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Keywords = metal-free modification

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18 pages, 2424 KB  
Article
Surface Activation Using Atmospheric Plasma to Improve PHB Coating Adhesion and Corrosion Resistance of AZ91D Magnesium Alloys
by Arturo Valenzo, María del Pilar Rodríguez-Rojas, Horacio Martínez, Victoria Bustos-Terrones, Alvaro Torres-Islas, Socorro Valdez and Arturo Molina-Ocampo
Polymers 2026, 18(2), 205; https://doi.org/10.3390/polym18020205 - 12 Jan 2026
Viewed by 172
Abstract
Polyhydroxybutyrate (PHB) is considered a coating material capable of limiting the corrosion of biodegradable metallic implants due to its biocompatibility and ability to form a physical barrier. In this study, PHB was deposited on commercial AZ91D magnesium alloy using the spin coating technique. [...] Read more.
Polyhydroxybutyrate (PHB) is considered a coating material capable of limiting the corrosion of biodegradable metallic implants due to its biocompatibility and ability to form a physical barrier. In this study, PHB was deposited on commercial AZ91D magnesium alloy using the spin coating technique. To improve adhesion at the polymer–substrate interface, the magnesium substrates were subjected to atmospheric pressure plasma treatment for different exposure times (5, 10, or 15 min) before coating. The optimal treatment time of 5 min significantly increased substrate wettability and surface free energy, facilitating stronger PHB adhesion. In addition, the PHB coatings were subjected to atmospheric pressure plasma treatment for 5, 10, or 15 s to evaluate potential surface modifications. Corrosion behavior under simulated physiological conditions was assessed via potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) in HANK’s solution at 37 °C. Pull-off tests were used to evaluate the adhesion strength between the coating and the substrate under each treatment condition. The results showed a significant decrease in the corrosion rate (Vcorr), from 4.083 mm/year for bare Mg-AZ91D to 0.001 mm/year when both the substrate and the polymer received plasma treatment. This indicates that the treatment modifies surfaces and improves interfacial bonding, enhancing polymer–metal interaction and producing durable, biocompatible coatings for medical implants. Full article
(This article belongs to the Special Issue Plasma Processing of Polymers, 2nd Edition)
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19 pages, 1058 KB  
Review
Protein Adsorption and Cell Adhesion on Metallic Biomaterial Surfaces
by Satoshi Migita and Masaki Sato
Adhesives 2025, 1(4), 15; https://doi.org/10.3390/adhesives1040015 - 18 Dec 2025
Cited by 1 | Viewed by 711
Abstract
Metallic biomaterials play essential roles in modern medical devices, but their long-term performance depends critically on protein adsorption and subsequent cellular responses at material interfaces. This review examines the molecular mechanisms governing these interactions and discusses surface modification strategies for controlling biocompatibility. The [...] Read more.
