Types Of Materials Research Articles

Unlocking the Multi-Redox (Nb5+/Nb4+/Nb3+) Reactions in Nasicon- Nb2(PO4)3 Anode for Li- and Na-Ion Batteries

NASICON (Natrium Super-Ionic CONductor) type materials are known for their high structural, and thermal stability and superior sodium ion mobility which make this framework an efficient electrode material for Na-ion batteries.1 In recent times NASICON-type compounds have been widely explored as Li- and Na-ion cathodes and solid-state electrolytes but are largely ignored as anodes due to their lower capacities and higher intercalation voltages, which reduce the overall energy densities of Li- and Na-ion batteries (LIBs and SIBs). NASICON structure has a general molecular formula of NaxMM′(PO4)3, where two MO6 octahedra corners are shared with three PO4 tetrahedra along the c-direction resulting in the “lantern units” and each lantern unit joins six other lantern units, generating a large interstitial space that can accommodate up to four alkali cations per formula unit.2 In the NASICON family usually all members contain Na/Li ions in terms of synthesis and electrochemical/chemical oxidation routes must be employed to remove the Na from the parent compound.Herein, for the first time we will present a comprehensive study on the structural and electrochemical properties of the empty NASICON-type (contains no Li or Na ions in its pristine state) mixed valance Nb2(PO4)3 and its potential application as an anode in LIBs and SIBs. Due to the multi-redox activity of Nb, it is possible to attain high insertion capacity (~ 150 mAh g-1 for SIBs and ~ 170 for LIBs) and relatively lower voltages (1.8 V vs. Li+/Li0 and 1.4 V vs. Na+/Na0) compared to Ti or V-based NASICON anodes.3,4 Our in-situ XRD measurements revealed multiple-phase transformations during Li and Na intercalation with the formation of short-range ordered Li3Nb2(PO4)3 and triclinic (P-1)-Na3Nb2(PO4)3 at the end of discharge. The distinct electrochemical Li and Na intercalation behavior of the Nb2(PO4)3 anode can be ascribed to the relative differences in size, filling of crystallographic sites, and chemical characters of Li and Na ions. Our density functional theory calculations are also in agreement with the in-situ XRD measurements in predicting a stable Na3Nb2(PO4)3 composition in the Na-Nb2(PO4)3 pseudo-binary system. X-ray absorption spectroscopy confirms the participation of multi-redox Nb5+/Nb4+/Nb3+ couples. Although the micron-sized anode showed moderate storage capacities (~106 and 84 mAh g-1 for Li and Na cells, respectively) at 1C rate after 200 cycles, further optimization of electrode and electrolytes is expected to produce better performance. In the future, pairing Nb2(PO4)3 anode with suitable cathodes can enable high-energy density batteries.5

