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Elastic properties of B2‐Fe0.67Ni0.06Si0.27 (15 wt.% Si) alloy have been investigated by combined high‐resolution inelastic X‐ray scattering and powder X‐ray diffraction in diamond anvil cells up to 100 GPa at room temperature. Densities (ρ), compressional (VP) and shear (VS) wave velocities were extrapolated to inner core conditions to enable comparison with the preliminary reference Earth model. The modeled aggregate compressional and shear wave velocities and densities of the two‐phase mixture of B2‐Fe0.67Ni0.06Si0.27 and hcp‐Fe‐Ni are consistent with inner core PREM values of VP, VS, and ρ based on a linear mixing model with 30(5) vol % B2‐Fe0.67Ni0.06Si0.27 and 70(5) vol % hcp Fe‐Ni, which corresponds to ∼3–5 wt.% Si and ∼5–12 wt.% Ni., Plain Language Summary: The composition of the inner core holds key information about how Earth evolved and how current processes such as the geomagnetic field work. Because the core cannot be directly sampled, our best estimates of its composition are based on the comparison of geophysical data with laboratory measurements of candidate materials. Decades of study have shown the inner core to be composed mainly of iron (with a minor amount of nickel) alloyed with one or more light elements, such as silicon. However, the effect of Si on the geophysical properties of Fe‐Ni alloys is not well established. In this study, we performed laboratory experiments to determine the density and sound velocity of Fe‐Ni‐Si alloy under extreme pressure conditions. We compared our results with seismological determinations and found that Earth's inner core can be accounted for by a mechanical mixture of cubic Fe‐Ni‐Si and hexagonal Fe‐Ni alloys. This mixture has a bulk composition of ∼3–5 weight % Si and ∼5–12 weight % Ni and is consistent with geophysical constraints., Key Points: Sound velocities and densities of B2‐Fe‐Ni‐Si alloy are determined at high pressure, up to 100 GPa, using inelastic X‐ray scattering and X‐ray diffraction. Seismologically observed compressional and shear wave velocities and density of Earth's inner core can be accounted for by a two‐phase mixture of 30 vol % B2‐Fe‐Ni‐Si and 70 vol % hcp Fe‐Ni alloys. Extrapolated results at inner core boundary conditions are consistent with an inner core composition containing ∼3–5 wt.% Si and ∼5–12 wt.% Ni., Japan Society for the Promotion of Science http://dx.doi.org/10.13039/501100001691, Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659, JSPS Japanese‐German graduate externship, https://doi.org/10.6084/m9.figshare.13370795.v1, https://doi.org/10.6084/m9.figshare.13370792.v1

A various kind of 2-substituted-8-quinolinols linked by the substituents possessing electron withdrawing groups at terminal carbon of ethane or ethylene bond have been synthesized. The acid dissociation constants (pKa) of ligands have been measured in 50% v/v aqueous dioxane by UV- Vis spectroscopy. The dissociation constants of imino hydrogen(pKa_1) are found to be smaller than the corresponding values for 8-quinolinol. In particular, 2-(2,2-Dicyanovmyl)-8-quinolinol showed the very low value of pKa_b which suggests it may result from a electron withdrawing erfect of cyano group and the steric hindrance by the ethylene framework.

To produce carbonate apatite (CAP) ceramics with the desired complex shapes using superplastic deformation, deformation behavior of CAP ceramics under constant loading as well as physical properties after deformation were evaluated. Sintered CAP ceramics were plastically deformed in an electric furnace attached to a universal hydraulic testing machine under a constant load. CAP ceramics subjected to an initial compressive pressure of 10 MPa showed an appreciable amount of plastic deformation at temperatures ranging from 720 to 800 degrees C. Plastic deformation increased with increasing temperature from about 10% to 70% after two hours of loading. X-ray diffraction analysis and SEM observation further revealed that some CAP crystals were elongated and aligned with the c-axis normal to the loading direction during superplastic deformation. It was thus concluded that a marked plastic deformation of about 70% at 800 degrees C would be sufficient for near-net-shape production of bioresorbable CAP bone substitutes with complex shapes.

