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The development of a simple and efficient method for preparing porous tungsten trioxide (WO3) electrochromic films using structure-directing agents is highly urgent for their industrialization. To this end, this work presents an efficient approach using rapid co-pyrolysis of polyethylene glycol 400 (PEG-400) and ammonium metatungstate (AMT) to produce mesoporous WO3 thin films. The findings indicate that the concentration of PEG influences both the wettability of the precursor solution on the FTO substrate and the state of the PEG micelle solution, ultimately leading to WO3 films with diverse morphologies after the co-pyrolysis of AMT and PEG. The porous structure significantly enhances hydrogen ion intercalation/deintercalation, and thus improves electrochromic properties. The optimized electrochromic films demonstrate a 54.5% optical modulation range at 633 nm, fast switching times (2.8 s for coloration and 1.5 s for bleaching), and a coloration efficiency of 83.2 cm2 C⁻1. In pursuit of broader optical modulation capabilities, we further innovated by developing a multilayer porous film strategy, enabling precise control over thickness through repeated spin-coating/heating cycles. Remarkably, a three-layer configuration achieved an extraordinary optical modulation of up to 87.2%, ranking among the best performances reported in the electrochromic field. This novel methodology paves the way for expedited manufacturing of porous amorphous metal oxide films and positions the enhanced WO3 film as a highly promising candidate for advanced electrochromic technologies. [ABSTRACT FROM AUTHOR]

Polymers exhibiting ion-conduction capabilities are essential components of water-purifying devices. These polymers not only transport selective ions but are also mechanically robust; thus, they can be processed as membranes. In this review, we highlight major acidic polymers and their engineered morphologies and optimized properties, including metal selectivity and water permeation or retention. Crucial phenomena, such as self-assembly in acid-group-functionalized polymers for driving water transportation, are discussed. It was observed that the phosphonic acid groups containing polymers are rather suitable for the selective adsorption of toxic metals, and thus, are superior to their sulfonated counterparts. Additionally, due to their amphoteric nature, phosphonated polymers displayed several modes of metal complexations, which makes them appropriate for eliminating a wide range of metals. Further observation indicates that aromatic-acid-functionalized polymers are more durable. Temperature- and pH-responsive polymers were also found to be promising candidates for a controlled water-treatment process. Nevertheless, considering the morphology, water retention, and metal adsorption, acid-functionalized polymers, especially phosphonated ones, have the potential to remain as the materials of choice after additional advancements. Further perspectives regarding improvements in acidic polymers and their fabricated membranes for water treatment are presented. [ABSTRACT FROM AUTHOR]

The electrochemical CO2 reduction reaction (CO2RR) to formate offers a promising pathway to mitigate the energy crisis and realize carbon neutrality. Bismuth (Bi), as a metal catalyst for the CO2RR, is considered to have great potential in producing formate, yet hindered in low current density and selectivity. Herein, we constructed an oxide-derived copper foam substrate (OD-Cu) to improve the electrocatalytic properties of Bi dendrites loaded on its surface. Bi electrodeposited on the OD-Cu (Bi/OD-Cu) grows as pinecone-like dendrites, exhibiting a high formate faradaic efficiency (FEformate) of 97.2% and a formate partial current density of ~24 mA·cm−2 at −0.97 V vs. RHE (reversible hydrogen electrode) in an H-cell. Notably, the Bi/OD-Cu electrode demonstrates an FEformate of 95.8% at −0.97 V vs. RHE and a total current density close to 90 mA·cm−2 at −1.17 V vs. RHE in a neutral flow cell. The experimental studies reveal that the remarkable CO2RR performance of the Bi/OD-Cu results from the electron transfer from Cu to Bi, which optimizes adsorption of the CO2•− and boosts reaction kinetics. This study emphasizes the crucial role of substrate engineering strategies in enhancing catalytic activity and shows the possibility for a porous metal electrode in advancing the industrialization of formate production. [ABSTRACT FROM AUTHOR]

Introduction: Acetabular bone loss represents a great challenge during hip arthroplasty procedures. This study aims at evaluating the efficacy and functional outcome of cost-friendly alternatives (autograft or allograft) when compared to the porous metal augments during reconstruction of acetabular defects in either complex primary or revision total hip replacement. Patients and Methods: This is a retrospective matched control study for evaluation of short and midterm results of metal augments versus bone graft during hip arthroplasty procedures. Inclusion criteria included adult patients who suffered from segmental acetabular defect and underwent hip arthroplasty procedure. The study included 34 cases divided into 2 groups. Group 1 cases were reconstructed with augment reconstruction. Group 2 was the control group which was reconstructed using graft reconstruction. Results: The mean age for Group 1 was 52.29 years (range: 30–68) and for Group 2 was 52.1 years, (range from 32 to 71 years). The mean follow-up period was 74.8 months in Group 1 (range: 66–85 months) and 71.5 months in Group 2 (range: 60–102 months). Both the groups included 13 males and 4 females. Group 1 had a mean postoperative Harris Hip Score (HHS) of 90.5 (range from 85 to 94), and Group 2 had a mean postoperative HHS of 88.7 (range from 80 to 94) with P = 0.236. Conclusion: Acetabular reconstruction using cost-friendly alternatives shows similar short-to-midterm results when compared to trabecular metal augments in a budget-conscious health setting. [ABSTRACT FROM AUTHOR]

This paper investigates the vibration and buckling analysis of porous metal foam thin-walled box beams. These beams exhibit a unique structural configuration with symmetrical and asymmetrical porosity distributions along their wall thickness, thereby altering the effective mechanical properties. The first-order shear deformable beam theory is employed and the governing equations are derived using the Hamilton's principle. Numerical results are presented for porous metal foam thin-walled box beams under simply-supported, clamped–clamped and clamped-free boundary conditions. The effects of various porosity parameters, length-to-side and side-to-wall-thickness ratios on the beams' performance are also examined. A comprehensive comparison between the porous metal foam thin-walled box beams and their counterparts in the form of equivalent homogeneous are presented. [ABSTRACT FROM AUTHOR]

The vibrations of rotating joined conical–conical shells with classical supported conditions have been studied extensively. As a matter of fact, in some cases, these classical boundary conditions cannot exactly model actual situations. Moreover, theoretical frameworks on them are still limited. This research aims to investigate the fundamental frequencies and dynamic mode shapes of the traveling wave of the rotating porous metal material joined conical–conical thin shells (PJCS) with elastic supports. By utilizing artificial spring technology, arbitrary elastic supported boundary conditions and classical boundary conditions are achieved efficiently. A new dynamic model has been formulated with the help of the first-order shear deformation theory (FSDT) and Hamilton's principle. By employing the generalized differential quadrature (GDQ) method along with stress boundary conditions and generalized eigenvalues, various factors such as porosity, semi-vertex angles and stiffness are analyzed for their impact on the fundamental frequencies of forward wave (FW), backward wave (BW) and mode shapes. The presented results are validated through the convergence and comparison studies from literatures. The interesting and novel results indicate that the in-plane displacement constraints have the most significant impact on the critical speed, while the lateral displacement constraint has the least effect. The vibrations are more easily excited for the part with a larger half vertex angle. Rotating PJCS with Type 1 has the biggest critical rotating speed. [ABSTRACT FROM AUTHOR]

