Search Results (253)

Separating azeotropes is an important, difficult, and expensive task, in particular for the 2-propanol–water mixture. The literature on the problem is rich in modeling studies but often lacking even the simplest experimental confirmation. In this paper, extractive distillation, liquid–liquid equilibrium-based extraction, and salting-out were experimentally tested for the desired separation. Among the four tested extractive distillation entrainers, none was able—in the investigated experimental setup—to push the system over the azeotropic composition threshold. Four novel hydrophobic deep eutectic extraction media were tested for the desired separation, and those based on menthol or thymol with decanoic acid were found most promising. Among 16 tested salting-out agents, 5 of them produced two-liquid phases, and only 4 hydrophilic inorganic salts promoted 2-propanol separation, with sodium carbonate being the most promising candidate. The purity of the products was tested with FTIR and ¹H-NMR. The experimental findings were compared with COSMO-RS model predictions, with moderate success. Full article

Background and Clinical Significance: The retreatment of failed dental implants remains a challenging clinical scenario, particularly when complicated by peri-implantitis and as sociated bone loss. Successful management requires a comprehensive and predictable approach that addresses both hard and soft tissue deficiencies. Case Presentation: This case report illustrates a fully digital, prosthetically driven workflow for the rehabilitation of a posterior mandibular site following implant failure. A 44-year-old female patient underwent removal of a failing implant and adjacent tooth due to advanced peri-implantitis and periodontitis. After healing, a digital workflow—including intraoral scanning, cone-beam computed tomography (CBCT), and virtual planning—was employed to design and fabricate a customized CAD/CAM titanium mesh for vertical guided bone regeneration. The grafting procedure utilized a composite mixture of autogenous bone and anorganic bovine bone (A-Oss). After nine months of healing, two implants with a hydrophilic surface (SOI) were placed using a fully guided surgical protocol (OneGuide system). Subsequent soft tissue grafting and final prosthetic rehabilitation with monolithic zirconia restorations resulted in stable functional and aesthetic outcomes. Conclusions: This case highlights how the integration of modern digital technologies with advanced regenerative procedures and innovative implant surfaces can enhance the predictability and long-term success of implant retreatment in compromised posterior sites. Full article

Glucose-responsive insulin delivery systems that effectively regulate insulin retention and release in response to real-time fluctuation of glucose levels are highly desirable for diabetes care with minimized risk of hypoglycemia. Herein, we report a class of glucose-sensitive copolymer microgels, prepared from a simple one-pot precipitation copolymerization of 4-vinylphenylboronic acid (VPBA), 2-(dimethylamino) ethyl acrylate (DMAEA), and oligo(ethylene glycol) methyl ether methacrylate (M_w = 300, MEO₅MA), for gated glucose-responsive insulin release within the physiologically desirable glucose level range. The composition of the p(VPBA-DMAEA-MEO₅MA) copolymer microgels were analyzed using NMR and FTIR spectra. The cis-diols of glucose can reversibly bind with the −B(OH)₂ groups of the VPBA component in the microgels, resulting in the formation of negatively charged boronate esters that induce the volume phase transition of the microgels. The DMAEA component is incorporated to reduce the pK_a of VPBA, thus improving the glucose sensitivity of the microgels at physiological pH. The neutral hydrophilic MEO₅MA component is used to tune the onset of the glucose responsiveness of the microgels to the physiologically desirable levels. The more the MEO₅MA component copolymerized in the microgels, the greater the glucose concentration required to initiate the swelling of the microgels to trigger the release of insulin. When the onset of the glucose response was tuned to 4−5 mM, the copolymer microgels retained insulin effectively in the hypo-/normo-glycemic range but also released insulin efficiently in response to the elevation of glucose levels in the hyperglycemic range, which is essential for diabetes management. The copolymer microgels display no cytotoxicity in vitro. Full article

Al-based nanocomposite energetic materials have broad application prospects in explosives and propellants, owing to their excellent energy release efficiency. However, their insufficient reliability, poor stability, and difficulty of formation limit their practical application. This study employed self-assembly using a hydrophilic polymer polyvinylpyrrolidone (PVP) together with nano-aluminum powder (Al), copper oxide (CuO), and ammonium perchlorate (AP) to obtain high-strength and high-activity composite micrometer-sized microspheres. The influence of PVP concentration on the mechanical behavior of Al/AP composite microspheres was systematically investigated, and Al was replaced with ultrasonically dispersed Al/CuO to explore the mechanism of action of PVP in the system and the catalytic behavior of CuO. PVP significantly enhanced the interfacial bonding strength. The Al/AP/5%PVP microspheres achieved a strength of 8.4 MPa under 40% compressive strain, representing a 365% increase relative to Al/AP. The Al/CuO/AP/5%PVP microspheres achieved a strength of 10.2 MPa, representing a 309% increase relative to Al/CuO. The mechanical properties of the composite microspheres were improved by more than threefold, and their thermal reactivities were also higher. This study provides a new method for the controlled preparation of high-strength, high-activity, micrometer-sized energetic microspheres. These materials are expected to be applied in composite solid propellants to enhance their combustion efficiency. Full article

