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Keywords = boronate complex

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17 pages, 4899 KB  
Article
Synthesis of Schiff Base–BF2 Complexes and Characterization of Their Excited State Dynamics
by Wenhui Zhu, Sandra Doria, Jianzhang Zhao, Gagik G. Gurzadyan and Mariangela Di Donato
Photochem 2026, 6(3), 36; https://doi.org/10.3390/photochem6030036 (registering DOI) - 9 Sep 2026
Abstract
The photophysics of a series of Schiff base–BF2 complexes was investigated using steady-state and femtosecond/nanosecond transient absorption spectroscopy, as well as theoretical computations. The native chromophore has a weak fluorescence and a short fluorescence lifetime (<30 ps, determined using the femtosecond fluorescence [...] Read more.
The photophysics of a series of Schiff base–BF2 complexes was investigated using steady-state and femtosecond/nanosecond transient absorption spectroscopy, as well as theoretical computations. The native chromophore has a weak fluorescence and a short fluorescence lifetime (<30 ps, determined using the femtosecond fluorescence upconversion method). No triplet state formation was observed for the compounds. Moreover, attachment of a heavy atom (iodine) to the phenyl ring did not enhance intersystem crossing (ISC), which was different from that observed with Bodipy analogs. We attribute the lack of ISC to the short lifetime of the S1 state, which decays rapidly through an efficient non-radiative decay channel, possibly geometry torsion. We also studied a Schiff base–BF2 complex with a twisted molecular structure, which showed a similarly short S1 state lifetime (<100 ps) and weak fluorescence. Using nanosecond transient absorption spectroscopy and intermolecular triplet–triplet energy transfer, we determined the triplet state lifetime of the Schiff base–BF2 complexes to be ca. 20 μs, which is much shorter than that of the Bodipy chromophore (100–800 μs). Based on femtosecond transient absorption spectra, we inferred that the decay of the emissive S1 state takes about 17–20 ps, leading to a non-emissive (dark) state, followed by the formation of a long-lived non-emissive singlet excited state. Theoretical computations demonstrated large spin–orbit coupling matrix elements (SOCMEs, up to 29 cm−1), but the fast non-radiative relaxation of the S1 state inhibits ISC. Thus, we propose that the fast internal conversion inhibits ISC of the iodo-containing molecules. A theoretical study of the zero-field splitting (ZFS) parameters of the triplet state indicates that the ZFS D parameter (45 cm−1) was overestimated for the iodo-containing compounds, whereas a reasonable value was obtained for the iodo-free compounds (ca. 0.03–0.06 cm−1). Full article
(This article belongs to the Special Issue Molecular Design, Synthesis and Application of Photosensitizers)
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49 pages, 3141 KB  
Review
Highly Oxygenated Biomolecules: Carbohydrates, Boron Complexes, and Their Biological Interfaces
by Valery M. Dembitsky and Alexander O. Terent’ev
Oxygen 2026, 6(3), 25; https://doi.org/10.3390/oxygen6030025 - 21 Aug 2026
Viewed by 182
Abstract
Carbohydrates are among the most highly oxygenated biomolecules in nature, possessing dense arrays of hydroxyl, ether, carbonyl, carboxylate, phosphate, and sulfate functionalities that govern hydration, hydrogen bonding, molecular recognition, and supramolecular organization. Their stereochemically organized oxygen-donor groups provide numerous appropriately oriented diol motifs [...] Read more.
Carbohydrates are among the most highly oxygenated biomolecules in nature, possessing dense arrays of hydroxyl, ether, carbonyl, carboxylate, phosphate, and sulfate functionalities that govern hydration, hydrogen bonding, molecular recognition, and supramolecular organization. Their stereochemically organized oxygen-donor groups provide numerous appropriately oriented diol motifs capable of selective and reversible coordination with boric acid and borate ions. This review examines the structural and physicochemical principles underlying carbohydrate–borate interactions, with particular emphasis on oxygen-rich biological interfaces. Pentoses, hexoses, oligosaccharides, polysaccharides, glycolipids, and membrane-associated glycoconjugates are considered to illustrate how hydroxyl-group orientation, molecular conformation, pH, hydration, and local environment determine borate recognition, complex stability, and dynamic assembly. Evidence from NMR and other spectroscopic methods, crystallography, mass spectrometry, calorimetry, and molecular simulations demonstrates that borate coordination follows common stereochemical and thermodynamic principles despite the remarkable structural diversity of carbohydrates. Biological examples include borate-mediated crosslinking in plant cell walls and interactions involving microbial carbohydrates, marine polysaccharides and glycoconjugates, photosynthetic membrane lipids, and cyanobacterial heterocyst glycolipids. Particular attention is given to distinguishing experimentally established borate complexes from membrane-associated interactions that remain proposed and require further characterization. Reversible borate crosslinking of oxygen-rich carbohydrate networks also provides the chemical basis for emerging applications in responsive hydrogels, biosensors, supramolecular assemblies, drug-delivery systems, and functional biomaterials. Collectively, the available evidence indicates that the spatial organization of oxygen donor atoms within carbohydrates provides the molecular basis for selective borate recognition, whereas boron can convert this functionality into reversible higher-order organization. This oxygen-centered perspective integrates coordination chemistry, glycobiology, membrane biology, and materials science into a unified framework for understanding carbohydrate–borate interactions in natural and engineered systems. Full article
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46 pages, 4362 KB  
Review
Low-Molecular-Weight Polyols as Key Factors in Sulfur- and Borate-Mediated Protomembrane Formation Before the RNA World
by Valery M. Dembitsky
Membranes 2026, 16(8), 272; https://doi.org/10.3390/membranes16080272 - 15 Aug 2026
Viewed by 290
Abstract
The emergence of biological membranes was a critical step in the origin of cellular life because compartmentalization enabled molecular concentration, selective interactions, and increasingly complex chemical evolution. While fatty acids are widely considered the primary constituents of primitive membranes, the origin of the [...] Read more.
