Single Ion System Research Articles

Si and Zn dual ions upregulate the osteogenic differentiation of mBMSCs: mRNA transcriptomic sequencing analysis

Both silicon (Si) and zinc (Zn) ions are essential elements to bone health and their mechanisms for promoting osteogenesis have aroused the extensive attention of researchers. Thereinto, the mechanism by which dual ions promote osteogenic differentiation remains to be elucidated. Herein, the effects of Si and Zn ions on the cytological behaviors of mBMSCs were firstly studied. Then, the molecular mechanism of Si-Zn dual ions regulating the osteogenic differentiation of mBMSCs was investigated via transcriptome sequencing technology. In the single-ion system, Si ion at the concentration of 1.5 mM (Si-1.5) had better comprehensive effects of cell proliferation, ALP activity and osteogenesis-related gene expression levels (ALP, Runx2, OCN, Col-I and BSP); Zn ion at the concentration of 50 μM (Zn-50) demonstrated better combining effects of cell proliferation, ALP activity and same osteogenic genes expression levels. In the dual-ion system, the Si (1.5 mM)-Zn (50 μM) group (Si1.5-Zn50) synthetically enhanced ALP activity and osteogenesis genes compared with single-ion groups. Analysis of the transcriptome sequencing results showed that Si ion had a certain effect on promoting the osteogenic differentiation of mBMSCs; Zn ion had a stronger effect of contributing to a better osteogenic differentiation of mBMSCs than that of Si ion; the Si-Zn dual ions had a synergistic enhancement on conducting to the osteogenic differentiation of mBMSCs compared to single ion (Si or Zn). This study offers a blueprint for exploring the regulation mechanism of osteogenic differentiation by dual ions.Graphical

Critical Minerals, Critical Capacity and Critical Evaluation

The battery industry is placed at a critical intersection between the two most extractive and unsustainable industries: mining and energy, where current ‘business as usual’ will lead to catastrophic outcomes for society and life on earth. This gives it a unique opportunity to be an extremely effective disruptive technology, helping end colonial systems which rely on extraction and transfer of wealth and resources from the global south to the global north, and create fair and just energy systems. In order to do this, the battery industry must make batteries from ethically sourced materials, with long lifetimes, that are recyclable. A key question remains on how exactly to evaluate the true sustainability of the components of the electric future, particularly lithium-ion batteries (LIB).This study presents electrochemical and materials characterisation data on several components of LIB, and a set of devised metrics for sustainability, to truly evaluate the potential of research cells in an industrial landscape.Lithium-ion batteries challenge the current energy system, rather than a single use system that must extract, ship and burn fuels constantly, LIB present a potential cyclical system where batteries are recharged, then repurposed before finally being recycled. Metals must still be mined, but this can be achieved sustainably in conjunction with the communities that reside in those areas, as part of an ESG initiative. In developing new technology and with the vast expansion of new industry particularly across Europe, there is enormous potential and responsibility to put in systems to facilitate a just energy transition. This applies all the way down at a materials development level. The systems to evaluate this however, are few and not widely discussed.In this work a case-study that aims to improve existing cell chemistry whilst focusing on its sustainability is presented. This includes the global context and in particular European criticality. The study builds on the premise behind the “Strategic materials Weighting And Value Evaluation" (SWAVE) framework to develop it further for new cell components and combinations.1 This study will focus primarily on the race to reduce cobalt and replace it with nickel and other transition metals. Reducing cobalt dependency is important to battery performance and ensuring that the energy transition is not reliant on a metal with restricted resourcing. However, whilst high nickel cathode content exhibits a higher specific capacity than cobalt-based material, it is less stable due to disordered Li+/Ni2+ cation mixing, lithium residuals upon the surface of the materials, and irreversible phase changes between the H2 and H3 phases at 4.2-4.3 V vs Li/Li+.2 Our results illustrate the difficulty in stabilizing the high nickel cathode materials with long lifetimes and discuss the possible successes in the results seen.Our study also explores the possibility of expanding beyond single ion systems, using alternative anode and electrolyte materials containing different ion transport. One example is Sodium, which offers a cheaper and more sustainable alternative to Lithium, and so replacing any sodium in existing cells would reduce the cost of the cell and reduce the reliance on the critical material lithium. With the creation of metrics of sustainability as within this study, any loss of capacity can be evaluated in context of the sustainability analysis to give the true ‘value’ of a potential cell in the industrial context. The feasibility of these full cell configurations are discussed, with formation, capacity and life-time testing. These results show some promising cell capacities with a variety of cell chemistries and components, whilst keeping in mind the overarching aim of a just energy transition to evaluate the developments made. References 1 R. Sommerville, P. Zhu, M. A. Rajaeifar, O. Heidrich, V. Goodship and E. Kendrick, Resour Conserv Recycl, 2021, 165, 105219.2 H. Ronduda, M. Zybert, A. Szczęsna-Chrzan, T. Trzeciak, A. Ostrowski, D. Szymański, W. Wieczorek, W. Raróg-Pilecka and M. Marcinek, Nanomaterials, 2020, 10, 2018.