Purpose: Collagen membranes with biomimetic mineralization are emerging as promising materials for bone regeneration, owing to their high biocompatibility. In this study, we developed a biogenic collagen membrane by combining citrate (C) pretreatment and carboxymethyl chitosan (CMC)-mediated mineralization and further evaluated its bone healing potential. Methods: C-CMC collagen membranes were prepared by lyophilization. The mineral composition and content were tested through X-ray diffraction (XRD), Fourier transform infrared (FTIR), and thermogravimetric analysis (TGA). The micromorphology was observed using transmission electron microscopy (TEM), scanning electron microscopy (SEM), and scanning probe microscopy (SPM). Physical and mechanical properties, including the swelling rate, porosity, hydrophilicity, tensile strength, Young’s modulus, degradation, and barrier function, were also evaluated. Bone mesenchymal stem cells (BMSCs) were cultured in vitro to observe their behavior. An in vivo critical-size rat calvarial defect model was used to validate the effects of the membrane on bone regeneration. Results: The C-CMC collagen membrane was successfully synthesized as a collagen–hydroxyapatite complex with intrafibrillar mineralization, exhibiting improved mechanical properties and an optimal swelling rate, porosity, hydrophilicity, and degradation rate. Additionally, the C-CMC collagen membrane promoted BMSC proliferation, adhesion, and osteogenesis while preventing epithelial cell infiltration. In vivo experiments indicated that C-CMC collagen membranes significantly stimulated bone regeneration without causing systemic toxicity. Conclusions: Our findings suggest that the C-CMC collagen membrane possesses satisfactory physical and mechanical properties, along with good biocompatibility and efficacy in bone defect regeneration, making it a potential candidate for a bioactive guided bone regeneration membrane in clinical applications. Full article

Polyethersulfone (PES) membranes are essential in separation processes; however, their inherent hydrophobicity can limit their effectiveness in water-intensive applications. This study aims to enhance PES membranes by modifying them with a NiFe₂O₄–nanoclay composite nanoparticle to improve both their hydrophilicity and photocatalytic potential as a photocatalytic membrane. The nanoparticles were synthesized using the sol–gel auto-combustion method and incorporated into PES membranes through mixed-matrix embedding (1 wt% and 3 wt%) and surface coating. X-ray diffraction confirmed the cubic spinel structure of the composite nanoparticles, which followed the second order kinetic reaction during the photodegradation–adsorption of crystal violet. The mixed-matrix membranes displayed a remarkable 170% increase in water flux and a 25% improvement in mechanical strength, accompanied by a slight decrease in contact angle at 1 wt% of nanoparticle loading. In contrast, the surface-coated membranes demonstrated a significant reduction in contact angle to 18°, indicating a highly hydrophilic surface and increased roughness. All membranes achieved high dye removal rates of 98–99%, but only the coated membrane system exhibited approximately 50% photocatalytic degradation, following mixed kinetics. These results highlight the critical importance of surface modification in advancing PES membranes, as it significantly reduces fouling and enhances water–material interaction qualities essential for future filtration and photocatalytic applications. Exploring hybrid strategies that combine both embedding and coating approaches may yield even greater synergies in membrane functionality. Full article

Both biosystems and engineering fields demand advanced friction-reducing and lubricating materials. Due to their hydrophilicity and tissue-mimicking properties, hydrogels are ideal candidates for use as lubricants in water-based environments. They are particularly well-suited for applications involving biocompatibility or interactions with intelligent devices such as soft robots. However, external environments, whether within the human body or in engineering applications, often present a wide range of dynamic conditions, including variations in shear stress, temperature, light, pH, and electric fields. Additionally, hydrogels inherently possess low mechanical strength, and their dimensional stability can be compromised by changes during hydration. This review focuses on recent advancements in using environmentally responsive hydrogels as lubricants. It explores strategies involving physical or structural modifications, as well as the incorporation of smart chemical functional groups into hydrogel polymer chains, which enable diverse responsive mechanisms. Drawing on both the existing literature and our own research, we also examine how composite friction materials where hydrogels serve as water-based lubricants offer promising solutions for demanding engineering environments, such as bearing systems in marine vessels. Full article

