance, as evidenced by a substantial increase in the average retention rate for 500 nm fluorescent microspheres from 54.61 % to 98.89 %. This study not only offers a practical method for the stable preparation of ceramic slurries, but also provide important reference for membrane morphology control and pore size regulation. These insights hold significant promise for advancing SiC membrane technology in applications such as wastewater treatment and resource recovery. [ABSTRACT FROM AUTHOR]

In this work, we have designed unique poly(lactic acid- co -glycolic acid)- b -poly(ethylene oxide)- b -poly(propylene oxide)- b -poly(ethylene oxide)- b -poly(lactic acid- co -glycolic acid) pentablock copolymers using Pluronic F68 and F108 triblock copolymers as macroinitiators. The poly(lactic acid- co -glycolic acid) (PLGA) blocks were attached as glycolide and lactide monomers at the both ends of each F68 and F108 triblock copolymer. The molecular weights and the block fractions were confirmed by gel permeation chromatography (GPC) and proton nuclear magnetic resonance (1H NMR) for the four kinds of pentablock copolymers. Using these pentablock copolymers as templates, we synthesized mesoporous ethane-silicas as well as silicas by the evaporation-induced self-assembly (EISA) method. 1,2-bis(triethoxysily)ethane (BTEE) were used as an organosilica precursor. The mesoporous ethane-silica samples were characterized using synchrotron small angle X-ray scattering (SAXS), nitrogen sorption experiments, transmission electron microscopy (TEM), and solid-state 29Si CP-MAS NMR. Based on the experimental results, it was confirmed that the porosity and pore diameter can be varied with the PLGA weight fraction of the pentablock copolymer. It is due to the PLGA block in polymer forming the hydrophobic domain in micelles, which leads to the formation of increased pore size over 20 nm without any additive pore expander. In addition, it seems that as the organosilica precursor increases, the association number of block copolymers forming one micelle decreases, resulting in a decrease in pore size. In summary, the polymer template plays a vital part in tuning the structure of the mesoporous ethane-silica samples. Thus, the development of synthetic method of mesoporous organosilica materials using polymer templates with different topology is still challenging and can endow the unique structure and property for mesoporous organosilica for future applications. [ABSTRACT FROM AUTHOR]

The porous SiC-Mullite porous ceramics with different pore size were prepared by SiC particles, kaolin, Al(OH) 3 , and flake graphite, V 2 O 5 and AlF 3 were used as mineralizers, the pore size was controllable by adjusting the size of flake graphite. Then the improved empirical formula and grey theory were used to study the effect of the change in pore size on the material properties. The results showed that with the increase of mean pore size from 1.1 μm to 8.5 μm, the cold modulus of rupture and cold crushing strength decreased by 20.8 MPa and 13.7 MPa, respectively. And the thermal conductivity increased from 1.213 W⋅m−1⋅K−1 to 1.721 W⋅m−1⋅K−1 at 800 °C. The <5 μm pores were helped enhance the strength and decreased the thermal conductivity. [ABSTRACT FROM AUTHOR]

Reduction in the utilization of carbon-based fossil energy is the inevitable pathway to fulfill the net-zero CO2 emission target. Hydrogen, one of favorable clean energy sources, becomes a heat topic at present while its safe and efficient storage remains a challenging issue. The majority of related research focus on the hydrogen injection into salt cavern as well as depleted oil/gas reservoirs, where hydrogen is highly compressed under high pressure. In this research, an alternative approach that stores hydrogen into nanopores using the essential adsorption property is investigated, and so does its advantage over traditional high-pressure injection method. First of all, a mechanical model for density distribution of nanoconfined hydrogen is established by the chemical potential equilibrium principle, in which both intermolecular interactions and molecule-wall interactions are taken into account. Additionally, shift of critical properties taking place in nanopores is coupled as well. Then, the nanoconfined hydrogen adsorption behavior is presented, influence of atmosphere parameters, like pressure and temperature, as well as nanopore physical properties, like pore size and strength the pore wall imposes on hydrogen molecules, are identified. The proposed model can reach excellent agreements with hydrogen adsorption data collected from the existed experiments and molecular simulation, clarifying its reliability. Results show that (a) Adsorption phase thickness approaches 0.5 nm, indicating 1–2 adsorption layers are formed, which is insensitive to pressure or temperature variation; (b) Nanoconfined hydrogen density is able to achieve as great as 7 times bulk-hydrogen density at relatively low pressure, suggesting nanopores could store more hydrogen molecules than the traditional high-pressure injection method; (c) Modifying nanopore surface chemistry to intensify molecule-wall interaction strength is a desirable method to dramatically improve nanoconfined hydrogen adsorption capacity. The research lays a fundamental framework to shed light on hydrogen adsorption from a microscopic viewpoint. [Display omitted] • A theoretical framework for nanoconfined hydrogen storage behavior is established. • Hydrogen amount that stores in nanopores could be over 7 times that regular method. • Thickness of adsorption hydrogen area ranges from 0.3–0.5 nm, 1 ∼ 2-layer molecule. • Intensifying molecule-wall interaction strength contributes to hydrogen storage capacity. • Hydrogen behavior in nanopores is governed by adsorption mechanism at low pressure. [ABSTRACT FROM AUTHOR]

Utilization of wastes for the preparation of ceramic foams has gradually become a major direction in the development of new building materials. In this paper, all wastes-based ceramic foams based on electrical insulators waste (EIW) and red mud (RM) were prepared through the high-temperature foaming method. The factors affecting the increase in pore size under different preparation conditions (RM content, temperature and time) were investigated separately by studying the changes in pore size. With the increase of RM content, sintering temperature and sintering time, the pore morphology gradually evolved from a regular spherical shape to a polygonal or irregular shape with a corresponding increase in pore size, albeit at different rates. The pore size enhancement ascribed to changes in RM content was primarily attributed to the synergistic influences of a plurality of factors including glass phase content, viscosity, and gas phase content. Sintering temperature mainly affected the balance between the forces acting inside and outside the pores and the gas phase solubility in the liquid phase to adjust the size of pores. The influence of sintering time on pore size and morphology emanated from the glass phase viscosity and the resulting changes in the release rate of gas phase. In summary, the study will help to investigate the actual controlling factors of composition and process on the pore structure, and provides significant insights into the optimization and adjustment of pore structure for samples obtained by high-temperature sintering. [ABSTRACT FROM AUTHOR]

The intrinsic in-plane (IP) permeability (K ∥) and through-plane (TP) permeability (K ⊥) of nonwoven geotextiles were measured experimentally. Also, the realistic 3D images of the samples were acquired by the nondestructive μCT technique and their microstructural characteristics were measured. This information was used to simulate virtual fibrous structures resembling the microstructure of geotextiles. The flow of fluid was then simulated through realistic and virtual structures and K ∥ and K ⊥ were calculated. The experimental and predicted results were compared with each other and those of some empirical, analytical and numerical studies. A non-linear relation between both the K ∥ and K ⊥ and geotextile porosity was observed. It was found that for the same porosity, coarser fibers provide higher K ∥ and K ⊥ and this is more pronounced at higher porosity values. It was observed that by increasing the IP fiber orientation in the flow direction, K ∥ increases exponentially, while K ⊥ is independent of IP fiber orientation. The anisotropic permeability ratios λ = K ∥ / K ⊥ of samples were calculated and it was established that nonwoven geotextiles show highly anisotropic behavior with λ tending to unity with the increase of geotextile porosity. It was shown that K ⊥ increases with the increase of fiber orientation through the thickness direction. • In- and through-plane hydraulic properties of nonwoven geotextiles were studied. • Realistic and virtual models were proposed to predict hydraulic properties. • Fiber orientation has a significant effect on nonwoven hydraulic properties. • Finer fibers show lower permeability, this is more pronounced at higher porosities. • The proposed models accord well with the experimental data and analytical models. [ABSTRACT FROM AUTHOR]

Calcium aluminate cement (CAC) is broadly used as a binder for ceramic materials as it can provide suitable setting times, green mechanical strength and refractoriness. When applied to directly-foamed macroporous refractories, this binder can set the fresh foam before bubble coalescence, favouring higher porosity. Nevertheless, its large particles tend to thermodynamically stabilize bigger bubbles, resulting in samples with larger pores and broader cell size distribution, which is undesirable for high-temperature thermal insulation applications. An alternative to overcome this issue is CAC milling, which can be carried out in water by using sodium gluconate (SG) to produce a stable suspension of this binder. By using 1 wt% of SG, it was possible to grind the CAC in water for 6 h without hydration. When applied to macroporous samples, milled CAC provided faster setting kinetics and in situ formation of hibonite after firing. Additionally, smaller average pore size and higher cold crushing strength were attained when used for the production of ultrastable foam-derived refractories, whereas less significant changes were observed for samples based on surfactant-stabilized foams. The study also showed that the CaO/Al 2 O 3 particle size ratio was an important feature to control the shrinkage/expansion effects after sintering, based on the morphological aspect of the resulting hibonite (CA 6) phase. [ABSTRACT FROM AUTHOR]

