Potential Of Mg Research Articles

Enhanced anti-fouling and selective performance of GO-modified nanofiltration membranes for lithium extraction from salt lake brine

Nanofiltration (NF) is a promising method in lithium extraction from salt lake brine with a high Mg2+/Li+ mass ratio. However, membrane fouling challenges its applicability and productivity. This study incorporated graphene oxide (GO) into the polyamide (PA) selective layer of NF membranes to enhance anti-fouling properties and improve lithium extraction from brine. Membrane structure analyses revealed that 0.002 wt% and 0.01 wt% GO facilitated the interfacial polymerization reaction. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) results indicated that the PA selective layers in the GO-0.002 % and GO-0.01 % membranes were denser, smoother, and thinner. In contrast, the addition of 0.05 wt% GO resulted in the Turing structures on the membrane surface. Adsorption kinetics indicated pollutant adhesion in the following order: GO-0.05 % > GO-0 % > GO-0.002 % > GO-0.01 %, which was attributed to calcium-carboxyl complexation, as directly measured by AFM and consistent with carboxyl density. The GO-0.002 % and GO-0.01 % NF membranes demonstrated excellent anti-fouling properties in brines, with lower initial fouling rates and higher flux recovery after cleaning, underscoring the significant role of calcium-carboxyl complexation in membrane fouling. The retention of Mg2+ increased to 95 %, while that of Li+ decreased to below −28 % for GO-0.002 % and GO-0.01 % membranes, indicating promising potential for Mg and Li separation. This study provides valuable insights into developing NF membranes with high Mg/Li selectivity and anti-fouling capabilities for lithium extraction from salt lake brine.

Biosynthesis and biological activities of magnesium hydroxide nanoparticles using Tinospora cordifolia leaf extract.

The synthesis of magnesium hydroxide nanoparticles (Mg(OH)2 NPs) using plant extracts are known to be a practical, economical, and an environmentally friendly approach. In this work, Mg(OH)2 NPs were synthesized using aqueous leaf extract of Tinospora cordifolia, a medicinal plant commonly found in India. The synthesized Mg(OH)2 NPs were characterized using various spectroscopic techniques. The ultraviolet-visible (UV-Vis) absorption peak of the Mg(OH)2 NPs was detected at 289nm, Fourier transform infrared (FTIR) analysis confirmed the presence of various functional groups, and X-ray diffraction (XRD) patterns revealed the well-crystallized structure of the Mg(OH)2 NPs. High-resolution transmission electron microscopy (HR-TEM) and scanning electron microscopy (SEM) analyses depicted spherical morphology and an average particle size (PS) of 27.71nm. The energy-dispersive X-ray (EDX) analysis confirmed the presence of C, O, and Mg elements, and the X-ray photoelectron spectroscopy (XPS) survey spectrum confirmed the elements for the Su 1s peak at 280.2eV. The dynamic light scattering (DLS) analysis displayed an average PS of 54.3nm, and the Zeta potential (ZP) was of 9.89mV. The fabricated Mg(OH)2 NPs displayed notable antibacterial activity against S. epidermidis, E. coli, and S. aureus. In addition, these NPs exhibited strong antioxidant properties (> 75%) based on DPPH, ABTS, and hydrogen peroxide (H2O2) assays. Further, the same NPs exerted a potent anti-inflammatory activity (> 65%) based on COX-1 and COX-2 evaluations. The anti-Alzheimer' disease (AD) potential of Mg(OH)2 NPs was assessed through effective inhibition (> 70%) of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activities. Molecular docking (MD) studies confirmed that caryophyllene has higher binding affinity with AChE (-5.3kcal/mol) and BuChE (-6.4kcal/mol) enzymes. This study emphasizes the green synthesis of Mg(OH)2 NPs using T. cordifolia as a plant source and highlights their potential for biomedical applications.