Metallic biomaterials play essential roles in modern medical devices, but their long-term performance depends critically on protein adsorption and subsequent cellular responses at material interfaces. This review examines the molecular mechanisms governing these interactions and discusses surface modification strategies for controlling biocompatibility. The physicochemical properties of oxide layers formed on metal surfaces—including Lewis acid-base chemistry, surface charge, surface free energy, and permittivity—collectively determine protein adsorption behavior. Titanium surfaces promote stable protein adsorption through strong coordination bonds with carboxylate groups, while stainless steel surfaces show complex formation with proteins that can lead to metal ion release. Surface modification strategies can be systematically categorized based on two key parameters: effective ligand density (σ_eff) and effective mechanical response (E_eff). Direct control approaches include protein immobilization, self-assembled monolayers, and ionic modifications. The most promising strategies involve coupled control of both parameters through hierarchical surface architectures and three-dimensional modifications. Despite advances in understanding molecular-level interactions, substantial challenges remain in bridging the gap between surface chemistry and tissue-level biological performance. Future developments must address three-dimensional interfacial interactions and develop systems-level approaches integrating multiple scales of biological organization to enable rational design of next-generation metallic biomaterials. Full article
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23 pages, 5241 KB  
Article
Zeolite Heulandite Modified with N,N′-bis(3-Triethoxysilylpropyl)thiourea—Adsorption of Ni(II) and Cu(II) Ions: A Quantum Chemical Insight into the Mechanism
by Elena G. Filatova, Arailym M. Nalibayeva, Oksana V. Lebedeva, Sergey A. Beznosyuk, Andrey V. Ryabykh, Elizaveta N. Oborina, Yerlan N. Abdikalykov, Mirgul Zh. Turmukhanova, Igor B. Rozentsveig and Sergey N. Adamovich
Molecules 2025, 30(24), 4811; https://doi.org/10.3390/molecules30244811 - 17 Dec 2025
Viewed by 399
Abstract
A new sorption material (GS) was obtained by the modification of heulandite zeolite (G) with N,N′-bis-(3-triethoxysilylpropyl)thiocarbamide (S). The composition, structure, and surface morphology of the GS material were confirmed using elemental analysis, IR-, NMR-spectroscopy, X-ray diffraction, scanning electron microscopy (SEM), energy dispersive X-ray [...] Read more.
A new sorption material (GS) was obtained by the modification of heulandite zeolite (G) with N,N′-bis-(3-triethoxysilylpropyl)thiocarbamide (S). The composition, structure, and surface morphology of the GS material were confirmed using elemental analysis, IR-, NMR-spectroscopy, X-ray diffraction, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), elemental mapping, and nitrogen adsorption/desorption (BET). The potential of GS as a sorbent for the removal of Cu(II) and Ni(II) ions from concentrated solutions was demonstrated. The nature of the adsorption of Cu(II) and Ni(II) ions was investigated using the Langmuir, Freundlich, and Dubinin–Radushkevich models. The adsorption value of Cu(II) and Ni(II) ions by the GS sorbent was found to be 1.7 and 2.1 times higher than that of heulandite, amounting to 0.128 mmol/g (8.1 mg/g) and 0.214 mmol/g (12.6 mg/g), respectively. The free energy of adsorption E for the adsorption of Cu(II) and Ni(II) ions was determined to be 12.5 and 16.2 kJ/mol, respectively. Calculations of changes in Gibbs energy based on quantum chemical modeling results (ΔG2980 = −38.5 kJ/mol for Ni and ΔG2980 = −56.5 kJ/mol for Cu) confirmed that adsorption of heavy metal ions onto the GS sample occurs through the formation of metal ion coordination complexes with the sorbent’s functional groups (chemosorption). The proposed method of obtaining new sorption materials based on natural heulandite is straightforward and cost-effective, enabling the production of high-capacity sorption products. Full article
(This article belongs to the Section Materials Chemistry)
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19 pages, 4089 KB  
Article
Improving the Strength of Eucalyptus Wood Joints Through Optimized Rotary Welding Conditions
by Jiankun Liang, Xiao Zhong, Yuqi Yang, Guifen Yang, Shuang Yin, Feiyan Gong, Chuchu Chen, Huali Li, Tong Meng, Yulan Jian, De Li, Caihong Long, Zhixian Song and Zhigang Wu
Materials 2025, 18(24), 5596; https://doi.org/10.3390/ma18245596 - 12 Dec 2025
Viewed by 320
Abstract
Conventional wood connections rely on adhesives and metal fasteners, causing environmental concerns. Wood rotary welding offers an adhesive-free alternative. This study systematically investigated rotary welding of eucalyptus wood, evaluating process parameters’ effects on joint performance. Chemical and microstructural transformations at the welding interface [...] Read more.