Silicon carbide ceramic membranes have been widely used in the treatment of various corrosive and high temperature wastewaters. However, SiC is a compound with strong covalent bond, thus the sintering temperature and then the energy consumption during sintering of SiC ceramics is high, which inhibits the scale-up manufacturing of SiC ceramic membranes. Here, a silicon carbide ceramic membrane support was prepared at 800 °C with a low melting-point glaze as the sintering aid. The glaze infiltrated the SiC skeleton during sintering, and gave rise to high fracture strength of the porous ceramics. With the content increase of sintering aid from 10 wt% to 30 wt%, the pore-formation mechanism of the ceramic membrane support transformed from SiC particles packing to SiC aggregations packing, leading to the increase in pore size and decrease in porosity. The permeance and selectivity of the support was investigated via pure-water and oil-in-water emulsion tests. Due to the high hydrophilicity, the pure-water flux increased from 32 L/(m2·h) to 87 L/(m2·h) while the oil rejection decreased from 99.0% to 93.1% with the increase of trans -membrane pressure. This work provides a feasible route for the preparation of SiC porous ceramics with low energy consumption. [ABSTRACT FROM AUTHOR]

Calcium aluminate cement (CAC) was used in this work as a novel binder of the foam slurries to prepare Al 2 O 3 foamed ceramics. The different foam stabilizers employed in the slurries would not only impact the foam stability, but also affect the setting behavior of CAC-containing foam slurries, consequently influencing the pore size and the heat-insulating property of the Al 2 O 3 foamed ceramics. In this paper, modified polyethoxylated silicone (MPS), sodium alginate (SA) and carboxymethyl cellulose (CMC) were selected respectively as the foam stabilizer. The effects of the different foam stabilizers on the setting behavior of foam slurries, and the dependence of the pore size and heat-insulating property of CAC-bonded foamed ceramics on the setting behavior of foam slurries were investigated. It is found that SA promotes the hydration of CAC in the foam slurries, while MPS and CMC postpone the hydration of CAC in the foam slurries; and the foamed ceramics with SA have better structural integrity, higher porosity, smaller average pore size and lower thermal conductivity than those with MPS or CMC. [ABSTRACT FROM AUTHOR]

The fundamental understanding on the relationship between the intrinsic textures and sodium storage performances of carbonaceous anodes is essential for the development of high-performance anodes for sodium-ion batteries (SIBs). However, the lack of methods to control the local atomic configurations of carbonaceous anodes has seriously hindered the revelation of the in-depth relationship between the designed structures and corresponding electrochemical performances. Herein, systematic measurements on the sodium storage of carbonaceous anodes derived from bimetallic-organic frameworks were reported with adjusted inner structure from hierarchical disordered structure to gradually increased graphitic ordered domains. Benefitting from the synergistic coupling of pore size controlling and ordered domain engineering, the optimized structure, featuring rich micropores/mesopores and ordered structure, possesses fast Na+ diffusion kinetics, low charge-transfer polarization, and favourable capacitive behaviors, thereby resulting in excellent sodium storage performances of 297.4 mAh g−1 (0.1 A g−1 up to 100 cycles) and 163.6 mAh g−1 (1.0 A g−1 up to 1000 cycles). Besides, this elaborate investigation might offer essential insights into the design of carbonaceous electrodes for efficient sodium storage. [Display omitted] [ABSTRACT FROM AUTHOR]

Metal-organic framework/graphene oxide (MOF/GO) composites have been regarded as potential room-temperature hydrogen storage materials recently. In this work, the influence of MOF structural properties, GO functional group contents and different amounts of doped lithium (Li+) on hydrogen storage performance of different MOF/GO composites were investigated by grand canonical Monte Carlo (GCMC) simulations. It is found that MOF/GO composites based on small-pore MOFs exhibit enhanced hydrogen storage capacity, whereas MOF/GO based on large-pore MOFs show decreased hydrogen storage capacity, which can be ascribed to the novel pores at MOF/GO interface that favors the enhanced hydrogen storage performance due to the increased pore volume/surface area. By integrating the small-pore MOF-1 with GO, the hydrogen storage capacity was enhanced from 9.88 mg/go up to 11.48 mg/g. However, the interfacial pores are smaller compared with those in large-pore MOFs, resulting in significantly reduced pore volume/surface area as well as hydrogen storage capacities of large-pore MOF/GO composite. Moreover, with the increased contents of hydroxyl, epoxy groups as well as carboxyl group modification, the pore volumes and specific surface areas of MOF/GO are decreased, resulting in reduced hydrogen storage performance. Furthermore, the room-temperature hydrogen storage capacities of Li+ doped MOF/GO was improved with increased Li+ at low loading and decrease with the increased Li+ amounts at high loading. This is due to that the introduced Li+ effectively increases the accessible hydrogen adsorption sites at low Li+ loading, which eventually favors the hydrogen adsorption capacity. However, high Li+ loading causes ion aggregation that reduces the accessible hydrogen adsorption sites, leading to decreased hydrogen storage capacities. MOF-5/GO composites with moderate Li+ doping achieved the optimum hydrogen storage capacities of approximately 29 mg/g. • Hydrogen storage capacities of MOF/GO composites are studied by molecular simulation. • Hydrogen storage capacity of MOF/GO composites depends on pore sizes of MOFs. • Li+ doped MOF/GO shows the enhanced hydrogen uptake. • Hydrogen storage capacity of Li+ doped MOF/GO depends on Li+ loading. • High Li+ loading causes ion aggregation, leading to reduced hydrogen storage capacity. [ABSTRACT FROM AUTHOR]

In this study, we generated a 3-dimensional (3D) collagen fibrous scaffold for potential pulp regeneration and investigated the influence of various pore sizes of these scaffolds on proliferation, odontoblastic differentiation of human dental pulp cells (hDPCs), and subsequent tissue formation during pulp regeneration. Electrospinning followed by freeze-drying was used to fabricate 3D fibrous collagen scaffolds. hDPCs were cultured on these scaffolds. Cell growth was detected by a Cell Counting Kit-8 assay and observed via scanning electron microscopy. Odontogenic genes and protein expression were analyzed by real-time reverse transcription polymerase chain reaction and immunofluorescence staining. The formation of mineralized nodules was tested by von Kossa staining, scanning electron microscopy, and energy-dispersive X-ray microanalysis. Subcutaneous transplantation of the seeded scaffold/tooth fragments into nude mice was performed to observe tissue formation for pulp regeneration. Collagen 3D fibrous scaffolds with 3 distinct mean pore sizes (approximately 20 μm, 65 μm, and 145 μm) were fabricated, which showed good biocompatibility and bioactivity. Scaffolds with larger mean pore sizes of 65 and 145 μm improved hDPC ingrowth and proliferation, with the 65-μm scaffold group presenting the highest level of odontogenic gene expression (DSPP and DMP-1), protein expression (DMP-1), mineralized area ratio, and vascular pulplike tissue formation after 6 weeks of subcutaneous implantation. The pore size of collagen 3D fibrous scaffolds significantly affected cell adhesion, proliferation, odontoblastic differentiation, and tissue rehabilitation. Scaffolds with a mean pore size of 65 μm presented superior results and could be an alternative for pulp regeneration. [ABSTRACT FROM AUTHOR]

Colloidal nanosilica is a byproduct of the etching process used in silica wafer production. This study assessed the effect of nanosilica incorporation on the performance of cement mortar and analyzed the influence of nanosilica based on mineralogical and microstructural characteristics. Tests regarding the flow, isothermal calorimetry, and compressive strength of cement mortars, and X-ray diffraction, Fourier transform infrared spectroscopy, mercury intrusion porosimetry, and compressive strength of cement pastes were performed at 3 and 28 days. The nanosilica-incorporated samples exhibited higher compressive strengths than the control sample. They did not exhibit pozzolanic reactivity but provided a pore-filling effect. At an early hydration age, the nanosilica particles refined the pore size and contributed to a reduction in the total porosity, leading to an enhancement in the compressive strength. Among the hydration products, the difference in Ca(OH) 2 between the nanosilica-incorporated samples and control samples was confirmed. During hydration, the difference in Ca(OH) 2 is assumed to be due to the blocking of the growth of Ca(OH) 2 by the nanosilica particles. • Colloidal nanosilica byproducts generated from silicon wafer processing were used. • Compressive strengths increased with the addition of the nanosilica byproducts. • Difference in Ca(OH) 2 between samples was confirmed resulting in pore refinement. • Growth of Ca(OH) 2 during hydration may have been blocked by nanosilica particles. [ABSTRACT FROM AUTHOR]