Effect of Zr content on the microstructure, mechanical properties, electrochemical behavior, and biocompatibility of Mg–3Zn–xZr alloy using powder metallurgy

Abstract In this study, Mg–3Zn–xZr (x = 0, 0.5, 1, 2 and 3) alloy were produced using powder metallurgy incorporating high-energy ball milling. Scanning electron microscope (SEM), energy dispersive X-ray (EDX) analyzer and X-ray diffraction (XRD) have been used to investigate the microstructure, chemical composition and phase distribution of the samples. XRD results show that the Mg solid solution wholly formed, and the milled powders were single phase, and no secondary phase was observed. While the secondary phases were formed after sintering. Hardness of Mg–Zn–xZr sample increased from 58.8 Hv (for Zr = 0) to 87.81 Hv with addition of 3 wt.% Zr. The result shows that the corrosion potential of Mg–Zn–Zr alloy was more positive than Mg–3Zn. However, the Mg–3Zn–Zr alloy exhibited higher corrosion current than Mg–3Zn due to galvanic effect of Zr rich area. All of Mg–3Zn–Zr alloys showed better antibacterial and biocompatibility properties than Mg–3Zn alloy due to the presence of Zr as additive. According to the mechanical, corrosion, and biological evaluations in this study, it can be concluded that the Mg–3Zn–1Zr alloy can be used as a suitable biomaterial for the use of orthopedic implants.

Improving Thermoelectric Performance of AgSbTe2 through Suppression of Ag2Te and Band Convergence via Mg and Ti Codoping.

In this study, the impact of codoping Mg and Ti on the thermoelectric performance of AgSbTe2 materials was investigated. Through a two-step synthesis process involving slow cooling and spark plasma sintering, AgSb0.98-xMg0.02TixTe2 samples were prepared. The introduction of Mg and Ti dopants effectively suppressed the formation of the undesirable Ag2Te phase. Density functional theory (DFT) calculations confirmed that Ti doping facilitated the band convergence, leading to a reduction in the effective mass of the carriers. This optimization enhanced carrier mobility and, consequently, electrical conductivity. Additionally, the codoping strategy resulted in the reinforcement of point defects, which contributed to a decrease in lattice thermal conductivity. The AgSb0.98-xMg0.02TixTe2 sample achieved a maximum figure of merit (ZT) value of 1.45 at 523 K, representing an 87% improvement over the undoped AgSbTe2 sample. The average ZT value over the temperature range of 323-573 K was 1.09, marking a significant enhancement in thermoelectric performance. This research demonstrates the potential of Mg and Ti codoping as a strategy to improve the thermoelectric properties of AgSbTe2-based materials.

Assessment of tissue response in vivo: PET-CT imaging of titanium and biodegradable magnesium implants

To study in vivo the bioactivity of biodegradable magnesium implants and other possible biomaterials, we are proposing a previously unexplored application of PET-CT imaging, using available tracers to follow soft tissue and bone remodelling and immune response in the presence of orthopaedic implants. Female Wistar rats received either implants (Ti6Al7Nb titanium or WE43 magnesium) or corresponding transcortical sham defects into the diaphyseal area of the femurs. Inflammatory response was followed with [18F]FDG and osteogenesis with [18F]NaF, over the period of 1.5 months after surgery. An additional pilot study with [68Ga]NODAGA-RGD tracer specific to αvβ3 integrin expression was performed to follow the angiogenesis for one month.[18F]FDG tracer uptake peaked on day 3 before declining in all groups, with Mg and Ti groups exhibiting overall higher uptake compared to sham. This suggests increased cellular activity and tissue response in the presence of Mg during the initial weeks, with Ti showing a subsequent increase in tracer uptake on day 45, indicating a foreign body reaction. [18F]NaF uptake demonstrated the superior osteogenic potential of Mg compared to Ti, with peak uptake on day 7 for all groups. [68Ga]NODAGA-RGD pilot study revealed differences in tracer uptake trends between groups, particularly the prolonged expression of αvβ3 integrin in the presence of implants.Based on the observed differences in the uptake trends of radiotracers depending on implant material, we suggest that PET-CT is a suitable modality for long-term in vivo assessment of orthopaedic biomaterial biocompatibility and underlying tissue reactions. Statement of significanceThe study explores the novel use of positron emission tomography for the assessment of the influence that biomaterials have on the surrounding tissues. Previous related studies have mostly focused on material-related effects such as implant-associated infections or to follow the osseointegration in prosthetics, but the use of PET to evaluate the materials has not been reported before. The approach tests the feasibility of using repeated PET-CT imaging to follow the tissue response over time, potentially improving the methodology for adopting new biomaterials for clinical use.