The current report describes the properties of a new apical barrier material formulated from carbonate-containing apatite (CAp) and collagen. CAp particles of around 50 nm were deposited on reconstituted collagen fibers. CAp/col with about 60 wt % CAp (corresponding to apatite content of bone) was obtained after 1 day of calcification. CAp content increased up to about 80 wt % in a 15-day calcification reaction. CAp/col was composed of fine calcified collagen fibers. The crystallinity and Ca/PO(4) ratio of CAp were comparable to those of bone apatite. The mixture of CAp/col and saline reached a pH of about 9. The optimum powder-to-liquid ratio (P/L) to set into a root canal was determined to be 1.2. Furthermore, the mixture (P/L = 1.2) condensed in a root canal was liquid permeable. Thus, the CAp/col was expected as an apical barrier material with osteoconductivity.

The cation-binding by two large ring-sized benzo-27-crown-9 and benzo-30-crown-10 has been evaluated by a solvent extraction of monovalent metal picrates (Na^+, K^+, Rb^+, Cs^+, Ag^+, and Tl^+) between water and dichlolomethane. The effect of ring size and benzo group upon the cation binding ability is discussed. The results are compared with benzo-type crown-6-8 (benzo-18-crown-6, benzo-21-crown-7 and benzo-24-crown-8) and simple unsubstituted crown-6-8 ethers (18-crown-6, 21-crown-7 and 24-crown-8) The cation-binding ability and complex formation are discussed in view of the size of the crown ether ring and the basicity of oxygen atoms.

The cation-binding by two large ring-sized benzo-21-crown-7 and benzo-24-crown-8 has been performed by the solvent extraction of monovalent metal picrates (Na^+, K^+, Rb^+, Cs^+, Ag^+, and Tl^+) between water and dichlolomethane. The effect of ring size and benzo group upon the cation binding ability is discussed. The results are compared with benzo-18-crown-6 and simple unsubstituted crown ethers (18-crown-6, 21-crown-7 and 24-crown-8). It was found that large ring benzo-crown ethers have lower cation binding ability as the ring size increases compared with simple unsubstituted crown ethers while cation selectivity for large cations (Cs^+ and Tl^+) has been observed.

The cation-binding by a series of benzo-type crown ethers with different ring size has been performed by the solvent extraction of monovalent metal picrates (Na^+, K^+, Rb^+, Cs^+, Ag^+, and TI^+) between water and dichlolomethane. The effect of ring size and symmetry of the crown ethers upon the cation binding ability is discussed. The results are compared with those of commercially available crown ethers (dibenzo-18-crown-6 and 18-crown-6) and it was found that the less-symmetrical benzo-crown ethers have lower cation binding ability while unique cation selectivity for thallium (I) has been observed.

A systematic investigation into the structure and properties of five commercially available nickel-based soft magnetic materials was carried out. The five systems are Fe23Ni77, Fei6Ni77Cu7, Fei6Ni77Cu5Cr2, Fei6Ni77Mo7 and Fei6Ni77Nb7. These alloy systems were processed by ball milling to obtain the compound with grain size of several tens of nanometers in length scale. Depending on the exact chemical composition, some amorphous or semi-amorphous phases were deposited at the inter-granular layers as evidenced from the TEM micrographs. As the grain size decreases to several tens of nanometer in scale, results of the ball milled powders showed that the all the five systems exhibited coercivities that increased with grain size, contrary to the random anisotropy model. These were attributed to the internal stress generated from the mechanical forces. Stress-annealed magnets sintered from the alloyed powders showed strong dependency of the anisotropy on grain size where the coercivity decreases with grain size. The effect of alloying elements on the magnetic properties of these nanostructured magnets suggest that it is less significant compared to the effect on grain size. Although the coercivity varies with the alloying elements, the critical factor on its behaviour is dominated by the grain / particle size.

