Hierarchical porous carbon (HPC) materials contain organized pores having different scales of diameters. These materials exhibit surprisingly high performance in various applications due to the ...functional combination of hierarchical pores. This paper reviews the preparation of HPC from waste and biomass, and their potential applications. Biomass with naturally organized hierarchical structure, such as wood, grass and nut shell, have been widely used as raw materials, from which, hierarchical porosity can be formed through simple pyrolysis-activation. Influences of the types and dosages of activating agent, as well as the pyrolysis/activation conditions on the specific surface area, pore volume and hierarchical porous structure of the structured biomass-based HPC are discussed. For non-structured raw materials such as sucrose, pitch and plastics, novel technologies have been developed to prepare HPC; these include hard-/soft-template methods, hydrothermal carbonization, chemical vapor deposition, spray pyrolysis and autogenic pressure carbonization. The approaches to design or control the structures and properties of HPC made from non-structured materials are also reviewed. Moreover, advanced applications of HPC in energy storage, deionization, adsorption and catalysis are summarized.
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The paper investigates the problem of fire safety in habitable space structures. The flame propagation over thermally destructing material is studied theoretically within the framework of the ...assumptions of the boundary layer theory and the presence of a diffusion flame. The solution is developed based on the concept of thermally thin fuel layer. Flame propagation velocity over structured material, on which different widths ribs are attached, in an opposed flow is determined analytically. PMMA sample of 10 mm thickness, on which ribs of widths 1–10 mm are attached in the direction of flow, is considered as an example. The analytical solution is compared with experimental data.
•Flame propagation velocity over structured material in an opposed flow is determined analytically.•The flame propagation velocity decreases with an increase in the width of the rib.•Slowing down the blower speed can help reduce the speed of flame propagation and the intensity of combustion.•The ribs create more favorable conditions for flame propagation.
We report here the rational design of novel black-to-highly transmissive electrochromic material consisting of two different complementary units and a π-conjugated pendant group. Polymerization of ...the triazine-cored super-structured molecule has yielded a high optical contrast black electrochromic conductive polymer by a combination of the complementary spectra of polycarbazole, polyaniline, and pyrene-based π-conjugated pendant group. The polymer has exhibited a high optical contrast of up to 81% covering the range of 400–800 nm in the spectrum. The PTPCFd film is highly transparent at neutral state, then gray, and finally turns to deep black color covering a broad absorption in the visible range at oxidized state. This work could provide a new method for the design and synthesis of practical black-to-transmissive materials.
Nanoarchitectonics, as a post-nanotechnology concept, is the methodology for constructing functional materials from nano-units, which bridges the gap between nanotechnology and materials science. The ...research accomplishes advocating nanoarchitectonics has increased dramatically as overviewed in the initial part of this review. Then, as socially impactful subjects, we exemplify nanoarchitectonics research for bacterial infections according to classifications featured with molecular tools, interfaces, and hierarchically structured materials. In particular, this review article discusses namely three kinds of antibacterial strategies: (i) new antimicrobial agents and therapeutic modalities based on nanoarchitectonics present high bactericidal efficacy against methicillin-resistant Staphylococcus aureus; (ii) antimicrobial nanoarchitectonics structures are integrated into the surface of medical devices to detach or kill approaching bacteria; (iii) the nanoarchitectonics hydrogels act as antimicrobial reservoirs to produce sustained-release antimicrobial agents for long-lasting bacterial killing.
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•Nanoarchitectonics has been proposed as a post-nanotechnology concept to construct functional materials from nano-units.•This review exemplifies nanoarchitectonics research for bacterial infections in classification featured with molecular tools, interfaces, and hierarchically structured materials.•Antimicrobial nanoarchitectonics structures are integrated into the surface of medical devices to detach or kill approaching bacteria.•Nanoarchitectonics hydrogels act as antimicrobial reservoirs to produce sustained-release antimicrobial agents for long-lasting bacterial killing.•Antimicrobial agents & therapeutic modalities upon nanoarchitectonics against methicillin-resistant Staphylococcus aureus.
Wire arc additive manufacturing (WAAM), thanks to the utilization of the electric arc as an energy source and metal wire as feedstock, has become one of the most cost-effective industrial-scale ...additive manufacturing techniques. The present study investigates the origin of the superior room temperature mechanical properties of AISI 316L stainless steel fabricated using WAAM. The yield strength (450 MPa ± 20 MPa) and uniform elongation (41.2% ± 2.5%) of the specimens extracted from the printed part are well higher than those reported in the case of conventionally manufactured counterparts. The findings from microstructural and elemental analyses reveal that the achieved non-equilibrium microstructure falls into the categories of dual-phase, periodic layered, and harmonic hetero-structured materials. In this respect, the contribution of hetero-deformation induced (HDI) strengthening in overall strength is determined to be 61.3 ± 2.2% through the loading-unloading reloading test.
•Machine Learning models are trained to predict bandgap and stability.•Validation of Regression model with Material Projects Data is performed.•Screening of ∼ 240 K prototypes to obtain 6855 new ...perovskites is done.•Comparative study is performed for DFT and ML predictions for RbSeF3.
In this work, machine learning (ML) techniques are used to discover perovskite structures. ML models are built using the bandgap, as a proxy to represent the efficiency of the solar cell materials. The dataset containing well-known perovskite materials along with bandgaps listed in the open-source database, is used in the learning process. 10-fold cross-validation results show that the random forest (RF) algorithm has better performance as compared to other models. A prediction pool of ∼ 240 K compounds with 7 different prototype structures is created, many of these compounds have never been explored. The RF model is then used to predict the bandgap of new perovskite materials. By screening materials based on formability 6855 new candidates are obtained. For the validation of results, DFT calculation is performed and compared with ML-predicted properties for a new compound.
