Magnesium Atoms Research Articles

A COMPARATIVE THEORETICAL INVESTIGATION OF MAGNESIUM INSERTION INTO THE C-X BOND IN VINYL HALIDES (X = F, Cl, AND Br)

In the present study, the insertion of the magnesium atom into the carbon halogen bond of vinyl halides (X = F, Cl, and Br) is studied via B3LYP density functional calculations with a 6-311G(d,p) basis set. A 3-centered transition state with a single imaginary frequency is obtained for all three reactions. The potential energy profile is determined in both directions for all the systems along the intrinsic reaction coordinate. All the transition states obtained lie on the potential energy surface. The three Grignard reactions are exothermic in nature, as indicated by the energetics of the reactions. Electron correlation inclusion has increased the exothermicity of the reactions. Atom in molecules (AIM) analysis predicted the ionic character of the Mg-C and X-Mg bond in the product, C2H3MgX, where X = F, Cl, and Br, as compared to all the other bonds. Results obtained in our study at the DFT level are in agreement with the previous MP2 and HF calculations.

Anisotropy in Carbon Dioxide Adsorption on Forsterite.

In this study, density functional theory (DFT) method were used to investigate the adsorption behavior and binding mechanism of CO2 molecules on six crystallographic surfaces of forsterite (Mg2SiO4). The influence of surface crystallographic orientation on CO2 adsorption efficiency was examined at the atomic level. Results showed stable binding of CO2 on all surfaces. The interaction strength decreases in the order: (001) > (101) > (120) > (111) > (010) > (110), with the (001) surface exhibiting the highest binding capacity due to accessible magnesium cations interacting with CO2. Detailed electronic property analysis revealed significant charge transfer between CO2 oxygen atoms and surface magnesium atoms, driven by hybridization of oxygen 2p and magnesium 2s orbitals, leading to the formation of ionic and covalent bonds. These interactions stabilize the adsorbed CO2 and are accompanied by changes in the electronic structure, such as energy level shifts and modifications in the partial density of states (PDOS). The computational analysis provides a theoretical foundation for understanding CO2 binding mechanisms by forsterite. The findings highlight the importance of crystallographic orientation and electronic properties of the mineral surface in adsorption efficiency, contributing to a deeper understanding of CO2 interactions with mineral surfaces.

Defective kinase activity of IKKα leads to combined immunodeficiency and disruption of immune tolerance in humans

IKKα is a multifunctional serine/threonine kinase that controls various biological processes, either dependent on or independent of its kinase activity. However, the importance of the kinase function of IKKα in human physiology remains unknown since no biallelic variants disrupting its kinase activity have been reported. In this study, we present a homozygous germline missense variant in the kinase domain of IKKα, which is present in three children from two Turkish families. This variant, referred to as IKKαG167R, is in the activation segment of the kinase domain and affects the conserved (DF/LG) motif responsible for coordinating magnesium atoms for ATP binding. As a result, IKKαG167R abolishes the kinase activity of IKKα, leading to impaired activation of the non-canonical NF-κB pathway. Patients carrying IKKαG167R exhibit a range of immune system abnormalities, including the absence of secondary lymphoid organs, hypogammaglobulinemia and limited diversity of T and B cell receptors with evidence of autoreactivity. Overall, our findings indicate that, unlike a nonsense IKKα variant that results in early embryonic lethality in humans, the deficiency of IKKα‘s kinase activity is compatible with human life. However, it significantly disrupts the homeostasis of the immune system, underscoring the essential and non-redundant kinase function of IKKα in humans.