The anodic dissolution kinetics of Mg alloys in water based on ab initio molecular dynamics simulations

AbstractThe corrosion susceptibility of magnesium (Mg) alloys presents a significant challenge for their broad application. Although there have been extensive experimental and theoretical investigations, the corrosion mechanisms of Mg alloys are still unclear, especially the anodic dissolution process. Here, a thorough theoretical investigation based on ab initio molecular dynamics and metadynamics simulations has been conducted to clarify the underlying corrosion mechanism of Mg anode and propose effective strategies for enhancing corrosion resistance. Through comprehensive analyses of interfacial structures and equilibrium potentials for Mg(0001)/H2O interface models with different water thicknesses, the Mg(0001)/72 H2O model is identified to be reasonable with −2.17 V vs. standard hydrogen electrode equilibrium potential. In addition, utilizing metadynamics, the free energy barrier for Mg dissolution is calculated to be 0.835 eV, enabling the theoretical determination of anodic polarization curves for pure Mg that aligns well with experimental data. Based on the Mg(0001)/72 H2O model, we further explore the effects of various alloying elements on anodic corrosion resistance, among which Al and Mn alloying elements are found to enhance corrosion resistance of Mg. This study provides valuable atomic‐scale insights into the corrosion mechanism of magnesium alloys, offering theoretical guidance for developing novel corrosion‐resistant Mg alloys.

Comprehensive impacts of the presence of proton exchange membrane on the efficiency of Mg-air fuel cell to remove nutrients and recover struvite

Mg-air fuel cell (MAFC) can achieve simultaneous recovery of phosphorus and nitrogen from wastewater in the form of struvite while generating electricity. This article investigated the comprehensive impacts of the presence of proton exchange membrane (PEM) on the efficiency of MAFC in treating synthetic wastewater, including phosphate and ammonium removal, power generation, and struvite generation. The results showed that the PO43−-P was completely removed within 20 min in the dural-chamber (DC) cell and the removal rate was 6.30 mg-P·cm−2·h−1, which was 1.55 times that of the single-chamber (SC) cell. The removal rate of NH4+-N in the DC cell was 3.37 mg-P·cm−2·h−1, which was 2.70 times that of the SC cell. However, the SC cell produced 63.10 mW·h of electricity, which was 4.61 times that of the DC cell. The precipitates were confirmed to be struvite, with a purity of 99.31 %(DC) and 93.95 % (SC). The low corrosion potential of Mg leads to hydrogen evolution corrosion during the reaction, resulting in low current efficiency, but the current efficiency increased with reaction time. PEM accelerated the hydrogen evolution corrosion, aggravated the magnesium corrosion, increased the internal resistance, and impaired electrical generation capacity, but provided more Mg2+ and alkalinity for the precipitation of struvite. In conclusion, the DC cell had a great capacity for removing nutrients (PO43− and NH4+) and producing high-purity struvite, while the SC cell had a strong ability to generate electricity.

Recent advances in mechanical properties of Mg matrix composites: a review

Magnesium (Mg), with a density of two-thirds of aluminium (Al) and one-fourth of steel, has become one of the most attractive materials for automotive and aerospace industries owing to the obligation to reduce fuel consumption and gas emissions. However, the poor mechanical property of Mg is one of the most significant barriers to its widespread use. The most widely used method to increase the use potential of Mg is the development of Mg matrix composites. This review focuses on the mechanical properties of recent Mg matrix composites. The effect of different reinforcement materials on the mechanical behaviour and failure mechanisms of Mg matrix composites was evaluated in detail.