Conventional wood connections rely on adhesives and metal fasteners, causing environmental concerns. Wood rotary welding offers an adhesive-free alternative. This study systematically investigated rotary welding of eucalyptus wood, evaluating process parameters’ effects on joint performance. Chemical and microstructural transformations at the welding interface were characterized using FT-IR, XPS, XRD, SEM, and TGA. Optimal parameters significantly enhanced connection strength compared to unwelded specimens. The welding process induced partial degradation of hemicellulose and cellulose, forming new chemical bonds and increasing carbonyl compounds. XRD revealed increased wood crystallinity, while SEM showed tighter interfaces with enhanced mechanical interlocking. TGA confirmed improved thermal stability at the welded interface. The findings demonstrate that rotary welding improves eucalyptus wood joint strength through combined chemical, thermal, and structural modifications, providing guidance for optimizing welding protocols in sustainable wood manufacturing. Full article
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13 pages, 16669 KB  
Article
Silver Mask-Mediated Synthesis and Plasmonic Nanoparticle Decoration of ZnO Nanosheaves
by Sergey Dubkov, Dmitry Gromov, Daria Dronova, Nikita Malahov, Denis Novikov, Andrey Tarasov, Sergey Gavrilov, Elena Skryleva, Valeryia Murashka, Veronika Koshkarova and Hanna V. Bandarenka
J. Compos. Sci. 2025, 9(12), 686; https://doi.org/10.3390/jcs9120686 - 10 Dec 2025
Viewed by 368
Abstract
Wide band gap (WBG) oxide and metal nanocomposites can possess bifunctionality from combining tightly coupled nanoobjects with different physicochemical properties. Adjusting synthesis conditions tunes these properties through modulating the process–morphology–function relationship. However, the controllable synthesis of such nanocomposites and their related applications are [...] Read more.
Wide band gap (WBG) oxide and metal nanocomposites can possess bifunctionality from combining tightly coupled nanoobjects with different physicochemical properties. Adjusting synthesis conditions tunes these properties through modulating the process–morphology–function relationship. However, the controllable synthesis of such nanocomposites and their related applications are still underexplored. Here, we present a novel process flow to synthesize crystalline ZnO nanosheaves dotted with silver nanoparticles. The uniqueness of our strategy lies in the use of a silver mask for vertical growth of ZnO nanosheaves and thermal evaporating/dewetting Ag film to form a photocatalytic/plasmonic heterostructure. Upon combining a huge specific surface area and nanocrystallinity of ZnO nanosheaves, we enabled its surface-enhanced Raman scattering (SERS)-activity free of plasmonic components, yet their Ag modification resulted in improving detection limit in relation to Ellman’s reagent. Ag/ZnO nanosheaves showed dramatic photocatalytic activity to clean SERS-active surface. The systematic approach to synthesize Ag/ZnO heterostructure holds great promise in practical applications associated with interest in both photocatalytic and plasmonic properties. Full article
(This article belongs to the Section Nanocomposites)
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19 pages, 3328 KB  
Article
Investigation of Surface Modification Effects on the Optical and Electrical Hydrogen Sensing Characteristics of WO3 Films
by Jiabin Hu, Jie Wei, Jianmin Ye, Wen Ye, Ying Li, Zhe Lv and Meng Zhao
Sensors 2025, 25(23), 7268; https://doi.org/10.3390/s25237268 - 28 Nov 2025
Viewed by 448
Abstract
The development of hydrogen energy is advancing rapidly, while the progress of hydrogen sensors has been relatively lagging behind and cannot meet the stringent performance requirements of hydrogen energy applications. WO3 has attracted significant attention due to its highly complementary optical and [...] Read more.
