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Search Results (325)

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19 pages, 2082 KB  
Article
Lipid Nanoparticles Based on a Di-N-Oxide Surfactant as an Innovative Strategy for the Development of Possible Cosmetic Applications
by Agnieszka Lewińska, Marta Domżał-Kędzia, Katarzyna Wiercigroch-Walkosz, Błażej Poźniak and Krzysztof Bojanowski
Appl. Sci. 2026, 16(13), 6349; https://doi.org/10.3390/app16136349 (registering DOI) - 24 Jun 2026
Abstract
The growing demand for effective delivery of active ingredients in cosmetic formulations has stimulated the development of advanced carrier systems. This study evaluates the potential of the dicephalic di-N-oxide surfactant N,N-bis [3,3-(dimethylamino)-propyl]dodecylamide (C12-(DAPANO)2) as a stabilizer for aqueous dispersions [...] Read more.
The growing demand for effective delivery of active ingredients in cosmetic formulations has stimulated the development of advanced carrier systems. This study evaluates the potential of the dicephalic di-N-oxide surfactant N,N-bis [3,3-(dimethylamino)-propyl]dodecylamide (C12-(DAPANO)2) as a stabilizer for aqueous dispersions of solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs). Lipid nanoparticles were prepared using three classes of solid lipids—cetyl palmitate, glyceryl behenate, and stearic acid—through high-speed homogenization followed by ultrasonication. Their physicochemical properties were characterized using DLS, TEM, AFM, DSC, and TGA. All formulations exhibited particle sizes below 300 nm and a low polydispersity index (<0.30), indicating good uniformity. High absolute zeta potential values and stability studies confirmed excellent physical stability, with all dispersions remaining stable for at least 90 days at room temperature. Compared with bulk lipids, nanoparticles showed lower melting temperatures and reduced crystallinity. NLCs exhibited lower crystallization and melting temperatures than SLNs and displayed a more spherical morphology. Cytotoxicity assessment using J774.E macrophages revealed no adverse effects. These findings highlight the surfactant’s potential as a stabilizing agent for lipid-based cosmetic nanocarriers, supporting the development of stable systems with improved active ingredient loading and controlled release properties. Full article
(This article belongs to the Special Issue Development of Innovative Cosmetics—2nd Edition)
23 pages, 10628 KB  
Article
Design and Development of a Bioink for Fabricating Crosslinked Hydrogel Microneedles via 3D Printing for Transdermal Delivery of Estradiol Nanoparticles
by Southamany Sisavengsouk, Teeratas Kansom, Boonnada Pamornpathomkul, Porawan Aumklad, Tanasait Ngawhirunpat, Praneet Opanasopit and Phuvamin Suriyaamporn
Pharmaceutics 2026, 18(7), 772; https://doi.org/10.3390/pharmaceutics18070772 (registering DOI) - 24 Jun 2026
Abstract
Background: Conventional transdermal drug delivery systems are often limited by poor skin permeability and low drug loading efficiency, necessitating the development of advanced delivery platforms. Objectives: This study aimed to develop and optimize photopolymerizable bioinks (PBs) for liquid crystal display (LCD)-based [...] Read more.