Graphene reinforced magnesium metal matrix composites by infiltrating coated-graphene preform with melt

Graphene’s exceptional mechanical, electrical, and thermal conductivity capabilities make it an ideal reinforcement for metal matrix composites. However, graphene is hard to be dispersed in the melt metal due to its high surface energy, non-wetting nature, and strong van der Waals interactions between graphene sheets, which weaken the reinforcing efficiency of composites. A novel process by infiltrating the coated-graphene preform with melt magnesium was proposed to improve the dispersion of graphene in the magnesium matrix. Graphene preforms with oriented pores were prepared by a directional freeze-drying method. Magnesium oxide coatings were deposited on the surface of graphene inside the graphene preform using the evaporation of magnesium atoms to enhance the strength as well as the wettability between the preform and magnesium matrix. Magnesium matrix composites were fabricated by liquid-solid pressure infiltrating coated-graphene preform with molten magnesium. The microstructure of graphene preforms and composites and mechanical properties of the composites were characterized. The results show that graphene is uniformly dispersed in the matrix and presents a reticular structure, and the hardness, elastic modulus, and compressive strength of the composite were improved apparently compared to the matrix. This study suggests that the method of preparing composites by infiltration provides a novel strategy for fabricating nano-material reinforced magnesium matrix composites.

An investigation on effect of tramp elements and solidification processing on homogenization kinetics of AA 7xxx series aluminum alloys

AA 7068 Aluminum alloy is produced via conventional solidification (CS) and controlled diffusion solidification (CDS) processing and homogenized at 450 °C for 6 and 12 h. Optical microscopy (OM) and scanning electron microscopy (SEM) equipped with an energy dispersive x-ray spectroscope (EDS) were used to examine the as-cast and homogenized samples. It was found that although the CS sample is more chemically homogenized in the as-solidified state, the CDS sample exhibits a higher homogenization rate during the treatment. The calculated phase diagram (CALPHAD) methodology was employed to study the effect of silicon and iron on the solidification path and homogenization of the alloy. Silicon consumes magnesium atoms on the surface of the α-Al phase to form the Mg2Si phase. Therefore, the magnesium concentration on the α-Al phase required for the formation of the σ phase must be increased. Calculations shows that all the Mg atoms at this stage are completely supplied from the bulk of the αAl phase. It can be hypothesized that during the last stage of solidification, a solid/liquid diffusion couple can be created between the primary αAl and the remaining liquid for several minutes (4 min at a cooling rate of 0.2 oC/s). As a result of the activation of this couple, the Mg atoms diffuse from the α-Al bulk to its surface, and vacancies diffuse from the surface to the bulk, forming a line of Kirkendall voids. With CDS processing, the surface of the primary phase is less Mg-concentrated than that in the CS process and this significantly reduces the formation of the Mg2Si phase. Conversely, the vacancy and Mg concentration of the αAl phase in CDS is higher than that of CS and this lets other alloying elements other than Mg diffuse to the primary phase, decreasing the homogenization time. The presence of Si in the alloy leads to the formation of the Mg2Si phase, which significantly reduces the final Mg concentration in the α-Al phase after full homogenization. In the pure alloy, the Mg concentration is 2.42 wt%, while in the FeSi-containing alloy, it is reduced to 1.58 wt% due to solid solution and dispersion strengthening mechanisms. Through CDS processing, the negative impact of Si can be reduced by disrupting the mechanism of Mg2Si formation.

Unveiling the adsorption mechanism of propanehydrazine derivatives on magnesium oxide surface: Insights from computational approach

