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Search Results (1,089)

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Keywords = C–O bond formation

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20 pages, 10909 KiB  
Article
Preparation Optimization and Antioxidant Properties of the β-Glucan and Ferulic Acid/Quercetin Complex from Highland Barley (Hordeum vulgare var. nudum)
by Yuanhang Ren, Yanting Yang, Mi Jiang, Wentao Gu, Yanan Cao, Liang Zou and Lianxin Peng
Foods 2025, 14(15), 2712; https://doi.org/10.3390/foods14152712 - 1 Aug 2025
Viewed by 179
Abstract
Polysaccharides and phenols are commonly co-localized in various plant-derived foods, including highland barley (Hordeum vulgare L. var. nudum Hook. f.). The interactions between these compounds can influence multiple characteristics of food products, including their physicochemical properties and functional performance, such as bioavailability, [...] Read more.
Polysaccharides and phenols are commonly co-localized in various plant-derived foods, including highland barley (Hordeum vulgare L. var. nudum Hook. f.). The interactions between these compounds can influence multiple characteristics of food products, including their physicochemical properties and functional performance, such as bioavailability, stability, and digestibility, which may support promising application of the phenol and polysaccharide complex in health food industry. In this study, two complexes with potential existence in highland barley, such as β-glucan-ferulic acid (GF) and β-glucan-quercetin (GQ), were prepared using the equilibrium dialysis method in vitro. FTIR and SEM results showed that ferulic acid and quercetin formed complexes with β-glucan separately, with covalent and non-covalent bonds and a dense morphological structure. The pH value, reaction temperature, and concentration of phosphate buffer solution (PBS) were confirmed to have an impact on the formation and yield of the complex. Through the test of the response surface, it was found that the optimum conditions for GF and (GQ) preparations were a pH of 6.5 (6), a PBS buffer concentration of 0.08 mol/L (0.3 mol/L), and a temperature of 8 °C (20 °C). Through in vitro assays, GF and GQ were found to possess good antioxidant activity, with a greater scavenging effect of DPPH, ABTS, and hydroxyl radical than the individual phenolic acids and glucans, as well as their physical mixtures. Taking GF as an example, the DPPH radical scavenging capacity ranked as GF (71.74%) > ferulic acid (49.50%) > PGF (44.43%) > β-glucan (43.84%). Similar trends were observed for ABTS radical scavenging (GF: 54.56%; ferulic acid: 44.37%; PGF: 44.95%; β-glucan: 36.42%) and hydroxyl radical elimination (GF: 39.16%; ferulic acid: 33.06%; PGF: 35.51%; β-glucan: 35.47%). In conclusion, the convenient preparation method and excellent antioxidant effect of the phenol–polysaccharide complexes from highland barley provide new opportunities for industrial-scale production, development, and design of healthy food based on these complexes. Full article
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19 pages, 4569 KiB  
Article
Tailored Magnetic Fe3O4-Based Core–Shell Nanoparticles Coated with TiO2 and SiO2 via Co-Precipitation: Structure–Property Correlation for Medical Imaging Applications
by Elena Emanuela Herbei, Daniela Laura Buruiana, Alina Crina Muresan, Viorica Ghisman, Nicoleta Lucica Bogatu, Vasile Basliu, Claudiu-Ionut Vasile and Lucian Barbu-Tudoran
Diagnostics 2025, 15(15), 1912; https://doi.org/10.3390/diagnostics15151912 - 30 Jul 2025
Viewed by 183
Abstract
Background/Objectives: Magnetic nanoparticles, particularly iron oxide-based materials, such as magnetite (Fe3O4), have gained significant attention as contrast agents in medical imaging This study aimsto syntheze and characterize Fe3O4-based core–shell nanostructures, including Fe3O4 [...] Read more.