This study aimed to optimize parameters for cultivating adipose-derived stem cells (ADSCs) in hollow fiber membrane systems. Enhanced ADSC cultivation was achieved in this study by utilizing a higher cell seeding rate (10 mL/min) and fibronectin coating (8 μg/cm²) on the membrane. A pulsatile flow perfusion (30 min on / 3 h off) for 24 h, followed by continuous flow perfusion at a lower rate (<20 mL/min), was employed. Notably, a two-day medium change maintained CD73 expression (79.26 %) compared to scenarios without changes (1.92 %) over eight days. Using a membrane cut-off of 20 kDa and <0.1 μm, a 1.4- and 2.8-fold increase in proliferated cells was observed; however, CD73 expression decreased by 10.07 and 33.63 %, respectively. The membrane with a pore size of <0.1 μm exhibited 1.4-fold higher exosome particle numbers. In conclusion, nutrient supplementation emerged as crucial for optimal ADSC cultivation in hollow fiber systems. [Display omitted] • This study aimed to optimize parameters for cultivating adipose-derived stem cells (ADSCs) in hollow fiber membrane systems. • Investigated hollow fiber feasibility for stem cell cultivation and exosome production. • Two-day medium change increased cell proliferation by 3 times. • Stemness marker increases 3x on <0.1 µm MWCO fiber membrane vs. 20 kDa membrane. • Proved nutrient supply significantly influences stemness, proliferation, and exosome production. [ABSTRACT FROM AUTHOR]

Lightweight MgO-MgAl 2 O 4 refractory aggregates were fabricated by using fine MgO and spherical Al(OH) 3 powders as starting materials. The evolutions of microstructure and pores and their effects on the properties of the specimens were investigated. During heating process, MgO crystallites diffused into the formed Al 2 O 3 pseudomorph, producing sub-micron intra-particle pores in both MgAl 2 O 4 cores and MgO matrix. Besides, larger inter-particle pores between the MgAl 2 O 4 cores and MgO matrix were occurred, attributing to the Kirkendall effect resulting from in-situ spinalization. As MgO content increased from 50 wt% to 80 wt%, due to reduction of the number of the porous MgAl 2 O 4 cores, the inter-particle pores caused by Kirkendall effect decreased sharply in both number and size, while no obvious changes occurred in the intra-particle pores as the porous MgO matrix amount increased simultaneously. The decrease of large inter-particle pores caused obvious improvement in strength but slight increase in thermal conductivity. With a further increase of MgO to 90 wt%, as the number of the porous MgAl 2 O 4 cores reduced further and the MgO matrix densification improved obviously, intra-particle pores and thermal insulation performance reduced significantly. The specimen with 80 wt% MgO showed the best performance, with a median pore diameter of 0.26 μm, apparent porosity of 36.0 %, flexural strength of 23.9 MPa, and thermal conductivity of 2.1 W/(m·K) at 500 °C. • MgO-MgAl 2 O 4 aggregates produced simultaneously has sub-micron pores, high strength and low conductivity. • Due to diffusion of MgO into Al 2 O 3 pseudomorph and spinalization, sub-micron pores produced in MgO matrix and MgAl 2 O 4 cores. • By adjusting MgO content, the number and size of inter-particle pores can be reduced, significantly improving the strength. • The conductivity is mainly determined by intra-particle pores, while the strength mainly depends on intra-particle pores. [ABSTRACT FROM AUTHOR]

This study employed a one-step synthesis method to prepare Beta zeolites (BZs) with various SiO 2 /Al 2 O 3 ratios and applied them as catalysts in the process of producing bio-oil from Kraft lignin (KL). The research investigated the changes in acidity and pore size of BZs under different SiO 2 /Al 2 O 3 ratios and their impact on the catalytic pyrolysis products of KL. Characterization and a series of physicochemical analyses of BZ with different SiO 2 /Al 2 O 3 ratios as well as catalytic pyrolysis products were carried out. The Pearson correlation coefficient was also used to correlate BZ SiO 2 /Al 2 O 3 ratios and the acidity/pore size of BZ as well as the distribution of the products and the deoxygenation effect. The results indicate that BZs with different SiO 2 /Al 2 O 3 ratios can effectively catalyze the upgrading of KL during pyrolysis. BZ with SiO 2 /Al 2 O 3 ratios of 45 exhibited stronger acidity, a more prominent layered porous structure, and a more orderly distribution of mesopores. It showed the best catalytic upgrading effect on KL, achieving a product yield of 58.4 %. More prominently, the oxygen content is reduced to 14.19 % and the deoxygenation extent of the heavy oil reached 37.1 %. [Display omitted] • The ratio of SiO 2 /Al 2 O 3 in Beta zeolites affects its acidity and pore structure. • The Beta zeolite with appropriate SiO 2 /Al 2 O 3 ratios has good lignin cleavage ability. • The use of correlation analysis is instructive in the selection of zeolites. [ABSTRACT FROM AUTHOR]

• MMC resins enhance HCP removal from mAb during post-protein A polishing. • Ligand structure with long non-aromatic moiety showed excellent HCP removal capacity. • Larger pore size in MMC resins enhances mAb loading capacity and HCP removal. • MMC resins with >440 nm pores exhibit improved HCP removal capacity. • These MMC prototypes can help enhance biopharmaceutical purification processes. Despite advancements in therapeutic monoclonal antibodies (mAbs) and cell line engineering, separating host cell proteins (HCPs) from mAbs during downstream purification remains challenging. Therefore, in this study, we developed a novel multimodal chromatography (MMC) resin to enhance HCP removal during mAb polishing processes. We evaluated the impact of both ligand structure and pore size of the MMC resin by purifying a post-protein A chromatography solution in flow-through mode. We observed that the efficiency of HCP clearance depended on the hydrophobic moiety structure of the ligand and predicted the mAb purification capability of MMC through linear salt-gradient elution experiments involving a mixture of transferrin, bovine serum albumin (BSA), and pepsin. Our findings revealed that the prototype immobilized 1,12-dodecanediamine via the formyl group exhibited the best performance attributed to its long alkyl chain. Furthermore, an investigation of effects of base bead pore size on HCP capacity using cellulose base beads of five different pore sizes showed that larger pore resin base beads had the highest HCP removal capacity. Specifically, MMC resins with a pore diameter exceeding 440 nm reduced the HCP level by three orders of magnitude under high mAb loading conditions (> 1000 mg/mL-resin). The MMC resin developed in this study, along with the insights gained into ligand structure and pore size, not only enhances mAb polishing efficiency but also contributes to improving downstream processes in mAb biopharmaceutical production. [ABSTRACT FROM AUTHOR]

Mesoporous carbon materials, known as graphene mesosponges (GMS), exhibit remarkable flexibility. These materials are expected to advance the field of physical chemistry through the investigation of phenomena induced by significant deformation of mesopores when mechanical forces are applied. In this work, GMS has been synthesized in the form of spherical microparticles, namely micro-spherical GMS (ms-GMS). The remarkable flexibility of ms-GMS has been validated through mercury intrusion tests, and also by methanol adsorption measurements with and without the application of mechanical force. Moreover, we successfully capture live footage of the elastic deformation of a single ms-GMS particle, enabling the determination of 'the Poisson's ratio. Furthermore, we are attempting to observe the non-Faradaic process that occurs within a single sphere during mechanical deformation, utilizing scanning electrochemical cell microscopy (SECCM). The results showed a noticeable decline in capacitive rate performance when the pore size decreased from 7 to 2 nm. This approach effectively minimizes interference from other structural variations that typically arise during carbon synthesis and electrode fabrication, offering a new avenue for elucidating the specific influence of pore size in such materials. [Display omitted] [ABSTRACT FROM AUTHOR]

The traditional view of Na+ as harmful and Ca2+ as beneficial doesn't always apply in multi-cationic soil solutions. Initially, adding Ca2+ promotes Na+ leaching, reducing salinity, but excess Ca2+ becomes counterproductive. As Na+ leaches, the soil's Ca2+-Na+-Mg2+ mix shifts to Ca2+-K2+-Mg2+, Ca2+'s function changes, even causing the opposite effect. To investigate the complex mechanism of Ca2+ to Na+-Mg2+ and K+-Mg2+, we conducted an indoor soil column experiment using saline water (4 dS m−1) with different cation compositions [Na+-Ca2+-Mg2+ (NCM), Na+-Mg2+ (NM), K+-Ca2+-Mg2+ (KCM), K+-Mg2+ (KM)] and deionized water as the control (CK). The results showed that NM exhibited the highest crack volume, while KM had the greatest macropore volume, with NM having approximately 15 % more crack volume than KM. Notably, only NM displayed a more pronounced inclination towards pore anisotropy value of 0 when compared to CK. NCM and KCM had higher pore anisotropy values than NM and KM. KM and KCM had more cracks angled ranging from 45–90° than NM and NCM. KCM notably decreased transitional macropores < 5.5 mm in length compared to KM, with no significant difference (P > 0.05) observed in widths < 2.5 mm between KCM and KM. NM displayed the shallowest macropore distribution and the highest variability in macropore length among all treatments. Only NCM showed significantly reduced variability in both macropore length and width compared to CK. In summary, Ca2+ exhibited distinct action patterns on K+-Mg2+ and Na+-Mg2+. For specific soil types and cationic compositions, Ca2+ may not fully exert its amendment effects. However, Ca2+'s effect is soil-specific, necessitating comprehensive studies across varied soil types. • For Na+-Mg2+, Ca2+ input inhibits crack formation with complex pore morphology. • In K+-Mg2+ environment, Ca2+ aids crack length growth and shapes uniform soil pores. • The impact of Ca2+ decreases with more wetting-drying cycles • Ca2+ triggers adverse effects on soil structure in certain conditions. [ABSTRACT FROM AUTHOR]