In the pursuit of environmental sustainability, reduced emissions, and alignment with circular economy principles, bio-epoxy resin nanocomposites have emerged as a promising alternative to traditional petroleum-based resins. This study investigates the development of novel bio-epoxy nanocomposites incorporating iron-oxide nanoparticles (Fe₂O₃, MnP) as multifunctional fillers at loadings of 0.5 wt.% and 3.0 wt.%. MnP nanoparticles were synthesized and subsequently functionalized with citric acid (MnP-CA) to enhance their surface properties. Comprehensive characterization of MnP and MnP-CA was performed using X-ray diffraction (XRD) to determine the crystalline structure, attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR), thermogravimetric analysis (TGA), and zeta potential measurements to confirm surface functionalization. The bio-epoxy resins matrix (bio-EP), optimized for compatibility with MnP and MnP-CA, was thoroughly analyzed in terms of chemical structure, thermal stability, curing behavior, dynamic–mechanical properties, and surface characteristics. Non-isothermal differential scanning calorimetry (DSC) was employed to evaluate the curing kinetics of both the neat (bio-EP) and the MnP/MnP-CA-reinforced composites, offering insights into the influence of nanoparticle functionalization on the resin system. Surface zeta potential measurements further elucidated the effect of filler content on the surface charge and hydrophilicity. Magnetic characterization revealed superparamagnetic behavior in all MnP- and MnP-CA-reinforced (bio-EP) composites. This research provides a foundational framework for the design of green bio-epoxy nanocomposites, demonstrating their potential as environmentally friendly materials and representing an emerging class of sustainable alternatives. The results underscore the viability of bio-epoxy systems as a transformative solution for advancing sustainable resin technologies across eco-conscious industries. Full article

Composite electrodeposited coatings hold significant potential for marine and aerospace applications due to their synergistic corrosion resistance and wear durability, yet nanoparticle agglomeration and interfacial incompatibility persistently undermine their performance. Conventional dispersion techniques—mechanical agitation, surfactants, or high-energy methods—fail to resolve these issues, often introducing residual stresses, organic impurities, or thermal damage to substrates. This study addresses these challenges through a novel thermal-assisted alkaline etching (TAE) protocol that synergistically removes surface oxides and enhances colloidal stability in β-SiC nanoparticles. By combining NaOH-based etching with low-temperature calcination (250 °C), the method achieves oxide-free SiC surfaces with elevated hydrophilicity and a ζ-potential of −25 mV, enabling submicron clustering (300 nm) without surfactants. Electrodeposited Co/SiC coatings incorporating TAE-SiC exhibited current-modulated reinforcement, achieving optimal SiC incorporation (5.9 at% Si) at 8 A/dm² through electrophoretic–hydraulic synergy, along with uniform cross-sectional distribution validated by SEM. Tribological assessments revealed shorter wear tracks in TAE-SiC-enhanced coatings compared to their untreated counterparts, suggesting enhanced interfacial coherence despite a comparable mass loss. Demonstrating scalability through cost-effective aqueous-phase chemistry, this methodology provides a generalized framework applicable to other ceramic-reinforced systems (e.g., Al₂O₃ and TiC), offering transformative potential for next-generation protective coatings in harsh operational environments. Full article

The design of high-performance drilling fluid systems is of vital importance for the safe and efficient exploitation of natural gas hydrates. Incorporating appropriate nanoparticles into drilling fluids can significantly enhance drilling fluid loss control, wellbore stability, and hydrate inhibition. However, the combined effects of nanoparticles and conventional additives on hydrate inhibition in drilling fluid systems remain poorly understood. In this study, the influence of nanoparticles on hydrate formation was first evaluated in a base mud, followed by an investigation of their combined effects with common drilling fluid additives. The results demonstrate that hydrophilic nano-CaCO₃ particles exhibit hydrate inhibitory effects, with the strongest inhibition observed at 3.0%. Composite system tests (incorporating nanoparticles with sepiolite, filtrate reducers, and flow modifiers) revealed diverse effects on hydrate formation. Specifically, the combination of nanoparticles and sepiolite promoted hydrate formation; the combination of nanoparticles and filtrate reducers showed divergent effects. Mixtures of nanoparticles with 0.2% low-viscosity anionic cellulose (LV-PAC), carboxymethyl starch (CMS), and low-viscosity carboxymethyl cellulose (LV-CMC) inhibited hydrate formation, while mixtures with 0.2% sulfonated phenolic resin (SMP-2) and hydrolyzed ammonium polyacrylonitrile (NH₄-HPAN) accelerated hydrate formation. Notably, the incorporation of nanoparticles with 0.3% guar gum, sesbania gum, high-viscosity carboxymethyl cellulose (HV-CMC), or high-viscosity polyanionic cellulose (HV-PAC) resulted in the complete inhibition of hydrate formation. By contrast, the synergistic inhibition effect of the nanoparticle/xanthan gum (XC) composite system was relatively weak, with the optimal compounding concentration determined to be 0.3%. These findings provide critical insights for the development of drilling fluid systems in natural gas hydrate reservoirs, facilitating the optimization of drilling performance and enhancing operational safety in hydrate-bearing formations. Full article