The development of hydrogen energy is advancing rapidly, while the progress of hydrogen sensors has been relatively lagging behind and cannot meet the stringent performance requirements of hydrogen energy applications. WO3 has attracted significant attention due to its highly complementary optical and electrical responses to hydrogen. In this study, hydrogen-sensitive WO3 thin films characterized by vertically aligned crystallites were fabricated by modulating the substrate temperature and oxygen pressure during pulsed laser deposition. Building upon this foundation, a comprehensive investigation into surface modification strategies for enhancing sensitivity was undertaken. The surface modifications encompassed eight distinct metals and four different metal oxides. Among the metal-modified samples, palladium (Pd) Pd exhibited a markedly enhanced electrical response, defined as the ratio of the resistance in hydrogen-free air to that in hydrogen, of 1022, corresponding to ~45 times higher than the value of 22.4 achieved for Pt-modified films and 120 times higher than the value of 8.4 for Au-modified films. In addition, Pd/WO3 films showed a measurable optical transmittance change of 9.7%, while all other metal-modified samples exhibited negligible optical responses (<1%). This enhancement is attributable to the catalytic and electronic sensitisation effects of Pd. Conversely, metals such as platinum (Pt), gold (Au), and silver (Ag) elicited negligible optical responses, suggesting minimal catalytic activity. The electrical response in these cases was primarily governed by electronic sensitization effects related to the work function of the metal, with higher work function values correlating with more pronounced sensitization. Regarding metal oxide modifications, the sensitization effect was more substantial when the disparity in work function between the oxide and WO3 was greater, and this enhancement was found to be independent of the charge carrier type of the modifying oxide. These results offer significant insights into the design principles underlying high-performance WO3-based hydrogen sensors and underscore the pivotal influence of surface modification in governing their sensing characteristics. Full article
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25 pages, 2987 KB  
Review
Polyhedral Oligomeric Silsesquioxanes (POSS) for Transparent Coatings: Material Properties and Applications
by Yujia Chen, Zhiwei Bian, Yunhao Wei, Xiaojie He, Xuemin Lu and Qinghua Lu
Polymers 2025, 17(22), 3050; https://doi.org/10.3390/polym17223050 - 18 Nov 2025
Viewed by 1500
Abstract
Polyhedral oligomeric silsesquioxanes (POSS) harness their molecularly precise organic–inorganic hybrid cage architecture to deliver hardness, scratch resistance, and programmable functionality for next-generation transparent coatings. Tailoring of solubility, thermal stability, mechanical robustness, electronic characteristics, and interfacial properties is achieved through strategic peripheral modifications enabled [...] Read more.
Polyhedral oligomeric silsesquioxanes (POSS) harness their molecularly precise organic–inorganic hybrid cage architecture to deliver hardness, scratch resistance, and programmable functionality for next-generation transparent coatings. Tailoring of solubility, thermal stability, mechanical robustness, electronic characteristics, and interfacial properties is achieved through strategic peripheral modifications enabled by versatile synthetic methodologies—spanning metal catalysis, metal-free routes, and selective bond activation. Advanced integration techniques, including covalent grafting, chemical crosslinking, UV–thermal dual curing, and in situ polymerization, ensure uniform dispersion while optimizing coating–substrate adhesion and network integrity. The resultant coatings exhibit exceptional optical transparency, mechanical durability, tunable electrical performance, thermal endurance, and engineered surface hydrophobicity. These synergistic attributes underpin transformative applications across critical domains: atomic-oxygen-resistant spacecraft shielding, UV-managing agricultural films, flame-retardant architectural claddings, mechanically adaptive foldable displays, and efficiency-enhanced energy devices. Future progress will prioritize sustainable synthesis pathways, emergent asymmetric cage architectures, and multifunctional designs targeting extreme-environment resilience, thereby expanding the frontier of high-performance transparent protective technologies. Full article
(This article belongs to the Section Polymer Applications)
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35 pages, 3619 KB  
Review
Research Progress on the Preparation, Modification, and Applications of g-C3N4 in Photocatalysis and Piezoelectric Photocatalysis
by Mengyang Li, Liuqing Yang, Yizhe Song, Hongru Hou, Yujie Fang, Yucheng Liu, Lihao Xie and Dingze Lu
Inorganics 2025, 13(9), 300; https://doi.org/10.3390/inorganics13090300 - 5 Sep 2025
Viewed by 2037
Abstract
The metal-free polymeric semiconductor graphitic carbon nitride (g-C3N4) has emerged as a promising material for photocatalytic applications due to its responsiveness to visible light, adjustable electronic structure, and stability. This review systematically summarizes recent advances in preparation strategies, including [...] Read more.