Preparation and Characterization of Mercapto-Functionalized Calcined Attapulgite and Its Removal of Pb (II) and Cd (II) Solution

To enhance the sorption efficacy of attapulgite for heavy metals, mercapto-functionalized attapulgite (ATP-SH) was synthesized with mercaptan functional groups. When the mass-to-volume ratio of calcined attapulgite (ATP-C) to 3-Mercapropyltrimethoxysilane (MPTMS) was 1 g:0.5 mL (ATP-SH-0.5) and the pH was set to 8, a strong adsorption capacity for Cd (II) and Pb (II) was demonstrated. This indicates excellent adsorption performance for these heavy metals. ATP-SH-0.5 exhibited a maximum adsorption capacity of 43.81 mg/g and 274.83 mg/g for Cd (II) and Pb (II), respectively, in a single ion system. In a binary ion system, the maximum adsorption capacity was 31.86 mg/L and 254.45 mg/L for Cd (II) and Pb (II), respectively. Various characterizations and experiments showed that the adsorption of Cd (II) and Pb (II) onto ATP-SH-0.5 involves ion exchange reactions involving hydroxyl and thiol functional group complexation reactions. This adsorption process follows a single-molecule layer adsorption mechanism. XPS results indicate that hydroxyl and grafted thiol functional groups on the surface of mercapto-functionalized attapulgite participated in surface complexation reactions with Cd (II) and Pb (II), resulting in the formation of Cd-S and Pb-S species. Overall, this study provides a promising mercapto-functionalized modification material for the remediation of polluted water and soil.

Conception of Hybrid Organic-Inorganic Membrane as New Electrolyte in All Solid-State Battery