The recirculating aquaculture system (RAS) has been rapidly adopted worldwide in recent years due to its high productivity, good stability, and good environmental controllability (and therefore friendliness to environment and ecology). Nevertheless, the effluent from seawater RAS contains a high level of ammonia nitrogen which is toxic to fish, so it is necessary to overcome the salinity conditions to achieve rapid and efficient nitrification for recycling. The moving bed biofilm reactor (MBBR) has been widely applied often by using PE fillers for efficient wastewater treatment. However, the start-up of MBBR in seawater environments has remained a challenge due to salinity stress and harsh inoculation conditions. This study investigated a new PE-filler surface modification method towards the enhanced start-up of mariculture MBBR by combining liquid-phase oxidation and maifanstone powder. The aim was to obtain a higher porous surface and roughness and a strong adsorption and alkalinity adjustment for the MBBR PE filler. The hydrophilic properties, surface morphology, and chemical structure of a raw polyethylene filler (an unmodified PE filler), liquid-phase oxidation modified filler (LO-PE), and liquid-phase oxidation combined with a coating of a maifanstone-powder-surface-modified filler (LO-SCPE) were first investigated and compared. The results showed that the contact angle was reduced to 45.5° after the optimal liquid-phase oxidation modification for LO-PE, 49.8% lower than that before modification, while SEM showed increased roughness and surface area by modification. Moreover, EDS presented the relative content of carbon (22.75%) and oxygen (42.36%) on the LO-SCPE surface with an O/C ratio of 186.10%, which is 177.7% higher than that of the unmodified filler. The start-up experiment on MBBRs treating simulated marine RAS wastewater (HRT = 24 h) showed that the start-up period was shortened by 10 days for LO-SCPE compared to the PE reactor, with better ammonia nitrogen removal observed for LO-SCPE (95.8%) than the PE reactor (91.7%). Meanwhile, the bacterial community composition showed that the LO-SCPE reactor had a more diverse and abundant AOB and NOB. The Nitrospira has a more significant impact on nitrification because it would directly oxidize NH₄⁺-N to NO₃⁻-N (comammox pathway) as mediated by AOB and NOB. Further, the LO-SCPE reactor showed a higher NH₄⁺-N removal rate (>99%), less NO₂⁻-N accumulation, and a shorter adaption period than the PE reactor. Eventually, the NH₄⁺-N concentrations of the three reactors (R1, R2, and R3) reached <0.1 mg/L within 3 days, and their NH₄⁺-N removal efficiencies achieved 99.53%, 99.61%, and 99.69%, respectively, under ammonia shock load. Hence, the LO-SCPE media have a higher marine wastewater treatment efficiency. Full article

The efficient removal of emulsified oil and trace organic pollutants via forward osmosis (FO) technology remains challenging due to limited water flux and membrane fouling. In this study, a series of metal oxide-modified PES-based composite FO membranes were fabricated and systematically evaluated to compare the effects of ZnO, Al₂O₃, and CuO nanoparticles on membrane structure and separation performance. The results demonstrated that the membrane modified with 0.04 g of ZnO nanoparticles achieved optimal synergy in terms of hydrophilicity, surface charge, and pore structure. The pure water flux increased from 5.48 L·m⁻²·h⁻¹ for the pristine membrane to 18.5 L·m⁻²·h⁻¹ for the ZnO-modified membrane, exhibiting a 237.5% increase in pure water flux compared to the pristine PES membrane, an oil rejection rate exceeding 97%, and over 95% rejection of typical negatively charged trace organic pollutants such as ibuprofen and tetracycline. Moreover, the ZnO-modified membrane showed excellent antifouling performance and structural stability in various organic solvent systems. This study not only optimized the interfacial chemistry and microstructure of the FO membrane but also enhanced pollutant repellence and the self-cleaning capability through increased hydrophilicity and surface negative charge density. These findings highlight the significant potential of ZnO modification for enhancing the overall performance of FO membranes and provide an effective strategy for developing high-performance, broadly applicable FO membranes for complex water purification. Full article