Background/Objectives: Magnetic nanoparticles, particularly iron oxide-based materials, such as magnetite (Fe3O4), have gained significant attention as contrast agents in medical imaging This study aimsto syntheze and characterize Fe3O4-based core–shell nanostructures, including Fe3O4@TiO2 and Fe3O4@SiO2, and to evaluate their potential as tunable contrast agents for diagnostic imaging. Methods: Fe3O4, Fe3O4@TiO2, and Fe3O4@SiO2 nanoparticles were synthesized via co-precipitation at varying temperatures from iron salt precursors. Fourier transform infrared spectroscopy (FTIR) was used to confirm the presence of Fe–O bonds, while X-ray diffraction (XRD) was employed to determine the crystalline phases and estimate average crystallite sizes. Morphological analysis and particle size distribution were assessed by scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX) and transmission electron microscopy (TEM). Magnetic properties were investigated using vibrating sample magnetometry (VSM). Results: FTIR spectra exhibited characteristic Fe–O vibrations at 543 cm−1 and 555 cm−1, indicating the formation of magnetite. XRD patterns confirmed a dominant cubic magnetite phase, with the presence of rutile TiO2 and stishovite SiO2 in the coated samples. The average crystallite sizes ranged from 24 to 95 nm. SEM and TEM analyses revealed particle sizes between 5 and 150 nm with well-defined core–shell morphologies. VSM measurements showed saturation magnetization (Ms) values ranging from 40 to 70 emu/g, depending on the synthesis temperature and shell composition. The highest Ms value was obtained for uncoated Fe3O4 synthesized at 94 °C. Conclusions: The synthesized Fe3O4-based core–shell nanomaterials exhibit desirable structural, morphological, and magnetic properties for use as contrast agents. Their tunable magnetic response and nanoscale dimensions make them promising candidates for advanced diagnostic imaging applications. Full article
(This article belongs to the Section Medical Imaging and Theranostics)
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16 pages, 2131 KiB  
Article
A Comparative Study on ZrO2- and MgO-Based Sulfonic Acid Materials for the Reactive Adsorption of o-Xylene
by Hongmei Wang, Xiaoxu Zhang, Ziqi Shen and Zichuan Ma
Molecules 2025, 30(15), 3171; https://doi.org/10.3390/molecules30153171 - 29 Jul 2025
Viewed by 223
Abstract
The recovery and abatement of volatile organic compounds (VOCs) have received increasing attention due to their significant environmental and health impacts. Supported sulfonic acid materials have shown great potential in converting aromatic VOCs into their non-volatile derivatives through reactive adsorption. However, the anchoring [...] Read more.
The recovery and abatement of volatile organic compounds (VOCs) have received increasing attention due to their significant environmental and health impacts. Supported sulfonic acid materials have shown great potential in converting aromatic VOCs into their non-volatile derivatives through reactive adsorption. However, the anchoring state of sulfonic acid groups, which is closely related to the properties of the support, greatly affects their performance. In this study, two supported sulfonic acid materials, SZO and SMO, were prepared by treating ZrO2 and MgO with chlorosulfonic acid, respectively, to investigate the influence of the support properties on the anchoring state of sulfonic acid groups and their reactive adsorption performance for o-xylene. The supports, adsorbents, and adsorption products were extensively characterized, and the reactivity of SZO and SMO towards o-xylene was systematically compared. The results showed that sulfonic acid groups are anchored on the ZrO2 surface through covalent bonding, forming positively charged sulfonic acid sites ([O1.5Zr-O]δ−-SO3Hδ+) with a loading of 3.6 mmol/g. As a result, SZO exhibited excellent removal efficiency (≥91.3%) and high breakthrough adsorption capacity (ranging from 38.59 to 82.07 mg/g) for o-xylene in the temperature range of 130 –150 °C. In contrast, sulfonic acid groups are anchored on the MgO surface via ion-paired bonding, leading to the formation of negatively charged sulfonic acid sites ([O0.5Mg]+:OSO3H), which prevents their participation in the electrophilic sulfonation reaction with o-xylene molecules. This work provides new insights into tuning and enhancing the performance of supported sulfonic acid materials for the resource-oriented treatment of aromatic VOCs. Full article
(This article belongs to the Special Issue Applied Chemistry in Asia)
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17 pages, 1308 KiB  
Article
Dual-Functional AgNPs/Magnetic Coal Fly Ash Composite for Wastewater Disinfection and Azo Dye Removal
by Lei Gong, Jiaxin Li, Rui Jin, Menghao Li, Jiajie Peng and Jie Zhu
Molecules 2025, 30(15), 3155; https://doi.org/10.3390/molecules30153155 - 28 Jul 2025
Viewed by 281
Abstract
In this study, we report the development of a novel magnetized coal fly ash-supported nano-silver composite (AgNPs/MCFA) for dual-functional applications in wastewater treatment: the efficient degradation of methyl orange (MO) dye and broad-spectrum antibacterial activity. The composite was synthesized via a facile impregnation–reduction–sintering [...] Read more.