The metal-free polymeric semiconductor graphitic carbon nitride (g-C3N4) has emerged as a promising material for photocatalytic applications due to its responsiveness to visible light, adjustable electronic structure, and stability. This review systematically summarizes recent advances in preparation strategies, including thermal polycondensation, solvothermal synthesis, and template methods. Additionally, it discusses modification approaches such as heterojunction construction, elemental doping, defect engineering, morphology control, and cocatalyst loading. Furthermore, it explores the diverse applications of g-C3N4-based materials in photocatalysis, including hydrogen (H2) evolution, carbon dioxide (CO2) reduction, pollutant degradation, and the emerging field of piezoelectric photocatalysis. Particular attention is given to g-C3N4 composites that are rationally designed to enhance charge separation and light utilization. Additionally, the synergistic mechanism of photo–piezocatalysis is examined, wherein a mechanically induced piezoelectric field facilitates carrier separation and surface reactions. Despite significant advancements, challenges persist, including limited visible-light absorption, scalability issues, and uncertainties in the multi-field coupling mechanisms. The aim of this review is to provide guidelines for future research that may lead to the development of high-performance and energy-efficient catalytic systems in the context of environmental and energy applications. Full article
(This article belongs to the Special Issue Featured Papers in Inorganic Materials 2025)
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26 pages, 4438 KB  
Review
Carbon Nitride Gels: Synthesis, Modification, and Water Decontamination Applications
by Qinglan Tang, Zhen Zhang, Yuwei Pan, Michael K. H. Leung, Yizhen Zhang and Keda Chen
Gels 2025, 11(9), 685; https://doi.org/10.3390/gels11090685 - 27 Aug 2025
Cited by 2 | Viewed by 988
Abstract
Graphitic carbon nitride (g-C3N4)-based materials hold significant promise for environmental remediation, particularly water purification, owing to their unique electronic structure, metal-free composition, and robust chemical stability. However, powdered g-C3N4 faces challenges such as particle aggregation, poor [...] Read more.
Graphitic carbon nitride (g-C3N4)-based materials hold significant promise for environmental remediation, particularly water purification, owing to their unique electronic structure, metal-free composition, and robust chemical stability. However, powdered g-C3N4 faces challenges such as particle aggregation, poor recyclability, and limited exposure of active sites. Structuring g-C3N4 into hydrogels or aerogels—three-dimensional porous networks offering high surface area, rapid mass transport, and tunable porosity—represents a transformative solution. This review comprehensively examines recent advances in g-C3N4-based gels, covering synthesis strategies such as crosslinking (physical/chemical), in situ polymerization, and the sol–gel and template method. Modification approaches including chemical composition and structural engineering are systematically categorized to elucidate their roles in optimizing catalytic activity, stability, and multifunctionality. Special emphasis is placed on environmental applications, including the removal of emerging contaminants and heavy metal ions, as well as solar-driven interfacial evaporation for desalination. Throughout, the critical interplay between gel structure/composition and performance is evaluated to establish design principles for next-generation materials. Finally, this review identifies current challenges regarding scalable synthesis, long-term stability, in-depth mechanistic understanding, and performance in complex real wastewater matrices. This work aims to provide valuable insights and guidance for advancing g-C3N4-based hydrogel and aerogel technologies in environmental applications. Full article
(This article belongs to the Topic Wastewater Treatment Based on AOPs, ARPs, and AORPs)
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35 pages, 3497 KB  
Review
Recent Advances in Dendrite Suppression Strategies for Solid-State Lithium Batteries: From Interface Engineering to Material Innovations
by Abniel Machín, Francisco Díaz, María C. Cotto, José Ducongé and Francisco Márquez
Batteries 2025, 11(8), 304; https://doi.org/10.3390/batteries11080304 - 8 Aug 2025
Cited by 1 | Viewed by 10036
Abstract
Solid-state lithium batteries (SSLBs) have emerged as a promising alternative to conventional lithium-ion systems due to their superior safety profile, higher energy density, and potential compatibility with lithium metal anodes. However, a major challenge hindering their widespread deployment is the formation and growth [...] Read more.