Enamel matrix proteins, including the most abundant amelogenin and lesser amounts of enamelin, ameloblastin, and proteinases, play vital roles in controlling crystal nucleation and growth during enamel formation. The cooperative action between amelogenin and the 32-kDa enamelin is critical to regulating the growth morphology of octacalcium phosphate crystals. Using biophysical methods, we investigated the interaction between the 32-kDa enamelin and recombinant pig amelogenin 148 (rP148) at pH 6.5 in phosphate-buffered saline (PBS). Dynamic light scattering results showed a trend of increasing particle size in the mixture with the addition of enamelin to amelogenin. Upon addition of the 32-kDa enamelin, the shift and intensity decrease in the ellipticity minima of rP148 in the circular dichroism spectra of rP148 illustrated a direct interaction between the 2 proteins. In the fluorescence spectra, the maximum emission of rP148 was blue shifted from 335 to 333 nm in the presence of enamelin as a result of complexation of the 2 proteins. Our results demonstrate that the 32-kDa enamelin has a close association with amelogenin at pH 6.5 in PBS buffer. Our present study provides novel insights into the possible cooperation between enamelin and amelogenin in macromolecular coassembly and in controlling enamel mineral formation

Ion adsorption inside electrified carbon micropores is pivotal for the operation of supercapacitors. Depending on the electrolyte, two main mechanisms have been identified so far, the desolvation of ions in solvents and the formation of superionic states in ionic liquids. Here, it is shown that upon confinement inside negatively charged micropores, transition-metal cations dissolved in water associate to form oligomer species. They are identified using in situ X-ray absorption spectroscopy. The cations associate one with each other via hydroxo bridging, forming ionic oligomers under the synergic effect of spatial confinement and Coulombic screening. The oligomers display sluggish dissociation kinetics and accumulate upon cycling, which leads to supercapacitor capacitance fading. They may be dissolved by applying a positive potential, so an intermittent reverse cycling strategy is proposed to periodically evacuate micropores and revivify the capacitance. These results reveal new insights into ion adsorption and structural evolution with their effects on the electrochemical performance, providing guidelines for designing advanced supercapacitors. Ministry of Education (MOE) National Research Foundation (NRF) Submitted/Accepted version This work was supported by Singapore Ministry of Education Academic Research Fund Tier 2 (Grant No. MOE-T2EP10220-0005), Academic Research Fund Tier 1 (Grant No. RG104/18), Singapore National Research Foundation (Nanomaterials for Energy and Water Management CREATE Programme), Energy Innovation Research Programme (EIRP) (Grant No. NRF2015EWT-EIRP002-008), and French National Research Agency (Labex STORE-EX, Grant No. ANR-10-LABX-0076).

The rise of electronic waste (e-waste) generation around the globe has become a major concern in recent times and its recycling is mostly focused on the recovery of valuable metals, such as gold, silver, and copper, etc. However, e-waste consists of a significant weight fraction of plastics (25-30%) which are either discarded or incinerated. There is a growing need for recycling of these e-waste plastics. The majority of them are made from high-quality polymers (composites), such as acrylonitrile butadiene styrene (ABS), high impact polystyrene (HIPS), polycarbonate (PC), polyamide (PA), polypropylene (PP) and epoxies. These plastics are often contaminated with hazardous materials, such as brominated flame retardants (BFRs) and heavy metals (such as Pb and Hg). Under any thermal stress (thermal degradation), the Br present in the e-waste plastics produces environmentally hazardous pollutants, such as hydrogen bromide or polybrominated diphenyl ethers/furans (PBDE/Fs). The discarded plastics can lead to the leaching of toxins into the environment. It is important to remove the toxins from the e-waste plastics before recycling. This review article gives a detailed account of e-waste plastics recycling and recovery using thermochemical processes, such as extraction (at elevated temperature), incineration (combustion), hydrolysis, and pyrolysis (catalytic/non catalytic). A basic framework of the existing processes has been established by reviewing the most interesting findings in recent times and the prospects that they open in the field recycling of e-waste plastics. Ministry of National Development (MND) National Environmental Agency (NEA) National Research Foundation (NRF) Authors would like to thank financial support from National Research Foundation, Prime Minister’s Office, Singapore, the Ministry of National Development, Singapore, and National Environment Agency, Ministry of Sustainability and the Environment, Singapore under the Closing the Waste Loop R&D Initiative as part of the Urban Solutions & Sustainability e Integration Fund (Award No. USS-IF-2018-4).