Background: Conventional transdermal drug delivery systems are often limited by poor skin permeability and low drug loading efficiency, necessitating the development of advanced delivery platforms. Objectives: This study aimed to develop and optimize photopolymerizable bioinks (PBs) for liquid crystal display (LCD)-based 3D printing of crosslinked hydrogel microneedles (cHMNs) to enhance transdermal delivery of estradiol valerate (E2V). Methods: A Box–Behnken design (BBD) was used to optimize the effects of Gantrez™ S-97, Jurymer™, and polyvinyl alcohol (PVA) on viscosity, exposure time, hardness, and elasticity, with strong predictive performance (R2 = 0.9702–0.9907). Results: Estradiol valerate-loaded nanoparticles (E2V-NPs) were prepared via ionotropic gelation, exhibiting a particle size of 698.33 (0.78) nm, PDI of 0.50 (0.06), zeta potential of −39.09 (7.32) mV, and high encapsulation efficiency (86.87 (0.78)%). The optimized PBs enabled fabrication of uniform cHMNs (~800 µm height) with adequate mechanical strength (hardness 20.45 (1.23) N; elasticity 2.97 (0.49) MPa) and effective insertion capability. The E2V-NPs-loaded cHMNs exhibited sustained drug release over 12 days (~56.92 (4.27)%). Skin permeation studies showed a significantly enhanced flux (10.81 (4.55) µg/cm2/h) and cumulative permeation (12.94 (2.06) µg/cm2) compared to topical E2V-NPs and suspension, along with increased skin accumulation (38.55 (0.10) µg). Cytotoxicity studies confirmed that E2V and E2V-NPs were biocompatible (>80% viability), while PBs showed concentration-dependent cytotoxicity. Conclusions: Overall, this integrated platform combining design of experiment, nanoparticles, microneedles, and LCD 3D printing offered a promising strategy for enhancing transdermal drug delivery efficiency and reproducibility. Full article
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13 pages, 1661 KB  
Article
Study on Efficient Potassium Removal and Lithium Recovery from Potassium-Rich Mother Liquor
by Lichao Wang, Tieqiang Lin and Jian Li
Metals 2026, 16(6), 619; https://doi.org/10.3390/met16060619 - 4 Jun 2026
Viewed by 220
Abstract
The potassium-rich mother liquor generated from the sulfuric acid process for lithium extraction from spodumene cannot be directly used for the production of battery-grade lithium salts, resulting in lithium resource loss. To address the issues of slow reaction rate and high seed crystal [...] Read more.
The potassium-rich mother liquor generated from the sulfuric acid process for lithium extraction from spodumene cannot be directly used for the production of battery-grade lithium salts, resulting in lithium resource loss. To address the issues of slow reaction rate and high seed crystal dosage in the traditional jarosite process for potassium removal, this paper systematically optimizes the type, dosage, and particle size of seed crystals based on the mechanisms of crystal nucleation and growth, ion occupancy competition, and interfacial crystallization-driven behavior. Results show that potassium jarosite seed offers high crystallographic compatibility, ease of preparation, and the best overall performance. Seed particle size must balance specific surface area and dispersibility; either too large or too small is detrimental to uniform crystal growth. Thermodynamic and kinetic analyses confirm that jarosite precipitation is strongly spontaneous and chemically controlled. Under the optimal process conditions (pH = 1.5, n(Fe3+)/n(K+) = 3.5:1, 1 g of potassium jarosite seed, 95 °C, 1 h), the potassium removal rate reaches (92.60 ± 0.48)%, and the lithium recovery rate is (95.20 ± 0.34)%. Lithium loss mainly arises from precipitate entrainment and insufficient washing; enhanced washing can further improve recovery. This study elucidates seed-mediated crystallization regulation and provides both theoretical guidance and technical reference for efficient potassium removal and high-value lithium recovery from potassium-rich mother liquor. Full article
(This article belongs to the Special Issue Green Technologies in Metal Recovery)
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17 pages, 15842 KB  
Article
Preparation of HMX/PMMA Composite Microspheres with Excellent Properties by Photoinitiated Emulsion Polymerization
by Shimin Zhang, Nan Wu, Kaixuan Jia, Xinyue Huang, Xudong Wu, Conghua Hou, Honglu Li and Jingyu Wang
Molecules 2026, 31(11), 1911; https://doi.org/10.3390/molecules31111911 - 2 Jun 2026
Viewed by 256
Abstract
High-energy insensitive energetic materials are currently a research focus. Octogen (HMX) is one of the best-performing nitramine explosives, but its poor crystal morphology causes high mechanical sensitivity, limiting its application. This study proposed a method combining spheroidization, nanosizing, and coating desensitization. Nano-SiO2 [...] Read more.