The emergence of biological membranes was a critical step in the origin of cellular life because compartmentalization enabled molecular concentration, selective interactions, and increasingly complex chemical evolution. While fatty acids are widely considered the primary constituents of primitive membranes, the origin of the hydrophilic molecular scaffolds required for more stable amphiphilic systems remains unresolved. In this review, we propose a new conceptual framework in which low-molecular-weight polyols—including ethylene glycol, glycerol, tetritols, and related sugar alcohols—served as key molecular intermediates linking abiotic carbohydrate chemistry with the emergence of proto-lipids and protomembranes during a pre-phosphate stage of Earth history. Experimental and theoretical studies indicate that abiotic carbon chemistry can generate abundant polyols capable of esterification, etherification, hydrogen bonding, and reversible complexation with borate species. We hypothesize that borate-mediated stabilization of sugars and polyols promoted molecular selection, while sulfur-rich geochemical environments supplied chemically diverse amphiphiles and redox-active reaction networks. Building upon these observations, we propose a pH-dependent evolutionary model in which acidic sulfur-rich environments favored sulfo-protolipids, near-neutral environments promoted mixed polyol–fatty acid membranes, and alkaline boron-rich systems facilitated borate-associated amphiphiles and dynamic supramolecular membrane organization. We further suggest that borate-cross-linked polyol hydrogels acted as transitional soft-matter systems connecting molecular synthesis, membrane self-assembly, compartmentalization, and the emergence of proto-informational assemblies. Modern glycolipids, sulfolipids, archaeal ether lipids, and calditol-containing tetraether membranes are discussed as structural analogues, rather than direct evolutionary descendants, supporting the chemical versatility of polyol-based membrane architectures. Although the proposed evolutionary framework remains hypothetical, it integrates current knowledge from prebiotic organic chemistry, membrane biophysics, boron coordination chemistry, sulfur geochemistry, and systems chemistry into a unified and experimentally testable model for the evolution of proto-lipids, protomembranes, and early protocellular organization. Full article
(This article belongs to the Section Biological Membranes)
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19 pages, 5045 KB  
Article
Innovative Nanomaterials for Remediation of Heavy Metal-Contaminated Soil: Electro-Structural and Vibration Analysis by Quantum DFT Insights
by Fatemeh Mollaamin and Majid Monajjemi
Chemistry 2026, 8(8), 109; https://doi.org/10.3390/chemistry8080109 - 10 Aug 2026
Viewed by 483
Abstract
Geogenic processes and human activities are both major causes of soil pollution. Soils can get toxic transition metals from the materials they are formed from, but most pollution comes from industrial and farming activities. The presence of these transition metals in soil can [...] Read more.