Oil mist coalescence and filtering are extensively used in the fields of natural gas purification and chemical production. However, it remains technically challenging to capture high-concentration, small-sized, oil mist droplets under complex industrial field conditions. To solve this problem, three novel high-efficiency coalescence filter cartridges are proposed, which have improved filter material arrangements. The filtering performance of the cartridges was evaluated in the laboratory and at a natural gas pipeline pressure station under different working conditions to understand the mechanism by which high-concentration small-sized droplets are captured. According to the laboratory results, the filtration efficiency for droplets> 0.2 µm can reach 99.99% if the first layer in the cartridge has a small pore size (1.5 µm). The use of a filtering material with a large pore size can reduce the pressure drop. An arrangement of layers with increasing pore sizes can significantly improve the quality factor of the cartridges and decrease secondary entrainment. In the field test, the size distributions of the oil mist under compressor "hot standby" and operating conditions were gained for the first time. The median size of oil mist droplets was 1.2 µm during hot standby and 0.5 µm during operation. Under both compressor modes, the downstream oil mist concentrations of the proposed cartridges were> 95% lower than that of an existing commercial cartridge once filtering reached a steady state. In a long-cycle test under field conditions, the proposed cartridges showed more stable filtering performance than the existing product, with the filtration efficiency being about 40% higher after 15 days. Moreover, the oil mist coalescence mechanism was determined by microscopic characterization of liquid channels. • An improved filter cartridge for oil mist separators was proposed. • An arrangement of layers with increasing pore sizes can significantly improve the quality factor and decrease secondary entrainment. • The proposed cartridges showed more stable filtering performance than the existing product. • The oil mist coalescence mechanism was determined by microscopic characterization of liquid channels. [ABSTRACT FROM AUTHOR]

This study was conducted to address the potential of combining porous biocompatible scaffolds with primary cells or autologous diced cartilage in cartilage tissue engineering in the animal model. The purpose of this study is an experimental evaluation of polycaprolactone (PCL) scaffold cell-based nasal implant using three-dimensional (3D) printing. In this study, we applied hollow PCL cage scaffolds with 200 and 400 µm pore sizes. The scaffolds were divided into three groups (n = 4 for each group): (1) PCL cage scaffolds loaded with agarose gel and chondrocytes; (2) PCL cage scaffolds loaded with agarose gel and fibroblasts, and (3) PCL cages loaded with autologous diced cartilage. In each group, chondrocytes and fibroblasts were seeded into the agarose gel at the density of 5 × 106 cells/mL. All implants showed sufficient integration into the surrounding tissue. It was revealed that chondrocytes were proliferated and differentiated better in the "400 µm" scaffolds than in the "200 µm" group. However, a pore size of 200 µm was optimal for fibroblasts' proliferation. In addition, the results of our study showed that the use of PCL-based scaffolds can achieve the desirable stable augmentation effect with almost none of the changes of contour. In this study, both groups: (1) PCL cage scaffolds loaded with agarose gel and chondrocytes and (2) PCL cages loaded with autologous diced cartilage demonstrated chondrogenic potential with scaffolds with 400 µm pore size. The PCL cage scaffolds loaded with agarose gel and fibroblasts demonstrated potential in cartilage tissue formation within the pore size of 200 µm. [ABSTRACT FROM AUTHOR]

Hydrogen adsorption with micro-structure deformation under ultra-high pressure in nanoporous carbon (NPC) has been studied. This study proposed a new ultra-high pressurization (UHP) method. It produces a gas atmosphere of over 100 MPa utilizing the cold isostatic pressing (CIP) device. NPC materials were pressurized under a hydrogen atmosphere at 100–400 MPa. NPC fabricated from rice husk via KOH activation possesses a high surface area achieving 3500 cm2/g and a micropore volume of over 2.0 cm3/g. The maximum hydrogen uptake reached 3.2 wt% (77 K, 0.1 MPa). Then, NPC materials were treated with 100–400 MPa pressurization in the hydrogen atmosphere. NPC showed a preferred deformation behavior of 1.1–1.2 nm after pressurization, which is the optimum size for hydrogen adsorption. Additionally, the maximum micropore volume increased to 2.51 cm3/g. However, the hydrogen uptake shows a slight decrease to 3.0 wt%. The isosteric heat of adsorption maintained at 8.0–10.3 kJ/mol. [Display omitted] • New ultra-high pressurization (UHP) method was proposed utilizing a cold isostatic pressing device. • Pore size distribution of nanoporous carbon (NPC) after pressurization was investigated. • Pore size distribution of NPC deformed after pressurization by (UHP). [ABSTRACT FROM AUTHOR]

In the present work, we propose a novel method to decrease the pore size as well as to enhance the strength of microporous Al 2 O 3 -MgAl 2 O 4 refractory raw materials, which were prepared by the vacuum impregnation treatment of porous Al 2 O 3 powders with at MgCl 2 solution. The effect of the MgCl 2 content (0–32.5 wt%) on the phase distribution, microstructures, and physical properties of the refractory raw materials was thoroughly investigated. The results demonstrated that the sub-micron pore structure inside the pseudomorph particles was effectively preserved due to the volume expansion effect of spinel and the spinel sintering neck formation between Al 2 O 3 microcrystallites. With the MgCl 2 content increasing from 0 to 11.9 wt%, the pseudomorph particles contained many sub-micron pores resulting from the introduction of the MgCl 2 solution, resulting in the decrease of the intra-particle pore size as well as the development of spinel sintering necks between pseudomorph particles. The strength of the aggregates was therefore enhanced. With a further increase of MgCl 2 content to 24.2 and 32.5 wt%, the inter-particle pore sizes increased due to the volume expansion and Kirkendall effect associated with the spinel formation between pseudomorph particles, which were responsible for the progressive decrease of the strength. Overall, the optimized samples were microporous Al 2 O 3 -MgAl 2 O 4 refractory aggregates with the addition of 11.9 wt% MgCl 2 , which exhibited an apparent porosity of 45.0%, a high compressive strength of 45.6 MPa, a median pore size of only 1.49 µm, and a high sub-micron pore volume content of 42.5 vol%. Meanwhile, it is possible to obtain the porous Al 2 O 3 -MgAl 2 O 4 powders with a large number of sub-micron pores by crushing and sieving the optimized aggregates. [ABSTRACT FROM AUTHOR]

As a major component of extracellular matrixes (ECMs), collagen is an attractive biomaterial to fabricate porous scaffold for tissue engineering due to their similarity to the in vivo static microenvironment. However, the collagen-based porous scaffolds were difficult to mimic the dynamically remolded porous structure of ECM during the cell proliferation and tissue development, and always have poor mechanical property and not easy to handle. Here, natural collagen and partially denatured collagen was used to prepare the stepwise degradable hybrid bioscaffold with suitable mechanical property and dynamically remolded inner porous structure, which is desirable for the applications of tissue engineering. The collagen-based microporous scaffold was first prepared and used as physical support, then, the mechanical strength of which was reinforced by the import of the partially denatured collagen to give the hybrid bioscaffold. The fabrication conditions of the hybrid scaffolds were optimized, of which the thermal stability, mechanical property, and swelling property was explored. The stepwise enzymatic degradation process and the corresponding porous structure variation of the hybrid scaffold was confirmed by SEM and cell culture assays. [ABSTRACT FROM AUTHOR]

Laser lighting is superior to light-emitting diodes (LEDs) in brightness, beam aperture and efficiency, which largely depends on the light extraction efficiency and thermal properties of color converters. In this paper, we proposed to improve the light extraction efficiency of red-emitting AlN-CaAlSiN 3 :Eu composite phosphor ceramics by controlling the light scattering, and to improve the thermal conductivity of the phosphor ceramics by increasing grain size. The composite phosphor ceramics with moderate light scattering and high thermal conductivity can be obtained by gas pressure sintering (GPS) and the followed hot isostatic pressing (HIP). The saturation threshold of the sample is increased from 7.0 to 10.8 W, and the luminous flux is enhanced from 32.3 to 51.0 lm after the HIP post-treatment, which is 55.5% higher than the previously reported dense AlN-CaAlSiN 3 :Eu composite phosphor ceramics (32.8 lm). This work emphasizes the role of pore size distribution in light extraction efficiency of phosphor ceramics. [ABSTRACT FROM AUTHOR]