International audience; In nanomedicine, the widespread concern of nanoparticles in general, and dendrimers, in particular, is the analysis of key in-vivo physicochemical parameters to ensure the preclinical and clinical development of ‘safe’ bioactive nanomaterials. It is clear that for biomedical applications, biocompatible dendrimers, used as nanocarriers or active per se, should be devoid of toxicity and immunogenicity, and have adequate PK/PD behaviors (adequate exposure) in order to diffuse in different tissues. Functionalization of dendrimers has a dramatic effect on in-vivo physicochemical parameters. In this review, we highlighted key in-vivo physicochemical properties, based on data from biochemical, cellular and animal models, to provide biocompatible dendrimers. Up-to-date, only scarce studies have been described on this topic.

The huge consumption of modern plastic with improper disposals has posed a great threat to the environment and human beings. To put these post-consumer plastics into the recycling chain, laser induced breakdown spectroscopy (LIBS) has been established as a potential tool for rapid grading of plastics online. Meanwhile, LIBS is a powerful tool for plastic investigations in the laboratory with the capacity of simultaneous qualitative and quantitative analysis. The present review describes the development and prospect of plastic investigations using LIBS, highlighting the intrinsic advantages of LIBS for plastic recycling. Moreover, the selection of hardware components and analysis methods are discussed, which may help to start a research on plastic using LIBS. National Environmental Agency (NEA) National Research Foundation (NRF) The authors are grateful for the financial support from SCARCE, which is supported by the National Research Foundationgs2:, Prime Minister's Office, Singapore, the Ministry of National Development, Singapore, and National Environment Agency, Ministry of Sustainability and the Environment, Singapore under the Closing the Waste Loop R&D Initiative as part of the Urban Solutions & Sustainability - Integration Fund (Award No. USS-IF-2018-4).

Success in obtaining higher-order twistarenes with precise structures is very important for fundamentally understanding the relationship between the structures and physical properties/optoelectronic applications. In this research, by using the advantages from a retro-Diels-Alder process (clean reaction) and the cross-conjugated nature of the pyrene unit, a novel dodeca-twistarene was prepared for the first time. Its structure, confirmed by single-crystal XRD analysis, indicates that it possesses a twisted angle (≈30°), and two neighboring molecules in the crystal lattice are perpendicular to each other because of the twisted character and the strong intermolecular CH-π interactions. However, its basic physicochemical properties suggest its instability in air derives from its elevated HOMO energy level, although NICS calculations confirm that the pyrene units contribution poorly to the π conjugation of the overall molecule. Ministry of Education (MOE) Accepted version Q.Z acknowledges financial support from AcRF Tier 1 (RG 111/17, RG 2/17, RG 114/16, RG 8/16) and Tier 2 (MOE 2017- T2-1-021), Singapore. Dr. Liu acknowledges funding support from M4062018.

International audience; Digital light processing technique was applied to manufacture alumina ceramic parts with two types of lattice structure units, i.e. vertex interconnect structure and edge structure. The internal porosity of the unit is 40%. The printed parts were sintered and the grain size is about 1.1 μm. The bending strength of the vertex interconnect structure is much larger than that of the edge structure. Materials genome initiative (MGI) aims to digital design and intelligent manufacture for advanced components. This research shows us an example to achieve this goal.