Electrodeposition of Magnesium in Deep Eutectic Solvents Based on Magnesium Chloride Hexahydrate and Choline Chloride with Urea Added

Magnesium (Mg) alloy has small density, large elastic modulus, good heat dissipation and corrosion resistance to organic matter and alkali. At present, magnesium alloy is more and more used in automotive industry, medical devices and aerospace industry. However, the traditional preparation method of Mg has the disadvantages of high investment, high labor intensity and great environmental pollution. Therefore, it is of great significance to develop simple, environment-friendly methods of the magnesium. In this study, urea was added to adjust the electrochemical property of the deep eutectic solvent (DES) mixed by choline chloride (ChCl) and magnesium chloride hexahydrate (MgCl2·6H2O). Cyclic Voltammetry (CV) curves reveals that the addition of urea made the reduction potential of Mg shifted from -0.9 V to -1.3 V. Among the CV curves, one was proposed as the “dividing line”, which shows that the electroactive species in the two DESs, ChCl-MgCl2·6H2O and urea-MgCl2·6H2O, are different due to the changes of the component of the DESs. Fourier transform infrared (FTIR) data shows the type of hydrogen bond had been changed with the increase of urea content. Furthermore, the Raman spectra indicates that Mg2+ was coordinated with urea chains, which did not exist in ChCl-MgCl2·6H2O. Moreover, it was found that urea changed the electrochemical performance of the ChCl-Urea-MgCl2·6H2O by changing the hydrogen bond in the system and coordination form of the electroactive species, rather than adsorbing onto the electrode surface. Combined with geometry calculations at the B3LYP/6-311++G (d, p), the most probable mechanism of electrodeposition process was deduced.

Study on optical blocking filter with Mg seed layer for soft X-ray space detection

In the field of X-ray space detection, the optical blocking filter which can transmit X-ray and block UV, visible and infrared light is required. The combination of polyimide film and Al coating is the most commonly used design of OBF. The Al island structure created during magnetron sputtering deposition affects the optical properties of OBF. In this work, the potential of Mg as a seed layer to improve the optical performance of OBF was investigated. Polyimide films coated with Mg–Al bilayer with different thickness parameters (the total thickness was the same, equaled to 80 nm) were prepared, and the effect of Mg on the optical properties of optical blocking filters was analyzed. The results show that the island structure of the Al coating is weakened by the addition of Mg seed layer. For optical blocking filter with 10 nm and 20 nm Mg seed layer, the UV, visible and infrared transmittance decreased significantly, and the X-ray transmittance increased slightly. The blocking performance of UV, visible and infrared light has no change with the variation of storage time.

Dissociation of edge and screw pyramidal I and II dislocations in magnesium

Pyramidal dislocations in magnesium (Mg) and other hexagonal close-packed metals play an important role in accommodating plastic strains along the c-axis. Bulk single crystal Mg only presents very limited plasticity in c-axis compression, and this behavior was attributed to out-of-plane dissociation of pyramidal dislocations onto the basal plane and resulted in an immobile dislocation configuration. In contrast, other simulations and experiments reported in-plane dissociation of pyramidal dislocations on their slip planes. Thus, the core structure and mode of dissociation of pyramidal dislocations are still not well understood. To better understand the dissociation behavior of pyramidal dislocations in Mg at room temperature, in this work, atomistic simulations were conducted to investigate four types of pyramidal dislocations at 300 K: edge and screw Py-I on {101¯1}, edge and screw Py-II on {112¯2} by using a modified embedded atom method (MEAM) potential for Mg and anisotropic elasticity dislocation model. The results show that when energy minimization was performed before relaxation, in-plane dissociation of edge dislocations on respective pyramidal plane could be obtained at room temperature for all four types of dislocation. Without energy minimization, the edge dislocations dissociated out-of-plane onto the basal plane. Calculations of potential energy and hydrostatic stress of individual atoms at the edge dislocation core show that the extraordinarily high energy and atomic stresses in the as-constructed dislocation structures caused the out-of-plane dissociation onto the basal plane. The core structures of all four types of pyramidal dislocation after in-plane dissociation were analyzed by computing the distribution of the Burgers vector.