In this study, we report the development of a novel magnetized coal fly ash-supported nano-silver composite (AgNPs/MCFA) for dual-functional applications in wastewater treatment: the efficient degradation of methyl orange (MO) dye and broad-spectrum antibacterial activity. The composite was synthesized via a facile impregnation–reduction–sintering route, utilizing sodium citrate as both a reducing and stabilizing agent. The AgNPs/MCFA composite was systematically characterized through multiple analytical techniques, including Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and vibrating sample magnetometry (VSM). The results confirmed the uniform dispersion of AgNPs (average size: 13.97 nm) on the MCFA matrix, where the formation of chemical bonds (Ag-O-Si) contributed to the enhanced stability of the material. Under optimized conditions (0.5 g·L−1 AgNO3, 250 °C sintering temperature, and 2 h sintering time), AgNPs/MCFA exhibited an exceptional catalytic performance, achieving 99.89% MO degradation within 15 min (pseudo-first-order rate constant ka = 0.3133 min−1) in the presence of NaBH4. The composite also demonstrated potent antibacterial efficacy against Escherichia coli (MIC = 0.5 mg·mL−1) and Staphylococcus aureus (MIC = 2 mg·mL−1), attributed to membrane disruption, intracellular content leakage, and reactive oxygen species generation. Remarkably, AgNPs/MCFA retained >90% catalytic and antibacterial efficiency after five reuse cycles, enabled by its magnetic recoverability. By repurposing industrial waste (coal fly ash) as a low-cost carrier, this work provides a sustainable strategy to mitigate nanoparticle aggregation and environmental risks while enhancing multifunctional performance in water remediation. Full article
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17 pages, 4225 KiB  
Article
Comparative Nitrene-Transfer Chemistry to Olefins Mediated by First-Row Transition Metal Catalysts Supported by a Pyridinophane Macrocycle with N4 Ligation
by Himanshu Bhatia, Lillian P. Adams, Ingrid Cordsiemon, Suraj Kumar Sahoo, Amitava Choudhury, Thomas R. Cundari and Pericles Stavropoulos
Molecules 2025, 30(15), 3097; https://doi.org/10.3390/molecules30153097 - 24 Jul 2025
Viewed by 410
Abstract
A 12-membered pyridinophane scaffold containing two pyridine and two tertiary amine residues is examined as a prototype ligand (tBuN4) for supporting nitrene transfer to olefins. The known [(tBuN4)MII(MeCN)2]2+ (M = Mn, Fe, Co, and [...] Read more.
A 12-membered pyridinophane scaffold containing two pyridine and two tertiary amine residues is examined as a prototype ligand (tBuN4) for supporting nitrene transfer to olefins. The known [(tBuN4)MII(MeCN)2]2+ (M = Mn, Fe, Co, and Ni) and [(tBuN4)CuI(MeCN)]+ cations are synthesized with the hexafluorophosphate counteranion. The aziridination of para-substituted styrenes with PhI=NTs (Ts = tosyl) in various solvents proved to be high yielding for the Cu(I) and Cu(II) reagents, in contrast to the modest efficacy of all other metals. For α-substituted styrenes, aziridination is accompanied by products of aziridine ring opening, especially in chlorinated solvents. Bulkier β-substituted styrenes reduce product yields, largely for the Cu(II) reagent. Aromatic olefins are more reactive than aliphatic congeners by a significant margin. Mechanistic studies (Hammett plots, KIE, and stereochemical scrambling) suggest that both copper reagents operate via sequential formation of two N–C bonds during the aziridination of styrene, but with differential mechanistic parameters, pointing towards two distinct catalytic manifolds. Computational studies indicate that the putative copper nitrenes derived from Cu(I) and Cu(II) are each associated with closely spaced dual spin states, featuring high spin densities on the nitrene N atom. The computed electrophilicity of the Cu(I)-derived nitrene reflects the faster operation of the Cu(I) manifold. Full article
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16 pages, 1188 KiB  
Article
Preparation and Performance Evaluation of Modified Amino-Silicone Supercritical CO2 Viscosity Enhancer for Shale Oil and Gas Reservoir Development
by Rongguo Yang, Lei Tang, Xuecheng Zheng, Yuanqian Zhu, Chuanjiang Zheng, Guoyu Liu and Nanjun Lai
Processes 2025, 13(8), 2337; https://doi.org/10.3390/pr13082337 - 23 Jul 2025
Viewed by 344
Abstract
Against the backdrop of global energy transition and strict environmental regulations, supercritical carbon dioxide (scCO2) fracturing and oil displacement technologies have emerged as pivotal green approaches in shale gas exploitation, offering the dual advantages of zero water consumption and carbon sequestration. [...] Read more.