The use of green and effective inhibitors for preventing metal oxide (MgO) corrosion in industrial applications is highly significant in promoting environmental protection and sustainable development. This study delves into the adsorption behavior and interfacial mechanism of environmentally friendly inhibitor derived from propane hydrazine (PH) on MgO surface. Specifically, PH1, PH2, PH3, and PH4 were explored for their effectiveness in preventing corrosion by using advanced theoretical simulations-based density functional theory (DFT) for assessing the reactivity and adsorption characteristics. The study considered a detailed exploration of local and global reactivity descriptors, providing insights into the inhibitors’ reactivity and adsorption abilities in both isolated and adsorbed states. These findings focus more in the mechanisms underlying organic-inorganic interactions and present promising prospects for further development and application. Using first-principles DFT calculations alongside quantitative molecular surface analyses, we examined the adsorption patterns of PHs on the MgO(100) surface. These investigations are boosted by the application of independent gradient model (IGM) framework, providing robust verification of PHs' adsorption behavior on MgO(100) surface. Our calculations reveal a substantial decrease in the energy gap following complex formation, suggesting that charge density changes occur upon interaction with MgO surfaces, thereby facilitating direct electron transfer in all the studied systems. Noreover, the results highlight the crucial role of intermolecular interactions in boosting the interaction between PHs and the [Mg(H2O)6]2+ cation. First-principles DFT calculations show that all PH molecules consistently display parallel adsorption on the MgO surface, where the oxygen atoms form bonds with adjacent magnesium atoms. The bond lengths vary from 2.18 to 2.35 Å when PHs bind to the Mg atoms in parallel orientations through the oxygen atom, suggesting a stable parallel arrangement for PH molecules on the MgO surface. The calculated adsorption energy (Eads) varies in the following order: MgO-PH3 (−815.14 Kcal mol−1) > MgO-PH2 (−803.85 Kcal mol−1)) > MgO-PH4 (−695.38 Kcal mol−1) > MgO-PH1 (−125.77 Kcal mol−1). This trend indicates that parallel interactions enhance the adsorption behavior and binding of PH compounds through inter- and intra-molecular interactions, resulting in the PHs being centered at specific sites on the MgO surface. The potential enhancement in electrochemical properties is believed to stem from the synergistic interaction between the PHs and the MgO surface, which theoretically allows for a precise adjustment of their adsorption and interaction within the composite structure. This understanding provides a fundamental framework for examining the complex interfacial dynamics between inhibitor structures and elucidating how these molecular interactions influence the selection of corrosion inhibitors and their adsorption behaviors on the corrosion layer's surface, rather than on metallic Mg.

A bidirectional-modification strategy for enhancing the reliability of thermoplastic-metal hybrid joint from atomic-scale

In this study, a strategy towards thermoplastic-metal hybrid joint via bidirectional modification for high reliability was designed. The chemical bond behavior and conditions at the interface were explored from atomic scale using density functional theory (DFT) calculation. Based on the bonding mechanism, the AZ31B alloy was oxidized and the carboxyl groups (COOH) were introduced in the resin chain to improve the strength of chemical bond. The mechanical property of the designed joint was significantly improved and the tensile-shear strength achieved 22.7 MPa after bidirectional modification, reaching 4.5 times that of untreated joints. It was mainly attributed to the generation of metal-carboxylate bridging complex—a typical strong coordination bond formed between two O atoms in COOH and two diagonal magnesium atoms in MgO. Experimental evidence also suggested the generation of new chemical bond at the CFRTP/AZ31B interface. Finally, the bidirectional modification was proved to be an efficient and reliable method with high industrial adaptability. The current work opened up a novel direction for reliability promotion of thermoplastic-metal hybrid structures.

Preparation of tunable magnesium atom-doped nickel oxide films with short response time and high coloring efficiency by sol-gel method

Nickel oxide, a representative electrochromic material, is commonly employed in environmentally conscious optoelectronic devices, such as multifunctional smart windows. In this paper, novel electrochromic nickel oxide films doped with magnesium atoms were prepared on indium tin oxide (ITO) substrates by sol-gel spin-coating method, and the results of X-ray diffraction and scanning electron microscopy show that the spin-coating is unique in that the existence of a small number of cracks on the surface of the sample is conducive to the enhancement of the electrochemical properties. UV–visible spectrophotometer and electrochemical workstation were used to explore the effect of Mg-atom doping concentration on the electrochromic performance of the nickel oxide thin films, and the results showed that at an annealing temperature of 400 °C, the optical modulation amplitude of the samples with a doping concentration of 4 % reached 43.12 %, and the coloring time and the fading time were reduced to 4.0 s and 3.1 s, respectively, with an increase in the coloring efficiency to 42.25 cm2C−1. In conclusion, Mg doping has an important reference value for the study of electrochromic performance of NiO thin films, and has good prospects for electrochromic applications.