Soft generators hold great promise both in powering flexible electronics and in signaling specific parameter variations. In particular, mechanical motions for electricity harvest have attracted great interests due to their ubiquity and relevance to human activities. Instead of the widely reported piezoelectric and triboelectric generators, in this study an efficient electric‐double‐layer (EDL) generator is designed by embedding liquid metal (LM) into biologic porous ionogels. When pulsating LM into or out of the ionogel pores, an alternating current would be produced from the variation of EDL area between LM and ionogels. The porous ionogels are produced unprecedentedly by partially fusing biologic nanofibrils and ionic liquid, whose porosities and adhesion to LM surfaces are tuned elaborately to ensure their reversible compressibility, freely moving of LM within the internal channels and hereby maximal variation of EDL area for optimal energy harvest, e.g., showing an alternating current with amplitude up to 25 µA cm−2 and energy power of 4 mW cm−2 higher than many piezoelectric and triboelectric generators. Besides electricity harvest from motions, this soft generator can also serve as a self‐powered and highly sensitive tactile sensor. [ABSTRACT FROM AUTHOR]

The current study experimentally investigates the performance of a hybrid standalone solar system of atmospheric water harvesting (AWH) and solar photovoltaic powering electrolyzer for green water and green hydrogen production. The system prototype is designed, constructed, and tested under outdoor summer and winter climate conditions of Alexandria, Egypt at different operating and design enhancement conditions. Water electrolyzes concept for green hydrogen production system driven by a photovoltaic panel and silica gel absorption/desorption atmospheric water harvesting solar still concept with insertion of porous sheet metals for freshwater production is performed and evaluated. The results show a rise of the AWH freshwater production of (60% and 120%) and (146% and 260%) in summer and winter, respectively with the insertion of one and two porous metal sheets, respectively. The maximum rise of the AWH efficiency is 82% in summer and 53.4% in winter by using 2 porous metal sheets. The hydrogen production rate of the system in summer is higher than that of winter by about 25%. System efficiency is almost doubled when electrolyzer KOH concentration increased from 4 gm/kg to 12 gm/kg water. The average daily system efficiency of the AWH, electrolyzer, and overall system reaches 11.6%, 65.1%, and 2.6% when operating at a KOH concentration of 12 gm/kg with two porous metal sheets. The study contributes to achieving mainly SDG goals 6, 7, and 13. • Standalone solar green hydrogen and atmospheric water harvesting system is studied. • Double porous metal sheets enhance water harvesting by 53.4–82%. • Double system efficiency obtained by rising electrolyte concentration of 12 gm/kg. • Daily system efficiency reaches 2.6% for 12 gm/kg electrolyte with two metal sheets. [ABSTRACT FROM AUTHOR]

The temperature distribution has a significant influence on the performance and lifespan of proton exchange membrane fuel cell (PEMFC) stacks. However, analyzing the temperature distribution of large PEMFC stacks is challenging and has been rarely conducted. In this study, a simplified model of a large PEMFC stack is developed using computational fluid dynamics (CFD) methods, which includes 300 cells and 60 cooling plates. The influence of cooling parameters, including configurations, dimension and flow rate, is discussed. The study indicates that U-type stack exhibits better temperature uniformity than Z-type stack. Increasing the coolant flow rate can effectively reduce the stack temperature. The study proposes a modified cooling design, which effectively reduces the heat accumulation at the end of the stack. Lastly, a comparison between traditional serpentine channels and porous foam metal flow fields reveals that the porous foam metal flow field exhibits superior thermal management characteristics. The results can offer insights for thermal management of large-scale PEMFC stacks. • A simplified model of water-cooled large-scale PEMFC stack with 300 single cells is established. • The effects of cooling parameters, including configurations, dimension and flow rate, are discussed. • U-type stack exhibits better temperature uniformity than Z-type stack. • The modified cooling design with one cooling plate at both ends can reduce the heat accumulation at the end of the stack. [ABSTRACT FROM AUTHOR]

The control incorporation of metals in silica hollow spheres (SHSs) may bring new functions to silica mesoporous structures for applications including catalysis, sensing, molecular delivery, adsorption filtration, and storage. However, the strategies for incorporating metals, whether through pre-loading in the hollow interior or post-encapsulation in the mesoporous shell, still face challenges in achieving quantitative doping of various metals and preventing metal aggregation or channel blockage during usage. In this study, we explored the doping of different metals into silica hollow spheres based on the dissolution-regrowth process of silica. The process may promote the formation of more structural defects and functional silanol groups, which could facilitate the fixation of metals in the silica networks. With this simple and efficient approach, we successfully achieved the integration of ten diverse metal species into silica hollow sphere (SHS). Various single-metal, dual-metal, triple-metal, and quadruple-metal doped SHSs have been prepared, with the doped metals being stable and homogeneously dispersed in the structure. Based on the structural characterizations, we analyzed the influence of metal types on the morphology features of SHSs. The synergistic effects of multi-metals on the catalysis applications were also studied and compared. IMPACT STATEMENT: Significance of this work: The control incorporation of metals in silica hollow spheres (SHSs) may bring new functions to silica mesoporous structures for applications including catalysis, sensing, molecular delivery, adsorption filtration, and storage. The incorporation of metals within SHSs is always either at the interior core or in the porous shells. The former method mainly utilizes metal nanoparticles as the core and regulates the synthesis of outer porous silica shells. The latter is primarily driven by the capillary force or intermolecular interactions with surface ligands to facilitate the post-loading of metal species in porous silica structures. The main problems associated with metal-doped SHSs include 1) controlled loading of different metals with a homogeneous distribution; 2) fixation of metal species in the structures to prevent aggregation during usage, particularly at high temperatures; 3) pore channel blockage after metal loading, which may hinder the loading of other external molecules. In this work, we developed the dissolution-regrowth of silica strategy for integrating various metals in porous SHSs (M@SHSs) by a one-pot hydrothermal process without using any anchoring molecules. Unlike other sol-gel formations, the growth rate of silica in this process is greatly reduced. It thus may bring more possibilities to introduce external metals within the silica frameworks instead of in the porous channels. By regulating the addition of metal salts in the silica nanoparticles dispersions, we have successfully synthesized stable and highly homogeneous single-metal, dual-metal, triple-metal, and quadruplemetal doped SHSs. Based on the structural characterizations, we analyzed the influence of metal types on the morphology features of SHSs. The synergistic effects of multi-metals on the catalysis applications were also studied and compared. Our results offer a facile and effective strategy for preparing multi-metals as nano-catalysts. Through proper design of the doped metals in SHSs, the structures should find more applications in catalysis, drug delivery, and adsorption with unique and enhanced properties. [ABSTRACT FROM AUTHOR]

Porous metal materials with special surface wettability are widely used in oily wastewater treatment. To realize efficient oil/water separation of porous metal material, layered spherical TiO2 and "woodchip" NiO micro-nano structures were constructed on the surface of nickel foam (NF) matrix by hydrothermal method, which endowed the porous metal material with superhydrophilic and underwater superoleophobic (SHI/USOB) characteristics. Moreover, the separation efficiency of various oil/water mixtures remained above 98%, and the water flux exceeded 2.66 × 105 L m−2 h−1. Meanwhile, the uniformly supported TiO2 nanoparticles showed excellent self-cleaning performance, and the oil droplets remaining on the sample surface could be effectively degraded under ultraviolet irradiation for 8 h. TiO2/NF has a lot of potential because of its three-dimensional micro-nano porous structure, self-cleaning capabilities and environmental friendliness. [ABSTRACT FROM AUTHOR]