High-energy insensitive energetic materials are currently a research focus. Octogen (HMX) is one of the best-performing nitramine explosives, but its poor crystal morphology causes high mechanical sensitivity, limiting its application. This study proposed a method combining spheroidization, nanosizing, and coating desensitization. Nano-SiO2 and TiO2 were used to modify methyl methacrylate (MMA), and HMX/PMMA composite energetic microspheres were successfully prepared with the assistance of an ultraviolet (UV) lamp for catalytic polymerization. Molecular dynamics simulations determined the optimal particle ratios, and the effects of modifier content on morphology, crystal form, thermal stability, mechanical properties, and static mechanical properties were experimentally investigated. The prepared HMX/PMMA/modifier microspheres exhibited uniform size, dense structure, excellent performance, and ideal coating. Thermal decomposition kinetics showed that the activation energy of HMX/PMMA/SiO2 (0.75 wt% SiO2) increased by 79.86 kJ/mol and 27.55 kJ/mol compared with raw HMX and HMX/PMMA, respectively. Its impact sensitivity was 3.6 times that of raw HMX, and its friction sensitivity was twice that of raw HMX. Static mechanical analysis revealed that the compressive strength of HMX/PMMA/SiO2 (0.75 wt% SiO2) and HMX/PMMA/TiO2 (0.5 wt% TiO2) microspheres increased by 7.3 MPa and 6.1 MPa, respectively, over HMX/PMMA, indicating significant improvement. Overall, HMX/PMMA/SiO2 and HMX/PMMA/TiO2 microspheres prepared by photoinitiated emulsion polymerization exhibited excellent thermal stability and mechanical properties. Full article
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50 pages, 2587 KB  
Review
Enzyme-Induced Carbonate Precipitation (EICP) for Soil Stabilization: A Review of Mechanisms, Applications, and Future Challenges
by Yong Li, Shengya Zhou, Fankai Liu, Zhiyu Dong, Xiangtai Fan, Zhi Ge, Chong Li and Hongzhi Zhang
Geotechnics 2026, 6(2), 53; https://doi.org/10.3390/geotechnics6020053 - 29 May 2026
Viewed by 389
Abstract
Enzyme-Induced Carbonate Precipitation (EICP) represents a sustainable advancement in geotechnical engineering for stabilizing fine-grained soils (e.g., silt). Utilizing plant-derived urease (~12 nm) to catalyze urea hydrolysis, this technique generates calcium carbonate (CaCO3) for soil reinforcement. Unlike Microbially Induced Carbonate Precipitation (MICP), [...] Read more.
Enzyme-Induced Carbonate Precipitation (EICP) represents a sustainable advancement in geotechnical engineering for stabilizing fine-grained soils (e.g., silt). Utilizing plant-derived urease (~12 nm) to catalyze urea hydrolysis, this technique generates calcium carbonate (CaCO3) for soil reinforcement. Unlike Microbially Induced Carbonate Precipitation (MICP), EICP overcomes microbial size constraints (0.5–3 µm) by penetrating soil micropores, enabling uniform cementation. Its innovative single-phase low-pH method achieves >98% calcium conversion efficiency, yielding 6.41 MPa unconfined compressive strength (UCS) in sand—a 92.97% improvement over MICP. EICP demonstrates versatility: enhancing soil strength (up to 650% for silt), erosion resistance (wind erosion modulus increased ~20-fold), anti-seepage performance (permeability reduced from 10−6 to <10−9 cm/s), and heavy metal immobilization (>99%). However, challenges include unstable crystal morphologies (e.g., excessive vaterite), urease stability/cost constraints, and environmental concerns related to NH3 emissions from urea hydrolysis. The manuscript acknowledges these emissions’ impacts and introduces mitigation strategies: ammonia capture technologies, optimized dosing protocols, and exploration of alternative N-sources. Long-term durability data under complex field conditions remain insufficient. Ongoing research addresses these gaps through nucleating agents (dried skim milk, biochar), enzyme immobilization, process optimization, and byproduct treatment. As a low-carbon technology with targeted mitigation measures, EICP advances environmentally conscious soil stabilization practices. This study presents a comparative narrative analysis of EICP’s performance and challenges, integrating laboratory findings and field applications. Full article
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19 pages, 3018 KB  
Article
Polypyrrole-Integrated Lanthanum Ferrite Electrochemical Platform for Sensitive Detection of Tinidazole
by Shakoor Ahmed Solangi, Jameel Ahmed Baig, Imam Bakhsh Solangi, Hassan Imran Afridi, Faisal K. Algethami, Khalil Akhtar, Sajjad Hussain, Latif Ullah Khan, Şükrü Gökhan Elçi and Mohamed N. Goda
Catalysts 2026, 16(6), 490; https://doi.org/10.3390/catal16060490 - 22 May 2026
Viewed by 751
Abstract
In the present research, lanthanum ferrite nanoparticles (LaFeO3 NPs) and lanthanum ferrite polypyrrole (LaFeO3/PPy) nanocomposites were synthesized and evaluated for electrochemical sensing of TNZ in biological and pharmaceutical samples. LaFeO3 NPs were synthesized using the sol–gel auto-combustion method, whereas [...] Read more.