K3MnO4 a New Cathode Material for K-Ion Batteries

To meet future energy demands, developing beyond-lithium energy storage technologies have become a major part of global research activities. Potassium-ion batteries (KIBs) represent a promising technology thanks to their chemical and economic advantages1–3. To succeed in developing commercial KIBs, it is necessary to develop new cathode materials4 which must be non-toxic, inexpensive, easy to prepare and have a reasonable K+ diffusion pathway to improve their electrochemical performance. Here we have chosen to explore the inexpensive and non-toxic K-Mn-O system, where only two-dimensional materials of the KxMnO2 type have been studied so far for their electrochemical properties5,6.In this system, a composition attracted our attention: K3MnO4. In principle, up to two potassium ions can be removed from the structure, leading to KMnO4 with a theoretical capacity of 227 mAh/g.Hagenmuller and co-workers succeeded in preparing two polymorphs of K3MnO4 as single crystals7. The high temperature polymorph γ-K3MnO4 has a cubic symmetry (P213) with a disordered distribution of K and Mn in similar tetrahedral sites. The low temperature polymorph β-K3MnO4, can be prepared by annealing γ-K3MnO4 under argon. This polymorph has a tetragonal symmetry (I-42m) with ordered MnO4 tetrahedra. Mn is reported at the edge and at the center of the tetragonal unit cell, surrounded by four oxygens. These phases could be described as a 0D-type structure built of isolated MnO4 tetrahedra surround by potassium ions.We recently succeed in the synthesis of a new polymorph of K3MnO4, labelled α-K3MnO4,8 prepared by a conventional solid-state route by annealing a mixture of KO2 and MnO under vacuum at 500°C in a Al2O3 boat. The structure of this polymorph could be described with a “zig-zag” distribution of the MnO4 tetrahedra (Fig. 1a) and is isostructural to the iron-based K3FeO4 9,10 with an orthorhombic symmetry (Pnma). The blue colour of the powder is classically associated to the Mn+V oxidation state, as confirmed by magnetic and EDS analyses. K3MnO4 exhibits a reversible capacity of 70 mAh/g in the 1.6-3.5 V vs. K+/K potential window at C/20 (Fig. 1b).In our presentation, we will detail the electrochemical behaviour of K3MnO4 and discuss the structure/properties relationship of this family of materials, showing the interest in the exploration of such a system. Xu, Y. et al. 2023 roadmap for potassium-ion batteries. J. Phys. Energy 5, 021502 (2023).Tian, Y. et al. Promises and Challenges of Next-Generation “Beyond Li-ion” Batteries for Electric Vehicles and Grid Decarbonization. Chem. Rev. 121, 1623–1669 (2021).Zhang, W., Liu, Y. & Guo, Z. Approaching high-performance potassium-ion batteries via advanced design strategies and engineering. Sci. Adv. 5, eaav7412 (2019).Nathan, M. G. T. et al. Recent Advances in Layered Metal-Oxide Cathodes for Application in Potassium-Ion Batteries. Adv. Sci. n/a, 2105882.Liu, T. et al. Insight of K-deficient layered KxMnO2 cathode for potassium-ions batteries. J. Energy Chem. 64, 335–343 (2022).Liu, C., Luo, S., Huang, H., Zhai, Y. & Wang, Z. Layered potassium-deficient P2- and P3-type cathode materials KxMnO2 for K-ion batteries. Chem. Eng. J. 356, 53–59 (2019).Olazcuaga, R., Reau, J.-M., Leflem, G. & Hagenmuller, P. Préparation, Proprietés Cristallographiques et Magnétiques des Phases K3XO4 (X=V, Cr, Mn). Z. Für Anorg. Allg. Chem. 412, 271–280 (1975).Sagot, A., Stievano, L. & Pralong, V. K3MnO4: A New Cathode Material for K-Ion Batteries. ACS Appl. Energy Mater. 6, 7785–7789 (2023).Kokarovtseva, I. G., Belyaev, I. N. & Semenyakova, L. V. Oxygen Compounds of Iron(VI, V, IV). Russ. Chem. Rev. 41, 929–937 (1972).Hoppe, R. & Mader, K. Zur Konstitution von K3[FeO4]. Z. F ür Anorg. Allg. Chem. 586, 115–124 (1990). Figure 1

KxFeO2 As Electrode Material for K-Ion Batteries

To meet future energy demands, developing beyond-lithium energy storage technologies have become a major part of global research activities. Potassium-ion batteries (KIBs) represent a promising technology thanks to their chemical and economic advantages1–3. The majority of the work on layered transition oxide was done on the KxMnO2 family4,5 due to their safety and price advantage.Interestingly, KFeO2 structure is not a layered structure as for LiFeO2 or NaFeO2; this structure is defined as FeO4 tetrahedral linked by their corners. In electrochemistry, a reversible capacity of 60 mAh/g (for 0.3K+) was delivers6.In our presentation, we will detail the electrochemical behaviour of KFeO2 and discuss the structure/properties relationship of this family of materials, showing the interest in the exploration of such a system. Xu, Y. et al. 2023 roadmap for potassium-ion batteries. J. Phys. Energy 5, 021502 (2023).Tian, Y. et al. Promises and Challenges of Next-Generation “Beyond Li-ion” Batteries for Electric Vehicles and Grid Decarbonization. Chem. Rev. 121, 1623–1669 (2021).Zhang, W., Liu, Y. & Guo, Z. Approaching high-performance potassium-ion batteries via advanced design strategies and engineering. Sci. Adv. 5, eaav7412 (2019).Kim, H. et al. Investigation of Potassium Storage in Layered P3-Type K0.5MnO2 Cathode. Adv. Mater. 29, 1702480 (2017).Liu, C., Luo, S., Huang, H., Zhai, Y. & Wang, Z. Layered potassium-deficient P2- and P3-type cathode materials KxMnO2 for K-ion batteries. Chem. Eng. J. 356, 53–59 (2019).Han, S. C., Park, W. B., Sohn, K.-S. & Pyo, M. KFeO2 with corner-shared FeO4 frameworks as a new type of cathode material in potassium-ion batteries. J. Solid State Electrochem. 23, 3135–3143 (2019).