Magnesium borohydride Mg(BH4)2 for energy applications: A review

Mg(BH4)2 with several polymorphs, known as a high capacity (14.9 wt.%) hydrogen storage material, has become more intriguing due to the recently found new functions of gas physisorption and ionic conductivity. Here we review the state-of-the-art on the energy related functions of Mg(BH4)2. Mg(BH4)2 tends to form the stable intermediate [B12H12]2− when the dehydrogenation temperature is above 400 °C, the strong B-B bonding of which makes the rehydrogenation condition very harsh. In contrast, lower borane intermediate [B3H8]2− facilitates the rehydrogenation even at a mild condition of 100 °C, suggesting the possibility of reversible hydrogen storage in Mg(BH4)2. The porous polymorph γ-Mg(BH4)2 shows attractive gas adsorption properties in view of its unique hydridic surface and pore shape, and potentially can be applied in hydrogen adsorption and Kr/Xe selectivity. A new diffraction-based adsorption methodology was developed to characterize adsorption thermodynamics and kinetics of γ-Mg(BH4)2, providing a novel idea for the characterization of crystalline porous materials. Moreover, the potential of Mg(BH4)2 as an electrolyte is discussed in the last part. Mg(BH4)2·THF/DME acts as a liquid electrolyte in Mg-batteries, while anion substituted or neutral molecule derivatives of Mg(BH4)2 can act as solid-state electrolyte.

Unveiling the electronic properties of native solid electrolyte interphase layers on Mg metal electrodes using local electrochemistry.

Magnesium-ion batteries (MIBs) are of considerable interest as environmentally more sustainable, cheaper, and safer alternatives to Li-ion systems. However, spontaneous electrolyte decomposition occurs due to the low standard reduction potential of Mg, leading to the deposition of layers known as native solid electrolyte interphases (n-SEIs). These layers may inhibit the charge transfer (electrons and ions) and, therefore, reduce the specific power and cycle life of MIBs. We propose scanning electrochemical microscopy (SECM) as a microelectrochemical tool to locally quantify the electronic properties of n-SEIs for MIBs. These interphases are spontaneously formed upon contact of Mg metal disks with organoaluminate, organoborate, or bis(trifluoromethanesulfonyl)imide (TFSI)-based electrolyte solutions. Our results unveil increased local electronic and global ionic insulating properties of the n-SEI formed when using TFSI-based electrolytes, whereas a low electronically protecting character is observed with the organoaluminate solution, and the organoborate solution being in between them. Moreover, ex situ morphological and chemical characterization was performed on the Mg samples to support the results obtained by the SECM measurements. Differences in the electronic and ionic conductivities of n-SEIs perfectly correlate with their chemical compositions.

Evaluating the applicability of classical and neural network interatomic potentials for modeling body centered cubic polymorph of magnesium

Magnesium (Mg) is one of the most abundant metallic elements in nature and presents attractive mechanical properties in the industry. Particularly, it has a low density and relatively high strength/weight and stiffness/weight ratios, which make it one of the most attractive lightweight metals. However, the huge potential of Mg is restricted by its low ductility, associated with its hexagonal close packed (hcp) structure. This problem can be solved if Mg adopts the body centered cubic (bcc) structure, which is stable at high pressure or in confinement with stiff bcc metals like Nb. Molecular dynamics method is a magnificent tool to study material’s structure and deformation mechanisms at the atomic level, however, requiring accurate interatomic potentials. The majority of the interatomic potentials available in the literature for Mg have only been fitted to the properties of its stable hcp phase. In the present work, we perform systematic study of applicability of currently available Mg potentials to modeling the properties of metastable bcc polymorph of Mg, taking into account cohesive energy curves, elastic constants, stacking fault energies, and phonon dispersion curves. We conclude that the modified embedded atom method (MEAM) potentials are the most suitable for investigating bcc Mg in Mg/Nb nano-composites, while the properties of high-pressure bcc Mg would be better modeled by neural network interatomic potentials after different local atomic environments corresponding to bcc Mg being included into the fitting database.