Compositional-Dependent Structural Parameters and Energetics of Hibonite: Quantum-Chemical Investigation.

One of the first minerals to condense from the early solar nebula was hibonite (CaAl12O19), demonstrating a hexagonal crystal structure. There are five unique aluminum cation sites (M1-M5) in hibonite. Although hibonite contains aluminum, it can also have 3d transitional metals that substitute at aluminum cation sites, such as titanium, and other metals such as magnesium. Titanium can occur in multiple oxidation states, linking to redox conditions. A single substitution occurs when a single aluminum atom is replaced by a single titanium atom, causing the Ti to take on a 3+ oxidation state. On the other hand, Ti achieves an oxidation state of 4+ during a double substitution when a pair of aluminum atoms is replaced by a titanium and a magnesium atom. A density functional theory-based calculation is used to explore the relationship between the number of substitutions and the lattice parameters of the hibonite crystal. The calculated results reveal that the lengths of both unit cells (a and c) increase with an increasing number of single or double substitutions. The rate of increment per substitution depends on the cation sites, M1-M5, and substitution types. Along with the expansion of the unit cell of the hibonite due to the substitution, the substituted unit cell gains energy (and in turn stability) compared to the substituted unit cell without expansion, dependent on the lattice site and substitutions.

Application of organic phosphonic acid dispersant in the separation and flotation of chalcopyrite and serpentine

The floatation of target minerals is often severely deteriorated in highly muddy mineral flotation systems. In this study, it was shown that the chalcopyrite recovery was significantly decreased due to the slime-coating of the serpentine fines. To enhance the floatability of chalcopyrite in the presence of serpentines, two phosphonic acids of 1-Hydroxyethylidene-1,1-diphosphonic acid (HEDP) and ethylenediamine tetramethylene phosphonic acid (EDTMP) were applied as dispersants in the floatation process. The micro-flotation tests indicated that HEDP and EDTMP could well eliminate the adverse effect of coated serpentine on the floatability of chalcopyrite. Adsorption tests and X-ray photoelectron spectra (XPS) analysis demonstrated that HEDP and EDTMP could selectively adsorb on the serpentine surface due to the chelation of phosphonic acid groups with the magnesium atoms on the serpentine surface, which was confirmed by the flight secondary ion mass spectrometry (TOF-SIMS) characterization. The zeta potential measurements showed that the adsorption of dispersants on serpentine changed the surface charges from positive to negative, while the zeta potential of chalcopyrite became more negative due to the dissolution of copper and iron cations from the chalcopyrite surface. Therefore, the electrostatic repulsion effectively prevented the slime-coating of serpentine on the chalcopyrite surface, which was also supported by the atomic force microscope (AFM) force measurements. As a result, the use of dispersants eliminated the adverse effects of serpentinite and greatly improved the floatability of chalcopyrite. The findings in this work indicate that the phosphonic acids of HEDP and EDTMP might find their application as effective dispersants to improve the floatability of target minerals in highly muddy mineral flotation systems.

Ba3Mg4Au4 – a ternary auride composed of BaAu2- and BaMg2Au-related slabs

Abstract The ternary auride Ba3Mg4Au4 was synthesized from the elements in a sealed tantalum ampoule. The Ba3Mg4Au4 structure was refined from single-crystal X-ray diffractometer data: Gd3Cu4Ge4 type, space group Immm, a = 447.95(10), b = 843.07(18), c = 1564.2(5) pm, wR2 = 0.0935, 680 F 2 values, 23 variables. Ba3Mg4Au4 is a 1:2 intergrowth structure of BaAu2-(AlB2 type) and BaMg2Au-(MgCuAl2 type) related slabs. The two crystallographically independent gold atoms both have tricapped trigonal prismatic coordination, i.e. Au1@Mg6Ba3 and Au2@Mg2Ba6Au. The Au–Mg (284–303 pm) and Ba–Au (331–349 pm) distances cover small ranges that are close to the sums of the covalent radii. The magnesium atoms in the MgCuAl2-related slab show Mg–Mg distances of 320–332 pm. The different coloring variants of the Gd3Cu4Ge4 type are briefly discussed.