In the present research, lanthanum ferrite nanoparticles (LaFeO3 NPs) and lanthanum ferrite polypyrrole (LaFeO3/PPy) nanocomposites were synthesized and evaluated for electrochemical sensing of TNZ in biological and pharmaceutical samples. LaFeO3 NPs were synthesized using the sol–gel auto-combustion method, whereas LaFeO3/PPy nanocomposites were produced through an in situ chemical oxidative polymerization process. The obtained materials were subjected to comprehensive characterization by multiple analytical techniques, including XRD, which confirms an orthorhombic crystal structure; SEM micrographs of LaFeO3 NPs and LaFeO3/PPy nanocomposites exhibit a highly agglomerated structure with non-uniform particle distribution and a more homogeneous, smoother surface morphology, respectively, with an average size of <70 nm. The LaFeO3/PPy nanocomposites exhibited an electron-transfer process governed by diffusion, as evidenced by cyclic voltammetry (CV) analysis. Using differential pulse voltammetry (DPV), the sensor achieved quantitative detection across a linear concertation range of 0.1–230 µM (R2 = 0.997), with a detection limit (0.023 µM). The developed sensor demonstrated excellent stability, remarkable sensitivity, and high reproducibility, confirming reliability and suitability (RSD% < 4.0) for the quantitative determination of TNZ in both biological and pharmaceutical matrices. Full article
(This article belongs to the Section Electrocatalysis)
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32 pages, 16655 KB  
Article
Sustainable Valorization of Blast Furnace Slag into NaA Zeolite via Selective Acetic Acid Leaching for Efficient Heavy Metal Adsorption
by Yifei Lv, Xinyue Lv, Mengyao Zhao, Jingyu Zhao, Jiayong Qiu, Yingjiang Wen, Kai Zhao, Junru Zhu, Yuhan Ge, Xinzhe Lu and Yongjia Dou
Sustainability 2026, 18(10), 5081; https://doi.org/10.3390/su18105081 - 18 May 2026
Viewed by 294
Abstract
Sustainable management of industrial solid waste is critical for a circular economy. This study presents a novel approach for valorizing blast furnace slag (BFS) into NaA zeolite through selective acetic acid leaching followed by hydrothermal crystallization. The leaching step selectively extracts Ca2+ [...] Read more.