Currently, the treatment of bone defects in arthroplasty is a challenge in clinical practice. Nonetheless, commercially available orthopaedic scaffolds have shown limited therapeutic effects for large bone defects, especially for massiveand irregular defects. Additively manufactured porous tantalum, in particular, has emerged as a promising material for such scaffolds and is widely used in orthopaedics for its exceptional biocompatibility, osteoinduction, and mechanical properties. Porous tantalum has also exhibited unique advantages in personalised rapid manufacturing, which allows for the creation of customised scaffolds with complex geometric shapes for clinical applications at a low cost and high efficiency. However, studies on the effect of the pore structure of additively manufactured porous tantalum on bone regeneration have been rare. In this study, our group designed and fabricated a batch of precision porous tantalum scaffolds via laser powder bed fusion (LPBF) with pore sizes of 250 μm (Ta 250), 450 μm (Ta 450), 650 μm (Ta 650), and 850 μm (Ta 850). We then performed a series of in vitro experiments and observed that all four groups showed good biocompatibility. In particular, Ta 450 demonstrated the best osteogenic performance. Afterwards, our team used a rat bone defect model to determine the in vivo osteogenic effects. Based on micro-computed tomography and histology, we identified that Ta 450 exhibited the best bone ingrowth performance. Subsequently, sheep femur and hip defect models were used to further confirm the osteogenic effects of Ta 450 scaffolds. Finally, we verified the aforementioned in vitro and in vivo results via clinical application (seven patients waiting for revision total hip arthroplasty) of the Ta 450 scaffold. The clinical results confirmed that Ta 450 had satisfactory clinical outcomes up to the 12-month follow-up. In summary, our findings indicate that 450 μm is the suitable pore size for porous tantalum scaffolds. This study may provide a new therapeutic strategy for the treatment of massive, irreparable, and protracted bone defects in arthroplasty. [ABSTRACT FROM AUTHOR]

The influence of pore size and hydrophilicity on the permeance of reverse osmosis (RO) membranes has been mostly focused. However, their influence is hardly to be clearly identified as these two kinds of factor interfere with each other. In this work, high-throughput molecular dynamics (HTMD) simulations with CNTs are used to extensively produce the data of water permeance and NaCl rejection. These data are then analyzed by machine learning (ML) method to obtain the optimized desalination performance. The HTMD results indicate that the pressure drop has little effect on the water permeance. Moreover, rising pore size and degrading hydrophilicity will generally boost water permeance but will somehow sacrifice the NaCl rejection. The interference effect between pore size and hydrophilicity is also found in this work, the mechanism of which is then revealed from molecular level. Additionally, ML is applied to analyze the abundant data of water permeance and NaCl rejection. The optimal conditions are identified to achieve the highest water permeance with 100% NaCl rejection, which are also validated via additional MD simulations. This work suggests that the integration of HTMD and ML promises the future of designing new kind of RO membranes for better performance. [Display omitted] • Optimized desalination performance is obtained by HTMD simulations & ML analysis. • Influence of pore size on water permeance is revealed from molecular level. • Effect of hydrophilicity on water permeance is also coupled with pore size. • Ion rejection of CNTs to NaCl is interactively affected by σ, ε, and Δ P. • Δ P has very little impact on water permeance as flux rises linearly with it. [ABSTRACT FROM AUTHOR]

Aluminum foams are desired for lightweight, high-performance, and cost-effective materials, particularly in automotive, aerospace, and advanced power plants. Expansion of their applications depends on developing a detailed understanding of the structural and mechanical properties of aluminum foams. In this research, open-cell aluminum foams with 25.51–81.88 % porosity were manufactured through powder metallurgy using a space holder technique, with varying carbamide (urea) ratios (17–80 %) and particle sizes (1–1.4 mm, 1.7–2 mm, 2–2.4 mm). Three different ceramic particles, B 4 C, Al 2 O 3 , and SiC were used as reinforcement to improve the compression properties and energy absorption capacity of the foam materials. The study determined open and closed porosity ratios, spherical diameter, sphericity values, micropore sizes, mechanical properties, and energy absorption capacity of the foam samples both with and without ceramic additives. The results show that porosity ratio, pore size, and ceramic particle addition significantly affect aluminum foams' structural and mechanical properties, allowing for tailored properties for specific applications. It was observed that as porosity increased, compressive stress decreased, and the length of the plateau region and the shape change where densification began increased. However, there was no significant change in compressive stress and specific energy values with changing pore size. The optimal B 4 C addition was found to be 4 %, which significantly improved compressive strength to 3.75 MPa and specific energy to 4.24 MJ m−3. • 4 % B 4 C addition maximized the compressive strength and energy absorption capacity of aluminum foams. • Increased porosity led to a decrease in maximum compressive stress but an increase in plateau length and energy absorption. • 1.7–2 mm pore size provided the highest efficiency in energy absorption capacity. • Presence of micropores significantly affected the mechanical properties of foams, especially at high porosity levels. • Ceramic particle addition improved the strength of aluminum foams without negatively impacting pore formation. [ABSTRACT FROM AUTHOR]

Ammonia is emerging as a promising carbon-free fuel in the pursuit of carbon neutrality due to its combustion process, which produces no carbon dioxide emissions. Membrane distillation (MD) for recovering ammonia from wastewater is an alternative to conventional energy-intensive production methods. However, the efficiency of MD processes is hindered by the low purity of the recovered ammonia stream, primarily due to excessive water permeation. In this study, we investigated the influence of membrane properties on water and ammonia permeation using poly(vinylidene fluoride- co -hexafluoropropene) (PVDF-HFP) nanofibrous membranes fabricated in-house via electrospinning. Additionally, we compared the impact of manipulating membrane characteristics with adjusting operating conditions, employing a commercial PVDF membrane as the conventional approach for controlling ammonia purity. Our findings revealed that increasing membrane thickness (from 82 to 283 μm) under isothermal conditions substantially enhanced the ammonia separation factor (from 4.07 to 7.28) by approximately 80 %, whereas reducing the feed temperature from 50 °C to 43 °C yielded only a 20 % improvement. Mechanistic modeling of MD for the water-ammonia system illustrated the critical role of membrane thickness in improving ammonia selectivity by markedly reducing water flux while maintaining relatively consistent ammonia flux. The combination of experimental and simulation outcomes suggests that modifying membrane properties or selecting membranes with specific characteristics can enhance ammonia selectivity without significant alterations to operating conditions or configuration. • NH 3 recovery from wastewater was applied using membrane distillation (MD). • Influence of membrane properties on MD permeation was studied to enhance NH 3 selectivity. • Increased membrane thickness under isothermal conditions enhanced NH 3 separation factor. • Mechanistic modeling highlighted the critical role of membrane thickness in NH 3 selectivity. • Modifying membrane properties offers a viable approach to enhance NH 3 selectivity in MD. [ABSTRACT FROM AUTHOR]

Porous starch (PS) was widely prepared for its large effective surface area, pore volume, and superior hydrophilic property, but its application is limited by enzyme and chemical use. In this study, a novel method to prepare PS with controllable hierarchical pores through ultrasound-ethanol precipitation and different amylose-amylopectin ratios is proposed. As shown in porous morphology and parameters, there were macropores, mesopores and micropores in the formed PS. Moreover, we found that the content of amylose (AM) was negatively related with the total pore volume and pore diameter in PS. The different surface tensions created through ethanol evaporation and water migration during oven drying are the main mechanisms of forming pores with controllable sizes. Based on the molecular information and the long-/short-range orders reflected by crystalline pattern, lamellas, and single-/double-helices, we conclude that AM is easier to form V -type inclusion complexes with ethanol. More single helix of V-amylose was transformed from B-type polymorph after ethanol exchange, which had significantly broadened d Lozentz in PS. The TG spectra proved that the novel PS has the stable thermodynamic property. Overall, the finding of an objective regular between AM and pore sizes of PS in this study may support the other work related to PS. [ABSTRACT FROM AUTHOR]

[Display omitted] • A hydrothermal activation method was proposed to enhance mineralization efficiency. • The optimum hydrothermal temperature and time affecting efficiency were determined. • Hydrothermal activation mineralization reaction mainly enhances the pores above 9 nm. • At pore sizes ≥9 nm, hydration swelling effect exceeds mineralization precipitation. To address the challenge of low mineralization efficiency of fly ash-supercritical carbon dioxide (CO 2), a hydrothermal activation method was proposed to enhance fly ash-supercritical CO 2 mineralization. The study systematically investigated the mechanism through which hydrothermal activation parameters influenced the efficiency of fly ash-supercritical CO 2 mineralization through a series of experimental reactions. The effects of hydrothermal activation temperature and time on mineralization efficiency were investigated macroscopically. The results indicated that the mineralization efficiency increased by 202.93 % when hydrothermally activated at 220 °C for 30 min. Furthermore, when the activation time was ≤10 min, 220 °C exhibited a significant effect on the mineralization efficiency. For activation time ≥20 min, mineralization efficiency exhibited high stability with increasing temperature. Subsequently, under 220 °C conditions, mineralization efficiency reached 18.79 % for 5 min and 21.69 % for 30 min, representing only a 15.43 % increase despite a six-fold increase in time. Microscopic analysis of the pore structure of hydrothermally activated fly ash indicated that pore parameters (volume, specific surface area, and volume change rate) exceeded those of original fly ash for pore diameters ≥9 nm, and the opposite was observed for pore diameters <9 nm. Additionally, compared with the pristine fly ash, the pore size and volume fraction of the mineralized fly ash macropores increased, while mesopores decreased, and small pores exhibited a slight decrease in volume fraction and size. This indicated that pores ≥9 nm were primarily affected by hydration expansion, while pores <9 nm were primarily affected by mineralization precipitation. The hydrothermal activation mineralization reaction predominantly affected medium and large pores ≥9 nm, exhibiting less effect on smaller pores. [ABSTRACT FROM AUTHOR]