Solid-state lithium batteries (SSLBs) have emerged as a promising alternative to conventional lithium-ion systems due to their superior safety profile, higher energy density, and potential compatibility with lithium metal anodes. However, a major challenge hindering their widespread deployment is the formation and growth of lithium dendrites, which compromise both performance and safety. This review provides a comprehensive and structured overview of recent advances in dendrite suppression strategies, with special emphasis on the role played by the nature of the solid electrolyte. In particular, we examine suppression mechanisms and material innovations within the three main classes of solid electrolytes: sulfide-based, oxide-based, and polymer-based systems. Each electrolyte class presents distinct advantages and challenges in relation to dendrite behavior. Sulfide electrolytes, known for their high ionic conductivity and good interfacial wettability, suffer from poor mechanical strength and chemical instability. Oxide electrolytes exhibit excellent electrochemical stability and mechanical rigidity but often face high interfacial resistance. Polymer electrolytes, while mechanically flexible and easy to process, generally have lower ionic conductivity and limited thermal stability. This review discusses how these intrinsic properties influence dendrite nucleation and propagation, including the role of interfacial stress, grain boundaries, void formation, and electrochemical heterogeneity. To mitigate dendrite formation, we explore a variety of strategies including interfacial engineering (e.g., the use of artificial interlayers, surface coatings, and chemical additives), mechanical reinforcement (e.g., incorporation of nanostructured or gradient architectures, pressure modulation, and self-healing materials), and modifications of the solid electrolyte and electrode structure. Additionally, we highlight the critical role of advanced characterization techniques—such as in situ electron microscopy, synchrotron-based X-ray diffraction, vibrational spectroscopy, and nuclear magnetic resonance (NMR)—for elucidating dendrite formation mechanisms and evaluating the effectiveness of suppression strategies in real time. By integrating recent experimental and theoretical insights across multiple disciplines, this review identifies key limitations in current approaches and outlines emerging research directions. These include the design of multifunctional interphases, hybrid electrolytes, and real-time diagnostic tools aimed at enabling the development of reliable, scalable, and dendrite-free SSLBs suitable for practical applications in next-generation energy storage. Full article
(This article belongs to the Special Issue Advances in Solid Electrolytes and Solid-State Batteries)
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14 pages, 1527 KB  
Article
The Effect of the Metal Impurities on the Stability, Chemical, and Sensing Properties of MoSe2 Surfaces
by Danil W. Boukhvalov, Murat K. Rakhimzhanov, Aigul Shongalova, Abay S. Serikkanov, Nikolay A. Chuchvaga and Vladimir Yu. Osipov
Surfaces 2025, 8(3), 56; https://doi.org/10.3390/surfaces8030056 - 5 Aug 2025
Cited by 3 | Viewed by 973
Abstract
In this study, we present a comprehensive theoretical analysis of modifications in the physical and chemical properties of MoSe2 upon the introduction of substitutional transition metal impurities, specifically, Ti, V, Cr, Fe, Co, Ni, Cu, W, Pd, and Pt. Wet systematically calculated [...] Read more.