Investigating the Effects of Anode Catalyst Conductivity and Loading on Performance for Anion Exchange Membrane Water Electrolysis

Water electrolysis (WE) is a promising route for carbon-free production of green hydrogen, which is increasingly considered to be an important energy carrier. Among the low-temperature WE technologies, anion exchange membrane water electrolysis (AEMWE) has the potential advantages of high operating current densities and low cost due to the use of zero-gap assembly and platinum group metal (PGM)-free components, respectively [1]. However, significant challenges remain for this technology, including low efficiency, insufficient durability, and poor performance in pure water operation. Recent efforts have yielded improvements in the individual components, particularly the oxygen evolution reaction (OER) catalysts and anion exchange polymers; however, to further improve the performance of the AEMWE, it is also necessary to understand and improve the integration of these materials into the membrane electrode assembly (MEA). Within the MEA, the anode and cathode catalyst layers (CLs) incorporate catalyst and ion-conducting and/or binding polymers, which are deposited onto either the membrane or the porous transport layer. The material properties of each component, as well as the loadings of the catalyst and ionomer and methods of dispersion and deposition, have significant impact on the catalyst layer morphology and uniformity [2]. These CL properties affect the transport of electrons, hydroxide ions, and evolved gases, ultimately controlling the accessibility and utilization of catalyst active sites, with significant consequences for both the performance and durability of AEMWEs.Most of the effort in catalyst development for AEMWE has focused on the OER, aiming to improve sluggish kinetics and improve stability at the highly oxidizing operating potentials. A number of PGM-free catalysts have shown promising activity in rotating disk electrode (RDE) tests, particularly oxides with varying ratios of Ni, Fe, and Co. The activity improvements with tuning the composition are often attributed to the increase in surface area and shift in redox potentials for the in-situ conversion to higher valence sites with higher intrinsic OER activity. However, these activity trends do not always translate into device-level performance because of differences in the operating environment, e.g. hydroxide concentration, reaction rates, etc. In the AEMWE, where typically an order of magnitude higher loadings and current densities are required, the challenges of conductivity and mass transport to allow for full site access are exacerbated. Electrochemical impedance spectroscopy (EIS) is a valuable tool for understanding the origin of voltage losses in the AEMWE, typically broken down into ohmic, kinetic, and mass transport losses. Recently, a transmission line model has been applied to non-Faradaic EIS to isolate another contribution to voltage loss: the catalyst layer resistance (CLR), which corresponds to in-plane and through-plane electronic and ionic resistances in the catalyst layer [3]. Using this approach, the roles of intrinsic catalyst activity and catalyst layer properties can be decoupled, helping to guide materials integration efforts.In this study, we investigate two types of OER catalyst materials, NiFe- and Co-based oxides. Within each composition, the catalysts have similar active sites but vary in electronic conductivity, crystal structure, and surface area. By comparing the AEMWE performance at different catalyst loadings, we are able to determine the role of catalyst properties in determining active site utilization and electronic resistance within the catalyst layer. Figure 1 shows the trends in performance and ohmic and catalyst layer resistance as a function of loading for high-conductivity (Co@Co3O4) and low-conductivity (Co3O4) catalysts. Despite nominally having the same surface chemistry and similar particle morphology, they display both different performance and different trends with loading. Using in-situ EIS diagnostics and ex-situ characterization of the catalyst layer morphology, the relationship between catalyst utilization, CLR, and the physical properties of the catalyst and catalyst layer is elucidated. This work provides insight into the catalyst properties that most strongly affect AEMWE performance, as well as how materials integration strategies must be tailored based on these properties.

The Circular Path Towards Decarbonising the Li-Ion Battery Value Chain

The rapid transition to clean energy and electric mobility has led to an unprecedented demand for Li-ion batteries (LIBs), necessitating a comprehensive decarbonisation of their entire value chain to meet climate goals [1]. This talk takes a holistic view at the LIB production and recycling system to explore cradle-to-cradle decarbonisation strategies. The Life Cycle Assessment (LCA) framework is used to quantify the comparative importance of developments in battery manufacturing, raw material sourcing and battery recycling in reducing greenhouse-gas emissions (GHG) arising from the globally-distributed LIB value chain.On the upstream side, sourcing low-carbon materials is found to reduce the GHG footprint of LIB manufacturing by up to a factor of 4, depending on raw material type and source, and battery chemistry [2]. The geographical links between battery Gigafactory location and GHG emissions are also explored, revealing substantial differences between US states, Chinese provinces and European countries, traced to the carbon intensity of electricity generation [2]. On the downstream side, hydrometallurgical and pyrometallurgical treatment options for end-of-life LIBs are shown to achieve a GHG benefit of up to 40%, when recovered materials are circulated back to LIB production [3].The battery production and recycling LCA models are integrated to present a comprehensive sensitivity analysis on the effectiveness of LIB recycling in reducing GHG emissions. This is shown to depend on battery chemistry, with lithium iron phosphate material recovery achieving lower benefits, but also on the geographical specificity of key operations, directly affecting the type of materials being displaced through secondary routes. The talk concludes with an outlook to 2035, presenting scenarios to reduce the GHG emissions of the battery value chain through technological developments, improvements in manufacturing and the establishment of circularity.