Microwave-assisted ionothermal strategies offer an effective pathway for rapid zeolite crystallization under mild conditions, while conventional ionothermal approaches are still constrained by prolonged crystallization cycles that limit their industrial applicability. Herein, we report a microwave-activated, ionic liquid-mediated synthesis strategy that enables the precise modulation of crystallization kinetics and composite assembly. By introducing ZSM-5 seeds into the ionic liquid system, the nucleation and growth of AlPO₄-5 were significantly accelerated, reducing crystallization time by up to 75% (optimal condition: 60 min). Among various imidazolium-based ionic liquids, [BMMIm]Br demonstrated an optimal balance of hydrophilic and hydrophobic interactions, yielding composite zeolites with high surface area (350 m²·g⁻¹) and large pore volume (0.28 cm³·g⁻¹). Comprehensive characterization (XRD, SEM-EDX, NH₃-TPD) confirmed the formation of well-defined ZSM-5/AlPO₄-5 core–shell structures and revealed tunable acid site distributions depending on the ionic liquid used. In methanol to olefins (MTO) reactions, the composite catalyst exhibited outstanding selectivity towards light olefins (C₂=–C₄=: 72.84%), markedly outperforming the individual ZSM-5 and AlPO₄-5 components. The superior catalytic behavior is primarily attributed to the synergistic effect of hierarchical acid site tuning and the integrated core–shell architecture, which together optimize reaction selectivity. This strategy provides a promising route for the rational design of high-performance zeolites with significant industrial applicability. Full article

Delivering of hydrophobic drugs by polymeric nanoparticles is an intensively investigated research and development field worldwide due to the insufficient solubility of many existing and potential new drugs in aqueous media. Among polymeric nanoparticles, micelles of biocompatible amphiphilic block copolymers are among the most promising candidates for solubilization, encapsulation, and delivery of hydrophobic drugs to improve the water solubility and thus the bioavailability of such drugs. In this study, amphiphilic ABA triblock copolymers containing biocompatible hydrophilic hyperbranched (dendritic) polyglycerol (HbPG) outer and hydrophobic poly(tetrahydrofuran) (PTHF) inner segments were synthesized using amine-telechelic PTHF as a macroinitiator for glycidol polymerization. These hyperbranched–linear–hyperbranched block copolymers form nanosized micelles with 15–20 nm diameter above the critical micelle concentration. Coagulation experiments proved high colloidal stability of the aqueous micellar solutions of these block copolymers against temperature changes. The applicability of block copolymers as drug delivery systems was investigated using curcumin, a highly hydrophobic, water-insoluble, natural anti-cancer agent. High and efficient drug solubilization up to more than 3 orders of magnitude to that of the water solubility of curcumin (>1500-fold) is achieved with the HbPG-PTHF-HbPG block copolymer nanomicelles, locating the drug in amorphous form in the inner PTHF core. Outstanding stability of and sustained curcumin release from the drug-loaded block copolymer micelles were observed. The in vitro bioactivity of the curcumin-loaded nanomicelles was investigated on U-87 glioblastoma cell line, and an optimal triblock copolymer composition was found, which showed highly effective cellular uptake and no toxicity. These findings indicate that the HbPG-PTHF-HbPG triblock copolymers are promising candidates for advanced drug solubilization and delivery systems. Full article

Proton exchange membrane (PEM) is a key component of PEM fuel cells, where the membrane plays a decisive role in determining system efficiency and overall performance. The modification of PEMs with hydrophilic dopants represents a promising strategy for extending the operational range of these devices, particularly in low-humidity and high-temperature regimes. In this study, Nafion membranes were modified with silica nanoparticles via the sol–gel method; samples with 1, 3, 5, and 10 wt.% of SiO₂ were obtained. Evaluation of key parameters demonstrated improvement of water uptake and proton conductivity for modified membranes with silica content up to 5 wt.%, while no significant changes in thermal stability (30–700 °C) were observed. The structural changes in the composite membranes were investigated using the small-angle X-ray scattering (SAXS) technique. SAXS data were analyzed using a model-dependent approach: the spherical ionic domain model was modified to account for the scattering contribution from silica nanoparticles. The results obtained demonstrated a reduction in the size of unmodified ionic domains, indicating reorganization of the composite membrane’s microstructure. Full article