All-solid-state lithium batteries (ASSBs) are considered like the next generation of electrochemical energy storage devices because of their safety and their high energy density up to 400Wh/kg. The all-solid-state battery is composed of a positive electrode (e.g., NMC (Li(Ni1∕3Mn1∕3Co1∕3)O2)), a negative one (Li), and a solid electrolyte, which is the critical component, composed of inorganic compound and/or solid polymer electrolyte (SPE) [1]. On the one hand, SPE have the advantage of an easy shaping with the technique already used in the manufacture of batteries and their flexibility allows obtaining a good interface with the electrode materials [2]. On the other hand, inorganic compounds generally have high ionic conductivity (10-3S/cm), they are stable electrochemically vs Li/Li+ and their transport number is close to 1 to promote the diffusion/migration of Li+ ions only. In order to combine the advantages of both types of materials, hybrid materials have been designed [3].First, a new adaptable polymer matrix based on PEO derivatives has been developed. A solvent-free synthesis has been designed from liquid and commercial precursors Poly(ethylene glycol) methyl methacrylate (PEGM) and Poly(ethylene glycol) dimethacrylate (PEGDM). These latter were copolymerized with Lithium 3-[(trifluoromethane)sulfonamidosulfonyl] propyl methacrylate (MTFSLi). The anion TFSI- is thus grafted to the PEO network, allowing exclusively the diffusion of the Li+ ion. This polymer matrix can be thus classified as single-ion conductor. In addition, the proportions between PEGM and PEGDM, acting as crosslinker, can be easily tuned. The PEGDM proportion controls the cross-linking density which modifies not only the glass transition temperature (Tg), but also the storage modulus (E’) and the free volume, and consequently the ionic conductivity of the polymer matrix which is the main property required for SPE. Finally, a ratio of PEGM:PEGDM (80:20) allows obtaining homogeneous SPE, self-standing and soft at room temperature, amorphous with a Tg of -41°C. The EO/Li ratio was then modulated in single-ion networks with the MTFSLi proportion, and an optimum in ionic conductivity of 2.10-7 S/cm @25°C has been measured for EO/Li ratio of about 20. The transport number measured by the Bruce and Vincent method [4] was t+=1,0 for the single ion conductor, demonstrating the effective grafting of the counter anion. This value has been validated by measuring the diffusion coefficients of 7Li and 19F in NMR. To our knowledge, this is the first time a real unity transport number is reported in the literature for a polymer electrolyte. Moreover, the electrochemical stability of this single ion system extends from 0 to 6V vs Li+/Li. These experiments suggest the interest of using the single-ion polymer in the formulation of composite positive electrode with high potential cathode materials, due to its stability in potential. Li metal is considered the ultimate anode for Li-batteries. The long-term electrochemical stability has been evaluated in symmetric Li/polymer electrolyte/Li cell. The cell is cycled at a constant current density of 0.2 mA/cm2. After 200 h of cycling the voltage reaches solely 2V. Accordingly, the grafting of the anion to the network limits an overpotential in the cell, allowing a more stable system over time.Second, the garnet Li6.4La3Zr2Al0.2O12 (LLZO) of the oxide family was associated to the previous polymer matrix. This garnet presents a high conductivity (10-4 S/cm @ 25°C), a good chemical stability not only against lithium metal but also against air and humidity, which is not the case of sulphides homologues. A 3D-fibrous network obtained by the electrospinning method was carried out with a solution containing the inorganic precursors, a polymer and an appropriate solvent [5]. Then this membrane is calcined at 850°C to obtain the 3D fibrous network of LLZO. The resulting self-standing porous inorganic material (~80% of porosity) exhibits a conductivity of the order of 10-6 S/cm @25°C. It was then impregnated with the polymer matrix precursors by capillarity and following by a polymerization. A self-standing membrane as thin as 80 µm containing 9%vol of LLZO was obtained. The conductivity of this hybrid membrane is comparable to that of the polymer (10-7S/cm @ 25°C). The resulting hybrid is mainly polymeric where the ionic conduction was realized by the polymeric matrix and the inorganic acts as a mechanical reinforcement. Preliminary results on high content of LLZO hybrid will also be presented, where a synergy of the both components is observed.[1] Janek. Nature Energy. 2016. Vol 1(9)p.16141. [2] Yue. Energy Storage Materials. 2016. Vol 5p.139-164. [3] Zheng. Chem Soc Rev. 2020. Vol 49p.8790-8839. [4] Bruce. Solid State Ion. 1988. Vol 28–30p.918–922. [5] A. La Monaca. Electrochemistry Communications. 2019. Vol 104p.106483. Figure 1

Regioselective One-Step Cyclization and Aromatization towards Directly Amino-Functionalized Covalent Organic Framework with Stable Benzodiimidazole Linkage.