In this study, we present a comprehensive theoretical analysis of modifications in the physical and chemical properties of MoSe2 upon the introduction of substitutional transition metal impurities, specifically, Ti, V, Cr, Fe, Co, Ni, Cu, W, Pd, and Pt. Wet systematically calculated the adsorption enthalpies for various representative analytes, including O2, H2, CO, CO2, H2O, NO2, formaldehyde, and ethanol, and further evaluated their free energies across a range of temperatures. By employing the formula for probabilities, we accounted for the competition among molecules for active adsorption sites during simultaneous adsorption events. Our findings underscore the importance of integrating temperature effects and competitive adsorption dynamics to predict the performance of highly selective sensors accurately. Additionally, we investigated the influence of temperature and analyte concentration on sensor performance by analyzing the saturation of active sites for specific scenarios using Langmuir sorption theory. Building on our calculated adsorption energies, we screened the catalytic potential of doped MoSe2 for CO2-to-methanol conversion reactions. This paper also examines the correlations between the electronic structure of active sites and their associated sensing and catalytic capabilities, offering insights that can inform the design of advanced materials for sensors and catalytic applications. Full article
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16 pages, 1188 KB  
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 948
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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24 pages, 5788 KB  
Review
Removal of Tetracycline from Water by Biochar: Mechanisms, Challenges, and Future Perspectives
by Lin Zhang, Wentao Yang, Yonglin Chen and Liyu Yang
Water 2025, 17(13), 1960; https://doi.org/10.3390/w17131960 - 30 Jun 2025
Cited by 5 | Viewed by 2987
Abstract
Tetracycline (TC) is widely used in medicine and livestock farming. TC is difficult to degrade and tends to persist and accumulate in aquatic environments, and it has gradually become an emerging pollutant. Biochar (BC) has strong potential for removing TC from water. This [...] Read more.
Tetracycline (TC) is widely used in medicine and livestock farming. TC is difficult to degrade and tends to persist and accumulate in aquatic environments, and it has gradually become an emerging pollutant. Biochar (BC) has strong potential for removing TC from water. This potential arises from its excellent surface properties, low-cost raw materials, and renewable nature. However, raw biomass materials are highly diverse, and their preparation conditions vary significantly. Modification methods differ in specificity and the application scenarios are complex. These factors collectively cause unstable TC removal efficiency by biochar. The chemical activation process using KOH/H3PO4 significantly enhanced porosity and surface functionality, transforming raw biochar into an activated carbon material with targeted adsorption capacity. Adjusting the application dosage and environmental factors (particularly pH) further enhanced the removal performance. Solution pH critically governs the adsorption efficiency: optimal conditions (pH 5–7) increased removal by 35–40% through strengthened electrostatic attraction, whereas acidic/alkaline extremes disrupted ionizable functional groups. The dominant adsorption mechanisms of biochar involved π–π interactions, pore filling, hydrophobic interactions, hydrogen bonding, electrostatic interactions, and surface complexation. In addition, the main challenges currently hindering the large-scale application of biochar for the removal of TC from water are highlighted: (i) secondary pollution risks of biochar application from heavy metals, persistent free radicals, and toxic organic leaching; (ii) economic–environmental conflicts due to high preparation/modification costs; and (iii) performance gaps between laboratory studies and real water applications. Full article
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18 pages, 4606 KB  
Article
Dynamic 3D-Network Coating Composite Enables Global Isolation of Phosphopeptides, Stepwise Separation of Mono- and Multi-Phosphopeptides, and Phosphoproteomics of Human Lung Cells
by Linlin Liu, Zhenhua Chen, Danni Wang, Weida Liang, Binbin Wang, Chenglong Xia, Yinghua Yan, Chuanfan Ding, Xiaodan Meng and Hongze Liang
Biomolecules 2025, 15(6), 894; https://doi.org/10.3390/biom15060894 - 18 Jun 2025
Cited by 1 | Viewed by 1308
Abstract
Protein phosphorylation is one of the most common and important post-translational modifications (PTMs) and is highly involved in various biological processes. Ideal adsorbents with high sensitivity and specificity toward phosphopeptides with large coverage are therefore essential for enrichment and mass spectroscopy-based phosphoproteomics analysis. [...] Read more.