Tellurium: A High-Performance Cathode for Magnesium Ion Batteries Based on a Conversion Mechanism.

Magnesium ion batteries (MIBs), due to the low redox potential of Mg, high theoretical capacity, dendrite-free magnesiation, and safe nature, have been recognized as a post-lithium energy storage system. However, an ongoing challenge, sluggish Mg2+ kinetics in the small number of available cathode materials of MIBs, restricts its further development. The existing cathodes mostly deliver unsatisfactory capacity with poor cycling life based on the traditional ion-intercalation mechanism. Herein, we fabricated a conversion-type Mg∥Te battery based on a reversible two-step conversion reaction (Te to MgTe2 to MgTe). High discharge capacities (387 mAh g-1) and rate capability (165 mAh g-1 at 5 A g-1) can be achieved. The diffusivity of Mg2+ can reach 3.54 × 10-8 cm2 s-1, enabled by the high electrical conductivity of Te and increased surface conversion sites. Subsequently, ab initio molecular dynamics simulation was also carried out to further confirm the conversion mechanism and fast Mg2+ transportation kinetics.

Unraveling Mg 〈c + a〉 slip using neural network potential

ABSTRACT Magnesium (Mg) activates 〈c + a〉 dislocation slip on the second order pyramidal slip plane. This slip mode is very complex compared to other modes including several metastable structures. Due to the complexity and very similar energies of the different structures, reliably modelling this slip mode is challenging. The problem is exacerbated when considering alloying, in which a combination of 1st order and 2nd order pyramidal slip is usually observed. Motivated by the need for a high fidelity potential for Mg alloys, we have developed first a highly accuracy potential for pure Mg. The new potential shows better agreement with density functional theory and experimental calculations than previous interatomic potentials for Mg. With the help of this new potential, we demonstrate that the basal dissociated 〈c + a〉 core is not sessile, as previously thought, and that constant stress molecular dynamics demonstrate clear preference for the 2nd order pyramidal system over the 1st order system.

Application Potential of Mg–Zn–Nd Alloy as a Gastrointestinal Anastomosis Nail Material

Application Potential of Mg–Zn–Nd Alloy as a Gastrointestinal Anastomosis Nail Material

Core-shell Mg66Zn30Ca4 bulk metallic glasses composites reinforced by Fe with high strength and controllable degradation

Mg–Zn–Ca bulk metallic glasses have emerged as a new biodegradable metal due to the excellent mechanical properties and good biocompatibility. In this study, we prepared nano Fe particles reinforced Mg66Zn30Ca4 bulk metallic glass composites via spark plasma sintering. Nano Fe particles covered on the surface of Mg66Zn30Ca4 glassy powder and formed a core-shell microstructure. We investigated the influence of different contents of Fe on strength and electrochemical behavior of the sintered composites. The strength increased from 574 MPa to 765 MPa with different contents of Fe. Moreover, with the addition Fe, the standard potential of Mg–Zn–Ca bulk metallic glasses improved 0.10 V and 0.14 V in Hank's and Saliva solutions, respectively. Thus, both of strength and corrosion resistance have significantly enhanced with the addition of Fe. In vitro cells experiment also proved that the materials are non-toxic, and it's beneficial to cells proliferation by adding Fe nanoparticles. The Fe@Mg66Zn30Ca4 BMG composites with high strength and controllable degradation can be considered a promising candidate for degradable implant materials.