Sustainable management of industrial solid waste is critical for a circular economy. This study presents a novel approach for valorizing blast furnace slag (BFS) into NaA zeolite through selective acetic acid leaching followed by hydrothermal crystallization. The leaching step selectively extracts Ca2+ and Mg2+ while efficiently retaining silicon and aluminum in the solid residue, producing a reactive aluminosilicate precursor that facilitates zeolite nucleation and growth. The effects of the silicon-to-aluminum molar ratio (n(Si)/n(Al)), crystallization temperature, and duration on the phase evolution and morphology were systematically investigated. The results demonstrate that phase-pure NaA zeolite with high crystallinity and a uniform cubic morphology can be obtained from precursor gels with n(Si)/n(Al) ratios of 0.5–1.25. Optimal synthesis conditions were identified as n(Na):n(Si):n(Al):n(H2O) = 6:1:1:240 at 373 K for 8 h. The resulting zeolites exhibit a BET specific surface area of 52.1 m2/g, a micropore volume of 0.016 cm3/g, an average adsorption pore size of 4.7 nm, and an external specific surface area of 12.8 m2/g. It achieved near-complete removal of Cu2+ and high adsorption efficiencies for Pb2+ (77.78%) and Ni2+ (71.79%) from 250 mg/L solutions at 298 K with a dosage of 4.0 g/L, following the affinity sequence Cu2+ > Pb2+ > Ni2+, with all pairwise differences statistically significant at p < 0.001, using one-way ANOVA and Tukey’s HSD tests. The adsorption of three metal ions was most accurately described by the Freundlich isotherm and pseudo-second-order kinetic models, indicating heterogeneous multilayer chemisorption. The theoretical maximum monolayer adsorption capacities (qmax) were 307.67 mg/g for Cu2+, 246.09 mg/g for Pb2+, and 173.79 mg/g for Ni2+, whereas the kinetic equilibrium adsorption capacities (qe) reached 62.69, 48.85 and 41.69 mg/g, respectively. This study demonstrates a value-added strategy for valorizing BFS into a micro-mesoporous adsorbent, advancing both circular resource utilization and environmental remediation. Full article
(This article belongs to the Section Waste and Recycling)
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16 pages, 5828 KB  
Article
Low-Temperature Hydrodeoxygenation of Lignin Model Compounds over Defect-Engineered Nickel Catalysts
by Yanliang Yang, Yaoru Du, Yue Luo, Ying Duan, Dong Sui, Yunmeng Wang, Xuechuan Lv and Tianliang Lu
Catalysts 2026, 16(5), 455; https://doi.org/10.3390/catal16050455 - 13 May 2026
Viewed by 275
Abstract
Catalytic hydrodeoxygenation (HDO) of aromatic aldehydes represents a core research direction in the efficient utilization of lignin. In this study, a cost-effective catalyst was constructed by incorporating rich lattice defects into Ni nanoparticles. The catalyst was synthesized via a uniform precipitation method, employing [...] Read more.
Catalytic hydrodeoxygenation (HDO) of aromatic aldehydes represents a core research direction in the efficient utilization of lignin. In this study, a cost-effective catalyst was constructed by incorporating rich lattice defects into Ni nanoparticles. The catalyst was synthesized via a uniform precipitation method, employing urea as the precipitant. By introducing aluminum nitrate during the precipitation process, nickel was effectively segregated to inhibit its growth and the generation of well-crystallized, defect-free Ni nanoparticles, thereby generating a substantial quantity of defective Ni nanoparticles with abundant lattice defects. The catalyst was characterized using XRD, TEM, HRTEM, EDS line and mapping scanning, XPS and H2-TPD, confirming the formation of Ni nanoparticles with a narrow size distribution of ~5 nm with numerous lattice defects. The hydrodeoxygenation of vanillin was employed to evaluate the catalyst’s activity, with investigations into the effects of Al content, solvents, temperature, H2 pressure, and reaction time. The reaction was successfully conducted at 363 K in water. The catalyst demonstrated excellent hydrodeoxygenation activity across a series of other aromatic aldehyde compounds. Cycle experiments confirmed the catalyst’s stability, maintaining its activity over at least five consecutive uses. Full article
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15 pages, 7085 KB  
Article
Hydrothermal Synthesis of Hierarchical Boehmite from Co-Processed Stainless Steel Dust and Aluminum Dross Residue
by Hongda Yao, Nan Wang, Min Chen and Xiaoqing Chen
Metals 2026, 16(5), 455; https://doi.org/10.3390/met16050455 - 22 Apr 2026
Viewed by 408
Abstract
Stainless steel dust and aluminum dross are large-volume solid wastes in the metallurgical industry. Synergistic treatment of these wastes recovers some metals but yields an Al-rich residue (Al2O3 > 50%) that represents both a resource loss and an environmental threat [...] Read more.