Computational intelligent techniques for predicting optical behavior of different materials

The current research introduces a comparison study of the utilization of artificial neural networks (ANN) and genetic programming (GP) for predicting the optical behavior of different materials. The experimental data for a variety of materials, including semiconductors, insulators, oxides, and halides are extracted and utilized in ANN and GP as inputs. Simulation and prediction processes are carried out based on ANN and GP techniques. The most important aim presented in the current research is to obtain two equations of n as a function of Eg by the two based on ANN and GP models. The first numerical equation is obtained based on the ANN model exhibiting mean squared error (MSE) does not exceed 10−1. The second nonlinear equation is obtained based on the GP model with an acceptable fitness value. The estimated results based on the proposed approaches ANN and GP presented a great match with their targets. It demonstrated that the trained results including simulated and predicted results based on ANN and GP introduce excellent fitting compared with alike results obtained based on the conventional theoretical techniques. The mean absolute percentage error values prove that the ANN model is significantly more accurate than the GP model. Since lower error values suggest better prediction, hence it is clear that ANN performed better than GP. The equation derived by the ANN model is utilized to predict the refractive index for binary and ternary compounds. The values of the refractive index have been predicted for materials for which measurements have been made practically as a test step to ensure the accuracy of the results obtained through the deduced mathematical equations. Then, the application of these equations was generalized to materials that were not measured experimentally. A detailed discussion of the modeling results is introduced and proved that ANN and GP models are effective and successful tools for predicting the refractive index for different types of materials.

Probiotics encapsulated by calcium pectin/chitosan-calcium pectin/sodium alginate-pectin-whey through biofilm-based microencapsulation strategy and their preventive effects on ulcerative colitis

Biofilm-based probiotics have emerged as a compelling approach for administering probiotics. Selecting appropriate wall materials for enclosing probiotics in biofilm structure is viewed as an advanced method of microencapsulation. In this study, Lactiplantibacillus paraplanturm LR-1 was enclosed in three different types of wall materials to create calcium pectin beads (CPB), chitosan-calcium pectin beads (C-CPB), and sodium alginate-pectin-whey beads (SPW). The biofilm cells of LR-1 were cultured externally and then encapsulated to create CPB-ex-LR-1, C-CPB-ex-LR-1 and SPW-ex-LR-1. In contrast, LR-1 was cultured within the microcapsules to form biofilms in situ, resulting in CPB-situ-LR-1, C-CPB-situ-LR-1 and SPW-situ-LR-1. The microcapsules displayed a relatively uniform morphology with the water contents below 10%. Nevertheless, there were noticeable edge effects in the distribution of strains within the in situ-type microcapsules. The detection of distinctive peaks unique to Lactiplantibacillus within the microcapsules confirmed the successful encapsulation. Additionally, a decrease in the intensity of the peaks linked to the wall materials indicated the formation of an amorphous structure within the microcapsules. The bacterial concentrations of situ-type microcapsules were found to surpass 10 lg CFU/g. The SPW-situ-LR-1 demonstrated superior tolerance performance, optimal release properties in simulated gastrointestinal fluids, and exceptional stability during the storage period. Additionally, SPW-situ-LR-1 showed similar effectiveness in alleviating colitis compared to fresh Biofilm-LR-1. Both Biofilm-LR-1 and SPW-situ-LR-1 pre-treatments exhibited positive effects on regulation, with SPW-situ-LR-1 administration significantly increasing the presence of Lactobacillus. This study provides valuable insights into the development of the next-generation probiotics.

MgH2 nanoparticles confined in reduced graphene oxide pillared with organosilica: a novel type of hydrogen storage material.