We describe an environmentally benign method for the synthesis of porous gold by gelation of a hydrophilic polymer bearing metal-coordination units (thiocarbonyl groups, denoted as HPMC) and Au(III) ions. The gelation was performed by dropwise addition of a dispersed aqueous solution of HPMC to an aqueous solution of Au(III) in a test tube. Concentrations of 15 and 20 wt% HPMC provided elongated and fibrous gels. Scanning electron microscopy and transmission electron microscopy analyses of the fibrous gels revealed the formation of porous gels containing Au nanoparticles. Calcination of the polymer parts in the porous gels at 550 °C for 7 h, followed by self-assembly of the remaining Au nanoparticles, provided the golds with micrometer-size pores. Thermogravimetric analysis of the porous golds indicated that its purity was high (96 ~ 99%). Because the metal-coordination unit has soft basic characteristics, it preferentially coordinate to soft acidic noble metal ions such as platinum group metal ions, Ag(I), and so on. Therefore, this method will be applied to synthesis of various porous metals. [ABSTRACT FROM AUTHOR]

Porous tantalum metal is a new orthopedic implant material made of tantalum metal that has been processed by porous treatment. This material has various advantages, including high hardness, good ductility, good biocompatibility, and strong bone integration ability. Porous tantalum metal has performed well in clinical application, demonstrating excellent medium‐ to long‐term curative effects. The use of implant products made of porous tantalum metal, such as porous tantalum rods, porous tantalum hip prostheses, and porous tantalum augments (MAs), is gradually increasing in the clinical application of hip surgery, and these products have achieved excellent therapeutic effects in the middle and late stages of various hip diseases. In recent years, the combined application of porous tantalum metal and three‐dimenional (3D) printing technology to create personalized 3D‐printed porous tantalum metal has led to new development directions for the treatment of complex hip joint surgical diseases. This review presents a summary of the application of porous tantalum metal in hip surgery in recent years, including clinical treatment effects and existing problems. In addition, the prospect of progress in this field is promoted. [ABSTRACT FROM AUTHOR]

Background: Pelvic discontinuity (PD) presents a complex challenge in revision hip arthroplasty. The traditional cup-cage construct, which involves a screw-secured porous metal cup and an overlying antiprotrusio cage, has shown promising mid- to long-term results. However, there is limited information on the outcomes of modifications to the original technique. Our study aims to evaluate a modified technique in which the cup position is determined by the placement of the overlying cage, allowing for adjustments to achieve optimal orientation. Questions/purposes: Among patients treated for PD with a cup-cage construct in which the cup position was dictated by the position of the cage: (1) What are Harris hip scores achieved at a minimum of 2 years of follow-up? (2) What is the Kaplan-Meier survivorship free from aseptic loosening or component migration? (3) What is the Kaplan-Meier survivorship free from revision for any reason? (4) What surgical complications are associated with the procedure? Methods: Between October 2013 and January 2022, we performed 805 acetabular revisions. Among these, 33 patients with PD confirmed intraoperatively were considered potentially eligible for a cup-cage construct; no other method of surgical management was used. We performed 64% (21 of 33) of these procedures from October 2013 to January 2018, with 6% (2 of 33) of patients lost to follow-up before the minimum study follow-up of 2 years; these 19 patients were monitored over a period ranging from 70 to 115 months. A further 12 patients underwent this procedure from January 2018 to January 2022, with one lost to follow-up before the minimum study follow-up of 2 years; the other patients met the minimum 2-year follow-up requirement. The remaining 30 patients with data analyzed here (10 men, 20 women) had a mean ± SD age of 61 ± 12 years and a median BMI of 29 kg/m2 (range 20 to 33 kg/m2) at the time of revision surgery. Twenty-one patients underwent revision due to aseptic loosening, and nine due to periprosthetic joint infection (PJI). The causes of PD in our patients were as follows: cup aseptic loosening without significant osteolysis in 20% (6 of 30), where the loose cup caused erosion of the host bone, leading to PD; PJI in 30% (9 of 30); intraoperative iatrogenic PD in 3% (1 of 30); and osteolysis in 47% (14 of 30), which also resulted in aseptic loosening. The median follow-up time was 79 months (range 25 to 115 months). The Harris hip score was used to evaluate clinical outcomes, with preoperative values compared with the most recent follow-up. Radiographs were reviewed by two experienced surgeons at each follow-up visit to assess component loosening (defined as migration > 5 mm or the presence of circumferential radiolucent lines) or clear migration. PD was considered healed if bridging callus or trabecular bone was visible across the site of the discontinuity. Complications were assessed through a comprehensive review of electronic medical records. Kaplan-Meier analysis was used to estimate implant survivorship and radiographic loosening, with aseptic loosening or component migration as the endpoint, as well as survivorship free from any reoperation. Results: The Harris hip score improved from a median of 39 (range 30 to 66) preoperatively to a median of 76 (range 30 to 90) postoperatively (median difference 33 [range 2 to 48]; p < 0.01). Within the limitations of two-dimensional (2D) radiographic imaging, successful bone graft integration and the healing of PD were noted in 83% (25 of 30) of patients. Kaplan-Meier survivorship free from radiographic signs of aseptic loosening or component migration was 100% (95% CI 100% to 100%) at 115 months. When any revision related to the acetabular component was considered the endpoint, survivorship free from acetabular component revision at 115 months after revision surgery was 100% (95% CI 100% to 100%). When the need for any reoperation was considered the endpoint, survivorship free from needing reoperation at 115 months after revision surgery was 85% for all patients (95% CI 73% to 100%). When including only patients with a follow-up time of > 4 years (20 of 30), survivorship free from needing reoperation at 115 months after revision surgery was 90% (95% CI 78% to 100%). Postoperative complications during the follow-up period included one early dislocation on the fifth day after surgery, treated with closed reduction and 6 weeks of abduction bracing. One femoral stem loosening occurred at 56 months postoperatively, although the acetabular component remained securely fixed; this patient declined revision surgery. One patient experienced a dislocation 5 months after surgery but refused treatment and opted for prolonged bed rest. Additionally, one patient underwent a debridement, antibiotics, and implant retention procedure 1 week after the revision surgery and subsequently showed no signs of infection at the latest follow-up, 38 months postoperatively. Conclusion: Our study highlights the effectiveness of a modified cup-cage technique in complex hip revisions, showing promising results in terms of construct survivorship and low complication rates. Surgeons could consider delaying screw fixation until after positioning the cage within the porous cup to allow for optimal adjustment and using metal augments for severe bone defects to achieve better alignment. Surgeon experience with the cup-cage technique is crucial for achieving optimal outcomes. Future studies should focus on long-term follow-up visits to assess the durability and effectiveness of these modifications and explore the comparative effectiveness versus other methods, such as custom triflange components and jumbo cups with distraction. Level of Evidence: Level III, therapeutic study. [ABSTRACT FROM AUTHOR]

Aluminum alloys with open-channel structure are fabricated by casting the melt of aluminum alloys using wire-extraction method. Template stainless steel wires are coated with release agents such as boron nitride and alumina, which are embedded in the melt of aluminum alloys. After solidified, the wires are extracted by tensile test machine to fabricate channel holes so that open-channel aluminum alloys are produced. The microvoids are formed in alloys AC4CH and Al-7%Si, when the wires are coated with boron nitride. However, no microviods are observed in the alloys A1050 and A6063. It is found that the formation of microvoids is attributed to the addition of silicon, which may evolve nitrogen gas pores. Cross-flow type microchannel heat exchangers are fabricated, and heat exchange performance is investigated. The experimental results of heat exchange rate and pressure loss are in good agreement with the predicted results based on heat transfer calculation, which suggests that open-channel aluminum alloys are superior for heat exchangers. [ABSTRACT FROM AUTHOR]