Against the backdrop of global energy transition and strict environmental regulations, supercritical carbon dioxide (scCO2) fracturing and oil displacement technologies have emerged as pivotal green approaches in shale gas exploitation, offering the dual advantages of zero water consumption and carbon sequestration. However, the inherent low viscosity of scCO2 severely restricts its sand-carrying capacity, fracture propagation efficiency, and oil recovery rate, necessitating the urgent development of high-performance thickeners. The current research on scCO2 thickeners faces a critical trade-off: traditional fluorinated polymers exhibit excellent philicity CO2, but suffer from high costs and environmental hazards, while non-fluorinated systems often struggle to balance solubility and thickening performance. The development of new thickeners primarily involves two directions. On one hand, efforts focus on modifying non-fluorinated polymers, driven by environmental protection needs—traditional fluorinated thickeners may cause environmental pollution, and improving non-fluorinated polymers can maintain good thickening performance while reducing environmental impacts. On the other hand, there is a commitment to developing non-noble metal-catalyzed siloxane modification and synthesis processes, aiming to enhance the technical and economic feasibility of scCO2 thickeners. Compared with noble metal catalysts like platinum, non-noble metal catalysts can reduce production costs, making the synthesis process more economically viable for large-scale industrial applications. These studies are crucial for promoting the practical application of scCO2 technology in unconventional oil and gas development, including improving fracturing efficiency and oil displacement efficiency, and providing new technical support for the sustainable development of the energy industry. This study innovatively designed an amphiphilic modified amino silicone oil polymer (MA-co-MPEGA-AS) by combining maleic anhydride (MA), methoxy polyethylene glycol acrylate (MPEGA), and amino silicone oil (AS) through a molecular bridge strategy. The synthesis process involved three key steps: radical polymerization of MA and MPEGA, amidation with AS, and in situ network formation. Fourier transform infrared spectroscopy (FT-IR) confirmed the successful introduction of ether-based CO2-philic groups. Rheological tests conducted under scCO2 conditions demonstrated a 114-fold increase in viscosity for MA-co-MPEGA-AS. Mechanistic studies revealed that the ether oxygen atoms (Lewis base) in MPEGA formed dipole–quadrupole interactions with CO2 (Lewis acid), enhancing solubility by 47%. Simultaneously, the self-assembly of siloxane chains into a three-dimensional network suppressed interlayer sliding in scCO2 and maintained over 90% viscosity retention at 80 °C. This fluorine-free design eliminates the need for platinum-based catalysts and reduces production costs compared to fluorinated polymers. The hierarchical interactions (coordination bonds and hydrogen bonds) within the system provide a novel synthetic paradigm for scCO2 thickeners. This research lays the foundation for green CO2-based energy extraction technologies. Full article
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15 pages, 2059 KiB  
Article
Strain Engineering of Cu2O@C2N for Enhanced Methane-to-Methanol Conversion
by Shuxin Kuai, Bo Li and Jingyao Liu
Molecules 2025, 30(15), 3073; https://doi.org/10.3390/molecules30153073 - 23 Jul 2025
Viewed by 249
Abstract
Inspired by the active site of methane monooxygenase, we designed a Cu2O cluster anchored in the six-membered nitrogen cavity of a C2N monolayer (Cu2O@C2N) as a stable and efficient enzyme-like catalyst. Density functional theory (DFT) [...] Read more.
Inspired by the active site of methane monooxygenase, we designed a Cu2O cluster anchored in the six-membered nitrogen cavity of a C2N monolayer (Cu2O@C2N) as a stable and efficient enzyme-like catalyst. Density functional theory (DFT) calculations reveal that the bridged Cu-O-Cu structure within C2N exhibits strong electronic coupling, which is favorable for methanol formation. Two competing mechanisms—the concerted and radical-rebound pathways—were systematically investigated, with the former being energetically preferred due to lower energy barriers and more stable intermediate states. Furthermore, strain engineering was employed to tune the geometric and electronic structure of the Cu-O-Cu site. Biaxial strain modulates the Cu-O-Cu bond angle, adsorption properties, and d-band center alignment, thereby selectively enhancing the concerted pathway. A volcano-like trend was observed between the applied strain and the methanol formation barrier, with 1% tensile strain yielding the overall energy barrier to methanol formation (ΔGoverall) as low as 1.31 eV. N2O effectively regenerated the active site and demonstrated strain-responsive kinetics. The electronic descriptor Δε (εd − εp) captured the structure–activity relationship, confirming the role of strain in regulating catalytic performance. This work highlights the synergy between geometric confinement and mechanical modulation, offering a rational design strategy for advanced C1 activation catalysts. Full article
(This article belongs to the Special Issue Exclusive Feature Papers in Physical Chemistry, 3nd Edition)
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20 pages, 4450 KiB  
Article
Synergistic Promotion of Selective Oxidation of Glycerol to C3 Products by Mo-Doped BiVO4-Coupled FeOOH Co-Catalysts Through Photoelectrocatalysis Process
by Jian Wang, Xinyue Guo, Haomin Gong, Wanggang Zhang, Yiming Liu and Bo Li
J. Compos. Sci. 2025, 9(8), 381; https://doi.org/10.3390/jcs9080381 - 22 Jul 2025
Viewed by 262
Abstract
The Mo:BiVO4/FeOOH photoelectrode was synthesized through the deposition of FeOOH onto the surface of the Mo:BiVO4 photoelectrode. The composite photoelectrode demonstrated a photocurrent of 1.8 mA·cm−2, which is three times greater than that observed for pure BiVO4 [...] Read more.