Hydrogen is a promising alternative fuel that can push forward the energy transition because of its high energy density (142 MJ kg-1), variety of potential sources, low weight and low environmental impact, but its storage for automotive applications remains a formidable challenge. MgH2, with its high gravimetric and volumetric density, presents a compelling platform for hydrogen storage; however, its utilization is hindered by the sluggish kinetics of hydrogen uptake/release and high temperature operation. Herein we show that a novel layered heterostructure of reduced graphene oxide and organosilica with high specific surface area and narrow pore size distribution can serve as a scaffold to host MgH2 nanoparticles with a narrow diameter distribution around ∼2.5 nm and superior hydrogen storage properties to bulk MgH2. Desorption studies showed that hydrogen release starts at relatively low temperature, with a maximum at 348 °C and kinetics dependent on particle size. Reversibility tests demonstrated that the dehydrogenation kinetics and re-hydrogenation capacity of the system remains stable at 1.62 wt% over four cycles at 200 °C. Our results prove that MgH2 confinement in a nanoporous scaffold is an efficient way to constrain the size of the hydride particles, avoid aggregation and improve kinetics for hydrogen release and recharging.

Flexible Metal-Organic Frameworks: From Local Structural Design to Functional Realization.

ConspectusFlexible metal-organic frameworks (MOFs), also known as soft porous crystals, exhibit dynamic behaviors in response to external physical and chemical stimuli such as light, heat, electric or magnetic field, or the presence of particular matters, on the premise of maintaining their crystalline state. The reversible structural transformation of flexible MOFs, a unique characteristic seldomly found in other types of known solid-state materials, affords them distinct properties in the realms of molecule separation, optoelectronic devices, chemical sensing, information storage, biomedicine applications, and so on. The mechanisms underlying their dynamic behaviors can be comprehensively investigated at the molecular level by means of in situ single-crystal or powder X-ray diffraction as well as other in situ spectroscopic techniques due to the high regularity of these crystalline materials during stimuli-responsive phase transitions. Through the introduction of specific stimuli-responsive groups/moieties into the well-defined and ordered molecular arrays, targeted applications can be achieved, and the performance of flexible MOFs can also be further improved via rational structural design.In this Account, we summarize our progress on the design, synthesis, and applications of flexible MOFs over the past few years. First, we highlight the construction principle of flexible MOFs, emphasizing the pivotal role of local structural design. Using an F-modified ligand, a flexible MOF with remarkable structural transformations can be obtained; the regulation of the metal coordination environment and interpenetrating frameworks is also crucial for achieving flexible MOFs. We also propose a strong correlation strategy based on the supramolecular interactions between the guest molecules and the framework, which realizes the temperature-responsive dynamic spatial "open-closed" regulation. Mechanisms of the dynamic behaviors investigated by the in situ techniques were also presented for the obtained materials. Second, some representative specific applications of the newly developed dynamic coordination systems were reviewed. The gas molecule responsive flexible MOFs show efficient short-chain alkane separation properties with discriminatory sorption behavior toward similar gaseous substrates. Smart sensing of temperature, pressure, and volatile organic compounds was achieved by several novel flexible fluorescent MOFs, with optimization potential through state-of-the-art chemical design. Furthermore, multiferroic materials with multiple bistable states and high working temperatures were also obtained based on flexible MOFs.Finally, we provide a discussion of the challenges of flexible MOFs in future research, including precise and efficient synthesis, in-depth structure-property relationship investigation, performance optimization, and industrialization. We hope that this Account will stimulate further research interest in developing next-generation smart materials based on flexible MOFs for applications in challenging chemical separation, extreme environmental sensing, massive information storage, and beyond.

Effect of the scanner type on the marginal gap and internal fit of two monolithic CAD/CAM esthetic crown materials: An in vitro study.

The durability of indirect restorations is significantly influenced by marginal adaptation and internal fit. The use of computer-aided design/computer-aided manufacturing (CAD/CAM) with digital impressions has reduced dental prosthesis fabrication errors, improving the long-term survivability of the restorations. The present study assessed the impact of intraoral and extraoral scanning methods on the marginal adaptation and internal fit of 2 different types of monolithic crowns manufactured using CAD/CAM. A total of 40 three-dimensional (3D) resin-printed dies were randomly assigned to 2 groups based on the type of crown material (n = 20 per group). Each group was divided into 2 subgroups (n = 10 per group) according to the die-scanning technique: subgroup A, scanned using the intraoral scanner (IOS) Primescan; and subgroup B, scanned using the extraoral scanner (EOS) inEos X5. The digitized photos were converted into a 3D virtual crown design using CAD software. The internal discrepancy values, and the marginal gap between the 3D resin-printed die and the crown were assessed using a ×50 digital microscope. The data was checked for normality with the Kolmogorov-Smirnov test, and the Mann-Whitney U test was used to compare the tested groups. The collected data was analyzed at a significance level set at p < 0.05. The different scanning techniques used had a statistically significant effect on the vertical marginal gap and the internal fit [μm] (p < 0.05). As far as the crown materials are concerned, BRILLIANT Crios showed a significantly higher marginal gap as compared to Tetric CAD when scanned with inEos X5 (p = 0.004), whereas the differences were insignificant with regard to the internal fit (p > 0.05).The crown parameters tested with both scanning systems were within the clinically acceptable ranges. Scanning methods and crown materials had an impact on the internal fit and vertical marginal gap of monolithic crowns.