The compatibility of crystallinity, stability, and functionality in covalent organic frameworks (COFs) is challenging but significant in reticular chemistry and materials science. Herein, it is presented for the first time a strategy to synthesize directly amino-functionalized COF with stable benzodiimidazole linkage by regioselective one-step cyclization and aromatization. Bandrowski's base with two types of amino groups is used as a unique monomer, providing not only construction sites for the material framework through specific region-selective reaction, but also amino active sites for functionality, which is usually difficult to achieve directly in COF synthesis because amino groups are the participants in COF bonding. In addition, the aromatic benzodiimidazole rings and the large conjugated system of the product effectively improve the crystallinity and stability, so that the as-prepared BBCOF remains unchanged in both acid and base solutions, which is obviously better than the conventional imine-linked COF. Impressively, the significantly enhanced conjugation degree by the benzodiimidazole structure also endows BBCOF with an efficient photocatalytic reduction of uranyl ion, with removal rate as high as 96.6% in single-ion system and 95% in multi-ion system. This study is of great importance to the design and synthesis of functional COFs with a commendable trade-off among crystallinity, stability, and functionality.

Selective adsorption of Pb (II) and Cu (II) on mercapto-functionalized aerogels: Experiments, DFT studies and LCA analysis

Mercapto-functionalized aerogels (MA-X) were fabricated using γ-mercaptopropyltrimethoxysilane (MPTMS) as a modification reagent to eliminate Pb (II) and Cu (II) ions from wastewater. Mercapto-functionalized aerogel (MA2) with the MPTMS/TEOS molar ratio of 0.5 exhibited the maximum adsorption amounts of 163.99 mg/g for Pb (II) and 172.41 mg/g for Cu (II) in single ion system, respectively. In binary ion system, selective adsorption experiments revealed that the equilibrium adsorption capacity for Cu (II) (161.29 mg/g) was significantly greater than Pb (II) (90.42 mg/g), and the selectivity factor α showed greater selectivity for Cu (II), demonstrating that Cu (II) was more readily adsorbed on MA2. The results showed that adsorption was consistent with pseudo-second order model and Langmuir model. Thermodynamic results demonstrated that adsorption phenomenon was an exothermic reaction that occurred spontaneously. XPS analysis and density functional theory (DFT) simulations showed that the main mechanism for the adsorption of Pb (II) and Cu (II) on MA2 was through coordination chelation of the –SH groups with Pb (II) and Cu (II). DFT calculations showed a lower adsorption energy (Eads) of Cu (II) (−2.72 eV) with respect to Pb (II) (−0.80 eV), indicating that Cu (II) was more stably adsorbed on MA2 and more difficult to exchange by Pb (II). In order to determine the environmental impact of the MA2 preparation process, a life cycle assessment (LCA) was conducted and contribution of each material to MA2 production was analyzed. Finally, a strategy that is environmentally friendly and effective has been proposed in order to facilitate MA-X adsorbents production and to improve their application for the treatment of heavy metal polluted wastewater.

Design and simulation of a low-energy single ion irradiation system for micro/nano-biosample investigation

A low-energy single ion irradiation system is developed in its initiation in Thailand to follow one of the trends in novel ion beam technology exploitation. Single ion irradiation of materials is a highly technological development of ion beam technology. The developed single ion irradiation systems worldwide are primarily in the MeV-energy range and for single cell studies, and recently the trend has been extended to the low-energy range (< 100 keV) but focused on microelectronic applications. Based on our previous research on low-energy ion beam irradiation of biological cells and DNA, we design and simulate a low-energy single ion implantation system, aiming at eventual construction of such a novel ion beam apparatus for applications to the biological studies. In the system, the ion energy is decreased to orders < 1 keV by the existing deceleration lens, then the low-energy ion beam passes through µm slits, and finally, low-energy single ions are obtained by beam scanning with appropriate frequencies from scanner plates and detected by a single ion detection device. Conceptual design, calculation and simulation of this single ion system are presented.