The Mo:BiVO4/FeOOH photoelectrode was synthesized through the deposition of FeOOH onto the surface of the Mo:BiVO4 photoelectrode. The composite photoelectrode demonstrated a photocurrent of 1.8 mA·cm−2, which is three times greater than that observed for pure BiVO4. Furthermore, the glycerol conversion rate was recorded at 79 μmol·cm−2·h−1, approximately double that of pure BiVO4, while the selectivity for glyceraldehyde reached 49%, also about twice that of pure BiVO4. The incorporation of Mo has been shown to enhance the stability of the BiVO4. Additionally, Mo doping improves the efficiency of electron-hole transport and increases the carrier concentration within the BiVO4. This enhancement leads to a greater number of holes participating in the formation of iron oxyhydroxide (FeOOH), thereby stabilizing the FeOOH co-catalyst within the glycerol conversion system. The FeOOH co-catalyst facilitates the adsorption and oxidation of the primary hydroxyl group of glycerol, resulting in the cleavage of the C−H bond to generate a carbon radical (C). The interaction between the carbon radical and the hydroxyl group produces an intermediate, which subsequently dehydrates to form glyceraldehyde (GLAD). Full article
(This article belongs to the Special Issue Optical–Electric–Magnetic Multifunctional Composite Materials)
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17 pages, 12649 KiB  
Article
Microstructure, Mechanical Properties, and Electrochemical Corrosion Behavior of CoCrFeNiNb and CoCrFeNiV High-Entropy Alloys Prepared via Mechanical Alloying and Spark Plasma Sintering
by Yan Zhu, Yiwen Liu, Zhaocang Meng and Jianke Tian
Metals 2025, 15(7), 814; https://doi.org/10.3390/met15070814 - 21 Jul 2025
Viewed by 282
Abstract
This study investigates the microstructural evolution, mechanical behavior, and electrochemical performance of CoCrFeNiNb and CoCrFeNiV HEAs fabricated via mechanical alloying and spark plasma sintering. Microstructural analyses reveal that the alloys have a face-centered cubic (FCC) matrix with Nb-enriched Laves and V-enriched σ phases. [...] Read more.
This study investigates the microstructural evolution, mechanical behavior, and electrochemical performance of CoCrFeNiNb and CoCrFeNiV HEAs fabricated via mechanical alloying and spark plasma sintering. Microstructural analyses reveal that the alloys have a face-centered cubic (FCC) matrix with Nb-enriched Laves and V-enriched σ phases. The CoCrFeNiNb HEA exhibits superior compressive strength and hardness than CoCrFeNiV due to uniform Laves phases distribution. Fracture surface analysis reveals that at lower sintering temperatures, the fracture is primarily caused by incomplete particle bonding, whereas at higher temperatures, brittle fracture modes dominated via transgranular cracking become predominant. The research results of potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) show that both alloys exhibited superior electrochemical stability in a 3.5 wt.% NaCl solution compared to the CoCrFeNi base alloy. X-ray photoelectron spectroscopy (XPS) analysis confirms the formation of stable oxide layers (Nb2O5 and V2O3) on the precipitated phases, acting as protective barriers against chloride ion penetration. The selective oxidation of Nb and V improves the integrity of the passive film, reducing the corrosion rates and enhancing the long-term durability. These findings highlight the critical role of precipitated phases in enhancing the corrosion resistance of HEAs, and emphasize their potential for use in extreme environments. Full article
(This article belongs to the Special Issue High-Entropy Alloys: Processing and Properties)
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26 pages, 6009 KiB  
Article
Integrated Mechanical and Eco-Economical Assessments of Fly Ash-Based Geopolymer Concrete
by Qasim Shaukat Khan, Raja Hilal Ahmad, Asad Ullah Qazi, Syed Minhaj Saleem Kazmi, Muhammad Junaid Munir and Muhammad Hassan Javed
Buildings 2025, 15(14), 2555; https://doi.org/10.3390/buildings15142555 - 20 Jul 2025
Viewed by 281
Abstract
This research evaluates the mechanical properties, environmental impacts, and cost-effectiveness of Hub Coal fly ash (FA)-based geopolymer concrete (FAGPC) as a sustainable alternative to ordinary Portland cement (OPC) concrete. This local FA has not been investigated previously. A total of 24 FAGPC mixes [...] Read more.