The Ubiquitous External Ejaculation: Examining Perceptions of Sexual Images Across Cultures.

The persistent debates over pornography have often focused on differences between males and females, not only in the frequency of consumption or the type of material consumed, but also on the different ways that individuals may perceive sexually explicit images and respond to them. Some of these differences may be due to sex differences in a number of factors including sexual strategies, pathogen or sexual disgust, and own mate value as well as within sex differences in these factors. Previous studies have demonstrated that perceptions of sexually explicit images are influenced by the sex of the target in the image and the target's emotional affect, as well as sex of the respondent, their sexual orientation, short-term mating orientation, and disgust measures. However, these previous studies were conducted with participants from the United States alone. This study compared the findings from these US samples to those from non-Western ones (Philippines and Brazil) in order to examine the replicability across cultures of the US results as well as whether some variables (religiosity, for example) account for more or less of the variance in perceptions in different populations. Results indicated that there were some differences in terms of the amount of variance in perceptions explained by different variables across populations. Participant and stimuli related variables explained more variance in the Philippines while individual difference variables accounted for more variance in Brazil.

Predictive modelling of HHV and LHV for sugar industry by-products: a study on sugarcane trash leaves, bagasse, and filter cake

ABSTRACT This study aimed to enhance the efficiency of by-product raw materials from the sugar industry for use as fuel. The approach involved developing an equation to calculate the higher heating value (HHV) for each type of raw material using a regression method. Additionally, a simplex-centroid mixture design (SCMD) was employed to estimate the lower heating value (LHV) based on the mixing ratios by weight of sugarcane trash leaves (SCL), sugarcane bagasse (SCB), and filter cake (FTC). The results demonstrated that the developed model accurately estimated the HHV for each raw material. The ultimate analysis showed high statistical appropriateness, with an R2 of 0.83. The standard error of estimation was 0.74 MJ/kg, and the mean absolute error was 0.76%. Furthermore, the SCMD effectively estimated the LHV of the SCL, SCB, and FTC mixture ratios, achieving an R2 of 99.77%. The evaluation and validation of the prediction equation revealed a mean absolute error of 7.57% and a mean bias error of 6.31%. The findings of this study can be used to enhance the combustion efficiency of sugar industry by-products for use as fuel by selecting the optimal mixing ratio for each type of raw material.

Crystalline Porous Organic Cage Membranes Constructed Using Fortified Intermolecular Interactions for Molecular Sieving.

Among the various types of materials with intrinsic porosity, porous organic cages (POCs) are distinctive as discrete molecules that possess intrinsic cavities and extrinsic channels capable of facilitating molecular sieving. However, the fabrication of POC membranes remains highly challenging due to the weak noncovalent intermolecular interactions and most reported POCs are powders. In this study, we constructed crystalline free-standing porous organic cage membranes by fortifying intermolecular interactions through the induction of intramolecular hydrogen bonds, which was confirmed by single-crystal X-ray analysis. To elucidate the driving forces behind, a series of terephthaldehyde building blocks containing different substitutions were reacted with flexible triamine under different conditions via interfacial polymerization (IP). Furthermore, density functional theory (DFT) calculations suggest that intramolecular hydrogen bonding can significantly boost the intermolecular interactions. The resulting membranes exhibited fast solvent permeance and high rejection of dyes not only in water, but also in organic solvents. In addition, the membrane demonstrated excellent performance in precise molecular sieving in organic solvents. This work opens an avenue to designing and fabricating free-standing membranes composed of porous organic materials for efficient molecular sieving.