Stainless steel dust and aluminum dross are large-volume solid wastes in the metallurgical industry. Synergistic treatment of these wastes recovers some metals but yields an Al-rich residue (Al2O3 > 50%) that represents both a resource loss and an environmental threat if untreated. In this work, boehmite (γ-AlOOH) was synthesized via a hydrothermal route using the Al-rich residue as the aluminum source. The aim was to valorize this waste stream while comprehensively evaluating the product’s phase, morphology, pore characteristics, efficacy and underlying mechanism for Cr(VI) removal from aqueous solutions. The hydrothermal process was optimized as pH = 11.0, under which high-purity and well-crystallized γ-AlOOH was successfully prepared without harmful by-products. The product had uniform particle size distribution without obvious agglomeration, with a specific surface area of 156.7 m2/g, pore volume of 0.60 cm3/g and average pore diameter of 14.6 nm. The boehmite synthesized at pH 11.0 achieved a Cr(VI) removal efficiency of 31.28% and a maximum adsorption capacity of 15.64 mg/g. This study provides a new path for the resource utilization of high-aluminum residue, with both environmental and economic benefits and potential application value. Full article
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40 pages, 5109 KB  
Article
Confinement Reweights Protein Orientational Phase Space in Crystallization: A PDB-Anchored Hamiltonian Comparison of Hanging-Drop and Langmuir–Blodgett Nanotemplates
by Eugenia Pechkova, Fabio Massimo Speranza, Paola Ghisellini, Cristina Rando, Katia Barbaro, Ginevra Ciurli, Stefano Ottoboni and Roberto Eggenhöffner
Crystals 2026, 16(4), 269; https://doi.org/10.3390/cryst16040269 - 16 Apr 2026
Viewed by 393
Abstract
This study quantifies how confinement changes the orientational phase space of proteins by comparing hanging-drop (HD) with Langmuir–Blodgett (LB) conditions within a unified probabilistic framework grounded in structural data from the Protein Data Bank (PDB). For each protein, principal moments of inertia are [...] Read more.
This study quantifies how confinement changes the orientational phase space of proteins by comparing hanging-drop (HD) with Langmuir–Blodgett (LB) conditions within a unified probabilistic framework grounded in structural data from the Protein Data Bank (PDB). For each protein, principal moments of inertia are computed from atomic coordinates, trace-normalized, and used to define a geometry-based benchmark for the probability of occupying a predefined productive-orientation set. In parallel, a Hamiltonian-weighted probability is obtained within a classical statistical–mechanical treatment by reconstructing the orientational distribution over the polar–azimuthal domain under a fixed global confinement protocol. The analysis is carried out on a ten-protein panel spanning diverse sizes and anisotropies, and the HD→LB contrast is characterized through probability gains, distributional distances, and an energy-basin decomposition that distinguishes basin depth from basin measure. Under identical parameterization, LB globally produces higher productive-orientation probabilities than HD across all proteins, establishing a uniform direction of the confinement effect while preserving protein-dependent magnitudes. The inertia-based benchmark exhibits broader dispersion in LB/HD amplification, whereas the Hamiltonian construction yields a more regular cross-protein gain, consistent with LB acting as a global reweighting of orientational phase space rather than a protein-specific re-tuning. By integrating PDB-derived structural descriptors with a statistical–mechanical operator, the framework provides a transparent bridge between molecular geometry and confinement-driven ordering and offers a compact basis for comparing crystallization-relevant confinement protocols across structurally heterogeneous proteins. Full article
(This article belongs to the Section Biomolecular Crystals)
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18 pages, 4220 KB  
Article
Controlled Synthesis and Infrared Emission Properties of Core–Shell TiO2 Hollow Microspheres
by Zeyu Liu, Yang Xiang, Zhihang Peng and Binzhi Jiang
Materials 2026, 19(7), 1447; https://doi.org/10.3390/ma19071447 - 4 Apr 2026
Viewed by 584
Abstract
With the growing demand for advanced passive cooling technologies in fields such as building energy efficiency, thermal protection of electronic devices, and personal thermal comfort, radiative cooling materials have garnered considerable attention due to their ability to achieve cooling without external energy input. [...] Read more.