Geogenic processes and human activities are both major causes of soil pollution. Soils can get toxic transition metals from the materials they are formed from, but most pollution comes from industrial and farming activities. The presence of these transition metals in soil can be shown through changes in chemical, biochemical, and microbial properties, as well as how plants react. This research aims to remove transition metals like chromium (Cr), manganese (Mn), iron (Fe), zinc (Zn), tungsten (W), and cadmium (Cd) from soil using a boron nitride (BN) nanocage. The electromagnetic and thermodynamic properties of these metals when trapped in BN were studied using materials modeling. The metals are captured through chemisorption. The research looked at how Cr, Mn, Fe, Zn, W, and Cd are trapped by BN to detect soil metal cations. BN was designed in the presence of these transition metals. The covalent characteristics of these complexes show similar energy levels and a view of the partial density of states between the p states of boron and nitrogen in BN and the d states of Cr, Mn, Fe, Zn, W, and Cd in B(X)N complexes. Also, nuclear magnetic resonance (NMR) analysis showed clear peaks around Cr, Mn, Fe, Zn, W, and Cd when they were trapped in BN during atomic detection and removal from soil, although there were some variations in chemical shielding for isotropic and anisotropic tensors. Based on these results, the ability of BN (as an atom sensor) to adsorb toxic metals, metalloids, and nonmetals is ordered as: Cd > Zn > Fe > Cr > Mn ≈ W. This article suggests that elements absorbed by BN could be used to develop and improve the optoelectronic properties of BN, helping to create photoelectric devices for soil cleaning. Full article
(This article belongs to the Section Chemistry at the Nanoscale)
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18 pages, 3448 KB  
Article
Optimizing Boron Content for Controlled Boride Formation in Fe–Ni–Cr–Cu–Si–B–C Alloy: A CALPHAD-Guided Experimental Study
by Farida Kapsalamova, Aliya Alimzhanova, Akmaral Rakhym, Gulnur Kanzhigit and Renat Beissenov
Metals 2026, 16(8), 889; https://doi.org/10.3390/met16080889 - 10 Aug 2026
Viewed by 476
Abstract
A combined CALPHAD-guided thermodynamic and experimental approach was employed to investigate the influence of boron on phase evolution and microstructural development in the Fe–Ni–Cr–Cu–Si–B–C alloy system. Thermodynamic calculations were performed using Thermo-Calc (FE13-2025b) and the TTFe thermodynamic database. Vertical phase-diagram sections and response [...] Read more.
A combined CALPHAD-guided thermodynamic and experimental approach was employed to investigate the influence of boron on phase evolution and microstructural development in the Fe–Ni–Cr–Cu–Si–B–C alloy system. Thermodynamic calculations were performed using Thermo-Calc (FE13-2025b) and the TTFe thermodynamic database. Vertical phase-diagram sections and response surface analysis were used to evaluate phase stability over the temperature range of 400–1500 °C and to identify temperature–composition domains favorable for the formation of strengthening phases. The calculations predicted complex multiphase equilibrium behavior involving boride-, carbide-, and silicide-containing phases. Within the investigated composition range, approximately 4 wt.% B provided a favorable balance between the metallic matrix and strengthening phases, while 638 °C corresponded to a thermodynamically favorable equilibrium phase constitution. Response surface analysis further demonstrated that temperature governs phase evolution, whereas boron primarily controls phase redistribution. The optimized alloy composition was characterized experimentally using scanning electron microscopy (SEM), wavelength dispersion spectroscopy (WDS), elemental mapping, and X-ray diffraction (XRD). The experimentally observed heterogeneous multiphase microstructure showed good agreement with the CALPHAD-predicted phase evolution at a qualitative level, demonstrating the usefulness of thermodynamic modeling for guiding alloy design. The proposed CALPHAD-guided workflow integrates thermodynamic modeling with targeted experimental characterization and provides a transferable framework for the accelerated design and optimization of complex Fe-based multicomponent alloys. Full article
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17 pages, 9794 KB  
Article
Thermodynamic Preference Between Deprotonation Pathways in Boronic Acid-Based Proteasome Inhibitors: Insights from a DFT Study
by Nikolay Toshev, Iliyan Dimitrov, Ovanes Muradyan, Vassil Delchev and Todor Dudev
Pharmaceuticals 2026, 19(8), 1251; https://doi.org/10.3390/ph19081251 - 8 Aug 2026
Viewed by 325
Abstract
Background/Objectives: Boronic acid-based proteasome inhibitors (BABPIs) including Bortezomib, Ixazomib, and Delanzomib are clinically relevant anticancer agents whose mechanism of action depends on direct interaction between the boronic acid warhead and the threonine residue at the first position (Thr1), leading to the formation [...] Read more.