Crystalline Porous Organic Cage Membranes Constructed Using Fortified Intermolecular Interactions for Molecular Sieving

AbstractAmong the various types of materials with intrinsic porosity, porous organic cages (POCs) are distinctive as discrete molecules that possess intrinsic cavities and extrinsic channels capable of facilitating molecular sieving. However, the fabrication of POC membranes remains highly challenging due to the weak noncovalent intermolecular interactions and most reported POCs are powders. In this study, we constructed crystalline free‐standing porous organic cage membranes by fortifying intermolecular interactions through the induction of intramolecular hydrogen bonds, which was confirmed by single‐crystal X‐ray analysis. To elucidate the driving forces behind, a series of terephthaldehyde building blocks containing different substitutions were reacted with flexible triamine under different conditions via interfacial polymerization (IP). Furthermore, density functional theory (DFT) calculations suggest that intramolecular hydrogen bonding can significantly boost the intermolecular interactions. The resulting membranes exhibited fast solvent permeance and high rejection of dyes not only in water, but also in organic solvents. In addition, the membrane demonstrated excellent performance in precise molecular sieving in organic solvents. This work opens an avenue to designing and fabricating free‐standing membranes composed of porous organic materials for efficient molecular sieving.

Trace Elements Anomalous Concentrations in Building Materials-The Impact of Secondary Mineralisation Processes.

The Pb, Cr, Cd, Ni, Zn, Cu, Co, As, Sr, Ba, and Zr content has been determined in the tested rock raw materials. The concentration of cadmium (Cd) was found to be elevated in all types of rock materials and was found on average to be: 1.39 mg/kg in limestones, 0.86 mg/kg-sandstones, 0.44 mg/kg-diatomites, 0.55 mg/kg-opoka rocks, 0.89 mg/kg-marls, 0.21 mg/kg-gaizes 0.42 mg/kg-kaolin clays, and 2.13 mg/kg-decalcified opoka rocks. Higher concentrations of arsenic (As) have also been recorded in sandstones and diatomites, as well as lead (Pb) in limestones and sandstones. The results obtained indicate that the anomalous level of elements is of natural origin and the results of identified secondary mineralisation processes that have affected the tested materials. Pyritization and sulfatization processes have been detected. Mineralogical research has shown that these processes can be associated with the activity of biochemical processes caused by the decomposition of the soft tissues of animal organisms and the organic substances of plant origin that fill the stylolites. It has been shown that the content of strontium (Sr) increases in geologically older Jurassic formations compared to younger Cretaceous formations, which can be used in the monitoring of building materials.

Visible Light-Driven Hypochlorous Acid Synthesis Using a Sustainable and Cost-Effective WO3/CdS Photocatalyst without Precious Metals.

Compared with traditional electrolytic technology, directly using photocatalytic materials to produce hypochlorous acid from chlorine-containing water undoubtedly has stronger low-carbon and environmentally-friendly characteristics. However, currently reported materials with photocatalytic chlorine production performance require precious metal Pt for catalysis, which undoubtedly greatly increases production costs. Therefore, developing new types of non-precious metal-based photocatalytic materials for efficient hypochlorous acid synthesis has significant implications. In this study, we demonstrate a novel breakthrough by showing that the WO3/CdS with a Z-scheme structure effectively generated 3.54 mg/L of free chlorine in a 0.5 M NaCl solution, while also exhibiting spectral bactericidal and algal inhibition properties. The Z-scheme structure can effectively prevent carrier recombination and improve photocatalytic efficiency. Therefore, this research provides a novel approach to photocatalytic antifouling and holds significant implications for the application of photocatalytic technology in the marine antifouling industry.

Construction materials and building techniques – Comparing anthropogenic sediments of three Middle Bronze Age sites from Hungary

This paper compares various ‘earthen’ construction materials and building techniques from three Middle Bronze Age tell (multi-layered settlement) sites in Hungary: Százhalombatta-Földvár, Kakucs-Turján (Vatya material culture) and Borsodivánka-Marhajárás-Nagyhalom (Otomani-Füzesabony Cultural Circle (OFCC)). It employs microscopic analyses – archaeological soil micromorphology and phytolith analysis within thin sections – to examine floor, wall and fire installation materials at a high resolution. The term ‘earthen construction materials’ is used in archaeology extensively to refer to anything from soils to sediments that sometimes lack proper classification or terminology. Through a closer look at the types of materials used at the three analysed sites, we describe more clearly what comprises ‘earthen’ construction materials. Using this data, we then employ a chaîne opératoire approach to think through various stages in the sourcing and preparation of building materials. In analysing this, the paper makes visible the decisions by Bronze Age builders and discusses their possible reasons, which include environmental conditions and socially learned practices. Further, by comparing three contemporary sites within a micro-landscape, our analysis highlights that even small variations in the environment and therefore the available raw materials impact building materials and techniques, and that different groups of people can make different decisions even when facing similar environments.