Uncovering the interactions and potentials of magnesium and boron nitride nanostructures for magnesium-ion batteries

In present research paper, relationships between a magnesium atom and a magnesium ion (Mg2+) were examined with four different nanostructures: a boron nitride nanotube and a boron nitride nanocone. Our goal was to determine cell voltage (V) values for Mg-ion batteries (MIBs). We conducted calculations employing ωB97XD level of theory and 6-31G(d) basis set to analyze total energy, optimize the geometry, and examine the frontier molecular orbitals. The DFT calculations provided clarification regarding the energy adsorption changes (Ead) between the Mg2+ ion and nanostructures, indicating that the order of Ead is BN tube > BN cone. However, the nanocone exhibits the highest Vcell value, and alterations in Vcell for Mg-ion batteries follow order of BN cone > BN tube. Present research provides theoretical insights into the potential of magnesium as an anode material in batteries, highlighting its favorable Vcell.

Analyzing the physical properties of perovskite oxides CeBO3 (B=Be, Mg) for optoelectronic and thermoelectric applications

The structural, electronic, elastic, thermoelectric and optical properties of CeBO3 (B = Be, Mg) oxide perovskites were investigated using density functional theory. Exchange and correlation effects were addressed through the GGA approximation and the TB-mBJ potential. Thermodynamic stability was confirmed by assessing cohesive energy and formation enthalpy. The band structures reveal a semiconductor nature with a moderate indirect band gap of 0.73 (CeBeO3) and 0.51 (CeMgO3). The TB-mBJ approximation has enhanced the gap value with a 55% approaching rate. These compounds exhibited a rigid and elastically anisotropic behavior with chemical bonds manifesting as a mixture of metallic and covalent types. The CeBeO3 displayed ductility while CeMgO3 exhibited brittleness. The optical examination suggests that these oxides exhibit activity across a broad range of the electromagnetic spectrum. Their strong reflectivity in the near-infrared region was particularly noteworthy suggesting potential use as effective shields in this domain. The replacement of beryllium with a magnesium atom enhanced thermoelectric performance by reducing thermal conductivity and increasing the merit factor. Based on the obtained results, the semiconductor perovskites CeBeO3 and CeMgO3 hold promise for efficient applications in optical and thermoelectric devices.

The crystal structures and magnetic properties of YbMg0.75In1.25 and Yb6Mg6.41In5.59

Abstract The quasi-binary system YbMg2-YbIn2 was studied around the equiatomic composition. In contrast to the ordered rare earth (RE) phases REMgIn (ZrNiAl type), ytterbium forms phases with different structures and pronounced Mg/In mixing (M sites). The structures of YbMg0.75In1.25 (CaLiSn type, P3m1, a = 501.95(7), c = 1087.3(2) pm, wR2 = 0.0490, 790 F 2 values, 32 variables) and Yb6Mg6.41In5.59 (Yb6Ir5Ga7 type, P63/mcm, a = 1060.77(14), c = 970.27(16) pm, wR2 = 0.0484, 701 F 2 values, 26 variables) were refined from single-crystal X-ray diffractometer data. YbMg0.75In1.25 is an AlB2 superstructure with a tripling of the subcell. The magnesium and indium atoms form three differently puckered layers of M 6 hexagons. The Yb6Mg6.41In5.59 structure is derived from the hexagonal Laves phase YbMg2 (MgZn2 type, P63/mmc). A klassengleiche symmetry reduction leads to four crystallographically independent M sites for the rows of corner- and face-sharing tetrahedra which allow a composition close to the equiatomic one. The M–M distances in both structures cover the broad range from 289 to 331 pm, comparable to the sums of the covalent radii. Temperature dependent magnetic susceptibility studies of the polycrystalline YbMg0.75In1.25 and Yb12Mg13In11 samples indicate Pauli paramagnetism with room temperature values of 2.8(1) × 10−3 emu mol−1 (YbMg0.75In1.25) and 5.2(1) × 10−3 emu mol−1 (Yb12Mg13In11).