In nanomedicine, the widespread concern of nanoparticles in general, and dendrimers, in particular, is the analysis of key in-vivo physicochemical parameters to ensure the preclinical and clinical development of ‘safe’ bioactive nanomaterials. It is clear that for biomedical applications, biocompatible dendrimers, used as nanocarriers or active per se, should be devoid of toxicity and immunogenicity, and have adequate PK/PD behaviors (adequate exposure) in order to diffuse in different tissues. Functionalization of dendrimers has a dramatic effect on in-vivo physicochemical parameters. In this review, we highlighted key in-vivo physicochemical properties, based on data from biochemical, cellular and animal models, to provide biocompatible dendrimers. Up-to-date, only scarce studies have been described on this topic.

Non-graphitized carbon (NGC) has been extensively utilized as carbonaceous anode in sodium-ion batteries (SIBs). However, more optimization to achieve competitive capacity and stability is still challenging for SIBs. In the study, the dopant strategy is utilized to construct nitrogen/sulfur-doped non-graphitized carbon (N-NGC or S-NGC) shell decorated on three-dimensional graphene foam (GF) as a self-support electrode. The highly disordered microstructures of heteroatom doped carbons are produced by applying a low-temperature pyrolysis treatment to precursors containing nitrogen and sulfur. The DFT calculations of Na-ion adsorption energies at diverse heteroatom sites show marginal-S, pyrrolic N and pyridinic N with more intensive Na-ion adsorption ability than middle-S, C[dbnd]O and pristine carbon. The N-NGC with dominant small graphitic regions delivers adsorption ability to Na-ion, while the S-NGC with significant single carbon lattice stripes demonstrates redox reaction with Na-ion. Evidently, in comparison with only adsorption-driven slope regions at high potential for N-NGC, the redox reaction-generated potential-plateau enables non-graphitized S-NGC superior discharge/charge capacity and cycle-stability in the slope region. This work could provide deep insight into the rational design of non-graphitized carbon with rich microstructure and composition. This work was supported by the National Natural Science Foundation of China (52272296, 51502092), the Fundamental Research Funds for the Central Universities (JKD01211601, 1222201718002), the National Overseas High-Level Talent Youth Program in China, and the Eastern Scholar Project of Shanghai.

International audience; At the intersection between treatment and diagnosis, nanoparticles technologies are strongly impacting the development of both therapeutic and diagnostic agents. Consequently, the development of novel modalities for concomitant noninvasive therapy and diagnostics known as theranostics as a single platform has gained significant interests. These multifunctional theranostic platforms include carbon-based nanomaterials (e.g., carbon nanotubes), drug conjugates, aliphatic polymers, micelles, vesicles, core-shell nanoparticles, microbubbles and dendrimers bearing different contrast agents and drugs, such as cytotoxic compounds in the oncology domain. Dendrimers emerged as a new class of highly tunable hyperbranched polymers, and have been developed as useful theranostic platforms. Magnetic resonance imaging, gamma scintigraphy, computed tomography and optical imaging are the main techniques developed with dendrimers in the theranostic domain in oncology. Different imaging agents have been used such as Gd(III), 19F, Fe2O3 (MRI), 76Br (PET), 111In, 88Y, 153Gd, 188Re, 131I (SPECT), 177Lu, gold (CT) and boronated groups, siliconnaphthalocyanines, dialkylcarbocyanines and QDs (optical imaging dyes).

International audience; Twinned dendrite growth of an Al-4.5 wt% Cu alloy with various sample sizes was found in Bridgman directional solidification. Under conditions of high thermal gradient and solidification rate, the effect of convection on feathery grain formation is examined as a function of sample diameter. Experimental results indicate that the increase in sample size has substantially changed the twinned morphologies. Moreover, there is a minimum of convective intensity inducing feathery grain formation in the appropriate conditions. According to the apparent “penetration” phenomena in solidification microstructures of sample diameter of only 5 mm, it is hypothesized that a new possible lateral propagation mechanism with no requirement for the nucleation of a new stacking fault.

