Search Results (444)

Chromium (Cr), a toxic heavy metal, poses significant environmental and health risks when industrial effluents containing Cr are discharged untreated. Addressing this challenge, this study developed a selective chromium removal strategy using IRA-900 resin in a sulfuric acid system with sodium phosphite (NaH₂PO₃) as a complexing agent. In the NaH₂PO₃-H₂SO₄ system, IRA-900 resin exhibited exceptional selectivity for Cr³⁺ with minimal co-adsorption of competing ions. The adsorption process followed the Langmuir isotherm model (R² > 0.99), indicating monolayer chemisorption dominated by homogeneous active sites, and achieved a maximum capacity of 103.56 mg·g⁻¹. Characterization via XPS, FT-IR, and SEM-EDS revealed a two-step mechanism: Cr³⁺ reacts with H₂PO₃⁻ to form an anionic complex, and then the complex undergoes electrostatic interaction and ion exchange with chloride ions (Cl⁻) on the quaternary ammonium groups of the resin. The chromium-loaded resin demonstrated remarkable structural stability, resisting Cr³⁺ desorption under conventional elution conditions. This property provides a novel pathway for chromium solidification in industrial wastewater, effectively minimizing secondary pollution risks. This work advances the design of ligand-assisted ion-exchange systems for targeted heavy metal removal, offering both high selectivity and environmental compatibility in wastewater treatment. Full article

To address critical limitations of ultra-low viscosity supercritical CO₂ fracturing fluids, including excessive fluid loss and inadequate proppant transport capacity, a series of thickeners designed to significantly enhance CO₂ viscosity were synthesized. Initially, FT-IR and ¹H NMR characterization confirmed successful chemical reactions and incorporation of both solvation-enhancing and -thickening functional groups. Subsequently, dissolution and thickening performance were evaluated using a custom-designed high-pressure vessel featuring visual observation capability, in-line viscosity monitoring, and high-temperature operation. All thickener systems exhibited excellent solubility, with 5 wt% loading elevating CO₂ viscosity to 3.68 mPa·s. Ultimately, molecular simulations performed in Materials Studio elucidated the mechanistic basis, electrostatic potential (ESP) mapping, cohesive energy density analysis, intermolecular interaction energy, and radial distribution function comparisons. These computational approaches revealed dissolution and thickening mechanisms of polymeric thickeners in CO₂. Full article

Actuating monolithic photonic components (particularly slab waveguides) requires higher force due to their inherent stiffness. However, two primary constraints must be addressed: actuator footprint and fabrication limits. Increasing the number of fingers to provide the required force is not a viable solution due to space constraints, and we must also adhere to the process design kits of standard fabrications and respect their design limits. Therefore, it is crucial to increase the actuator force output without significantly enlarging the actuator footprint while maintaining the necessary travel range. In order to achieve this, we utilize arrays of electrostatic comb drives, with each repeating cell geometry optimized to produce the highest force per actuator footprint. Our optimization strategy focuses on finger geometry, the arrangement of fingers and arms design in the comb structure, including the number of fingers per arm and arm length, ensuring that each repeating cell delivers maximum force per unit area or force intensity. Co-optimizing a repeatable, footprint-optimized comb-array unit cell (arm length, arm width, finger pitch, finger count) and validating it against an asymmetric slab waveguide load, we reach a maximum pre-pull-in force intensity of about 342 N m⁻² at 70 V with about 6 µm travel, confirmed by analytical modeling, numerical simulation, and measurement. Despite fabrication challenges such as over-etching and variations in electrode dimensions, detailed SEM analyses and correction functions ensure that the theoretical models closely match the experimental data, confirming the robustness and accuracy of the design. These optimized actuators, capable of achieving substantial force output without sacrificing travel range or mechanical stability, are particularly effective for applications in optical beam steering for in-plane silicon-photonics and related optical microsystems applications. Full article