Atomic and Electronic Structure in MgO-SiO2.

Understanding disordered structure is difficult due to insufficient information in experimental data. Here, we overcome this issue by using a combination of diffraction and simulation to investigate oxygen packing and network topology in glassy (g-) and liquid (l-) MgO-SiO2 based on a comparison with the crystalline topology. We find that packing of oxygen atoms in Mg2SiO4 is larger than that in MgSiO3, and that of the glasses is larger than that of the liquids. Moreover, topological analysis suggests that topological similarity between crystalline (c)- and g-(l-) Mg2SiO4 is the signature of low glass-forming ability (GFA), and high GFA g-(l-) MgSiO3 shows a unique glass topology, which is different from c-MgSiO3. We also find that the lowest unoccupied molecular orbital (LUMO) is a free electron-like state at a void site of magnesium atom arising from decreased oxygen coordination, which is far away from crystalline oxides in which LUMO is occupied by oxygen's 3s orbital state in g- and l-MgO-SiO2, suggesting that electronic structure does not play an important role to determine GFA. We finally concluded the GFA of MgO-SiO2 binary is dominated by the atomic structure in terms of network topology.

Manipulating polarization effect in nonsequential double ionization.

We report on a theoretical study of nonsequential double ionization (NSDI) of magnesium atoms by using combined linearly and circularly polarized fields. By employing a concise model including the dynamic ionic dipole potential, we show that the polarization effects can be controlled by tuning the subcycle waveform of the electric field of the two-color pulses. We demonstrate that the influence of the dipole potential on NSDI depends on the symmetry of two-color laser fields by tracing back the electron trajectories. Furthermore, we propose a method allowing for manipulating the returning trajectories with the initial direction of the tunneled electrons almost unchanged.

Phase transitions and spectral shifts: a quantum mechanical exploration of vibrational frequency in magnesium ferrite.

Spinel ferrites represent an integral subset of magnetic materials, with their inherent properties largely influenced by cation occupancy and spin interaction. In this study, we present an in-depth theoretical exploration of the phase transition landscape of pure magnesium-ferrite, deploying hybrid functionals and a local Gaussian basis set to scrutinize the relaxed lattice structure, relative energy, magnetic properties, electronic characteristics, and vibrational frequencies. Our investigation reveals that the ground state of magnesium-ferrite is an open-shell system with an inverse structure. This is characterized by the complete occupancy of octahedral sites by magnesium atoms, with Iron atoms dispersed between both tetrahedral and octahedral sites. We found a relative energy difference of 0.41 eV between the antiferromagnetic ground configuration and the ferro arrangement within the inverse structure. Furthermore, our research also delved into the impact of spin rearrangement and inversion (X = 0.0, 0.5 and 1) on Raman and infrared spectra. Notably, the lattice distortion from the cubic form, apparent in the optimized structure, resonates in the IR and Raman spectra, resulting in significant splitting. The frequencies calculated in this study align well with experimental values, suggesting that the literature's current assignments warrant reevaluation in light of this new data. The results presented herein can be instrumental in detecting the phase of Mg ferrites from experimental spectra, thereby paving the way for a more profound comprehension of their properties and possible uses.