This research evaluates the mechanical properties, environmental impacts, and cost-effectiveness of Hub Coal fly ash (FA)-based geopolymer concrete (FAGPC) as a sustainable alternative to ordinary Portland cement (OPC) concrete. This local FA has not been investigated previously. A total of 24 FAGPC mixes were tested under both ambient and heat curing conditions, varying the molarities of sodium hydroxide (NaOH) solution (10-M, 12-M 14-M and 16-M), sodium silicate to sodium hydroxide (Na2SiO3/NaOH) ratios (1.5, 2.0, and 2.5), and alkaline activator solution to fly ash (AAS/FA) ratios (0.5 and 0.6). The test results demonstrated that increasing NaOH molarity enhances the compressive strength (CS.) by 145% under ambient curing, with a peak CS. of 32.8 MPa at 16-M NaOH, and similarly, flexural strength (FS.) increases by 90% with a maximum FS. of 6.5 MPa at 14-M NaOH. Conversely, increasing the Na2SiO3/NaOH ratio to 2.5 reduced the CS. and FS. of ambient-cured specimens by 12.5% and 10.5%, respectively. Microstructural analysis revealed that higher NaOH molarity produced a denser, more homogeneous matrix, supported by increased Si–O–Al bond formation observed through energy-dispersive X-ray spectrometry. Environmentally, FAGPC demonstrated a 35–40% reduction in embodied CO2 emissions compared to OPC, although the production costs of FAGPC were 30–35% higher, largely due to the expense of alkaline activators. These findings highlight the potential of FAGPC as a low-carbon alternative to OPC concrete, balancing enhanced mechanical performance with sustainability. New, green, and cheap activation solutions are sought for a new generation of more sustainable and affordable FAGPC. Full article
(This article belongs to the Section Building Materials, and Repair & Renovation)
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19 pages, 5463 KiB  
Article
Evaluation of Aqueous and Ethanolic Extracts for the Green Synthesis of Zinc Oxide Nanoparticles from Tradescantia spathacea
by Pedro Gerardo Trejo-Flores, Yazmin Sánchez-Roque, Heber Vilchis-Bravo, Yolanda del Carmen Pérez-Luna, Paulina Elizabeth Velázquez-Jiménez, Francisco Ramírez-González, Karen Magaly Soto Martínez, Pascual López de Paz, Sergio Saldaña-Trinidad and Roberto Berrones-Hernández
Nanomaterials 2025, 15(14), 1126; https://doi.org/10.3390/nano15141126 - 20 Jul 2025
Viewed by 425
Abstract
In this work, we report a green synthesis of zinc oxide (ZnO) nanoparticles using aqueous and ethanolic extracts of Tradescantia spathacea (purple maguey) as bioreducing and stabilizing agents, which are plant extracts not previously employed for metal oxide nanoparticle synthesis. This method provides [...] Read more.
In this work, we report a green synthesis of zinc oxide (ZnO) nanoparticles using aqueous and ethanolic extracts of Tradescantia spathacea (purple maguey) as bioreducing and stabilizing agents, which are plant extracts not previously employed for metal oxide nanoparticle synthesis. This method provides an efficient, eco-friendly, and reproducible route to obtain ZnO nanoparticles, while minimizing environmental impact compared to conventional chemical approaches. The extracts were prepared following a standardized protocol, and their phytochemical profiles, including total phenolics, flavonoids, and antioxidant capacity, were quantified via UV-Vis spectroscopy to confirm their reducing potential. ZnO nanoparticles were synthesized using zinc acetate dihydrate as a precursor, with variations in pH and precursor concentration in both aqueous and ethanolic media. UV-Vis spectroscopy confirmed nanoparticle formation, while X-ray diffraction (XRD) revealed a hexagonal wurtzite structure with preferential (101) orientation and lattice parameters a = b = 3.244 Å, c = 5.197 Å. Scanning electron microscopy (SEM) showed agglomerated morphologies, and Fourier transform infrared spectroscopy (FTIR) confirmed the presence of phytochemicals such as quercetin, kaempferol, saponins, and terpenes, along with Zn–O bonding, indicating surface functionalization. Zeta potential measurements showed improved dispersion under alkaline conditions, particularly with ethanolic extracts. This study presents a sustainable synthesis strategy with tunable parameters, highlighting the critical influence of precursor concentration and solvent environment on ZnO nanoparticle formation. Notably, aqueous extracts promote ZnO synthesis at low precursor concentrations, while alkaline conditions are essential when using ethanolic extracts. Compared to other green synthesis methods, this strategy offers control and reproducibility and employs a non-toxic, underexplored plant source rich in phytochemicals, potentially enhancing the crystallinity, surface functionality, and application potential of the resulting ZnO nanoparticles. These materials show promise for applications in photocatalysis, in antimicrobial coatings, in UV-blocking formulations, and as functional additives in optoelectronic and environmental remediation technologies. Full article
(This article belongs to the Special Issue Advanced Nanocatalysis in Environmental Applications)
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21 pages, 4054 KiB  
Article
Benzo[c]cinnolinium Trifluoromethanesulfonate Architectures Induced by Organotin(IV) Complexes
by Hélène Cattey and Laurent Plasseraud
Crystals 2025, 15(7), 655; https://doi.org/10.3390/cryst15070655 - 17 Jul 2025
Viewed by 357
Abstract
Four novel crystalline architectures based on benzo[c]cinnolininium trifluoromethanesulonate salts, [C12H9N2]+[CF3SO3], have been isolated as single-crystals, and their structures have been determined by X-ray diffraction analysis. The formation [...] Read more.