Organic dye pollution in industrial wastewater is severe and difficult to degrade, posing a significant challenge to environmental management and water resource security. To meet the demand for the efficient elimination of Congo Red (CR) dye from industrial wastewater, this work prepared two zirconium-based metal–organic framework (MOF)–biochar composites, UIO-66@BY and UIO-67@BY, by in situ loading zirconium-based MOFs (UIO-66 and UIO-67) onto biochar (BY) via a solvothermal method. The composite material was comprehensively characterized using transmission electron microscopy (TEM), BET surface area analysis, and X-ray photoelectron spectroscopy (XPS). The adsorption results indicate that UIO-67@BY exhibits a significantly higher maximum adsorption capacity for CR dye compared to pristine biochar (BY), while UIO-66@BY also shows enhanced adsorption performance, but one that is slightly lower than that of UIO-67@BY. Further investigations reveal that the adsorption behavior conformed to a pseudo-second-order kinetic model and was well described by the Langmuir isotherm, suggesting that the adsorbent exhibited a homogeneous adsorption surface, and that chemical adsorption played a dominant role in the process. The primary mechanisms responsible for CR dye uptake by the composite include pore structure characteristics, coordination with functional groups, π–π stacking interactions, and electrostatic forces. The composite material developed herein provides an environmentally sustainable and economically efficient strategy for mitigating wastewater contamination. Full article

Synthetic dyes are increasingly relevant pollutants due to their widespread use and discharge into water bodies. This study examines how the solution pH affects the morphology of chitosan–cellulose cryogel (Ch-C-EGDE) and its impact on dye transport to adsorption sites. Adsorption tests with dyes Y5, R2, and B1 over a pH range of 2–12 revealed optimal performance at pH 2.5. High hydronium ion concentrations significantly improved adsorption capacities (945–1605 mg/g), with a hierarchy B1 > R2 > Y5 at 250 mg/L initial concentration. The dependence of the dye adsorption on the acidic pH of the solution suggests that there is a mechanism of adsorption by electrostatic forces due mainly to the protonation of the amino group (NH₃⁺). During the dye adsorption studies, a decrease in the diameter of the cryogel beads was observed, as well as a possible “zipper effect” in the pores of the Ch-C-EGDE cryogel beads, which depends on the pH at which the anionic molecules of the dyes attract the positively charged chitosan-based adsorbent walls, which physically closes the pores and results in a decrease in pore size as well as a geometric and/or load-bearing impediment. The experimental data fitted well with the pseudo-second-order kinetic models and the Sips isotherm model, indicating multilayer and heterogeneous adsorption behavior. In the Sips model, a value of n > 1 was obtained, which confirms favorable adsorption conditions and suggests strong dye-adsorbent material interactions, especially at higher dye concentrations. Full article

Carboxymethyl chitosan (CMC)-based hydrogels have emerged as promising candidates for wound dressing applications due to their excellent biocompatibility and tunable physicochemical properties. In this study, a novel hydrogel functionalized with hyaluronic acid (HA) and RGD peptides (RGD) was fabricated and evaluated for its structural characteristics and wound-healing potential. Using CMC as the base matrix and EDC/NHS as crosslinking agents, four hydrogel variants were fabricated: CMC gel, CMC-HA gel, CMC-RGD gel, and CMC-HA-RGD gel. The preliminary cell compatibility experiment identified the optimal formulation as 1% CMC, 0.9% HA, and 0.02 mg/mL RGD, crosslinked with 1 vol% EDC and 0.05 wt% NHS. Scanning electron microscopy showed a porous architecture (100–400 μm), conducive to fibroblast viability and proliferation. Zeta potential measurements (|ζ| > 30 mV) indicated colloidal stability of the hydrogel system. Fourier-transform infrared spectroscopy confirmed successful crosslinking and integration of HA and RGD via hydrogen bonding and electrostatic interactions, forming a stable three-dimensional network. Thermogravimetric analysis revealed enhanced thermal stability upon HA/RGD incorporation. CCK-8 assays demonstrated significantly improved cell viability with HA/RGD loading (p < 0.05), while Ki-67 immunofluorescence confirmed enhanced fibroblast proliferation, with the CMC-HA-RGD gel showing the most pronounced effect. In vitro scratch assay results demonstrated that the CMC-HA-RGD hydrogel dressing significantly enhanced cellular migration compared to other carboxymethyl chitosan-based hydrogel groups (p < 0.05). The observed statistically significant improvement in cell migration rate versus controls underscores the distinctive enhancement of synergistic HA and RGD modification in accelerating cellular migration and facilitating wound repair. Collectively, these findings suggest that the CMC-HA-RGD hydrogel possesses favorable physicochemical and biological properties and holds strong potential as an advanced wound dressing for the treatment of chronic and refractory wounds. Full article