Mechanisms of arsenate and cadmium co-immobilized on ferrihydrite inferred from ternary surface configuration

Elucidating the interfacial interactions of arsenate (AsO43-) and cadmium (Cd) on minerals can better reveal their environmental behavior under various geological settings. Herein, the adsorption of Cd on ferrihydrite (Fh) in the presence of arsenate was investigated through batch experiments, surface complexation, and spectroscopic techniques. We determined the concentration-dependent interactions of Cd (II) and As (V) on each other’s behavior on Fh. Cadmium and arsenate tended to co-precipitate at high Cd/As ratios, whereas adsorption dominated at low Cd/As ratios. Compared with the single-ion system, the coexistence of Cd(II) and As on Fh significantly reduces the respective mobility of Cd(II) and As(V). The results of in situ attenuated total reflection–Fourier-transform infrared spectroscopy and charge distribution multisite complexation modeling revealed that the synergistic effects originated from electrostatic interactions and the formation of a ternary complex. The curve fitting of the spectra revealed three deconvolution peaks at ~ 765 cm−1, ~813 cm−1, and ~ 870 cm−1, which were assigned to As–OX (X = H+, cations, and H2O), As–O–Fe, and As–Oumcomplexed, respectively. After the addition of Cd(II), the intensity of As–OX increased at different pH values, indicating the formation of an As–O–Cd ternary complexes. We infer that two types of surface complex were assembled on the surface of Fh: namely anion-bridged Fe–As–Cd and cation-bridged Fe–Cd–As. These results contribute to our understanding of the behavior of multiple contaminates in an iron-rich environment and are helpful for the development of the corresponding restoration technology.

Experimental Determination of PT-Symmetric Exceptional Points in a Single Trapped Ion.

Exceptional points (EPs) of a non-Hermitian Hamiltonian with parity-time-reversal (PT) symmetry have the potential to drastically enhance the capabilities of metrology and sensing through their power-law growing sensitivity to external perturbation. With the ability of generating and tuning dissipation in a single trapped ion system, we observe rich dynamics and detailed quantum phase transitions from the PT-symmetric phase to the symmetry-breaking phase. In this single qubit full quantum system, we develop a method to precisely determine the location of EP without any fitting parameter, and extract the eigenvalues in a unified way through all parameter regions. We can also obtain the full density matrix by quantum state tomography. Finally, we suggest from theoretical analysis that the periodically driving PT-symmetric non-Hermitian system can be used to measure the magnitude, frequency, and phase of time-dependent perturbation with EP enhancement.

Magnetite encapsulated alginates tailored material for the sustainable treatment of electroplating industrial wastewater: column dynamics and mass transfer studies

The current study proposes the use of magnetic beads for the treatment of nickel ions of the industrial wastewater system. More specifically, the removal of nickel ions is studied in single and multi-metal ion systems which enabled the scalability of nano-enabled technology to industrial systems. The current synthesis neither involves expensive precursors nor complex procedures. Indeed, the improved surface properties of the adsorbent are due to the use of Lantana camara, in the synthesis. The surface properties and functional attributes of the magnetic beads were characterized by FTIR and SEM analyses. The breakthrough experiments were done for selected column depths, varying feed flow rates and metal ion concentrations. In particular, the interventions of the interfering ions of the electroplating effluents are captured in the breakthrough analysis. Besides the lowest bed capacity reported in the multi-metal systems, the column operated with nickel ions showed a maximum bed capacity of 12.36 mg/g at a flow rate of 2 mL/min in the 20 cm bed. Furthermore, an extended breakthrough time of 780 min is obtained for 50 mg/L nickel ion solution at a flow rate of 2 mL/min. In addition, the modelling of breakthrough curves using Thomas, Yoon–Nelson and BDST models have shown reasonable fits. In addition, repeated cycles of regeneration studies showed improved efficiency of 65% in the first cycle. More specifically, the alginate validated the selective preferential adsorption of cationic substances over anionic components in the studied column.