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•Strategies for the production of porous particles with controllable structures.•Template-assisted spray drying method with its particle formation mechanism.•Regulation of spray ...drying process conditions and precursor formulations.•Concentration, size, and electrostatic charges for controlling particle structure.•Porous particles for advanced functional materials (e.g. catalyst, adsorbent, etc.).
Developing strategies for the production of porous particles with controllable structures using a spray-drying method has attracted attention of researchers for decades. Although many papers have reported their successful production of porous particles using this method, information on how to create and control the porous structures as well as what parameters involving and what formation mechanism occurring during the synthesis process are still not clear. To meet these demands, the present review covers strategies in the spray-drying developments for the fabrication of porous particles with controllable structure. This information is important for optimizing the production of porous particles with desirable properties. Regulation of process conditions and precursor formulations are also explained, including composition, type, and physicochemical properties of droplet and raw components used (i.e., host component, template, and solvent). The electrostatic interactions between the individual components and the droplets are also presented, while this information tends to be neglected in the conventional spray-drying process. To clarify how the porous particles are designed, current experimental results completed with illustrations for the proposal particle formation mechanism are presented. The review also completed with the opportunities and potential roles of the changing porous structures in practical uses. This review would provide information on how to produce porous particles that can be used for advanced functional materials, such as catalysts, adsorbents, and sensors.
Amongst the universal infectious diseases, the urinary tract infection (UTI) is one of the most prevalent bacterial infections. Pathogenic microorganisms causing UTI mainly enter the human body from ...the unhygienic toilet environment. In this study, a graphene structured material (GSM) supported Cu2O-Ag2O composite was synthesized using the co-precipitation method and its photocatalysis-assisted disinfection performance against UTI-causing pathogens was assessed under LED irradiation. The metagenomic analysis of UTI-causing sites was performed by targeting the 16 S rRNA gene region using Illumina sequencing. The results showed that the common phylum identified in the toilets under study is Proteobacteria (76%) and the most dominating genera identified were Acinetobacteria (33%) and Pseudomonas (26%). 8 × 106 CFU mL−1 of Acinetobacter baumanii, Pseudomonas aeruginosa, and Escherichia coli were completely disinfected using the GSM-Cu2O-Ag2O composite within 30 min under LED irradiation. Enterococcus faecalis and mixed bacterial culture took 40 and 75 min, respectively, for complete inactivation. Holes are the major reactive species responsible for photocatalytic inactivation of bacteria. The structural changes of the cells were observed using scanning electron microscopy which indicates that photocatalytic disinfection caused drastic damage to the bacterial cell walls and it was further substantiated by the measurements of DNA and K+ leakage. The composite displayed complete inactivation, remarkable stability and acceptable reusability even after four consecutive cycles. The green composite, after degradation, is supposed to get sequestered in the natural environment without any persistence and bio-magnification prospects. Its potential use can usher in a new greener alternative to traditional toxic disinfectants like benzalkonium chlorides that can exert adverse impacts on the biological environment including human health.
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•Graphene structured material (GSM) supported Cu2O-Ag2O showed high photocatalysis assisted disinfection activity.•Cell damage process was examined through the scanning electron microscopy images.•Holes are the major reactive species in the photocatalysis assisted-inactivation process.•K+ and DNA leakage confirmed the rupture of cell wall.
•A development of microstructure of 12YWT was studied by addition of Zr and Ta.•Ta was only seen in CrTaO4 particles and the main part was found in solution state.•Zr could create finer complex ...nano-oxide particles compared to that of base alloy.•Zr reduced inter-particle spacing and mean particle size while Ta was not effective.•Utilizing Zr was successful to achieve smaller grain size with respect to Ta.
In this study Zr and Ta were employed to improve the microstructural characteristics of 12YWT ODS steel. The mechanically alloyed powders containing different contents of Zr (0.5–1.5%) and Ta (0.05–0.15) were extruded at 850°C and microstructural properties of these steel nanocomposites were investigated. Experimental analysis indicated that the addition of zirconium element reduced inter-particle spacing and encouraged Y–Zr–Ti–O complex oxide and ZrO2 phase with average dispersoid size of 10nm at 1.5% Zr compared to 34nm for base alloy which can effectively prevent grain growth so that the grain size was obtained about 57nm rather than 112nm. The effect of tantalum on reduction of grain size and particle size of dispersoids regardless of zirconium was not noticeable. However, regarding the considerable difference between the total amount of incorporating tantalum and constituent amount in dispersoids, it appeared that this element was mostly in solid solution.
Alkaline water electrolysis (AWE) is a mature water electrolysis technology that can produce green hydrogen most economically. This is mainly attributed to the use of Ni-based materials that are easy ...to process and inexpensive. The nickel-based meshes with various structures such as woven mesh and expanded mesh are widely used as electrode in the AWE due to its common availability and easy fabrication. However, the morphological effect of meshes on hydrogen evolution reaction (HER) performance has not been studied. Here a new parameter to determine the structural effect of mesh on HER performance was first proposed. The key factors of the parameter were found to be the strand width, pore width and the strand surface area. The woven mesh with the ratio of pore width to strand width that converges to 1 showed the lowest the overpotential. The expanded mesh with the higher the structural surface area exhibited the lowest the overpotential. This study will help to choose an optimal structure for the mesh with the HER electrode.
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