Key drivetrain components in wind turbines are prone to misalignment faults due to long-term operation under fluctuating loads and harsh environments. Because misalignment develops gradually rather than occurring instantly, reliable evaluation of structural designs and surface treatments requires long-duration, multi-sensor, and multi-condition experiments that generate massive heterogeneous datasets. Traditional data management relying on manual folders and USB drives is inefficient, redundant, and lacks traceability. To address these challenges, this study presents a dedicated misalignment experimental data management platform specifically designed for wind power applications. The innovation lies in its ability to synchronize vibration, electrostatic, and laser alignment data streams in long-term tests, establish a traceable and reusable data structure linking experimental conditions with sensor outputs, and integrate laboratory results with field SCADA data. Built on Laboratory Information Management System (LIMS) principles and implemented with an MVC + Spring Boot + B/S architecture, the platform supports end-to-end functions including multi-sensor data acquisition, structured storage, automated processing, visualization, secure sharing, and cross-role collaboration. Validation on drivetrain shaft assemblies confirmed its ability to handle multi-terabyte datasets, reduce manual processing time by more than 80%, and directly integrate processed results into fault identification models. Overall, the platform establishes a scalable digital backbone for wind turbine misalignment research, supporting structural reliability evaluation, predictive maintenance, and intelligent operation and maintenance. Full article

This work reports a one-step, green synthesis of silver-micro cellulose nanocomposite (Ag@Ce NCs) using Azadirachta indica A. Juss leaf extract to load micro-cellulose isolated from peanut shells with silver nanoparticles, followed by comprehensive physicochemical characterization (FTIR, TEM, EDX-SEM, zeta potential, and XRD). The composite has pH_PZC ≈ 5.0 and was tested for simultaneous removal of methylene blue (MB) and safranin O (SO) under batch conditions across various pH levels, doses, contact times, initial concentrations, ionic strengths, and temperatures. The high removal efficiencies observed at pH 10 for MB and 6.0 for SO. The adsorption reached the maximum at 45 min before partially declining, indicating reversible binding on saturated surfaces. Isotherm study favored the Langmuir model, with similar affinities (K_L ≈ 0.106, and 0.110 L/mg) and monolayer capacities of 17.99 mg/g for MB and 14.90 mg/g for SO, suggesting non-selective competition on uniform sites. Kinetic data fitted the pseudo-second-order model, while thermodynamic analysis indicated mainly exothermic and physisorption interactions. Higher ionic strength reduced removal efficiency (at 1.0 M NaCl, %RE ≈ 33–48%), highlighting salt sensitivity typical of electrostatic attraction. The adsorbent maintained about 90% of its initial performance after five adsorption–desorption cycles in 0.1 M H₂SO₄, indicating excellent reusability. Overall, Ag@Ce NCs provide an inexpensive, eco-friendly, and reuseable platform for treating binary mixtures of cationic dyes. Full article