Improving the performance of high-temperature ultrasonic transducers is a goal of major importance in many industrial applications. To this aim, we propose to use porous metals that support high temperatures as backings. Thus, the acoustic properties of stainless steel and porous stainless steel with porosity of 25% and 35% are determined at ambient temperature and up to 400 °C. Over the temperature range, the longitudinal wave velocity variation is comprised between 5% and 6% in the porous metals. We find that temperature does not significantly affect the attenuation in the material. The pulse-echo response and frequency response of a LiNbO3-based transducer with a porous backing are simulated using a one dimensional electroacoustic model. These simulations, compared to those of a reference transducer, show that the axial resolution with such a design allows these transducers to be used for imaging and/or Non-Destructive Testing and evaluation at high temperature. [ABSTRACT FROM AUTHOR]

Photocatalytic nitrogen fixation is a green method for converting N2 to NH3, but it remains a challenging task due to the lack of effective photocatalysts. Herein, a series of porous metal covalent organic polymers (MCOPs) with the integration of dinuclear rhodium(II) catalytic centers were rationally constructed for photocatalytic N2 fixation. Interestingly, the porous MCOPs had double‐layers two‐dimensional (2D) structures with the coordinated Rh(II) as the point of registry. The photocatalytic experiment showed that Rh‐TAPA with significant donor‐acceptor (D−A) features exhibited a high activity toward NH3 production with a rate of 319.8 μmol g−1 h−1. The electron transfer process, N2 adsorption and activation mechanism of RhCOPs were further investigated through comprehensive characterization, including DFT calculations and in situ characterization. This work provided a valuable insight into the photocatalytic N2 fixation process with porous materials. [ABSTRACT FROM AUTHOR]

Calcium sulfate is an established carrier for localized drug delivery, but a means to non‐invasively measure drug release, which would improve our understanding of localized delivery, remains an unmet need. We aim to quantitatively estimate the diffusion‐controlled release of small molecules loaded into a calcium sulfate carrier through a gadobutrol‐based contrast agent, which acts as a surrogate small molecule. A central cylindrical core made of calcium sulfate, either alone or within a metal scaffold, is loaded with contrast agents that release into agar. Multi‐echo scans are acquired at multiple time points over 4 weeks and processed into R2* and quantitative susceptibility mapping (QSM) maps. Mean R2* values are fit to a known drug delivery model, which are then compared with the decrease in core QSM. Fitting R2* measurements of calcium sulfate core while constraining constants to a drug release model results in an R2‐value of 0.991, yielding a diffusion constant of 4.59 × 10−11 m2 s−1. Incorporating the carrier within a metal scaffold results in a slower release. QSM shows the resulting loss of susceptibility in the non‐metal core but is unreliable around metal. R2* characterizes the released gadobutrol, and QSM detects the resulting decrease in core susceptibility. The addition of a porous metal scaffold slows the release of gadobutrol, as expected. [ABSTRACT FROM AUTHOR]

The unique catalytic properties of natural enzymes have inspired chemists to develop biomimetic catalyst platforms for the intention of retaining the unique functions and solving the application limitations of enzymes, such as high costs, instability and unrecyclable ability. Porous materials possess unique advantages for the construction of biomimetic catalysts, such as high surface areas, thermal stability, permanent porosity and tunability. These characteristics make them ideal porous matrices for the construction of biomimetic catalysts by immobilizing enzyme-mimic active sites inside porous materials. The developed porous biomimetic catalysts demonstrate high activity, selectivity and stability. In this feature article, we categorize and discuss the recently developed strategies for introducing enzyme-mimic active species inside porous materials, which are based on the type of employed porous materials, including metal-organic frameworks (MOFs), covalent organic frameworks (COFs), molecular sieves, porous metal silicate (PMS) materials and porous carbon materials. The advantages and limitations of these porous materials-based biomimetic catalysts are discussed, and the challenges and future directions in this field are also highlighted. [ABSTRACT FROM AUTHOR]

Experimental data on the movement of the superfluid helium in a U-shaped cylindrical channel filled with and without a permeable porous backfill of metal monodisperse spheres are considered. The results of experiments are presented in the form of the time dependences of the position of the helium-II–vapor interface in the channel. A comparison of the amplitudes and frequencies of vibration of this interface, depending on the pressure in the channel, in the cases of free channel and where it is filled with porous backfill has been performed. It is shown that, in the channel with a monodisperse porous backfill, a stationary state of the interface is possible. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Advanced functionalization‐decorated porous organic polymers (POPs) are emerging as a prominent research focus, spanning from their construction to applications in gas storage and separation, catalysis, energy storage, electrochemistry, and other areas. Furthermore, the inherent organic nature, tailored pore structures, and adjustable chemical components of POPs offer a versatile platform for the incorporation of various metal active sites. Meticulously designed molecular building blocks can serve as organic ligands uniformly distributed throughout POPs, leading to the effective isolation of inorganic metal active sites at the molecular level. In this manner, POPs containing active metal centers bridge the gap between organic and inorganic scaffolds. This review aims to provide an overview of recent research progress on metal‐decorated POPs, focusing on strategies for incorporating metal active sites into POPs and their applications in adsorption, separation, catalysis, and photoelectrochemistry. Finally, current challenges and future prospects are discussed for further research. Key Scientists: Advanced functionalized porous organic polymers have become a new research hotspot, ranging from their construction to their use in gas storage and separation, catalysis, energy storage, electrochemistry, and other applications. In 2002, the McKeown group was the first to report phthalocyanine‐based MPOPs with permanent porosity and a moderate surface area. In 2010, the Yu group prepared nanoporous polyporphyrin materials P(Fe‐TTPP) from the metallated porphyrin with functionalized thiophenyl groups by the FeCl3 catalyzed oxidation couple reaction showing the surface area of 1522 m2·g–1. Subsequently, in 2013, the Deng group was the first to use metalated salens as the original building blocks for preparing MPOPs. The Morin group was the first to produce a series of ferrocene‐based nanoporous frameworks via radical polymerization, with surface areas ranging from 385 to 899 m2·g–1. In 2016, the Han group synthesized two N‐pyridinylphenylcarbazole (PPC) ligands to produce a series of metalized polycarbazole networks. Recently, the Tan group reported a solvent‐knitting hyper‐cross‐linking reaction to produce HUST‐1, which contains a porphyrin unit. The porphyrin moiety provides a centered square‐planar metal post‐coordination site, resulting in the metalated HUST‐1‐Co, which exhibits high efficiency in the catalytic conversion of CO2. Additionally, the Kegnæs group combined the decomposition of the palladium complex with an in situ catalyzed polymerization reaction, enabling the confinement of nascent Pd particles in the developing polymer network. This review focuses on recent research progress in metal‐decorated POPs, emphasizing strategies for incorporating metal active sites into POPs and their applications. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Advanced functionalization‐decorated porous organic polymers (POPs) are emerging as a prominent research focus, spanning from their construction to applications in gas storage and separation, catalysis, energy storage, electrochemistry, and other areas. Furthermore, the inherent organic nature, tailored pore structures, and adjustable chemical components of POPs offer a versatile platform for the incorporation of various metal active sites. Meticulously designed molecular building blocks can serve as organic ligands uniformly distributed throughout POPs, leading to the effective isolation of inorganic metal active sites at the molecular level. In this manner, POPs containing active metal centers bridge the gap between organic and inorganic scaffolds. This review aims to provide an overview of recent research progress on metal‐decorated POPs, focusing on strategies for incorporating metal active sites into POPs and their applications in adsorption, separation, catalysis, and photoelectrochemistry. Finally, current challenges and future prospects are discussed for further research. Key Scientists: Advanced functionalized porous organic polymers have become a new research hotspot, ranging from their construction to their use in gas storage and separation, catalysis, energy storage, electrochemistry, and other applications. In 2002, the McKeown group was the first to report phthalocyanine‐based MPOPs with permanent porosity and a moderate surface area. In 2010, the Yu group prepared nanoporous polyporphyrin materials P(Fe‐TTPP) from the metallated porphyrin with functionalized thiophenyl groups by the FeCl3 catalyzed oxidation couple reaction showing the surface area of 1522 m2·g–1. Subsequently, in 2013, the Deng group was the first to use metalated salens as the original building blocks for preparing MPOPs. The Morin group was the first to produce a series of ferrocene‐based nanoporous frameworks via radical polymerization, with surface areas ranging from 385 to 899 m2·g–1. In 2016, the Han group synthesized two N‐pyridinylphenylcarbazole (PPC) ligands to produce a series of metalized polycarbazole networks. Recently, the Tan group reported a solvent‐knitting hyper‐cross‐linking reaction to produce HUST‐1, which contains a porphyrin unit. The porphyrin moiety provides a centered square‐planar metal post‐coordination site, resulting in the metalated HUST‐1‐Co, which exhibits high efficiency in the catalytic conversion of CO2. Additionally, the Kegnæs group combined the decomposition of the palladium complex with an in situ catalyzed polymerization reaction, enabling the confinement of nascent Pd particles in the developing polymer network. This review focuses on recent research progress in metal‐decorated POPs, emphasizing strategies for incorporating metal active sites into POPs and their applications. [ABSTRACT FROM AUTHOR]