Implementing two-qubit phase gates by exchanging non-Abelian quasiparticles

We study how to implement two-qubit phase gates by exchanging non-Abelian quasiparticles. We firstly investigate quantum dynamics of a single trapped ion with two stable electronic ground states and with a larger energy gap from the rest of the spectrum, which is held in the Lamb–Dicke regime of a driven optical lattice. A set of degenerate Schrodinger’s cat states with the same expected energy is found, and wavepackets of the probability densities occupying different spin states are identical to the quasiparticles obeying the proposed non-Abelian interchange. The controlled transitions between different instantaneous degenerate ground states are illustrated for an array of $$\delta $$-shaped laser pulses. Making use of the mathematical equivalence between the single-ion system and the center-of-mass system of two trapped ions, the two-qubit phase gates are implemented by exchanging the non-Abelian quasiparticles of the center-of-mass motion via the periodic state-dependent forces. Such phase gates depend on geometric and topological properties of the system, which makes them resistant to certain errors. The results can be justified with the current experimental capability and may be extended to an array of weakly coupled trapped-ion pairs for demonstrating the non-Abelian statistics of the quasiparticles and for encoding the topological qubits.

Tyrosine-Immobilized Montmorillonite: An Efficient Adsorbent for Removal of Pb2+ and Cu2+ from Aqueous Solution

Herein, a new effective material, tyrosine-functionalized montmorillonite (Tyr-Mt), was prepared and used in the adsorption of Pb2+ and Cu2+ ions. Tyr-Mt is synthesized by modifying sodium montmorillonite (Na-Mt) with l-tyrosine. The X-ray diffraction, ζ-potential, Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller, and thermal analysis results showed that the modifier was successfully inserted into the interlayer of montmorillonite. In single-ion systems, various parameters were thoroughly evaluated, such as the amount of the modifier, pH value, the initial concentration of M2+, and contact time, affecting the adsorption processes in sodium montmorillonite (Na-Mt) and Tyr-Mt composites. The adsorption experiments of Pb2+ and Cu2+ showed that the adsorption effect of Tyr-Mt was better than that of Na-Mt. The balanced adsorption of Pb2+ by Tyr-Mt was 106.21 (higher than that by Na-Mt, 89.08 mg/g) and of Cu2+ was 28.31 mg/g (higher than that by Na-Mt, 23.93 mg/g). The adsorption model conforms ...

Entropy Exchange and Thermodynamic Properties of the Single Ion Cooling Process.

A complete quantum cooling cycle may be a useful platform for studying quantum thermodynamics just as the quantum heat engine does. Entropy change is an important feature which can help us to investigate the thermodynamic properties of the single ion cooling process. Here, we analyze the entropy change of the ion and laser field in the single ion cooling cycle by generalizing the idea in Reference (Phys. Rev. Lett. 2015, 114, 043002) to a single ion system. Thermodynamic properties of the single ion cooling process are discussed and it is shown that the Second and Third Laws of Thermodynamics are still strictly held in the quantum cooling process. Our results suggest that quantum cooling cycles are also candidates for the investigation on quantum thermodynamics besides quantum heat engines.

Combinatorial effects of inorganic ions on adhesion and proliferation of osteoblast-like cells.

Combinatorial effects of three ions, namely silicate (Si), calcium (Ca), and magnesium (Mg) ions, on the adhesion and proliferation of MC3T3-E1 mouse osteoblast-like cells were evaluated. The cells were cultured in single-, dual-, or triple-ion-conditioned culture media with systematically changed ion concentrations. The ranges of Si, Ca, and Mg ion concentrations were set as 10-70, 80-400, and 25-500 ppm, respectively. The numbers of adherent live cells were measured after culturing for 3 h and for 1, 3, and 5 days to examine cell adhesion and proliferation, respectively. Mg ions predominantly enhanced cell adhesion in both the dual-ion (xSi-zMg and yCa-zMg) and triple-ion (xSi-yCa-zMg) systems but had no effect when they acted individually in the single-ion system. Conversely, Si ions predominantly enhanced cell proliferation in most single- and triple-ion-conditioned media. Evaluation of the combinatorial effects of the three ions on cell adhesion and proliferation revealed that the dual- and triple-ion-conditioned media mainly conferred synergistic effects on adhesion but antagonistic effects on proliferation. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 1042-1051, 2019.