A Defect Spinel Cathode Material for Long-Life and High-Energy-Density Magnesium Rechargeable Batteries

Magnesium rechargeable batteries (MRBs) have been a promising candidate for next-generation batteries due to the following reasons: (i) Mg can deposit without dendritic formation, enabling us to safely use Mg metal itself as a high-capacity (2205 mAh/g) anode. (ii) The electrode potential of Mg (-2.4 V vs. SHE) is relatively low among metal anodes for multivalent batteries, which is attractive for achieving high cell voltage. (iii) Mg is an abundant and non-toxic element. The development of MRBs, however, has been hindered by the lack of high-performance cathode materials. The difficulty in the development of cathode materials is derived from the high charge density of divalent Mg2+ ion, which is almost twice that of monovalent Li+ ion since their ionic radii are similar. This leads to the high activation energies for Mg2+ diffusion in cathode materials by the strong electrostatic interaction with anions. High-temperature operation is a way to prevent the problem of the sluggish Mg2+ diffusion; thus, we have been developing high-potential spinel oxide cathode materials that can work at 150℃. We have found several promising cathode materials (e.g., MgCo2O4, ZnCo2O4) [1,2], but they show rapid capacity fading during battery cycling. Such stoichiometric spinel oxides coherently transform to the rocksalt structure accompanied by Mg insertion in the two-phase reaction [1]. Therefore, the cycle degradation can be attributed to the formation of the rocksalt phase on the surface of active material particles, which would impede the diffusion of Mg2+ ions and degrade the reversibility of structural change in discharge/charge.Very recently, we have proposed a strategy of utilizing defect spinel oxides, which contain cation deficiencies at the octahedral sites in the spinel structure, to suppress the structure transition into the densely packed rocksalt phase in the early stage of discharge (i.e., Mg insertion) [3]. We have chosen ZnMnO3 as a promising candidate for defect spinel-type cathode material in that Zn stabilizes the spinel structure [2] and Mn allows the valence change from tetravalent to divalent [1]. By the theoretical and experimental approach, we have confirmed that ZnMnO3 with cation deficiencies at the octahedral sites is stable, and Mg2+ ions are preferentially inserted into the cation-deficient sites at the potential of 2–3 V vs. Mg2+/Mg with keeping spinel-based structures. As a consequence, it has been demonstrated that ZnMnO3 cathode exhibits a long-term cyclability exceeding 100 cycles (see Figure 1), which is in strong contrast to the previous stoichiometric spinel oxides. In this presentation, we will show a general guideline for designing spinel cathode materials suitable for MRBs, and discuss the origin of the high performances of defect spinel ZnMnO3 in terms of element selection, structure modification, and phase-change behavior.

Cytotoxic effect of galvanically coupled magnesium-titanium particles on Escherichia coli.

Orthopedic device-related infections (ODRIs) are difficult to control due to microbial biofilm formation and associated with high-level resistance to conventional antibiotics. In many cases, the only treatment option for ODRI is explantation. Previous studies have shown that application of cathodic potentials at the metal surface can eradicate biofilms, and Mg and Mg-Ti particles have the same effect as cathodic potentials. This study investigated the effects of Mg and Mg-Ti particles on established biofilms and planktonic cells E. coli. Bacterial cultures with developed biofilms or planktonic cells were treated with Mg or Mg-Ti particles, and the viability were assessed using flow cytometry or visual assessment methods (i.e., observation from SEM images and opacity of the solution). It was found that viability of biofilms treated with 16.67 mg/ml of Mg was 2.8 ± 0.96% at the end of 6-hr killing compared to untreated controls. This extent of killing was more significant compared to 24-hr grown biofilms treated with ofloxacin, an antibiotic known to be effective against these bacteria. Biofilms treated with 50 and 100 μg/ml of ofloxacin had 62 ± 4.6% and 52 ± 19.3% survival, respectively, where ofloxacin at these concentrations is known to kill planktonic counterparts very effectively. Inhibition zone tests revealed that biofilms within 2 mm of Mg or Mg-Ti particle clusters were effectively killed. These results demonstrated the potential of Mg or Mg-Ti particles in killing microbial biofilms and potential for controlling ODRI.