With the growing demand for advanced passive cooling technologies in fields such as building energy efficiency, thermal protection of electronic devices, and personal thermal comfort, radiative cooling materials have garnered considerable attention due to their ability to achieve cooling without external energy input. In this study, TiO2 hollow microspheres with a core–shell structure were successfully synthesized via a solvothermal method using TiCl4 as the titanium source and (NH4)2SO4 and CO(NH2)2 as structure-directing agents. The effects of reaction temperature (120–200 °C) and reaction time (0.5–36 h) on the morphology, crystal phase, specific surface area, pore structure, and infrared optical properties of the microspheres were systematically investigated. The results indicate that all prepared samples consisted of anatase-phase TiO2, with the microstructure significantly influenced by the synthesis conditions. An increase in reaction temperature promoted the transition from solid to hollow structures; the microspheres exhibited the most regular morphology and the largest specific surface area at 180 °C. Prolonging the reaction time facilitated the Ostwald ripening process, leading to a more complete hollow structure at 24 h. Infrared optical performance analysis revealed that all samples exhibited high emissivity approaching 100% in the 8–15 μm wavelength range, attributed to the intrinsic lattice vibration absorption of TiO2. In the 3–8 μm range, however, the emissivity was strongly modulated by the microstructure. Samples synthesized at 180 °C for 12–24 h demonstrated stable emissivity characteristics owing to their dense shells, uniform particle size, and well-defined hollow structures. This study elucidates the intrinsic relationship between microstructural evolution and infrared emission performance in TiO2 hollow microspheres, providing a theoretical foundation and process optimization strategy for their application in radiative cooling coatings, device thermal protection, and personal thermal management textiles. Full article
(This article belongs to the Section Porous Materials)
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19 pages, 7197 KB  
Article
Microstructural Assessment of a Single-Crystal Ex-Service Land-Based Gas Turbine Blade
by Clara Pohl, Jonathan Streitberger, Larissa Heep, Takuma Saito, David Bürger, Alexander Kauffmann, Antonín Dlouhý and Gunther Eggeler
Crystals 2026, 16(4), 219; https://doi.org/10.3390/cryst16040219 - 25 Mar 2026
Viewed by 1018
Abstract
In this study, we examine an ex-service, Ni-base single-crystal blade made of alloy PWA1483, which was in service for 6000 h. Using light optical, scanning, and transmission electron microscopy, we analyzed the microstructure at the blade’s tip, middle, and root. Key focus areas [...] Read more.
In this study, we examine an ex-service, Ni-base single-crystal blade made of alloy PWA1483, which was in service for 6000 h. Using light optical, scanning, and transmission electron microscopy, we analyzed the microstructure at the blade’s tip, middle, and root. Key focus areas included surface features, dendrite spacings, γ’-particle sizes, and dislocation densities. The findings reveal that the bulk microstructure hardly evolved. Dendrite spacings exhibited a consistent microstructure across all locations and there were no significant differences between the local alloy chemistries of dendritic and interdendritic regions, indicating high-quality processing. A bimodal γ’-particle distribution was observed. Variations in γ’-sizes and γ-channel widths were noted, with the tip showing rounded γ’-particles. Small spherical particles occurred only in the root and middle of the blade. The middle location exhibited the highest hardness. Dislocation densities were low and uniform, with the highest density correlating with the highest hardness. Full article
(This article belongs to the Section Materials for Energy Applications)
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13 pages, 2128 KB  
Article
Study of Crystallization Kinetics of Picromerite in the K2SO4-MgSO4-H2O System
by Songliang Ma, Yiqi Cui, Guangfeng Dong and Qingwang Liu
Materials 2026, 19(5), 957; https://doi.org/10.3390/ma19050957 - 2 Mar 2026
Cited by 1 | Viewed by 413
Abstract
The crystallization kinetics of picromerite play a crucial role in optimizing the fertilizer quality. This study developed a crystallization kinetics model of picromerite. Results show that increasing temperature mainly leads to higher supersaturation, which, in turn, enhances both nucleation and growth rates, with [...] Read more.