WITHDRAWN: Adsorption properties of Pb2 + and Cu2 + by threonine functionalized montmorillonite in single-ion system

WITHDRAWN: Adsorption properties of Pb2 + and Cu2 + by threonine functionalized montmorillonite in single-ion system

Fabrication and characterization of a novel biosorbent and its evaluation as adsorbent for heavy metal ions

Firstly, gelatin type B was extracted from the black tilapia fish wastes, and in the following, a novel gelatin-based nanocomposite biosorbent was synthesized via free radical graft copolymerization of acrylic acid (AcA) and butyl methacrylate (BuMc) onto gelatin backbone in a homogeneous medium. The nanocomposite biosorbent structure was confirmed by FTIR, SEM, EDX, XRD and TGA techniques. The metal ion-loaded nanocomposite biosorbent was also characterized by FTIR, SEM and EDX analysis. The maximum of adsorption capacities 172.3 and 192.4 mg g−1 for Cd2+ and Cu2+ in single-ion system were determined under optimum conditions. The results of adsorption isotherms also showed that the Langmuir model described the adsorption mechanism better than the Freundlich. The kinetic adsorption for both metal ions was also followed the pseudo-second-order model. In addition, the biosorbent exhibited satisfactory adsorption capacities for the metal ions (162.4 mg g−1 for Cu2+ and 128.7 mg g−1 for Cd2+ at ambient temperature) in the local river water and in the presence of other metal ions, and as a result, this favorable material can be used to facilitate the reuse of valuable metals.

Carbonate Adsorption to Ferrihydrite: Competitive Interaction with Phosphate for Use in Soil Systems.

Carbonate (CO3) interacts with Fe-(hydr)oxide nanoparticles, affecting the availability and geochemical cycle of other important oxyanions in nature. Here, we studied the carbonate–phosphate interaction in closed systems with freshly prepared ferrihydrite (Fh), using batch experiments that cover a wide range of pH values, ionic strength, and CO3 and PO4 concentrations. The surface speciation of CO3 has been assessed by interpreting the ion competition with the Charge Distribution (CD) model, using CD coefficients derived from MO/DTF optimized geometries. Adsorption of CO3 occurs predominately via formation of bidentate inner-sphere complexes, either (≡FeO)2CO or (≡FeO)2CO··Na+. The latter complex is electrostatically promoted at high pH and in the presence of adsorbed PO4. Additionally, a minor complex is present at high CO3 loadings. The CD model, solely parametrized by measuring the pH-dependent PO4 adsorption as a function of the CO3 concentration, successfully predicts the CO3 adsorption to Fh in single-ion systems. The adsorption affinity of CO3 to Fh is higher than to goethite, particularly at high pH and CO3 loadings due to the enhanced formation (≡FeO)2CO··Na+. The PO4 adsorption isotherm in 0.5 M NaHCO3 can be well described, being relevant for assessing the reactive surface area of the natural oxide fraction with soil extractions and CD modeling. Additionally, we have evaluated the enhanced Fh solubility due to Fe(III)-CO3 complex formation and resolved a new species (Fe(CO3)2(OH)23−(aq)), which is dominant in closed systems at high pH. The measured solubility of our Fh agrees with the size-dependent solubility predicted using the surface Gibbs free energy of Fh.