• Highly-efficient purification of CH 3 F electronic gas was realized using carbon adsorbent C-HCP-1. • C-HCP-1 performs C 3 H 8 uptake of 0.164 mmol g−1 at 0.01 kPa and 298 K, and record C 3 H 8 /CH 3 F IAST selectivity up to 40.0. • C-HCP-1 demonstrates one-step CH 3 F purification from 4 N to 7 N-grade with a CH 3 F breakthrough capacity of 3715 L kg−1. Ultra-pure fluoride electronic gas is an indispensable cleaning and etching gas in the semiconductor industry. Adsorptive separation based on porous materials can be a promising technology to effectively separate ultra-pure CH 3 F (>99.9999 %) from trace C 3 H 8 impurity (∼100 ppm). Herein, a series of glucose-derived carbon adsorbents (GCAs) were prepared using a combination strategy of pre-oxidation and KOH activation. Among obtained adsorbents, C-HCP-1 showed a high micropore surface area of 1472 m2 g−1 and ultramicropore (<8 Å) volume of 0.332 cm3 g−1. The rich ultramicroporosity enabled C-HCP-1 to exhibit a remarkable C 3 H 8 uptake of 0.164 mmol g−1 at 0.01 kPa and 298 K, and C 3 H 8 /CH 3 F IAST selectivity of 40.0. A highly linear correlation (R2 > 0.98) has been observed between C 3 H 8 /CH 3 F selectivity and ultramicropore volume. Breakthrough experiments verified that 7 N-grade CH 3 F could be produced from C 3 H 8 /CH 3 F mixtures (1/9999, v/v) with a record productivity of 3715 L kg−1. Meanwhile, excellent cycle stability and moisture stability suggest C-HCP-1 as a competitive candidate for highly-efficient purification of industrial electronic gas. [ABSTRACT FROM AUTHOR]

Worldwide, a considerable amount of oily wastewater is generated, with oil droplets from 2 to 200 nm that are difficult to separate because of their size and colloidal stability. This study presents a novel approach for effectively separating microemulsions via cubic silicon carbide (3C-SiC)-coated alumina (Al 2 O 3) membranes fabricated based on low pressure chemical vapor deposition (LPCVD). SiC was deposited at a relatively low temperature at 860 °C on 100 nm Al 2 O 3 membranes using two precursors: SiH 2 Cl 2 and C 2 H 2. With the increase in deposition time, up to 25 min, the pore size decreased from 41 nm to 33 nm, which is a smaller pore size of a SiC membrane than previously used for oil/water separation. The polycrystalline 3C-SiC-coated membranes showed improved hydrophilicity (water contact angle of 15°) and highly negatively charged surfaces (−65 mV). Microemulsion filtration experiments were carried out at a constant permeate flux (80 Lm−2 h−1) for six cycles with varying deposition time, pH, surfactant types, and pore sizes. The fouling of the SiC-coated membrane was, compared to the Al 2 O 3 membrane, effectively mitigated due to the enhanced electrostatic repulsion and hydrophilicity. Surfactant adsorption mainly occurred when the surface charge of the microemulsion and the membranes were opposite. Therefore, the surface charge of the alumina membrane changed from positive to negative when soaked in negatively charged microemulsions, whereas SiC-coated membranes remained negatively charged regardless of surfactant type. The membrane fouling was alleviated when the membrane and oil droplets had the same charge. Lastly, the 62 nm SiC-coated membrane with 20 min coating time was the best choice for the filtration of the microemulsion, because of the high rejection of the oil droplets and low fouling tendency. [Display omitted] • Ultrathin (18 nm) polycrystalline 3C-SiC was deposited onto a Al 2 O 3 membrane. • SiC membrane with the smallest pore size (33 nm) for oil/water separation. • Highly hydrophilic membranes with a negative surface charge were produced. • Various pore sizes of 3C-SiC coated membranes were compared. • A combination of high oil rejection and low (ir)reversible fouling was achieved. [ABSTRACT FROM AUTHOR]

• Atomic-level dispersion in silica optimized the Ti utilization efficiency. • Mesoporous SiO 2 with only 3 wt% Ti is compatible with pure TiO 2 photocatalyst. • The pore size of mesoporous silica affects CO 2 photoreduction selectivity. • Findings can guide the optimization of photocatalytic efficiency for CO 2 conversion. The photocatalytic conversion of CO 2 into chemicals and fuels is a promising approach for reducing atmospheric CO 2 and addressing energy demands. This study investigates the impact of titanium (Ti) content and pore size in mesoporous silica on CO 2 photoreduction (CO 2 PR) efficiency. Ordered mesoporous silica with a large surface area and stability is used as a matrix for Ti dispersion. Two sets of photocatalysts with varying Ti contents and pore sizes are synthesized and assessed for their microstructures, photoelectric properties, and CO 2 PR efficiency in both solid–gas and liquid–gas modes. The results reveal that photocatalysts with only 3.0 wt% Ti perform comparably to commercial TiO 2 (P25) and can be recycled and reused. Moreover, an enhancement in photocatalytic activity with increasing pore sizes of the photocatalysts is observed. Notably, a photocatalyst with 3.0 wt% Ti and about 8 nm pore size significantly outperforms P25, producing much higher CH 4 , CO, and CH 3 OH yields. These findings are crucial for optimizing photocatalyst efficiency and are applicable across various compositions. [ABSTRACT FROM AUTHOR]

Thymol is synthesized from m-cresol alkylation reaction with 2-propanol. A few commercial zeolites have been tested in this reaction, but the influence of acidity and porosity of a zeolite on the m-cresol conversion and thymol yield is scarcely studied. Isomorphously-substituted Al-, Ga-, Fe-, B-, and In-UTL with different heteroelements and thus different ratio between strong and weak sites give insight into the effect of acidity. Isoreticular zeolites Al-UTL, Al-IPC-7, and Al-IPC-2 with different pore sizes reveal the effect of porosity. In this study, m-cresol conversion was far from comparable over Al-UTL or Ga-UTL (X = 18–19 %) and Fe-UTL, B-UTL, or In-UTL (X = 2–3 %) having different concentration of strong Brønsted acid sites. Thymol yield was also higher over Al- and Ga-UTL (Y = 11–13 %) than over Fe-, B-, and In-UTL (Y = 1–2 %). The easier accessibility to the strong Brønsted acid sites in Al-UTL, provided by bigger pore sizes, resulted in higher m-cresol conversion and thymol yield compared to Al-IPC-7 (X = 15 % and Y = 8 %) and Al-IPC-2 (X = 6 % and Y = 2 %). In addition, the stronger Brønsted acidity and large and extra-large porosity in Al-UTL and Ga-UTL facilitated the rearrangement of isopropyl-3-methylphenyl ether - the product of the O-alkylation pathway - to thymol. Thus, Al-UTL and Ga-UTL (along with Al-FAU reference material) confirmed the optimum structural properties for a high selectivity to thymol. [Display omitted] • Isomorphous substitution in UTL gives zeolites with varied acid properties. • ADOR process in UTL gives isoreticular zeolites with varied pore sizes. • Strong Brønsted acid sites favor thymol formation from m-cresol isopropylation. • Pores of at least 12-MR provide sufficient accessibility of m-cresol to acid sites. • iPr-3-MPh ether rearranges to thymol on strong Brønsted acid sites in large pores. [ABSTRACT FROM AUTHOR]

The presence of pores in a microarc oxidation (MAO) coating is an inherent characteristic that results from the expulsion and rapid solidification of molten material during the MAO process. The pore size in the MAO coating on the titanium alloy strongly affects the biocompatibility, but how to control it is unclear. The present study utilizes the advantages of NaOH to modulate pore size and plasma discharge, thereby effectively regulating the pore structure of the coating. The FIB-lift-out method was employed to directly extract the cross-sectional samples from the coating, enabling a detailed investigation of the pore microstructure using transmission electron microscopy (TEM). The structure surrounding the discharge channels exhibit layered zoning characteristics, with an amorphous layer near the discharge channel and a distinct crystal structure further away from it. The addition of NaOH enables the regulation of electrochemical and energy release processes, while also facilitating efficient discharge and spark generation to effectively disrupt the oxide layer and establish a plasma discharge channel. The presence of pores in a microarc oxidation (MAO) coating is an inherent characteristic resulting from the expulsion and rapid solidification of molten material during the MAO process. The pore size of the MAO coating on the titanium alloy strongly affects the biocompatibility, but how to control this effect is unclear. The present study utilizes the advantages of NaOH to modulate pore size and plasma discharge, thereby effectively regulating the pore structure of the coating. The FIB-lift-out method was specifically employed to directly extract cross-section samples from the surface of the microarc oxidation coating, enabling a detailed investigation of the pore microstructure using transmission electron microscopy (TEM). The structure surrounding the discharge channel exhibits layered zoning characteristics, with an amorphous main structure near the discharge channel and a distinct crystal structure further away from it. The addition of NaOH ultimately enables the regulation of electrochemical and energy release processes while also facilitating efficient discharge and spark generation to effectively disrupt the oxide layer and establish a plasma discharge channel. [Display omitted] • A porous MAO coating on Ti-6Al-4 V with good biocompatibility is enabled by the addition of NaOH in a silicate electrolyte. • The porosity, pore size and thickness of MAO coatings are regulated by adjusting NaOH concentration. • Distinct layered band characteristics including crystalline and amorphous structure form surrounding the discharge channel. [ABSTRACT FROM AUTHOR]