When a severe medial wall defect is present in revision total hip arthroplasty (THA), simple bone grafting (BG) may not be sufficient, and trabecular metal (TM) augmentation is often necessary. We aimed to evaluate whether there were differences in outcomes of revision THA with medial wall defects depending on the use of TM augmentation. Between 2009–2021, 130 patients were classified into two groups: 80 patients undergoing bone grafting (BG group) and 50 patients undergoing both bone grafting and TM augmentation (BG/TM group). We evaluated the postoperative center of rotation (COR) position and changes in vertical and horizontal COR at last follow-up. Additionally, we categorized the fate of the transplanted bone graft into four groups: unchanged, initially changed, resorption-no further intervention, and resorption-revision. The mean horizontal COR changes were −3.50 mm in the BG group and −1.07 mm in the BG/TM group (p = 0.005). In the BG/TM group, a higher proportion of the patients showed unchanged or only initial changes when compared to the BG group (88.0% and 65.0%, respectively). The BG/TM group showed more favorable results regarding horizontal changes in the COR and fate of the bone graft. Therefore, for revision THA in patients with severe medial wall defects, the combined use of bone graft and TM augmentation can be a suitable option. [ABSTRACT FROM AUTHOR]

Comminuted proximal humerus fractures are often repaired by metal plates, but potentially still experience bone refracture, bone "stress shielding," screw perforation, delayed healing, and so forth. This "proof of principle" investigation is the initial step towards the design of a new plate using alternative materials to address some of these problems. Finite element modeling was used to create design graphs for bone stress, plate stress, screw stress, and interfragmentary motion via three different fixations (no, 1, or 2 "kickstand" [KS] screws across the fracture) using a wide range of plate elastic moduli (EP = 5–200 GPa). Well‐known design optimization criteria were used that could minimize bone, plate, and screw failure (i.e., peak stress < ultimate tensile strength), reduce bone "stress shielding" (i.e., bone stress under the new plate ≥ bone stress for an intact humerus, titanium plate, and/or steel plate "control"), and encourage callus growth leading to early healing (i.e., 0.2 mm ≤ axial interfragmentary motion ≤ 1 mm; shear/axial interfragmentary motion ratio <1.6). The findings suggest that a potentially optimal configuration involves the new plate being manufactured from a material with an EP of 5–41.5 GPa with 1 KS screw; but, using no KS screws would cause immediate bone fracture and 2 KS screws would almost certainly lead to delayed healing. A prototype plate might be fabricated using alternative materials suggested for orthopedics and other industries, like fiber‐metal laminates, fiber‐reinforced polymers, metal foams, pure polymers, shape memory alloys, or 3D‐printed porous metals. [ABSTRACT FROM AUTHOR]

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In this work, a numerical evaluation of the melting/solidification performance of phase change material (PCM) filled inside a triplex‐tube latent heat storage unit has been carried out. To enhance the melting/solidification performance, the porous Cu metal foam (MF) was embedded inside PCM (termed as composite PCM). Alternative segments of pure PCM and composite PCM have been allocated in such a way that both the pure PCM and composite PCM occupy the equal annular area (i.e., equal volumes). Influence of increasing number of segments was delineated on the melting/solidification rate, complete melting time, and thermal energy storage/recovery enhancement. The comparisons were drawn with reference to the model having two segments of PCM and composite PCM. The results show that the model containing 64 segments with alternate allocations of PCM and composite PCM has a faster melting/solidification rate than other models. With 32 alternate segments of MF, the full melting/solidification time reduced by 23%/77% with respect to the case with one segment of MF only. The melting/solidification performance gets saturated beyond 32 segments (M‐5) and negligible variation (only ~1%) in the thermal performance was noticed upon further segmentation. Finally, the model M‐5 proved as the best model considering the aspects of augmented melting/solidification rate and associated complexities. Moreover, the heterogeneity of MF applied in 32‐segment model confirmed that the anisotropic MF results in an increased melting rate and leads over other random isotropic distributions of MF. [ABSTRACT FROM AUTHOR]

Indoor air pollution is one of the major threads in developed countries, notably due to high concentrations of formaldehyde, a harmful molecule difficult to eliminate. Addressing this purification challenge while adhering to the principles of sustainable development requires the use of innovative, advanced sustainable materials. Here we show that by combining state-of-the-art spectroscopic techniques with density-functional theory molecular simulations, we have developed an advantageous mild chemisorption synergistic mechanism using porous metal (III or IV) pyrazole- di-carboxylate based metal-organic framework (MOF) to trap formaldehyde in a reversible manner, without incurring significant energy penalties for regeneration. A straightforward, environmentally friendly, and scalable synthesis protocol was established for the porous, water-stable aluminum pyrazole dicarboxylate known as Al-3.5-PDA or MOF-303, capable of functioning as a highly efficient and reusable filter. It demonstrates selectivity and high storage capacity for formaldehyde under conditions typical of severe indoor use, such as in housing or vehicle cockpits, including varying VOC mixtures and concentrations, humidity, and temperature, without any accidental release. Furthermore, we have successfully regenerated this sorbent using a simple domestic protocol, ensuring the material reusability for at least 10 cycles. Indoor air pollution from harmful and carcinogenic formaldehyde is a concern in developed countries. The authors present a sustainable solution using porous Metal-Organic Frameworks (MOFs) for efficient trapping of formaldehyde and regeneration. [ABSTRACT FROM AUTHOR]