Capillary trapping of various nanomaterials on additively manufactured scaffolds for 3D micro-/nanofabrication

High-precision additive manufacturing technologies, such as two-photon polymerization, are mainly limited to photo-curable polymers and currently lacks the possibility to produce multimaterial components. Herein, we report a physically bottom-up assembly strategy that leverages capillary force to trap various nanomaterials and assemble them onto three-dimensional (3D) microscaffolds. This capillary-trapping strategy enables precise and uniform assembly of nanomaterials into versatile 3D microstructures with high uniformity and mass loading. Our approach applies to diverse materials irrespective of their physiochemical properties, including polymers, metals, metal oxides, and others. It can integrate at least four different material types into a single 3D microstructure in a sequential, layer-by-layer manner, opening immense possibilities for tailored functionalities on demand. Furthermore, the 3D microscaffolds are removable, facilitating the creation of pure material-based 3D microstructures. This universal 3D micro-/nanofabrication technique with various nanomaterials enables the creation of advanced miniature devices with potential applications in multifunctional microrobots and smart micromachines.

An Experimental Study on the Performance of Materials for Repairing Cracks in Tunnel Linings under Erosive Environments

Addressing the current lining cracking problem in coastal tunnels, this paper independently introduces a novel type of repair material for tunnel lining cracks—the composite repair material consisting of waterborne epoxy resin and ultrafine cement (referred to as EC composite repair material). Through indoor testing, we have analyzed the change rule of the mass change rate, compressive strength, flexural strength, and chloride ion concentration of the repair material samples in erosive environments, with the dosage of each component in the EC composite repair material being varied. We have also investigated the working performance, mechanical properties, and microstructure of the repair material. The results of this study show that when the proportion of each component of ultrafine cement, waterborne epoxy resin, waterborne epoxy curing agent, waterborne polyurethane, defoamer, and water is 100:50:50:2.5:0.5:30, the performance of the EC composite repair material in a chloride ion-rich environment is optimal in all aspects. When the mixing ratio of each component of the EC composite repair material is as stated above, the repair material exhibits the best performance in a chloride ion erosion environment. With this ratio of components in the EC composite repair material, the fluidity, setting time, compressive strength, flexural strength, and bond strength of the repair material in a chloride ion erosion environment can meet the requirements of relevant specifications, and it is highly effective in repairing tunnel lining cracks. The polymeric film formed by the reaction between the waterborne epoxy resin emulsion and the curing agent fills the pores between the hydration products, resulting in a densely packed internal structure of EC composite repair material with enhanced erosion resistance, making it very suitable for repairing cracks in tunnel linings in erosive environments.

Study on the promotion multiple of blood flow velocity on human epidermal microcirculation of volcanic rock polymer fiber seamless knitted fabric

Abstract As a material that can release infrared rays, volcanic rock polymer fibers can be used in textiles to improve human microcirculation, which is helpful to relieve chronic inflammatory diseases such as perishoulder arthritis. In this article, there are two different kinds of exterior yarns. Volcanic rock blended polyester, volcanic rock blended polyamide, polyester and polyamide are chosen as the material type of exterior yarn Ⅰ, whereas the material type of exterior yarn II is conductive polyamide yarn. The exterior yarn feed ratio of exterior yarn Ⅰ and exterior yarn II is designed as 8:0, 7:1 and 6:2 when weft plain stitch, 1 + 1 mock rib and 1 + 3 mock rib are used as the knitted structure of the fabric. According to the three-factor four-level orthogonal experimental design method, the sample protocol was established, and 16 knitted sample fabrics were produced. Then, the promotion multiple of blood flow velocity on human epidermal microcirculation of each sample was tested and analyzed. The results show that the promotion multiple of blood flow velocity on human epidermal microcirculation of the fabrics woven by volcanic rock polymer fibers is better than that of the blank control group, and the difference between fabrics with different volcanic rock polymer fibers is small. The higher the proportion of exterior yarn Ⅰ is, the better the promotion multiple of blood flow velocity on human epidermal microcirculation of fabric will be. The effect of knitted structure on the promotion multiple of blood flow velocity on human epidermal microcirculation of fabrics is not obvious. This study provides reference for the design of medical or health textiles for chronic inflammatory diseases.