Four novel crystalline architectures based on benzo[c]cinnolininium trifluoromethanesulonate salts, [C12H9N2]+[CF3SO3], have been isolated as single-crystals, and their structures have been determined by X-ray diffraction analysis. The formation of the new salts results from reactions involving the dimeric hydroxo di-n-butylstannane trifluoromethanesulfonato complex [n-Bu2Sn(OH)(H2O)(CF3SO3)]2 (1) and benzo[c]cinnoline (C12H8N2, BCC). Organic salts I, II, III, and IV were crystallized through slow evaporation at room temperature from a mixture of toluene/dichloromethane. The cystallographic structures of I, II, and IV exhibit the presence of monoprotonated benzo[c]cinnolinium cations in interactions with a free benzo[c]cinnoline molecule through N–H···N hydrogen bonding, while for salt III, the monoprotonated cation directly interacts with the CF3SO3 anion via an N–H···O interaction. For all four salts, aromatic π-π interactions involving rings of various components (free benzo[c]cinnoline molecule, benzo[c]cinnolinium cation, toluene molecule), combined with weak C–H···O and C–H···F interactions implying the trifluoromethanesulfonate anion, promote the solid-state self-assembly of supramolecular stacks. In parallel to the formation of benzo[c]cinnolinium based-salts, organotin(IV) 1 was converted into a distannoxane compound, 2{[n-Bu2(μ-OH)SnOSn(μ-η2-O3SCF3)n-Bu2]2[n-Bu2(η1-O3SCF3)SnOSn(μ-OH)n-Bu2]2} (3), which was also isolated as a single crystal and whose crystallographic structure was previously established by us. Full article
(This article belongs to the Section Macromolecular Crystals)
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25 pages, 4764 KiB  
Article
Biogenic Synthesis of Calcium-Based Powders from Marine Mollusk Shells: Comparative Characterization and Antibacterial Potential
by Adriana-Gabriela Schiopu, Mihai Oproescu, Alexandru Berevoianu, Raluca Mărginean, Laura Ionașcu, Viorel Năstasă, Andra Dinache, Paul Mereuță, Kim KeunHwan, Daniela Istrate, Adriana-Elena Bălan and Stefan Mira
Materials 2025, 18(14), 3331; https://doi.org/10.3390/ma18143331 - 15 Jul 2025
Viewed by 340
Abstract
Marine mollusk shells are a promising renewable source of calcium-based materials, offering a sustainable alternative for their synthesis. In this study, five types of marine shells—Chamelea gallina, Mya arenaria, Rapana venosa, Mytilus edulis, and Pecten maximus—were calcined [...] Read more.
Marine mollusk shells are a promising renewable source of calcium-based materials, offering a sustainable alternative for their synthesis. In this study, five types of marine shells—Chamelea gallina, Mya arenaria, Rapana venosa, Mytilus edulis, and Pecten maximus—were calcined at 900 °C for 2 h. The resulting powders were characterized by XRD, FTIR, SEM, PSD, and zeta potential analyses. XRD confirmed the dominant presence of CaO, with residual calcite and portlandite. FTIR spectra supported these findings, indicating the decomposition of carbonate phases and the formation of Ca–O bonds. SEM imaging revealed species-specific microstructures ranging from lamellar and wrinkled textures to compact aggregates, while particle size distributions varied from 15 to 37 μm. Thermogravimetric analysis revealed a two-step decomposition process for all samples, with significant species-dependent differences in mass loss and conversion efficiency, highlighting the influence of biogenic origin on the thermal stability and CaO yield of the resulting powders. Zeta potential measurements showed low colloidal stability, with the best performance found in Rapana venosa and Pecten maximus calcinated samples. Antibacterial activity was evaluated using a direct contact method against Escherichia coli and Enterococcus faecalis. All samples exhibited complete inactivation of E. coli, regardless of exposure time, while E. faecalis required prolonged contact (3.3 h) for full inhibition. The results highlight the potential of biogenic CaCO3 and CaO powders as functional, antimicrobial materials suitable for environmental and biomedical applications. This study underscores the viability of marine shell waste valorization within a circular economy framework. Full article
(This article belongs to the Section Biomaterials)
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20 pages, 15499 KiB  
Article
Molecular Dynamics Unveiled: Temperature–Pressure–Coal Rank Triaxial Coupling Mechanisms Governing Wettability in Gas–Water–Coal Systems
by Lixin Zhang, Songhang Zhang, Shuheng Tang, Zhaodong Xi, Jianxin Li, Qian Zhang, Ke Zhang and Wenguang Tian
Processes 2025, 13(7), 2209; https://doi.org/10.3390/pr13072209 - 10 Jul 2025
Viewed by 284
Abstract
Water within coal reservoirs exerts dual effects on methane adsorption–desorption by competing for adsorption sites and reducing permeability. The bound water effect, caused by coal wettability, significantly constrains coalbed methane (CBM) production, rendering investigations into coal wettability crucial for efficient CBM development. Compared [...] Read more.