Wearable sensors for continuous monitoring of biomarkers in body fluids have gained significant attention for their potential in disease diagnostics and health management, but lack sustainable power supply and advanced sensing strategies. Herein, sweat wearable biofuel cells (w‐BFCs) based on metal hydrogels are demonstrated with high output and outstanding stability, which harvest energy directly from human sweat and simultaneously enable self‐powered sensing of epidermal biomarkers. Experimental and computational results elucidate that the highly porous and flexible metal hydrogels exhibit superior electrocatalytic capabilities for oxidizing ascorbic acid (AA), a sweat metabolite at the anode, and reducing O2 at the cathode. Consequently, the assembled AA/O2 BFC delivers a high and stable power output, with a maximum output power density of 35 µW cm−2 at an ultralow AA concentration and long‐term stability over 30 days, and a self‐powered, sensitive sensing for AA detection. When applied to the skin of the volunteers, this integrated w‐BFC powers the biosensor using human sweat AA as fuel and allowing real‐time monitoring of AA sensing signal via smartphone. This work not only advances energy harvesting for wearable sensors but also paves new avenues for real‐time, online monitoring of epidermal sweat biomarkers. [ABSTRACT FROM AUTHOR]

Porous organic cages (POCs) with permanent porosity and excellent host–guest property hold great potentials in regulating ion transport behavior, yet their feasibility as solid-state electrolytes has never been testified in a practical battery. Herein, we design and fabricate a quasi-solid-state electrolyte (QSSE) based on a POC to enable the stable operation of Li-metal batteries (LMBs). Benefiting from the ordered channels and cavity-induced anion-trapping effect of POC, the resulting POC-based QSSE exhibits a high Li+ transference number of 0.67 and a high ionic conductivity of 1.25 × 10−4 S cm−1 with a low activation energy of 0.17 eV. These allow for homogeneous Li deposition and highly reversible Li plating/stripping for over 2000 h. As a proof of concept, the LMB assembled with POC-based QSSE demonstrates extremely stable cycling performance with 85% capacity retention after 1000 cycles. Therefore, our work demonstrates the practical applicability of POC as SSEs for LMBs and could be extended to other energy-storage systems, such as Na and K batteries. Highlights: A porous organic cage (POC)-based quasi-solid-state electrolyte (QSSE) with cavity-induced anion-trapping effect was rationally designed to enable the stable operation of Li-metal batteries. The POC-based QSSE exhibits a high Li+ transference number of 0.67 and a high ionic conductivity of 1.25×10−4 S cm−1 with a low activation energy of 0.17 eV. The POC-based QSSE demonstrates a highly reversible Li plating/stripping cycling for 2000 h and superior Li||LFePO4 cycling for thousands of cycles at room temperature. [ABSTRACT FROM AUTHOR]

The rational utilization of hydrogen is crucial for addressing the challenges of resource depletion and environmental pollution resulting from rapid industrialization. However, the development of the hydrogen industry is significantly hindered by inadequate hydrogen storage technologies and materials. As a new type of porous crystalline materials with ultra-high specific surface area, tunable pore sizes and structure as well as tailorable chemical functionality, metal-organic framework materials (MOFs) hold great promise for efficient hydrogen storage. In this review, we summarize the recent and important progress of MOFs for hydrogen storage, and provide a comprehensive understanding by exploring the influencing factors, mechanisms, and strategies for improving hydrogen storage capacity. Special emphasis is given to the influence of pore structure, isosteric enthalpy of hydrogen adsorption and synthesis parameters on the hydrogen storage capacity of MOFs. And the strategies for enhancing hydrogen storage performance of MOFs are also systematically introduced and discussed. Finally, we present a short conclusion give a brief outlook on the future development of MOFs as hydrogen storage materials, providing guidance for the rational design and synthesis of advanced MOFs suitable for hydrogen storage. • Recent and important progress of MOFs for H 2 storage is summarized. • Factors, mechanisms, and strategies for improving H 2 storage capacity in MOFs are analyzed. • Pore structure, adsorption enthalpy, synthesis parameter of MOFs are emphasized. • Challenges and new trends of MOFs for H 2 storage are prospected. [ABSTRACT FROM AUTHOR]

This study explored the development of hierarchical graphitic carbon structures (HGCs) from harmful inedible seaweed waste harvested in the summer. Elevated sea temperatures during the summer increase the cellulose content of seaweeds, making them unsuitable for consumption. By utilizing seaweed biomass, this study addresses critical marine environmental issues and provides a sustainable solution for promising electrode materials for energy storage devices. The fabrication process involved impregnating seaweed with Ni ions, followed by annealing to create a highly crystalline carbon structure. Subsequent etching produced numerous nano-sized pores and a large surface area (806 m2/g), significantly enhancing the number of electrically active sites. The resulting HGCs exhibited a high capacitance and maintained their capacity even after 10,000 cycles in fast-current systems. This innovative approach not only mitigates the environmental burden of seaweed waste but also offers a sustainable method for converting it into efficient energy storage materials. [ABSTRACT FROM AUTHOR]

In recent years, in an effort to reach Net Zero Emissions, there has been growing interest by various academic and industry communities to develop chemicals and industrial processes that are circular, sustainable and green. We report the rapid, simple and effective surface modification of a porous metal oxide with organic dyes using supercritical carbon dioxide (scCO2). Titanium dioxide (TiO2) photoanodes were coated in very short times, under mild conditions and the excess dye recovered afterwards for reuse. The process obviates the need for conventional toxic solvents, the generation of unwanted waste streams, and more importantly, we see an unexpected device performance enhancement of 212 and 163 % for TerCOOTMS, 2 a and TerCN/COOTBDMS, 4 dyes, respectively, when compared to the conventional solvent deposition method. [ABSTRACT FROM AUTHOR]

Porous hexagonal nanoplatelets of mixed metal oxide (MMO) derived from the calcination of MgAl layered double hydroxide exhibits a CO2 sorption capacity of 1.99 mmol g−1 at 30 °C, with a retention of 87% sorption capacity over 10 carbonation–decarbonation cycles and a CO2 sorption capacity of 1 mmol g−1 at 200 °C with a 40% increase in capacity over 10 cycles. The high sorption capacity is attributed to the porous nanoplatelet structure of the MMO with a BET surface area of 115 m2 g−1, which enables increased CO2 diffusion. Upon partially replacing magnesium with calcium (33, 50 and 66 mol%), the CO2 sorption capacity of the MMO increases with an increase in temperature. MMO derived from LDH, in which 66% of magnesium is replaced by calcium (MgCaAl-66), delivers CO2 sorption capacities of 1.38, 1.31, 2.50, 4.85 and 7.75 mmol g−1 at 200, 300, 350, 400 and 600 °C, respectively, which is significant for application in the sorption-enhanced water gas shift (SEWGS) process. MgCaAl-66 MMO exhibits a sorption capacity of 1 mmol g−1, which is stable over 10 cycles at 200 °C, and a sorption capacity of 3.68 mmol g−1 at 400 °C with 85% capture efficiency retention over 10 cycles. While the incorporation of Ca2+ serves multiple purposes such as increasing basic defect sorption sites and improving stability to repress the sintering-induced limitation of MMO over sorption cycles, the porous nanoplatelets act as individual sorbent units resisting volume changes through carbonation–decarbonation cycles. [ABSTRACT FROM AUTHOR]

A one-dimensional computational model has been developed that can be used to identify operating conditions for the cathode side of a proton exchange membrane fuel cell such that both the inlet and outlet relative humidity is equal to 100%. By balancing the calculated pressure drop along the cathode side flow channel with the change in molar composition, inlet conditions for the cathode side can be identified with the goal of avoiding channel flooding. The channel length, height, width and the land-to-channel width ratio are input parameters for the model so that it might be used to dimension the cathode flow field. The model can be used to calculate the limiting current density, and we are presenting unprecedented high values as a result of the high pressure drop along the flow channels. Such high current densities can ultimately result in a fuel cell power density beyond the typical value of 1.0–2.0 W/cm2 for automotive fuel cells. [ABSTRACT FROM AUTHOR]