International audience; Effect of static magnetic field on longitudinal macro segregation of primary silicon phase has been investigated in directionally solidified hypereutectic Al-Si alloy. Experimental and numerical simulation results indicate that the melt flow of Al-21 wt% Si alloy under magnetic field is the dominant factor leading to macro segregation of primary silicon phase. The intense melt flow, i.e., recirculation loops and microscopic flow, promotes solute Si to the mushy zone and sidewall of the crucible where the temperature is low and the primary silicon is more likely to precipitate, resulting in the formation of the U-shaped interface. The precipitated primary silicon tends to disappear during directional solidification, which induces the transition from the U-shaped interface to the planar interface. The increase of magnetic field intensity accelerates this transition process and increases the macro segregation. Furthermore, the freely drifted fine silicon particles in the bulk melt are transported to mushy zone by the forced flow, which contributes to macro segregation. This work facilitates the understanding of forced flow greatly changing the solidification structures of alloys under the magnetic field during directional solidification.

The stomatopod is a fascinating animal that uses its weaponized appendage dactyl clubs for breaking mollusc shells. Dactyl clubs are a well studied example of biomineralized hierarchical structures. Most research has focused on the regions close to the action, namely the impact region and surface composed of chitin and apatite crystallites. Further away from the site of impact, the club has lower mineralization and more amorphous phases; these areas have not been as actively studied as their highly mineralized counterparts. This work focuses on the side of the club, in what is known as the periodic and striated regions. A combination of laboratory micro-computed tomography, synchrotron X-ray diffraction mapping and synchrotron X-ray fluorescence mapping has shown that the mineral in this region undergoes the transition from an amorphous to a crystalline phase in some, but not all, clubs. This means that this side region can be mineralized by either an amorphous phase, calcite crystallites or a mixture of both. It was found that when larger calcite crystallites form, they are organized (textured) with respect to the chitin present in this biocomposite. This suggests that chitin may serve as a template for crystallization when the side of the club is fully mineralized. Further, calcite crystallites were found to form as early as 1 week after moulting of the club. This suggests that the side of the club is designed with a significant safety margin that allows for a variety of phases, i.e. the club can function independently of whether the side region has a crystalline or amorphous mineral phase. Published version We thank the Danish Agency for Science, Technology and Innovation for funding the instrument center DanScatt. We acknowledge DESY (Hamburg, Germany), a member of the Helmholtz Association HGF, for the provision of experimental facilities. Beam time was allocated for proposal I20180923EC. The research leading to this result has been supported by the project CALIPSOplus from the EU Framework Programme for Research and Innovation HORIZON 2020 (grant no. 730872). We thank Alexander Bernthz Jensen, Kristine Hjerrild Neldeborg, Jonas Palle and Maja Østergaard for help with measuring data on P06 at Petra III. We acknowledge the MAX IV Laboratory for time on Beamline DanMAX (proposal no. 20210507). Research conducted at MAX IV, a Swedish national user facility, is supported by the Swedish Research council (contract no. 2018-07152), the Swedish Governmental Agency for Innovation Systems (contract no. 2018-04969) and Formas (contract no. 2019-02496). DanMAX is funded by NUFI (grant no. 4059- 00009B). We thank Peter Alling Strange Vibe for assistance with measuring data at DanMAX. Use of the Novo Nordisk Foundation research infrastructure AXIA (grant no. NNF19OC0055801) is gratefully acknowledged. We acknowledge support from the ESS lighthouse on hard materials in 3D, SOLID, funded by the Danish Agency for Science and Higher Education (grant no. 8144-00002B).