Protein phosphorylation is one of the most common and important post-translational modifications (PTMs) and is highly involved in various biological processes. Ideal adsorbents with high sensitivity and specificity toward phosphopeptides with large coverage are therefore essential for enrichment and mass spectroscopy-based phosphoproteomics analysis. In this study, a newly designed IMAC adsorbent composite was constructed on the graphene matrix coated with mesoporous silica. The outer functional 3D-network layer was prepared by free radical polymerization of the phosphonate-functionalized vinyl imidazolium salt monomer and subsequent metal immobilization. Due to its unique structural feature and high content of Ti4+ ions, the resulting phosphonate-immobilized adsorbent composite G@mSiO2@PPFIL-Ti4+ exhibits excellent performance in phosphopeptide enrichment with a low detection limit (0.1 fmol, tryptic β-casein digest) and superior selectivity (molar ratio of 1:15,000, digest mixture of β-casein and bovine serum albumin). G@mSiO2@PPFIL-Ti4+ displays high tolerance to loading and elution conditions and thus can be reused without a marked decrease in enrichment efficacy. The captured phosphopeptides can be released globally, and mono-/multi-phosphopeptides can be isolated stepwise by gradient elution. When applying this material to enrich phosphopeptides from human lung cell lysates, a total of 3268 unique phosphopeptides were identified, corresponding to 1293 phosphoproteins. Furthermore, 2698 phosphorylated peptides were found to be differentially expressed (p < 0.05) between human lung adenocarcinoma cells (SPC-A1) and human normal epithelial cells (Beas-2B), of which 1592 were upregulated and 1106 were downregulated in the cancer group. These results demonstrate the material’s superior enrichment efficiency in complex biological samples. Full article
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21 pages, 2036 KB  
Review
A Mini-Review of Sludge-Derived Biochar (SDB) for Wastewater Treatment: Recent Advances in 2020–2025
by Lia Wang, Lan Liang, Ning Li, Guanyi Chen, Haixiao Guo and Li’an Hou
Appl. Sci. 2025, 15(11), 6173; https://doi.org/10.3390/app15116173 - 30 May 2025
Cited by 4 | Viewed by 5447
Abstract
Sludge-derived biochar (SDB) synthesized by the pyrolysis of sludge is gaining enormous interest as a sustainable solution to wastewater treatment and sludge disposal. Despite the proliferation of general biochar reviews, a focused synthesis on SDB-specific advances, particularly covering the recent surge in multifunctional [...] Read more.
Sludge-derived biochar (SDB) synthesized by the pyrolysis of sludge is gaining enormous interest as a sustainable solution to wastewater treatment and sludge disposal. Despite the proliferation of general biochar reviews, a focused synthesis on SDB-specific advances, particularly covering the recent surge in multifunctional wastewater treatment applications (2020–2025), receives little emphasis. In particular, a critical analysis of recent trends, application challenges, and future research directions for SDB is still limited. Unlike broader biochar reviews, this mini-review highlights the comparative advantages and limitations of SDB, identifies emerging integration strategies (e.g., bio-electrochemical systems, catalytic membranes), and outlines future research priorities toward enhancing the durability and environmental safety of SDB applications. Specifically, this review summarized the advances from 2020 to 2025, focusing exclusively on functional modifications, and practical applications of SDB across diverse wastewater treatment technologies involved in adsorption, catalytic oxidation, membrane integration, electrochemical processes and bio-treatment systems. Quantitative comparisons of adsorption capacities (e.g., >99% Cd2+ removal, >150 mg/g tetracycline adsorption) and catalytic degradation efficiencies are provided to illustrate recent improvements. The potential of SDB in evaluating traditional and emerging contaminant degradation among the Fenton-like, persulfate, and peracetic acid activation systems was emphasized. Integration with membrane technologies reduces fouling, while electrochemical applications, including microbial fuel cells, yield higher power densities. To improve the functionality of SDB-based systems in targeting contamination removal, modification strategies, i.e., thermal activation, heteroatom doping (N, S, P), and metal loading, played crucial roles. Emerging trends highlight hybrid systems and persistent free radicals for non-radical pathways. Despite progress, critical challenges persist in scalability, long-term stability, lifecycle assessments, and scale-up implementation. The targeted synthesis of this review offers valuable insights to guide the development and practical deployment of SDB in sustainable wastewater management. Full article
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