Constructing low-cost, high-catalytic-performance anode electrocatalysts is a significant challenge for methanol oxidation (MOR) and urea oxidation (UOR) reactions. Using paper templates with abundant pores to prepare thin porous metal materials helps to obtain high-performance electrode materials. The nano amorphous B-doped Ni/crystalline Ni (nanoam Ni-B/Ni) foil composite electrodes were derived from paper templates prepared by impregnation, high-temperature reduction, and electrodeposition methods. Porous Ni foils (Nip) derived thinnest rice ("Xuan") paper, initially used for Chinese calligraphy and painting, exhibits the best performance due to its strong adsorption and wettability. Compared to direct current electrodeposition, pulse electrodeposition yields finer amorphous B-doped Ni nanoparticles with good catalytic performance. Under a current density of 100 mA·cm−2, the nanoam Ni-B/Ni composite electrode prepared under a duty cycle of 0.5–1.0 s achieved current densities of 290.4 mA·cm−2 (MOR) and 340.4 mA·cm−2 (UOR) at 0.8 V, which are improved by 37.1% and 55.1%, respectively, compared to those of Nip. After 2000 cycles, with solution replacement, the current densities maintained 99.2% (MOR) and 81.6% (UOR) of the original values, showing excellent electrocatalytic stability. This research provided a new use for Chinese rice paper, and the prepared Nip-based electrode, with a thickness of about 60 μm and a low area quality, had a simple preparation process and good electrochemical properties, and can be used as a potential substitute for commercial Ni foam for portable or small electrochemical devices. [ABSTRACT FROM AUTHOR]

Realizing efficient immobilization of lithium polysulfides (LiPSs) as well as reversible catalytic conversion between LiPSs and the insoluble Li2S is vital to restrain the shuttle effect, which requires highly reactive catalysts for highperformance Li-S batteries. Here, three-dimensional ordered porous Mo-based metal phosphides (3DOP Mo3P/Mo) with heterogeneous structures were fabricated and utilized as separator-modified coatings for Li-S batteries to catalyze the conversion of LiPSs. The adsorption, catalytic and electrochemical performance of the corresponding cells were compared among 3DOP Mo3P/Mo and 3DOP Mo, by kinetic and electrochemical performance measurements. It was found that the cell with 3DOP Mo3P/Mo modified separator deliver better electrochemical performance, with a high specific capacity of 469.66 mAh g-1after 500 cycles at a high current density of 1°C. This work provides an idea and a guideline for the design of the separator modification for high-performance Li-S batteries. [ABSTRACT FROM AUTHOR]

Aqueous zinc‐ion batteries (AZIBs) possess high theoretical capacity and good safety, making them highly hopeful for large‐scale energy storage applications. Nevertheless, the uncontrolled growth of Zn dendrites on anode significantly reduces the cycle life of AZIBs. In this study, a series of porphyrin‐based porous organic polymers (CuTAPP‐NTCDA‐POP and ZnTAPP‐NTCDA‐POP) are synthesized using aminophenylporphyrin (TAPP) and aromatic dianhydride, which are served as porous protective coating layers for Zn anode. The coating effectively prevents the formation of Zn dendrites and guides the deposition of Zn2+ because of the abundance of zincophilic sites. As expected, the symmetric cells equipped with the optimum ZnTAPP‐NTCDA‐POP@Zn anode demonstrate a longer cycle life of over 1200 h at 0.5 mA cm−2 compared to bare Zn (64 h). Moreover, when the ammonium vanadate (NHVO) cathode is coupled with ZnTAPP‐NTCDA‐POP@Zn anode, the resulting full cell displays superior cycle stability that sustains over 350 cycles with a higher invertible capacity (225 mAh g−1 at 1 A g−1). This performance surpasses that of a full cell equipped with just a bare Zn anode. This work proposes a viable strategy to address Zn dendrites, presenting a promising horizon for the widespread application of AZIBs. [ABSTRACT FROM AUTHOR]

This document is a correction notice for an article titled "A robust and porous titanium metal-organic framework for gas adsorption, CO2 capture and conversion" published in the journal Dalton Transactions. The correction notice, numbered 12797, acknowledges an error in the original article but does not provide any specific details about the nature of the error or the correction made. The article itself explores the topic of a titanium metal-organic framework and its potential applications in gas adsorption, CO2 capture, and conversion. The journal, published by The Royal Society of Chemistry, covers a wide range of topics in inorganic chemistry and is a respected resource in the field. [Extracted from the article]

Supramolecular chemistry–mediated synthesis has thus far been employed for the design of ordered mesoporous structures surrounded by various metal oxides that are helpful as nanometer-scaled unique reaction containers with high specific surface area, large pore volume and uniform mesopores useful for the storage and mass transport of large-sized molecules. The evaporation-induced self-assembly (EISA) process is very powerful for fabricating mesoporous metal oxide films with the rapid evaporation of solvents. Although a similar EISA process is also applied to synthesize mesoporous metal oxide powders using the room-temperature drying process with slow evaporation of solvents, the control of the evaporation rate should be quantified for the complete reproduction of high-quality metal oxide powders. In this feature article, I introduce our recent challenge in synthesizing highly porous metal oxides in powder form with the smart optimization of synthetic conditions by combining several EISA processes to eliminate the mismatch of the rate of solvent evaporation, inducing the self-assembly of amphiphilic organic molecules. [ABSTRACT FROM AUTHOR]

Thermal management technology based on loop heat pipes (LHPs) has broad application prospects in heat transfer control for aerospace and new energy vehicles. LHPs offer excellent heat transfer performance, reliability, and flexibility, making them suitable for high-heat flux density, high-power heat dissipation, and complex thermal management scenarios. However, due to limitations in heat source temperature and heat transfer power range, LHP-based thermal management systems still face challenges, especially in thermohydraulic modeling, component design, and optimization. Steady-state models improve computational efficiency and accuracy, while transient models capture dynamic behavior under various conditions, aiding performance evaluation during start-up and non-steady-state scenarios. Designs for single/multi-evaporators, compensation chambers, and wick materials are also reviewed. Single-evaporator designs offer compact and efficient start-up, while multi-evaporator designs handle complex thermal environments with multiple heat sources. Innovations in wick materials, such as porous metals, composites, and 3D printing, enhance capillary driving force and heat transfer performance. A comprehensive summary of working fluid selection criteria is conducted, and the effects of selecting organic, inorganic, and nanofluid working fluids on the performance of LHPs are evaluated. The selection process should consider thermodynamic properties, safety, and environmental friendliness to ensure optimal performance. Additionally, the mechanism and optimization methods of the start-up behavior, temperature oscillation, and non-condensable gas on the operating characteristics of LHPs were summarized. Optimizing vapor/liquid distribution, heat load, and sink temperature enhances start-up efficiency and minimizes temperature overshoot. Improved capillary structures and working fluids reduce temperature oscillations. Addressing non-condensable gases with materials like titanium and thermoelectric coolers ensures long-term stability and reliability. This review comprehensively discusses the development trends and prospects of LHP technology, aiming to guide the design and optimization of LHP. [ABSTRACT FROM AUTHOR]