High-mobility van der Waals ambipolar semiconductors are promising in logic and reconfigurable circuits, integrated optoelectronic circuits, due to the excellent gate-controlled capability and effectively tunability of major charge carriers by electrostatic field. Controllable growth of high-quality ambipolar semiconductors with high mobility and stability is highly glamorous and indispensable for further research. Here, we demonstrate a straightforward space-confined chemical vapor deposition (CVD) method to synthesize high-quality quasi-one-dimensional (1D) tellurium (Te) nanoribbons (NRs). By introducing H2 into the gas flow, endothermic compound H2Te was generated from the reaction of liquid Te with H2, and consequently decomposed into elemental Te at low temperature. Further, the Te NRs have been utilized for in-situ fabrication of field-effect transistors (FETs) without transferring process. Ambipolar features are achieved using nickel (Ni) as an ohmic contact. More importantly, the mobilities of the Te NR transistor for hole/electron are as high as 1755/28.6 cm2V−1s−1 and 4024/278 cm2V−1s−1 at room temperature and under a temperature below 20 K, respectively. Our findings confirm the novel strategy for synthesizing 1D elemental semiconductors and their applications with ambipolar behaviors. Agency for Science, Technology and Research (A*STAR) National Research Foundation (NRF) Submitted/Accepted version The authors gratefully acknowledge financial support by National Key Research and Development Program of China (2020YFB2008501), the National Natural Science Foundation of China (61974120 and 11904289), Key Research and Development Program of Shaanxi Province (2020ZDLGY04-08, 2020GXLH-Z-027, and 2021JZ-43), the Natural Science Foundation of Shaanxi Province (2023-JC-YB-495 and 2022JQ-659), the Key Program for International Science and Technology Cooperation Projects of Shaanxi Province (2018KWZ-08), the Natural Science Foundation of Ningbo (202003N4003), the Fundamental Research Funds for the Central Universities (3102019PY004, 31020190QD010, and 3102019JC004), the start-up funds from Northwestern Polytechnical University, and open research fund of the State Key Laboratory of Organic Electronics and Information Displays. This work was also supported by National Research Foundation–Competitive Research Program NRF-CRP22-2019-0007 and NRF-CRP21-2018-0007, and supported by A*STAR under its AME IRG Grant (Project No. A2083c0052).

The progression of green technologies has driven higher future demands for valuable metals such as lithium, cobalt, nickel, and manganese, hence necessitating the recycling of lithium-containing energy storage systems. Restrategizing conventional metal recycling technologies with sustainable biological approaches can explore the potential to curtail expensive process costs and emissions of hazardous by-products. This article advocates the benefits and persuasion for future studies and applications to exploit current concepts of microbial-based metal recycling technologies as environmentally cleaner options. National Environmental Agency (NEA) National Research Foundation (NRF) Submitted/Accepted version This research/project is supported by the National Research Foundation, Singapore, and National Environment Agency, Singapore, under its Closing the Waste Loop Funding Initiative (award no. USSIF- 2018-4).

Two-dimensional (2D) materials including graphene, transition metal dichalcogenides, black phosphorus, MXenes, and semimetals have attracted extensive and widespread interest over the past years for their many intriguing properties and phenomena, underlying physics, and great potential for applications. The vast library of 2D materials and their heterostructures provides a diverse range of electrical, photonic, mechanical, and chemical properties with boundless opportunities for photonics and plasmonic devices. The infrared (IR) regime, with wavelengths across 0.78 μm to 1000 μm, has particular technological significance in industrial, military, commercial, and medical settings while facing challenges especially in the limit of materials. Here, we present a comprehensive review of the varied approaches taken to leverage the properties of the 2D materials for IR applications in photodetection and sensing, light emission and modulation, surface plasmon and phonon polaritons, non-linear optics, and Smith-Purcell radiation, among others. The strategies examined include the growth and processing of 2D materials, the use of various 2D materials like semiconductors, semimetals, Weyl-semimetals and 2D heterostructures or mixed-dimensional hybrid structures, and the engineering of light-matter interactions through nanophotonics, metasurfaces, and 2D polaritons. Finally, we give an outlook on the challenges in realizing high-performance and ambient-stable devices and the prospects for future research and large-scale commercial applications. Agency for Science, Technology and Research (A*STAR) National Research Foundation (NRF) This work is partially supported by the National Research Foundation, Singapore, under its CRP program (NRF-CRP26- 2021-0004) and A*STAR AME IRG (A20E5c0084). Z.L. acknowledges the support from PHC Merlion Program 2020. L.W. gratefully acknowledges the Start-Up Research Grant from the Singapore University of Technology and Design via Grant No. SRG SMT 2021 169, and National Research Foundation Singapore via Grant Nos. NRF2021-QEP2-02-P03 and NRF2021-QEP2-03-P09. Y.L. acknowledges the support from A*STAR Career Development Fund - Seed Projects (C222812008). M.Z. acknowledges the support from A*STAR Career Development Fund (C210812027).