The crystallization kinetics of picromerite play a crucial role in optimizing the fertilizer quality. This study developed a crystallization kinetics model of picromerite. Results show that increasing temperature mainly leads to higher supersaturation, which, in turn, enhances both nucleation and growth rates, with significant improvements in crystal size and uniformity. Higher stirring speed was found to have positive effects on crystal nucleation and growth rate. The decrease in supersaturation leads to the diminution of the driving force for crystallization and the gradual decline in crystallization. The study provides a comprehensive analysis of the relationships between these crystallization conditions and the resultant crystal properties. Full article
(This article belongs to the Special Issue Functional Polymers and Materials: Synthesis and Application)
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16 pages, 7538 KB  
Article
Effect of Hot-Pressing Temperature on β-Phase Formulation in 3D-Printed Polyvinylidene Fluoride (PVDF)
by Sadia Rahman Toru, Imjoo Jung and Sunhee Lee
Polymers 2026, 18(5), 617; https://doi.org/10.3390/polym18050617 - 28 Feb 2026
Viewed by 842
Abstract
The purpose of this study is to combine 3D printing and hot-pressing to improve polyvinylidene fluoride (PVDF) by making its surface smoother, enhancing crystallinity and electrical and mechanical performance. Before printing, PVDF filament was analyzed using rheology, differential scanning calorimetry (DSC), Thermogravimetric Analysis [...] Read more.
The purpose of this study is to combine 3D printing and hot-pressing to improve polyvinylidene fluoride (PVDF) by making its surface smoother, enhancing crystallinity and electrical and mechanical performance. Before printing, PVDF filament was analyzed using rheology, differential scanning calorimetry (DSC), Thermogravimetric Analysis (TGA), and extrusion tests. Based on these results for printing, 250 °C was fixed as the optimized printing temperature. PVDF samples were printed using an Ultimaker S5 dual-nozzle 3D printer, with a size of 30 × 30 × 0.2 mm3. After printing, samples were hot-pressed at five different temperatures, 100, 125, 150, 175, and 200 °C, for 10 min each. Then, the hot-pressed samples were tested using morphology, Fourier transform infrared (FTIR), X-ray diffraction (XRD), DSC, tensile, and electrical properties. From the morphology, the sample thickness decreased from 0.25 to 0.24 mm, making the surface smoother, removing pores after hot-pressing. From FTIR and XRD results, all samples showed similar patterns, but the hot-pressed sample showed slightly stronger β-phase diffraction and peaks near 20° and 840, 1066, and 1275 cm−1, indicating better crystal ordering. The DSC results showed a small increase in melting temperature and stable thermal behavior after hot-pressing, confirming improved thermal stability. The tensile property results confirmed that the hot-pressed samples, around 150 and 175, showed higher strength and better flexibility. The electrical I-V test showed stable and uniform conductivity, and the hot-pressed samples performed more consistently. Overall, hot-pressing improved the surface quality, crystallinity, mechanical, and electrical properties of 3D-printed PVDF, making it more reliable for advanced applications. Full article
(This article belongs to the Special Issue Additive Manufacturing of Polymer Based Materials)
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13 pages, 2885 KB  
Article
Effect of Growth Orientation on the Standard Heat Treatment Microstructure of Nickel-Based Single-Crystal Superalloy DD6
by Zhenyu Yang, Xiaogong Liu, Ji Wang, Zhiqiang Yang, Songsong Hu, Jian Zhang, Yushi Luo and Shenglong Dai
Materials 2026, 19(4), 800; https://doi.org/10.3390/ma19040800 - 18 Feb 2026
Viewed by 582
Abstract
Using the seeding method, nickel-based single-crystal superalloy DD6 specimens with different growth orientations were prepared in a liquid metal cooling (LMC) directional solidification furnace. Subsequent standard heat treatment was carried out, and the influence of growth orientation on the microstructure of the (001) [...] Read more.
Using the seeding method, nickel-based single-crystal superalloy DD6 specimens with different growth orientations were prepared in a liquid metal cooling (LMC) directional solidification furnace. Subsequent standard heat treatment was carried out, and the influence of growth orientation on the microstructure of the (001) crystal plane of the alloy after heat treatment was investigated. Results show that with the increase in growth orientation deviation angle from the <001> orientation, the area fraction of residual eutectic content is reduced, the average size and volume of pore and γ′ strengthening phase increase, and the cubicity of the γ′ strengthening phase decreases. The growth orientation does not significantly affect the morphology of residual eutectic content or the morphology of the strengthening phase of the γ′ in the dendrite cores and interdendrite regions. However, the size uniformity of the γ′ strengthening phase in dendrite cores and the width of the γ matrix channels decrease as the growth orientation deviation angle increases. Full article
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