Background/Objectives: Boronic acid-based proteasome inhibitors (BABPIs) including Bortezomib, Ixazomib, and Delanzomib are clinically relevant anticancer agents whose mechanism of action depends on direct interaction between the boronic acid warhead and the threonine residue at the first position (Thr1), leading to the formation of covalent tetrahedral complex. Although the formation of this complex is well studied, the subsequent behavior of the boronic acid warhead, particularly the possible formation of monoanionic boronate species through deprotonation of one of the two boronic hydroxyl groups, remains unexplored. Therefore, the present study addresses whether the formation of Thr1-OH and a monoanionic boronate species is thermodynamically favorable and which of the two hydroxyl groups is more favorable for deprotonation. Methods: Density Functional Theory (DFT) calculations at the B3LYP/6-311+G(d,p) level, combined with the Polarizable Continuum Model (PCM), were used to study two competing deprotonation pathways for the inhibitors and for a simplified warhead model. To mimic the proteasome environment, reactions were modeled in different polar media—diethyl ether (ε = 4), methanol (ε = 33), and water (ε = 78). Results: Our DFT calculations confirmed that the covalent tetrahedral complex could convert into Thr1-OH and a monoanionic boronate species, representing the deprotonation of one of the boronic hydroxyl groups. Deprotonation via pathway 1 is more favorable than deprotonation via pathway 2 for all inhibitors, especially in polar solvents. Bortezomib demonstrated a strong preference for -OH1 deprotonation with ∆∆G ≈ −7 kcal·mol−1. In contrast, Ixazomib, Delanzomib, and the simplified warhead model showed smaller ∆∆G values (≈−2 kcal·mol−1), within the method’s uncertainty (±2 kcal·mol−1), suggesting both deprotonation modes under physiological conditions. Conclusions: These results provide comparative thermodynamic insight into the deprotonation behavior of BABPIs, suggesting that the two hydroxyl groups are not equivalent during deprotonation. This finding offers a physicochemical framework that may support the rational design of next-generation BABPIs. Full article
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32 pages, 11550 KB  
Article
A Thermal-Environment-Informed Evaluation Index for Particle Combustion in Solid Rocket Ramjet Afterburner
by Delei Shi, Lin Sun, Futing Bao, Xiaoyu Lei and Chenmin Gao
Aerospace 2026, 13(8), 697; https://doi.org/10.3390/aerospace13080697 - 31 Jul 2026
Viewed by 336
Abstract
Efficient particle combustion is crucial for improving the overall performance of solid rocket ramjets. However, particle combustion is jointly constrained by multiple environmental factors, such as oxidizer supply, gas–solid transport, and residence characteristics, which are difficult to characterize using conventional mixing-ratio-based evaluations fully. [...] Read more.
Efficient particle combustion is crucial for improving the overall performance of solid rocket ramjets. However, particle combustion is jointly constrained by multiple environmental factors, such as oxidizer supply, gas–solid transport, and residence characteristics, which are difficult to characterize using conventional mixing-ratio-based evaluations fully. To provide a diagnostic evaluation of particle combustion potential under complex flow-field organization during design and optimization, a thermal-environment-informed particle combustion index ITPCI is proposed in this study. The index incorporates oxidizer availability, particle–oxidizer transport, residence-related effects, gas thermal environment, and particle thermal reactivity, and is intended to indicate regions where particle oxidizer-consumption capability can be retained under favorable thermochemical conditions. The reacting duct case shows that ITPCI provides a combustion-potential-oriented description of particle consumption. In the canonical jet-interaction flow, the conventional mixing degree mainly identifies shear-layer-dominated transport boundaries, while ITPCI emphasizes the regions with particle-consumption potential. Application to the afterburner further shows that particle combustion potential is governed by the match among oxidizer supply, particle transport, residence condition, and thermal environment. The head region has favorable thermal and residence conditions but remains oxygen-lean, whereas the downstream regions receive additional oxidizer but are constrained by nonuniform oxygen–particle distributions, thermal environment, and residence time. In the pulsed-jet cases, the variation of ITPCI provides a diagnostic interpretation of changes in particle source-term distribution. For the present configuration, upstream pulsed actuation mainly enhances the head-region response, and the selected case increases the full-domain gaseous-product source term associated with boron combustion by 2.96%. These results indicate that the proposed index can support combustion-potential diagnosis and flow-control assessment in solid rocket ramjet afterburners. Full article
(This article belongs to the Section Astronautics & Space Science)
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29 pages, 8272 KB  
Article
Synthesis, Luminescent Properties and Photo-Oxidation Catalysis of Brominated Boron Pyridine Hydrazone Fluorenones and Their σ-Platinum Complexes
by Lea Bauer, David J. Spänkuch, Michael Linseis and Rainer F. Winter
Inorganics 2026, 14(8), 197; https://doi.org/10.3390/inorganics14080197 - 24 Jul 2026
Viewed by 409
Abstract
Three new isomeric pyridone fluorenone hydrazone-based boron complexes, 3-BrN to 5-BrN, with bromination at the 3-, 4-, or 5-position of the pyridone ring and their corresponding σ-platinum complexes trans-Pt(PEt3)2(n-N)X (n = 3, 4, or 5; X = [...] Read more.