Bismuthene as a novel anode material of magnesium/zinc ion batteries with high capacity and stability: a DFT calculation.

In our research, we utilize density functional theory (DFT) to explore the properties of magnesium and zinc atoms adsorbed on bismuthene. Our findings indicate that the hollow site is the most favorable adsorption site for Mg and Zn atoms on bismuthene. The results indicate that Mg and Zn adsorption on the bismuthene surface results in significantly high conductivity, with notable adsorption energies of -3.38 eV for Mg and -3.91 eV for Zn. The bismuthene structure can adsorb 9 Mg and 18 Zn atoms with negative average adsorption energy. These findings suggest excellent stability of bismuthene during the adsorption of magnesium and zinc. Notably, we propose theoretical storage capacities of 2308 mA h g-1 for magnesium-ion batteries (MgIBs) and 4616 mA h g-1 for zinc-ion batteries (ZnIBs), while maintaining structural stability during the adsorption of these metal ions. The observed average open-circuit voltages for bismuthene are 0.01 V for Mg and 0.03 V for Zn, with the material retaining its metallic properties throughout the adsorption process. Furthermore, the calculated diffusion barriers for Mg and Zn are 0.1 eV and 0.21 eV, respectively. Our findings like storage capacity, diffusion energies, and low OCV surpass those of most studied two-dimensional materials, positioning bismuthene as a promising anode material for metal-ion rechargeable batteries.

Probing the effect of magnesium doping on the structural and electronic properties of boron clusters

In this paper, a global search for the lowest energy structure of Mg2Bn0/- (n = 1–12) clusters is performed based on Density functional theory combined with the particle swarm optimization algorithm program CALYPSO. The geometry, stability, charge transfer, and bonding properties of the clusters were analyzed at the B3LYP/def2-tzvp level. Then Mg2B8 with high symmetry D4h was found to be the magic numbers cluster among them. The doped clusters Mg2Bn0/− were compared with the pure boron clusters Bn+20/− (n = 1–12) at the same level. The following results are obtained: as the number of boron atoms increases, the boron clusters doped with Mg atoms change from a two-dimensional planar or quasi-plane structure to a three-dimensional structure. The doped magnesium atoms are always positively charged in the convex capped position. And the doping of Mg atoms drives the overall stabilization of the boron clusters and makes the clusters more compact. There is a large amount of charge transfer between the Mg atom and the B atom, and the main orbitals involved are the S and p orbitals. There are strong interactions between the two atoms of boron and magnesium. Through the analysis of the bonding properties, it was found that the s-p hybridization mode between MgB is the main reason for the enhanced cluster stability.

The interaction mechanism of a novel polymer depressant with apatite and dolomite surface and its implication on flotation: Experimental tests and DFT calculation

The efficient removal of dolomite from phosphate ores is vital for the subsequent production of phosphate fertilizer. This work investigated the interaction mechanism of poly(sodium styrene sulfonate) (PSS) on apatite and dolomite surface and its implication on flotation through Micro-flotation, adsorption capacity, Zeta potential, SEM-EDS and density functional theory simulation. Flotation results proved that PSS was able to depress dolomite efficiently in broad pH range (8–12). Contact angle, Zeta potential, adsorption capacity and SEM-EDS measurement confirmed that PSS was more prone to adsorb on dolomite rather than that on apatite, which hindered sodium oleate (NaOL) to adsorb on dolomite but almost didn’t influence NaOL to interact with apatite surface. DFT calculations confirmed that the 2p orbital of oxygen atoms within sulfonate groups hybridized with 4s orbital of calcium and 3s orbital of magnesium atoms on dolomite surface to form OCa, OCa and OMg covalent bond, while PSS weakly physisorbed on apatite via electrical interaction, due to the significant difference in steric hindrance and active atom density. PSS exhibited good selectivity and environmental compatibility as dolomite depressant in the beneficiation of phosphate ores for sustainable production of phosphate fertilizer.