Sheet metals subjected to biaxial plane stress loading typically fail due to localized necking in the thickness direction. Classical plasticity models using a smooth yield surface and the normality flow rule cannot predict localized necking at realistic strain levels when both the in-plane principal strains are tensile. In this paper, a recently developed multi-surface model for porous metal plasticity is used to show that the development of vertices on the yield surface at finite strains due to microscopic void growth, and the resulting deviations from plastic flow normality, can result in realistic predictions for the limit strains under biaxial tensile loadings. The shapes of the forming limit curves predicted using an instability analysis are in qualitative agreement with experiments. The effect of constitutive features such as strain hardening and void nucleation on the predicted ductility are discussed. [ABSTRACT FROM AUTHOR]

The formation of macroscopic deformation bands constitutes undesired stress fluctuations in the compression of porous metals. This research is aimed at revealing the predictability of the formation of deformation bands in porous metals with unidirectional through‐pores. Finite element analyses of compression tests of such porous metals are conducted with the commercial code Abaqus/Standard and Explicit 2018. Three cubic specimens with different L/d (specimen edge length L, pore diameter d) but with the almost same porosity are prepared, and quasi‐static compression is simulated. The results suggest that the formation of horizontally propagated deformation bands is suppressed as L/d increases. A path search is performed to predict the location of deformation bands on a graph that represents equivalent plastic strain (PEEQ) distribution in the specimens. It is revealed that horizontally propagated deformation bands at compressive strain e = 10.0 pct can be predicted as the path with the largest mean of PEEQ at e = 1.0 pct when the following two conditions are met; the minimum PEEQ in the path has to be larger than zero, and the standard deviation of the PEEQ mean in candidate paths has to be sufficiently large. [ABSTRACT FROM AUTHOR]

With the growing interest in additive manufacturing technology, assessing the biocompatibility of manufactured elements for medical and veterinary applications has become crucial. This study aimed to investigate the corrosion properties and cytotoxicity of porous structures designed to enhance the osseointegration potential of implant surfaces. The structures were fabricated using BJ technology from 316L stainless steel powder, and their surfaces were modified with a DLC coating. The studies carried out on porous metal samples with and without DLC coatings demonstrated low cytotoxicity. However, no significant differences were found between the uncoated and DLC-coated samples, likely due to variations in the thickness of the coating on the porous samples and the occurrence of mechanical damage. [ABSTRACT FROM AUTHOR]

With the gradual increase in energy demand in global industrialization, the energy crisis has become an urgent problem. Due to high heat storage density, small volume change, and nearly constant transition temperature, phase change materials (PCMs) provide a promising method to store thermal energy. In this work, we designed and fabricated three kinds of porous metal structures with hexagonal, rectangular, and circular pores and explored the phase change process of PCMs within them. A two-dimensional numerical model was established to investigate the heat transfer process of PCMs within different shapes of porous metal structures and analyze the influence of heat source location on the thermal performance of the thermal storage units. Visualization experiments were also carried out to reveal the melting process of PCMs within different porous metal structures by a digital camera. The results show that paraffin in a porous metal structure with hexagonal pores has the fastest melting rate, while that in a porous metal structure with circular pores has the slowest melting rate. Under the bottom heating mode, the melting time of the paraffin in porous metal structures with hexagonal pores is shortened by 18.6% compared to that in porous metal structures with circular pores. Under the left heating mode, the corresponding melting time is shortened by 16.7%. These findings in this work will offer an effective method to design and optimize the structure of porous metal and improve the thermal properties of PCMs. [ABSTRACT FROM AUTHOR]

Metal oxides possessing a large surface area, pore volume and desirable pore size provide more varieties and active industrial potentials. Nevertheless, it is very challenging to produce crystal metal oxides while keeping satisfactory porosity features, especially for ternary compositions. High temperature is usually needed to produce crystal metal oxides, which readily leads to the collapse of the pore structure. Herein, by employing a 'soft' dispersant agent and a hard silica template, ZrO2, TiO2 and Zr-Ti solid solutions having a tetragonal crystal structure are produced and the silica-leached materials are characterized from macroscopic to atomistic scales. The micron-sized particulate powders are composed of nanoscale 'building blocks', with crystallite sizes between ~8 and 21 nm. These polycrystalline ceramic powders exhibit a high specific surface area (up to ~200 m2·g−1) and pore volume (up to 0.5 cm3·g−1), with a pore size range of ~5–20 nm. Importantly, the Zr/Ti–O–Si–OH chemical bonds exist on the particle surface, with about two-thirds of the surface covered by silica. The hydroxyl groups can further post-graft organic ligands or directly associate with species. Synthesized mesoporous metal oxides are highly homogenous and could potentially be used in various applications because of their tetragonal structure and porosity features. [ABSTRACT FROM AUTHOR]

Engineering-efficient, stable and low-cost electrocatalyst is facing with essential demand for overall water cracking to generate hydrogen and oxygen. Higher activation energy and sluggish kinetics are the main limiting factors for improved yield. In this paper, ZIF-67 was applied to prepare porous metal sulfide and foreign Fe atoms were introduced to substitute Co atoms in situ in CoS to modulate the electronic structure of the active centers. The as-constructed catalytic system reveals expected pH-universal HER performance and alkaline OER activity, and requires quite small over-potentials. Our theoretical prediction verifies the effective charge transfer between the doped Fe atom and its neighboring S atoms on the surface and the chemical environment variation in the doping sites. In addition, the improved conductivity and the decreased activation energy barriers are calculated in the FeCoS catalyst, further explaining its superiority in catalyzing OER and HER processes. This strategy is expected to be expandable to multiple energy transformation applications and provide a constructive strategy for fast charge transfer in water splitting. [Display omitted] • Non-precious bifunctional electrocatalyst were facile established. • FeCoS/NF-2 exhibited excellent performance for HER in the full pH range. • The chemical environment variation in the doping sites was explored. • DFT calculation explained the reasons for the excellent properties. [ABSTRACT FROM AUTHOR]

Catalyst deactivation by sintering and coking is a long‐standing issue in metal‐catalyzed harsh high‐temperature hydrocarbon reactions. Ultrathin oxide coatings of metal nanocatalysts have recently appeared attractive to address this issue, while the porosity of the overlayer is difficult to control to preserve the accessibility of embedded metal nanoparticles, thus often leading to a large decrease in activity. Here, we report that a nanometer‐thick alumina coating of MgAl2O4‐supported metal catalysts followed by high‐temperature reduction can transform a nonporous amorphous alumina overlayer into a porous Mg1‐xAl2Oy crystalline spinel structure with a pore size of 2–3 nm and weakened acidity. The high porosity stems from the restrained Mg migration from the MgAl2O4 support to the alumina overlayer through solid‐state reactions at high temperatures. The resulting Ni/MgAl2O4 and Pt/MgAl2O4 catalysts with a porous crystalline Mg1‐xAl2Oy overlayer achieved remarkably high stability while preserving much higher activity than the corresponding alumina‐coated Ni and Pt catalysts on MgO and Al2O3 supports in the reactions of dry reforming of methane and propane dehydrogenation, respectively. [ABSTRACT FROM AUTHOR]

AbstractThe variable thickness function is innovatively added. The carbon fiber layer and the porous foam metal aluminum, are selected to composite the composition of a variable thickness cantilevered trapezoidal plate for modeling and free vibration analysis. Hamilton’s principle is used to develop the motion control equation of the trapezoidal plate with variable thickness cantilevered sandwich, and Galerkin’s approach is used to determine the inherent frequency of the system. The research employs suitable analytical methods to solve them, and analyzes the outcomes to uncover the effects of geometric parameters, material properties, and thickness variations on the structure. [ABSTRACT FROM AUTHOR]