Three new isomeric pyridone fluorenone hydrazone-based boron complexes, 3-BrN to 5-BrN, with bromination at the 3-, 4-, or 5-position of the pyridone ring and their corresponding σ-platinum complexes trans-Pt(PEt3)2(n-N)X (n = 3, 4, or 5; X = Cl, Br, I) resulting from oxidative addition of the aryl-Br bond of n-BrN to Pt(PEt3)2 and, for X = Cl, I, subsequent substitution of the halogenide ligand, were synthesized and characterized by NMR, UV–Vis absorption, and photoluminescence spectroscopy. The molecular structures of dyes 3-BrN to 5-BrN and of seven complexes, including the cis-isomer of the bromo complex resulting from 3-BrN, were established by single X-ray diffraction. The nearly orthogonal orientation of the Pt coordination plane with respect to the plane of the dye ligand limits intermolecular π-stacking interactions in the crystalline state while giving rise to extensive C-H···halogen and C-H···π interactions, resulting in intricate packing patterns. Electronic absorption spectra of dyes 3-BrN to 5-BrN show a prominent HOMO-LUMO absorption band at ca. 520 nm, which is red-shifted and intensifies on platination. All compounds are dual fluorescence and phosphorescence emitters in the range of 520 to 670 nm, or at ca. 1000 nm, both at room temperature and at 77 K. The population of an excited triplet state and their photostability even towards continuous light irradiation renders these compounds efficient sensitizers for singlet oxygen generation and catalysts for the photo-oxidation of triphenylphosphine. Full article
(This article belongs to the Special Issue State-of-the-Art Inorganic Chemistry in Germany, 2nd Edition)
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36 pages, 21044 KB  
Review
Covalently Modified Polyoxometalate Organic–Inorganic Hybrids for Visible-Light Photoactivation
by Yunliang Yu, Rui Bi, Weixian Wang, Xiaoxia Wang, Yuliang Liu and Chao Zou
Inorganics 2026, 14(7), 192; https://doi.org/10.3390/inorganics14070192 - 19 Jul 2026
Viewed by 681
Abstract
Polyoxometalates (POMs) are anionic metal oxide nanoclusters with rich redox chemistry, making them promising candidates for photocatalysis. However, their strong UV-light absorption and rapid charge recombination hinder visible-light applications. This review focuses on covalent organic–inorganic hybridization as a modular strategy to engineer POMs [...] Read more.
Polyoxometalates (POMs) are anionic metal oxide nanoclusters with rich redox chemistry, making them promising candidates for photocatalysis. However, their strong UV-light absorption and rapid charge recombination hinder visible-light applications. This review focuses on covalent organic–inorganic hybridization as a modular strategy to engineer POMs for visible-light photoactivation. By grafting chromophoric ligands, metalloporphyrins, or organometallic complexes onto POM surfaces via robust covalent bonds (e.g., Si–C, P–C, C–C), two key photochemical pathways are enabled: (i) direct visible-light excitation of organic sensitizers followed by intramolecular charge transfer to/from POMs and (ii) modified ligand-to-metal charge transfer (LMCT) transitions in POMs via ligand-induced electronic structure perturbation. We discuss how organic ligands regulate POM frontier orbital energy levels (HOMO/LUMO), redox potentials, and photoresponse range, supported by experimental and density-functional theory (DFT) studies. We also review hybrid systems with organic photosensitizers (e.g., pyrene, boron dipyrromethene (BODIPY)), metalloporphyrins, and organometallic complexes (e.g., Ru(II), Ir(III)), emphasizing structure–activity relationships in electron-transfer efficiency, charge-separation lifetime, and catalytic performance (e.g., hydrogen evolution, selective oxidation). Finally, we outline current challenges and prospects for designing multifunctional POM hybrids with tailored visible-light photocatalytic properties. Full article
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12 pages, 1163 KB  
Article
Metallothermic Production of Chromium–Nickel Ferroalloy and Viscosity of the Resulting Slags
by Ruslan Sultangaziyev, Alexey Orlov, Kalamkas Titosheva and Astra Makasheva
Metals 2026, 16(7), 775; https://doi.org/10.3390/met16070775 - 11 Jul 2026
Viewed by 369
Abstract
This article presents the results of experimental studies on the production of chromium–nickel ferroalloy from the nickel ore of the Batamshinskoye deposit by the metallothermic method. Boron-containing ferrosilicochromium was used as a complex reducing agent and alloying material, and lime was applied as [...] Read more.