Pore-size controlled ordered mesoporous CeWTix catalyst with framework confinement structure protected highly dispersed active sites from SO 2 attacking. Importantly, the ordered mesoporous structure with larger pore sizes promoted the decomposition of ammonium bisulfate (ABS) at lower temperature, effectively alleviating the deposition behavior of ABS on the catalyst surface, thereby improving the catalyst's ability to resist SO 2 poisoning. [Display omitted] • ABS poisoning had been investigated on pore-size controlled ordered mesoporous CeWTix catalyst. • Highly dispersed active sites were protected from SO 2 attacking by framework confined structure. • Larger pore size could promote the decomposition of ABS at lower temperature. SO 2 poisoning had long been recognized as the key to disrupting the longevity of SCR catalysts. The deposition of the toxic component ammonium bisulfate (ABS) on the catalyst was the main cause of its SO 2 poisoning, so it was essential to active and promote the decomposition of ABS. In this study, the decomposition of ABS on catalyst surface was adjusted by controlling the pore size of ordered mesoporous catalyst. The results showed that the framework confined ordered mesoporous catalyst with larger pore size had stronger confinement effect on the active components Ce and W, which protected them from being attacked by sulfate group and ensured active components participating in SCR reaction effectively. In addition, according to the Kelvin equation, it was proved that the ABS deposited at a larger pore size would be subject to a larger surface vapor pressure, which would easily vaporize and decompose. This not only reduced the deposition of ABS, but also reduced the formation of metal sulfate from the conversion of ABS. Therefore, the framework confined ordered mesoporous CeWTix catalysts with larger pore sizes showed better SO 2 -resistance. This study provided a new path for the design of SCR catalysts with good SO 2 -resistance. [ABSTRACT FROM AUTHOR]

[Display omitted] • The influence of pore size and pore structure on the adsorption performance were systematically compared. • The small pore size and the cubic mesoporous structure could reduce the suppression effect of temperature. • The cubic mesoporous structure could inhibit the generation of urea. • The silica with large pore sizes suited PEI, and the silica with small pore sizes suited DETA. Silica impregnated with amines has attracted much attention as a promising alternative to amine scrubbing. This study selected SBA-15, MCM-41, and MCM-48 as support materials and set amine types (PEI and DETA), amine loadings (20–45 %), and temperatures (40–120 ℃) as parameters, systematically exploring the influence of pore size and pore structure on the adsorption performance. The pore size and pore structure had little impact on the type of chemical functional group and thermal stability, but played an important role in the CO 2 adsorption capacity as well as the response of adsorption performance to temperature and amine. By comparison, the silica with large pore sizes was more suitable for PEI, while the silica with small pore sizes was more suitable for DETA. The hexagonal mesoporous structure was congenial to DETA and low PEI loading, while the cubic mesoporous structure was congenial to high PEI loading. The small pore size and the cubic mesoporous structure were proven to maintain the promotion effect of the adsorption temperature, while the hexagonal mesoporous structure could relieve the amine volatilization during the adsorption–desorption cycles. The cubic mesoporous structure could inhibit the generation of urea. By comparison, SBA-15 modified with 45 % had excellent performance, reaching a CO 2 uptake of 160.55 mg/g and an amine efficiency of 0.360. This product could also control the total percentage of CO 2 uptake lost after 30 cycles within 2.0 %, demonstrating the potential for practical application. [ABSTRACT FROM AUTHOR]

Concrete is a commonly utilized material in the construction of infrastructure in Northwest China. However, its durability in saline environments is hindered by its susceptibility to salt and freeze-thaw erosion. By incorporating basalt fibers (BF), reticulated polypropylene fibers (RP), and calcium carbonate whiskers (CW) into concrete, the crack resistance of the material can be enhanced from the micro to macro level. Previous research has yet to thoroughly examine the enduring erosion resistance of CW-BF-RP concrete (CBPC) over extended periods amidst diverse salt-freezing conditions. Additionally, the precise mechanism through which CW impacts the deterioration of the interfacial transition zone (ITZ) between fibers and the cement matrix remains incompletely elucidated. This study examines the variability in compressive strength, mass loss, and damage degree of CBPC when exposed to various types of salts (sulfate/chloride) and erosion conditions of different concentrations. And the corrosion mechanism of CBPC in different freeze-thaw conditions was revealed by Fourier Transform Infrared Spectroscopy, Thermogravimetry, Nuclear Magnetic Resonance, Scanning Electron Microscopy and Atomic Force Microscopy. The findings suggest that the strength reduction rate, mass loss rate, and damage degree of CBPC increase with the rise in salt concentration and freeze-thaw cycles. The three indicators in chloride salt conditions are significantly higher than FW, with values of 78.64%, 223.6%, and 309.0%, respectively, compared to 47.63%, 155.4%, and 162.4% in S-3, indicating that CBPC exhibits greater resistance to sulfate salts than chloride salts. The consumption of CH is a key factor in the occurrence of AFt and Friedel's salt and pore degradation. Concrete pore degradation between 3.25μm and 6.81μm leads to rapid disintegration, with detachment of the mortar occurring when the pore size reaches 31.95μm. CW maintains its integrity in sulfate salt and FW conditions, but experiences severe corrosion in chloride salt. At this point, the maximum ITZ of 7.5 μm for BF is less than that of 22.8 μm for RP, indicating that the bonding of BF to the matrix is stronger than that of RP. The longitudinal height difference of fiber-cement aggregate ITZ in chloride conditions ranges from 42.8 nm to 59.8 nm, creating water channels of 5.70μm to 6.91μm, thereby weakening the adhesion of the matrix. Finally, a Wiener stochastic model is established for life prediction under different salt-freezing conditions, with the maximum life expectancy in sulfate conditions being 1.26–1.86 times that in chloride conditions. These research findings can provide theoretical references for the durability design of concrete in the salt-freezing areas of northwest China. • Add CW-BF-RP into concrete to study the freeze-thaw endurance degradation law. • The decrease rate of each index of concrete increases with the increase of salt concentration. • CW suffers from severe corrosion due to the decrease of concrete alkalinity in chloride salt condition. • ITZ deterioration in chloride salt condition is significantly greater than that in sulfate and FW conditions. • Wiener stochastic model can effectively characterise the endurance life of concrete in salt-aggressive environments. [ABSTRACT FROM AUTHOR]

• UiO-66-18 with hierarchical structure and abundant active sites were synthesized with trifluoroacetic acid as modulator. • The U(VI) adsorption capacity of UiO-66-18 reached 622.75 mg/g and outperformed most reported UiO-66 based absorbents. • The effects pore structure on the adsorption process toward different U(VI) species were revealed. • The adsorption active sites of UiO-66-18 towards U(VI) were probably Zr-O− and -COO− groups. A defective metal–organic framework UiO-66–18 synthesized via a facile solvothermal synthesis method with trifluoroacetic acid as modulator was demonstrated to be highly efficient for the elimination of uranium from wastewater. The maximum adsorption capacity of UiO-66–18 toward uranium reached 622.75 mg g−1, which was approximately 1.43 times higher than that of pristine UiO-66–0 prepared without TFA modulation. The superior elimination performance of UiO-66–18 was because the TFA modulation induced the generation of more missing-linker defects that endowed UiO-66–18 with hierarchical structure and more adsorption active sites for U(VI) capture. Further adsorption mechanism studies indicated that the elimination of U(VI) was endothermic monolayer chemisorption dominated by mass transfer-decomplexation-adsorption process. In addition, the effects of common ions on the elimination efficiency as well as the reusability of UiO-66–0 and UiO-66–18 were studied. This work provides a promising strategy and a theoretical basis for the design and preparation of efficient uranium adsorbent from the points of defects engineering and pore structure design. [ABSTRACT FROM AUTHOR]

The recent paper "Low-field 1 H NMR study on geopolymers: The effect of paramagnetic Fe(III)" is discussed. After examining the NMR test method and results, it is deduced that, the relaxation signals of the geopolymers with various Fe(III) contents were inconsistently obtained and interpreted without attention to total intensity. The calibration of surface relaxivity was also questionable. These inappropriate interpretations not only make the experimental results about the effect of Fe(III) loading on spin relaxation unreliable, but also make the discussion about its effect on pore structure of the geopolymers too ambitious, which is further incompatible with current understandings of geopolymerization. [ABSTRACT FROM AUTHOR]