Influence of phosphate on tungstate sorption on hematite: A macroscopic and spectroscopic evaluation of the mechanism

The environmental fate of the tungstate (VI) oxyanion [ e.g. mono tungstate and several polytungstate, generally expressed by W (VI)] is largely controlled by sorption on soil minerals, especially on iron oxide minerals. Molecular scale evaluation of W (VI) retention on iron oxides in the presence of competing oxyanions is scarce in literature. Here we report surface interaction mechanisms of W (VI) on hematite in the presence of phosphate (P) using macroscopic and in situ attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopic experiments. Batch sorption experiments were conducted using 2 g L−1 hematite and 100 μM W (VI) and P, in single ion system and in binary mixtures as a function of pH (4–11). In situ ATR-FTIR spectroscopic evaluation of P and W (VI) sorption on hematite was also carried out. The results from macroscopic experiments indicated that W (VI) sorption on hematite was not affected by P when W (VI) was added first. The influence of P on W (VI) sorption was noticed when W (VI) & P were added simultaneously or P was added first. The in situ ATR-FTIR spectroscopic data corroborated these findings. In addition, the spectroscopic data revealed that in the presence of P, the surface complexation mode of W (VI) differed as noted from either the absence of WO antisymmetric infrared (IR) band or the WOW stretching band. This study provides useful information on molecular level understanding of W (VI) surface complexation on hematite in the presence of competing ions such as P.

The Effect of Modifying the Macrocyclic Ring Size on Zn3Ln (Ln = Dy, Er, and Yb) Single‐Molecule Magnet Behavior

Three tetranuclear heterometallic ZnII‐LnIII complexes of the 30‐membered [3+3] hexaimine macrocycle (LEt)6–, with general formula ZnII3LnIII(LEt)(NO3)2OAc·5H2O (LnIII = DyIII, ErIII, YbIII), were prepared using our established one‐pot synthesis methodology, whereby the individual components of the whole system are poised to assemble themselves into a mixed 3d/f4f macrocyclic system. This uses a 3:1:3:3 reaction of ZnII acetate, the appropriate LnIII nitrate, 1,4‐diformyl‐2,3‐dihydroxybenzene, and 1,2‐diaminoethane. These ten individual building blocks readily assemble into tetrametallic complexes, analogous to our previously reported examples with larger macrocycles. Identity was confirmed by IR spectroscopy (imine), micro‐ (C, H, N) and metal‐ (Zn, Ln) analysis, TGA (solvent content), and mass spectrometry. Magnetic properties were studied down to 2 K and with ac susceptibility measurements were used to check for slow relaxation of the magnetization characteristic of Single‐Molecule Magnet (SMM) behavior. As is often the case for single ion systems (only Ln is paramagnetic) no such behavior was observed. However, under an applied dc field, an out‐of‐phase ac susceptibility signal is seen for all three complexes. We speculate that shrinkage of macrocyclic ring size (30) compared to that of the original ZnII3DyIII system (33) has led to a less favorable coordination arrangement for the DyIII and ErIII ions through a change in the imposed coordination environment of the LnIII ion.

Harnessing the Power of Plastics: Nanostructured Polymer Systems in Lithium-Ion Batteries

Nanostructure-forming polymers have tremendous potential to enhance the performance and safety of lithium-ion batteries (LiBs) as a result of their ability to simultaneously optimize often contradictory properties, such as ionic conductivity and mechanical stability, in a single material. These macromolecules can be harnessed in both LiB electrolyte and electrode components. With respect to electrolytes, advances in salt-doped and single-ion systems are highlighted herein with a focus on strategies that improve conductivities to rival that found in gel and liquid electrolytes, while also permitting further enhancements in electrochemical and mechanical stability. In the arena of electrodes, three major functions are considered: binders to maximize active material efficiency, polymer electrodes to enable fully organic LiBs, and sacrificial constructs that template high surface area, well-ordered metal oxide or metallic electrodes to improve electrode capacity. Additionally, the application of theory and si...