This article presents the results of experimental studies on the production of chromium–nickel ferroalloy from the nickel ore of the Batamshinskoye deposit by the metallothermic method. Boron-containing ferrosilicochromium was used as a complex reducing agent and alloying material, and lime was applied as a fluxing component to control the composition and basicity of the slag. Laboratory smeltings were carried out in a Tammann furnace and an induction furnace at a temperature of 1630–1650 °C, producing slags with different basicities—0.4, 0.5, and 0.6. It was established that the use of boron-containing ferrosilicochromium provides the effective reduction of nickel, chromium, and iron oxides with the formation of a complex ferroalloy containing Fe, Cr, Ni, Si, and B. It is shown that an increase in slag basicity contributes to a decrease in its viscosity, a reduction in the content of chromium oxides in the slag, and an improvement in the conditions for the separation of the metal and slag phases. The crystallization temperatures of the slags, which decrease from 1410 to 1335 °C with an increase in basicity from 0.4 to 0.6, were determined by the method of semi-logarithmic processing of viscosity polytherms. The slag basicity range of 0.5–0.6 is recognized as optimal for the process. Full article
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17 pages, 4851 KB  
Article
Enhanced Fracture Toughness in Diamond/B4C Composites Through Residual-Stress-Induced Crack Deflection
by Yiyang Zhan, Zhengxin Li, Mu Qiao, Yujie Wang, Xuefei Fang, Yakun Lan, Guangli Zhu, Yuanmin Zou, Wenjie Yang and Chenyang Shi
Materials 2026, 19(13), 2708; https://doi.org/10.3390/ma19132708 - 24 Jun 2026
Viewed by 381
Abstract
Boron carbide (B4C) holds significant application potential in the fields of lightweight, high-hardness protective and high-end wear-resistant components due to its low density and exceptional hardness. However, its strong covalent bonding leads to low sintering activity and weak grain-boundary cohesion, resulting [...] Read more.
Boron carbide (B4C) holds significant application potential in the fields of lightweight, high-hardness protective and high-end wear-resistant components due to its low density and exceptional hardness. However, its strong covalent bonding leads to low sintering activity and weak grain-boundary cohesion, resulting in high brittleness and crack sensitivity. These inherent properties make it difficult to achieve simultaneous full densification and toughness enhancement, severely limiting the reliability of B4C under complex service conditions. Although diamond is an attractive reinforcement because of its high elastic modulus and low coefficient of thermal expansion, the simultaneous realization of densification, graphitization suppression, and fracture-resistance improvement in diamond/B4C composites remains insufficiently understood. In this study, diamond particles were introduced into the B4C matrix and consolidated by rapid high-temperature and high-pressure (HTHP) sintering to synergistically promote densification and fracture toughening. The effects of sintering temperature and diamond content on phase evolution, densification, microstructure, and mechanical properties were systematically investigated, and the associated toughening mechanisms were analyzed. The results indicate that the hardness generally increases with rising sintering temperature and diamond content. The primary toughening mechanisms are identified as the pull-out of diamond particles and crack deflection induced by residual stresses generated during the cooling process. Although the composite with 20 wt.% diamond exhibits higher hardness, it also experiences severe macroscopic cracking. The composite with 10 wt.% diamond sintered at 1450 °C under 5.3 GPa for 4 min exhibits the optimal balance of properties, achieving a relative density of 98.85%, a Vickers hardness of 40.72 GPa, and a fracture toughness of 9.20 MPa·m1/2. This work confirms the effectiveness of combining diamond reinforcement with HTHP sintering in simultaneously achieving densification and toughening of B4C-based composites, providing a new pathway for developing high-performance lightweight protective ceramics. Full article
(This article belongs to the Special Issue Advances in Low-Carbon and Zero-Carbon Metallurgical Technologies)
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24 pages, 9473 KB  
Article
Durable Superhydrophobic F-SiO2@h-BN/PAE Composite Coating Fabricated via Scalable Facile Method
by Hui Liu, Yu Zhu, Xin Cheng, Zhenhua Dong and Qiang Liu
Coatings 2026, 16(6), 711; https://doi.org/10.3390/coatings16060711 - 15 Jun 2026
Cited by 1 | Viewed by 539
Abstract
Superhydrophobic materials offer promising prospects for utilization in energy, environmental, and related fields. However, their long-term stability in natural environments is constrained by factors such as mechanical wear and aging, which compromise their practical effectiveness and service life. While notable experimental results have [...] Read more.