Global warming due to greenhouse gas emissions has continuously threatened the climate and environment. Zirconium-based metal-organic frameworks (Zr-MOFs) with Zr 6 inner cores represent a subfamily of nanoporous materials with good physicochemical stabilities, showing significant prospects for practical applications in gas separation. A molecular simulation study is reported here to investigate the membrane separation of CO 2 /N 2 and CO 2 /CH 4 mixtures in five Zr-MOFs (Zr-fum, UiO-66, DUT-52, Zr-cca, UiO-67) with similar ligand in their structures and different pore-limiting diameter (PLD) ranging from 0.36 nm to 0.59 nm. The gas permeation and separation performance are evaluated with the concentration gradient-driven molecular dynamics (CGD-MD) method. The results show that the separation of both gas mixtures is dominated by the preferential sorption of CO 2 over N 2 and CH 4 , respectively. Meanwhile, the PLD of MOFs is also a significant factor governing permeation. MOFs with a larger PLD have a higher permeability and a lower selectivity for CO 2 /N 2 and CO 2 /CH 4 separation. Free-energy profiles were calculated to describe the insights into CO 2 separation, that the larger PLD can cause a lower energy barrier when gases transport through the pore of MOFs. The results were compared with the grand canonical Monte Carlo and equilibrium molecular dynamics (GCMC + EMD) approach, a traditional method to predict gas adsorption and diffusion in MOFs. As the GCMC+EMD approach neglected the interaction between components and potential mass transfer resistance at the surface of the membranes, the results obtained from the CGD-MD method in this work are more reliable. This study provides microscopic insights into CO 2 separation in Zr-MOF membranes and suggests their potential use for gas separation. [ABSTRACT FROM AUTHOR]

The migration of fluids, such as the dissociation of natural gas hydrates, can affect the stability of the seabed and even induce submarine geological disasters and change the marine environment. The migration of fluids in sediments depends on its permeability properties. Therefore, it is crucial to investigate the sediment permeability and its influencing factors. This paper investigates the particle size, porosity, pore size distribution, and permeability of surface clay-bearing sediments in the Shenhu Area of the South China Sea by physical property tests, computed tomography (CT) scanning tests, constant rate of strain (CRS) consolidation tests, and nuclear magnetic resonance (NMR) tests. The permeability of the surface sediments in the Shenhu Area ranges from 3.32 × 10−15–6.76 × 10−14 m2. The pore size mainly ranges between 10−5 and 10−1 mm, exhibiting a bimodal distribution with peaks from 10−4 and 10−2 mm. The increase in clay content leads to enhanced permeability due to the bimodal distribution of pore sizes, which will cause the enlargement of pores. As the pore size increases, the sediment permeability also increases. Sediment permeability linearly decreases with increasing effective axial stress and deformation due to compression of the pore space. Additionally, a new model for calculating permeability with different sediment properties is established, which improves the accuracy of permeability calculations for clay-bearing sediments compared to previous research. The findings of our study can provide a reference for exploring the influence of sediment parameters on fluid migration mechanisms in clay-bearing sediments. • The bimodal distribution of pore size affects the correlation between clay content and permeability. • Variation of permeability has linear relationships with deformation and effective axial stress. • A new model is established to more accurately calculate the permeability of clay-bearing sediments. [ABSTRACT FROM AUTHOR]

Using the mixed powder of TiH 2 , graphite, aluminum and vanadium as starting materials, porous TiVAlC ceramics were fabricated by the reactive synthesis technology at 1300 °C. The chemical steadiness of porous TiVAlC along with the effects of sintering temperature on the viscous permeability coefficient, strength, porosity, pore size and volume expansion rate of the porous TiVAlC were explored, and the mechanism of pore formation was also revealed. The preparation process includes five steps as follows: (i) the complete decomposition of stearic acid at 500 °C; (ii) the pyrolysis of TiH 2 at 700 °C, converting TiH 2 into hydrogen and titanium (iii) The solid-liquid chemical reaction of solid vanadium, titanium and molten aluminum at 700 °C, converting the mixture into V–Al and Ti–Al compounds; (iv) At 900–1100 °C, Surplus V and Ti interact with graphite to synthesize carbides of TiVC 2 , VC, and TiC; (v) Reactive synthesized carbides (TiVC 2 , VC, and TiC), Ti 2 AlC, V–Al and Ti–Al compounds that yield porous TiVAlC at 1300 °C. [ABSTRACT FROM AUTHOR]

Adding pre-foamed colloidal alumina to ultrastable Al 2 O 3 -stabilised foams can be a path towards partially counteracting the firing shrinkage of these materials and producing macroporous ceramics with smaller pores. Nevertheless, this system still presents a long setting time and high sintering-induced shrinkage, which hinders the production of larger samples and reduces its porosity. In the present work, it was observed that adding calcium aluminate cement suspension (CAC S) and CaCO 3 (calcite) to the aforementioned system can speed up its solidification kinetics, improve its mechanical strength and reduce its shrinkage after firing, maintaining high porosity and smaller pore sizes. By using these raw materials, samples with an average pore size below 60 μm, total porosity above 70%, and a narrower pore size distribution were attained after thermal treatment at 1600 °C for 5h. Moreover, due to the in situ formation of calcium hexaluminate, their shrinkage after sintering was almost halved (from ~20% to 11%). [ABSTRACT FROM AUTHOR]

• The micropores in chitosan-based carbon (PC-C) are available to KOH electrolyte. • PC-C is not suitable for H 2 SO 4 electrolyte due to its small pore size. • Trimesic acid is introduced as a carbon precursor to tune the porous structure. • The modified carbon (PC-CT) shows expanded pore size and mesopres. • Compared with PC-C, PC-CT exhibits high-rate performance in H 2 SO 4 electrolyte. Microporous carbon (PC-C) was prepared using chitosan and ZnCl 2 as carbon precursor and activating agent, respectively. Electrochemical measurements and material characterization show that the microporous nature of PC-C limits the ion transfer in H 2 SO 4 electrolyte, resulting in a lower specific capacitance and rate performance in H 2 SO 4 electrolyte compared with KOH electrolyte. Trimesic acid was introduced into the carbon precursor to regulate the porous structure by generating more meso - and macropores, which facilitate the transmission of electrolyte ions with bigger ionic size. In this case, the specific capacitance of the modified carbon can reach up to 180 from 84.6 F g−1 in H 2 SO 4 electrolyte. The assembled supercapacitor cell in H 2 SO 4 electrolyte can deliver an energy density of 4.9 Wh kg−1 at a high-power density of 2500 W kg−1, which is much higher than that (0.4 Wh kg−1) of PC-C. Our study provides a guidance for the preparation and regulation of porous carbon suitable for different aqueous electrolytes. [ABSTRACT FROM AUTHOR]

Fabricating the non-precious-metal catalyst with desirable catalytic performance towards oxygen reduction reaction (ORR) is essential for Mg-air battery that adopts neutral brine electrolyte. However, the classic metal-nitrogen-carbon materials with strong ORR catalytic activity in alkaline solution usually display inferior performance than platinum-based catalysts in neutral environment. Herein, we construct a hybrid catalyst composed of cobalt nanoparticles and nitrogen-doped carbon nanotubes, based on pyrolyzing the mixture of melamine, pyrazole, hexadecyl trimethyl ammonium bromide, and 2-methylimidazole chelated with Co2+ and Zn2+ ions. This catalyst possesses abundant ORR catalytic active sites and mesoporous structure with large pore volume, which can result in the superior performance of Mg-air battery than that using Pt/C catalyst. Furthermore, its ORR catalytic mechanism is unraveled according to microstructure characterization and electrochemical response. • A hybrid catalyst composed of cobalt nanoparticles and carbon nanotubes is prepared. • The carbon nanotubes contain abundant Co/Zn−N x moieties as active sites for ORR. • Cobalt and zinc can jointly enlarge the specific surface area and mesopore volume. • This hybrid exhibits superior performance than Pt/C when used for Mg-air battery. [ABSTRACT FROM AUTHOR]

This study addressed the ambiguity surrounding the relationship between the pore size of covalent organic frameworks (COFs) and their adsorption capacity and rate. To achieve this, we synthesized COFs with five distinct pore sizes (COF1-COF5) and conducted a comprehensive analysis using kinetic models. Our findings indicated that the adsorption capacity and rate of methyl orange (MO) increased linearly with the pore size of COFs, from 1.25 nm to 2.57 nm. Notably, COF3, with a pore size of 2.57 nm, exhibited the highest adsorption performance for MO, boasting an impressive capacity of 43.07 mg/g. Furthermore, we tackled the challenge of COFs powder recovery by employing a one-pot synthesis method to create SP-COFs, where COFs powder was loaded onto polyurethane sponge. Through rigorous adsorption and analytical experiments, we demonstrated that SP-COF3 achieved rapid recovery while efficiently adsorbing MO, maintaining a high removal efficiency of over 95% even after 8 reuse cycles. The mechanism underlying MO adsorption on SP-COF3 was attributed to electrostatic interaction and hydrogen bonding, with the possibility of π-π interaction also being considered. Overall, this study provides valuable new insights into the tailored synthesis of COFs with specific structures and functionalities, shedding light on the crucial relationship between pore size and adsorption behavior. The development of SP-COFs presents a promising approach to enhance the practical application of COFs as highly efficient adsorbents. [Display omitted] • Through exploring the pore size of COFs and adsorption performance, SP-COF3 with suitable pore size was synthesized. • The pore size affected the diffusion of MO molecules and the affinity of COFs for MO to control the adsorption process. • The SP-COF3 exhibited high adsorption capacity and stable cycling stability within 8 cycles. • The intraparticle diffusion, electrostatic attraction and π-π interaction were proposed in MO adsorption on COFs. [ABSTRACT FROM AUTHOR]