Water within coal reservoirs exerts dual effects on methane adsorption–desorption by competing for adsorption sites and reducing permeability. The bound water effect, caused by coal wettability, significantly constrains coalbed methane (CBM) production, rendering investigations into coal wettability crucial for efficient CBM development. Compared with other geological formations, coals are characterized by a highly developed microporous structure, making the CO2 sequestration mechanism in coal seams closely linked to the microscale interactions among gas, water, and coal matrixes. However, the intrinsic mechanisms remain poorly understood. In this study, molecular dynamics simulations are employed to investigate the wettability behaviors of CO2, CH4, and water on different coal matrix surfaces under varying temperature and pressure conditions, for coal macromolecules representative of four coal ranks. The study reveals the evolution of water wettability in response to CO2 and CH4 injection, identifies wettability differences among coal ranks, and analyzes the microscopic mechanisms governing wettability. The results show the following: (1) The contact angle increases with gas pressure, and the variation in wettability is more pronounced in CO2 environments than in CH4. As pressure increases, the number of hydrogen bonds decreases, while the peak gas density of CH4 and CO2 increases, leading to larger contact angles. (2) Simulations under different temperatures for the four coal ranks indicate that temperature has minimal influence on low-rank Hegu coal, whereas for higher-rank coals, gas adsorption on the coal surface increases, resulting in reduced wettability. Interfacial tension analysis further suggests that higher temperatures reduce water surface tension, cause dispersion of water molecules, and consequently improve wettability. Understanding the wettability variations among different coal ranks under variable pressure–temperature conditions provides a fundamental model and theoretical basis for investigating deep coal seam gas–water interactions and CO2 geological sequestration mechanisms. These findings have significant implications for the advancement of CO2-ECBM technology. Full article
(This article belongs to the Special Issue Coalbed Methane Development Process)
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16 pages, 2293 KiB  
Article
Molecular Dynamics Simulation of the Thermosensitive Gelation Mechanism of Phosphorylcholine Groups-Conjugated Methylcellulose Hydrogel
by Hongyu Mei, Yaqing Huang, Juzhen Yi, Wencheng Chen, Peng Guan, Shanyue Guan, Xiaohong Chen, Wei Li and Liqun Yang
Gels 2025, 11(7), 521; https://doi.org/10.3390/gels11070521 - 4 Jul 2025
Viewed by 348
Abstract
The intelligently thermosensitive 2-methacryloyloxyethyl phosphorylcholine (MPC) groups-conjugated methylcellulose (MC) hydrogel, abbreviated as MPC-g-MC, exhibits good potential for prevention of postoperative adhesions. However, its thermosensitive gelation mechanism and why the MPC-g-MC hydrogel shows a lower gelation temperature than that of MC hydrogel are still [...] Read more.
The intelligently thermosensitive 2-methacryloyloxyethyl phosphorylcholine (MPC) groups-conjugated methylcellulose (MC) hydrogel, abbreviated as MPC-g-MC, exhibits good potential for prevention of postoperative adhesions. However, its thermosensitive gelation mechanism and why the MPC-g-MC hydrogel shows a lower gelation temperature than that of MC hydrogel are still unclear. Molecular dynamics (MD) simulation was thus used to investigate these mechanisms in this work. After a fully atomistic MPC-g-MC molecular model was constructed, MD simulations during the thermal simulation process and at constant temperatures were performed using GROMACS 2022.3 software. The results indicated that the hydrophobic interactions between the MPC-g-MC molecular chains increased, the interactions between the MPC-g-MC molecular chains and H2O molecules decreased with the rise in temperature, and the hydrogen bonding structures were changed during the thermal simulation process. As a result, the MPC-g-MC molecular chains began to aggregate at about 33 °C (close to the gelation temperature of 33 °C determined by the rheological measurement), bringing about the formation of the MPC-g-MC hydrogel in the macroscopic state. The mechanism of MPC-g-MC hydrogel formation showed that its lower gelation temperature than that of the MC hydrogel is attributed to the increase in the interactions (including hydrophobic interactions, hydrogen bonding interactions, Van der Waals and Coulomb forces) induced by the side MPC groups of MPC-g-MC molecules. The thermosensitive gelation mechanism revealed in this study provides an important reference for the development of novel thermosensitive MC-derived hydrogels with gelation temperatures close to human body temperature. Full article
(This article belongs to the Special Issue Advances in Functional and Intelligent Hydrogels)
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