Superhydrophobic materials offer promising prospects for utilization in energy, environmental, and related fields. However, their long-term stability in natural environments is constrained by factors such as mechanical wear and aging, which compromise their practical effectiveness and service life. While notable experimental results have been obtained worldwide, scalable application remains limited by the complexity of the requisite fabrication processes. In this study, a durable superhydrophobic coating was developed through a facile one-step process, utilizing a polyaspartic ester (PAE) matrix reinforced with a composite of self-synthesized fluorinated silica (F-SiO2) and hexagonal boron nitride (h-BN) micro-/nano-structures. This strategy effectively enhanced filler dispersion within the resin matrix and promoted hydrophobicity, yielding a stable superhydrophobic surface. The resulting coating exhibits significant potential for scalable application. The optimized coating demonstrated a water contact angle of 161.2° and a roll-off angle of 7.6°, showing excellent repellency to water, corrosive liquids, and fluids across a wide pH range, along with remarkable self-cleaning performance. Benefiting from the synergistic enhancement of h-BN and F-SiO2, the coating also exhibits superior mechanical durability, maintaining a contact angle of 144.4° after 1000 abrasion cycles. Furthermore, in low-temperature anti-icing tests, the coating significantly delayed ice formation on its surface. Notably, after 1000 h of UV aging tests, the F-SiO2@BN/PAE coating retained its intact superhydrophobic structure, with the water contact angle only slightly decreasing from 159.6° to 152.8°, still within an excellent superhydrophobic state, demonstrating outstanding weather resistance. By integrating surface functionalization with mechanical reliability through a facile one-step fabrication process, this study provides significant insights for the large-scale application of hydrophobic materials in the energy and transportation sectors. Full article
(This article belongs to the Special Issue Recent Progress on Functional Films and Surface Science)
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17 pages, 10449 KB  
Article
Adsorption of Naphthalene in Liquid Paraffin by Using Boron-Containing Nanoclay Derived from the Boron Enrichment Process Waste
by Tolga Duran and Necip Atar
Micro 2026, 6(2), 44; https://doi.org/10.3390/micro6020044 - 12 Jun 2026
Viewed by 549
Abstract
The adsorption of aromatic hydrocarbons from liquid paraffin is essential because of their harmful nature, long-lasting presence, and detrimental effects on the quality of the product. In this study, we investigated the adsorption of naphthalene from liquid paraffin by using a nanoclay-based adsorbent [...] Read more.
The adsorption of aromatic hydrocarbons from liquid paraffin is essential because of their harmful nature, long-lasting presence, and detrimental effects on the quality of the product. In this study, we investigated the adsorption of naphthalene from liquid paraffin by using a nanoclay-based adsorbent prepared from boron enrichment process waste. The characterization of the prepared adsorbent was carried out by using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), X-ray Photoelectron Spectroscopy (XPS) and N2 adsorption–desorption techniques, which confirmed the development of a layered nanostructure containing boron that possesses a porous and high-surface-area format appropriate for the adsorption. The hydrothermal treatment significantly increased the BET surface area from 35.42 to 112.15 m2/g, indicating the successful formation of a porous nanostructure. The kinetic and isotherm parameters of the adsorption process were calculated from experimental data. The adsorption of naphthalene followed pseudo-second-order kinetics and the isotherm fit well to the Langmuir model. Adsorption experiments revealed that the optimum adsorption performance was achieved at pH 4.0, and equilibrium was reached within 90 min. The adsorption kinetics were best described by the pseudo-second-order model (R2 > 0.99), while the equilibrium data showed excellent agreement with the Langmuir isotherm model (R2 = 0.995), suggesting monolayer adsorption. The maximum adsorption capacity of BNC was determined as 365.20 mg/g, which was more than twice that of the raw BEW (247.59 mg/g). Thermodynamic analysis indicated that the adsorption process was spontaneous at lower temperatures and exothermic, with a ΔH° value of −15.42 kJ/mol for BNC. The results suggest that the adsorption occurs through a multi-step process, beginning with external film diffusion, followed by pore diffusion and surface interaction. Based on the kinetic, isotherm, and spectroscopic data, a supramolecular adsorption mechanism is suggested, which encompasses π-π interactions, van der Waals forces, and surface complexation between naphthalene and the nanoclay structure. These results indicate that boron enrichment process waste-derived nanoclay is a sustainable, economical, and efficient adsorbent for removing naphthalene from liquid paraffin. Full article
(This article belongs to the Section Microscale Materials Science)
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32 pages, 2227 KB  
Review
Potential Activity of Non-Platinum Metal-Based Organic Complexes Against Different Cancer Cell Types
by Dobrina Tsvetkova, Stefka Ivanova and Danka Obreshkova
Pharmaceuticals 2026, 19(6), 925; https://doi.org/10.3390/ph19060925 - 12 Jun 2026
Cited by 1 | Viewed by 865
Abstract
The disadvantages of Cisplatin in anticancer treatment are connected to its poor selectivity, resistance developed of cancers to the drug, and its toxicity against normal organs. An important strategy in anticancer treatment is the synthesis and clinical investigation of non-platinum metal complexes with [...] Read more.