Three-dimensional/low-dimensional perovskite solar cells afford improved efficiency and stability. The design of low-dimensional capping materials is constrained to tuning the A-site organic cation, as Pb2+ and Sn2+ are the only options for the metal cation. Here we unlock access to a library of low-dimensional capping materials with metal cations beyond Pb2+/Sn2+ by processing a full precursor solution containing both metal and ammonium halides. This enables easier synthetic control of the low-dimensional capping layer and greater versatility for low-dimensional interface engineering. We demonstrate that a zero-dimensional zinc-based halogenometallate (PEA2ZnX4; PEA = phenethylammonium, X = Cl/I) induces more robust surface passivation and stronger n–N isotype three-dimensional/low-dimensional heterojunctions than its lead-based counterpart. We exhibit p–i–n solar cells with 24.1% efficiency (certified 23.25%). Our cells maintain 94.5% initial efficiency after >1,000 h of operation at the maximum power point. Our findings expand the material library for low-dimensional interface engineering and stabilization of highly efficient three-dimensional/low-dimensional perovskite solar cells. Ministry of Education (MOE) National Research Foundation (NRF) Submitted/Accepted version This work is supported by the Ministry of Singapore under its AcRF Tier 1 (Project RG6/21 (2021-T1-001-072) to Y.M.L.) and Tier 2 grants (MOE2019-T2-1-006 to T.C.S., MOE2019-T2-1-085 to Y.M.L. and MOE-T2EP50120-0004 to T.C.S.), and the National Research Foundation (NRF) Singapore under its NRF Investigatorship (NRF-NRFI2018-04 to T.C.S.).

Bacterial biofilms reduce the performance and efficiency of biomedical and industrial devices. The initial step in forming bacterial biofilms is the weak and reversible attachment of the bacterial cells onto the surface. This is followed by bond maturation and secretion of polymeric substances, which initiate irreversible biofilm formation, resulting in stable biofilms. This implies that understanding the initial reversible stage of the adhesion process is crucial to prevent bacterial biofilm formation. In this study, we analyzed the adhesion processes of E. coli on self-assembled monolayers (SAMs) with different terminal groups using optical microscopy and quartz crystal microbalance with energy dissipation (QCM-D) monitoring. We found that a considerable number of bacterial cells adhere to hydrophobic (methyl-terminated) and hydrophilic protein-adsorbing (amine- and carboxy-terminated) SAMs forming dense bacterial adlayers while attaching weakly to hydrophilic protein-resisting SAMs [oligo(ethylene glycol) (OEG) and sulfobetaine (SB)], forming sparse but dissipative bacterial adlayers. Moreover, we observed positive shifts in the resonant frequency for the hydrophilic protein-resisting SAMs at high overtone numbers, suggesting how bacterial cells cling to the surface using their appendages as explained by the coupled-resonator model. By exploiting the differences in the acoustic wave penetration depths at each overtone, we estimated the distance of the bacterial cell body from different surfaces. The estimated distances provide a possible explanation for why bacterial cells tend to attach firmly to some surfaces and weakly to others. This result is correlated to the strength of the bacterium-substratum bonds at the interface. Elucidating how the bacterial cells adhere to different surface chemistries can be a suitable guide in identifying surfaces with a more significant probability of contamination by bacterial biofilms and designing bacteria-resistant surfaces and coatings with excellent bacterial antifouling characteristics. Published version This work was supported by the JSPS KAKENHI grant (Grant Numbers JP22H04530, JP21H05511, and JP20H05210).