The disadvantages of Cisplatin in anticancer treatment are connected to its poor selectivity, resistance developed of cancers to the drug, and its toxicity against normal organs. An important strategy in anticancer treatment is the synthesis and clinical investigation of non-platinum metal complexes with superior anticancer activity and improved selectivity compared to Cisplatin, combined with lower toxicity, fewer side effects and decreased resistance of cancer to the drug. In the current study, we aim to summarize the potential of important non-platinum metal-based organic compounds as therapeutic agents against different cancer cell types. The review covers the general principles of chemotherapy. A literature analysis shows that organic complexes of the metalloids arsenic (As), boron (B), antimony (Sb), and selenium (Se), and of metals, such as Ag, Au, Co, Cu, Fe, Mn, Mo, Ni, Zn, Ce, Ga, Gd, Ir, Os, Pd, Re, Rh, Ru, Ti, and V, have been investigated for potential applications in cancer therapy. This is due to their antiproliferative effects against different cancer types: lung [Cd(II), Co(II), Cu(II), Ni(II), Mn(II), Ru(II), Zn(II)]; breast [Ag(I), Cu(I), Cu(II), Ir(III), Ni(II), Mn(II),. Rh(III), Ru(II)]; gastric [Cu(II), Cu(II)-La(III)]; colon [Ag(I), Cu(II), Ir(III), Pd(II), Rh(III), Ru(II), vanadium(V)]; colorectal [Ag(I), Co(II), Cu(II), Zn(II)]; liver [Ag(I), Co(II), Cu(II), Gd(III), vanadium(V)]; pancreatic [vanadium(IV)]; bladder [Ag(I), Cu(II), Ru(II)]; cervical [Ag(I), Au(I), Cu(I), Cu(II), Fe(II), Ir(III), Rh(III), Ru(II)]; testicular [vanadium(IV)]; prostate [Cu(II), Pd(II), Zn(II)]; leukemia [Ag(I), Co(II), Cu(II), Pd(II), Zn(II)]; sarcoma [Co(II), Ni(II), Zn(II)]; mesothelioma [Cu(II)]; neuroblastoma [Cu(II)]; glioma [Cu(II)]; and melanoma [Au(I), Cu(II), Pd(II), Ru(II)]. The main goals for increasing anticancer metal-based complexes include increasing anticancer activity and selectivity, reducing toxicity, and avoiding cancer cell resistance. Compared to Cisplatin, organocomplexes of copper, ferrocene, and ruthenium are more active. Ruthenium and copper complexes, in particular, are also more selective. Notably, ruthenium and ferrocene derivatives are less toxic than Cisplatin. Lastly, cancers appear to exhibit less resistance against copper, gold, ruthenium, palladium, and ferrocene complexes. Full article
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Article
Improvement in Thermal Conductivity in UV-Curable Polymer Composites via h-BN and Graphite Hybrid Fillers for DLP 3D Printing
by Marco Fortunato, Cristina Stifani, Alessandra Fava, Maria Rita Mancini, Ugo De Angelis, Giuseppe De Santis, Giuseppe Corallo and Daniele Mirabile Gattia
Materials 2026, 19(11), 2304; https://doi.org/10.3390/ma19112304 - 29 May 2026
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Abstract
UV-curable polymer composites are attractive for fabricating complex components by digital light processing (DLP), but improving thermal transport while preserving printability remains challenging at high filler loadings. In this work, solvent-free UV-curable formulations filled with hexagonal boron nitride (h-BN) and h-BN/graphite hybrids were [...] Read more.
UV-curable polymer composites are attractive for fabricating complex components by digital light processing (DLP), but improving thermal transport while preserving printability remains challenging at high filler loadings. In this work, solvent-free UV-curable formulations filled with hexagonal boron nitride (h-BN) and h-BN/graphite hybrids were developed for DLP 3D printing using commercially available equipment. The effects of filler composition on viscosity, printability, microstructure, through-thickness thermal conductivity, electrical conductivity, and tensile behavior were investigated. Viscosity increased markedly with filler loading, yet reliable DLP printing was achieved up to 40 wt% h-BN through composition-dependent adjustment of build parameters. Thermal analysis supported negligible macroscopic sedimentation during printing, while optical and FE-SEM observations revealed generally uniform platelet dispersion, visible 50 μm layer stratification, and limited phase segregation in the hybrid systems. The through-thickness thermal conductivity increased from ~0.25 W/mK for the neat resin to ~1.95 W/mK at 40 wt% h-BN. At a fixed 20 wt% h-BN, graphite addition led to a smaller increase in thermal conductivity, up to ~1.16 W/mK, while increasing electrical conductivity and reducing mechanical performance. A phenomenological percolation-type model captured the thermal-conductivity trend of the h-BN series. Overall, h-BN-rich formulations provided the most effective route to enhance thermal conductivity while preserving electrical insulation. Full article
(This article belongs to the Special Issue Advanced Materials and Processing Technologies, 2nd Edition)
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