Cardiac hypertrophy is a critical contributor to cardiac dysfunction and the development of heart failure, yet effective therapeutic strategies remain limited. Propylene glycol alginate sulfate sodium (PSS) is a marine sulfated polysaccharide drug used in the treatment of cardiovascular diseases and has shown cardiac function benefits. Here, we designed a pH-responsive PSS-loaded nanoparticle drug delivery system. It was self-assembled by negatively charged PSS with positively charged trimethyl chitosan glycocholic acid (TMC-GA) via electrostatic interaction, and further stabilized the nanoparticles with Hydroxypropyl methylcellulose phthalate (HP55) excipients. The prepared TMC-GA/HP55@PSS nanoparticles were spherical, with a mean particle size of 361.5 ± 1.26 nm, zeta potential of −30.3 ± 0.9 mV, and encapsulation efficiency of 92.52 ± 2.4%. In vitro release study demonstrated the pH-responsive property of TMC-GA/HP55@PSS under intestinal conditions and facilitated nanoparticles absorption in the intestinal epithelium. In vitro experiments confirmed the biocompatibility of PSS and its ability to improve myocardial cell hypertrophy. In vivo, both PSS and its nanoparticles significantly ameliorated pressure overload–induced cardiac hypertrophy in mice, with TMC-GA/HP55@PSS exhibiting better cardioprotective efficacy. This study is the first to integrate pH-responsiveness and bile acid transport-mediated uptake into PSS nanocarrier systems. The findings provide valuable data and enlightenment for designing novel formulations and expanding the clinical applications of PSS. Full article

As a common semiconductor material, BiOBr has a unique layered structure and a suitable bandgap. However, the slow electron–hole separation efficiency leads to poor photocatalytic performance. To solve this problem, BiOBr/BNQDs heterojunctions were constructed. BiOBr/BNQDs composite photocatalysts were prepared by the solvothermal method, and the cocatalyst BNQDs were loaded onto BiOBr via electrostatic adsorption to enhance the photocatalytic degradation activity towards Rhodamine B (RhB). The photocatalysts were characterized by FT-IR, XRD, XPS, SEM-EDS, UV-Vis, PL, EIS, etc. Compared with pure BiOBr, the construction of heterojunctions BiOBr/BNQDs realized the rapid elimination of weak carriers and the effective separation and enrichment of high-energy carriers, which improved the efficiency of photocatalytic degradation of RhB. Among them, BiOBr/BNQDs-8.3% demonstrated the highest photocatalytic activity. The degradation rate of RhB under visible light irradiation for 60 min was up to 98.56%, and the reaction rate constant was 0.0696 min⁻¹, which was 2.80 times that of pure BiOBr. Moreover, after five photocatalytic cycles, the degradation rate was still 87.58%, demonstrating good cycling stability. Full article

The development of an economical and efficient method for recovering phosphate (PO₄³⁻-P) and ammonium nitrogen (NH₄⁺-N) is of paramount importance for environmental remediation. The preparation of Mg/Fe-loaded biochar (Mg/Fe-BC) was achieved through chemical precipitation followed by pyrolysis in this study. Single solution adsorption studies indicated that temperature significantly affected how effectively Mg/Fe-BC could adsorb and remove NH₄⁺-N, whereas PO₄³⁻-P adsorption showed minimal temperature sensitivity. In mixed simulated solutions, In the mixed simulated solution, the maximum adsorption capacities of Mg/Fe-BC for PO₄³⁻-P and NH₄⁺-N were 145.97–153.05 mg/g and 112.63–121.51 mg/g, respectively. The optimal dosage for synergistic adsorption was determined to be 3 g/L, while pH values ranging from 3 to 9 exhibited negligible effects on the adsorption of both contaminants. The presence of Ca²⁺ and HCO₃⁻ in the solution may interfere with the simultaneous adsorption of PO₄³⁻-P and NH₄⁺-N. SEM-EDS and XPS analyses revealed that the primary adsorption mechanisms of PO₄³⁻-P and NH₄⁺-N by Mg/Fe-BC involved electrostatic attraction, ion exchange, and hydrogen bonding. In practical applications using chicken manure biogas slurry, Mg/Fe-BC demonstrated synergistic adsorption effects, achieving removal efficiencies of 86.86% for PO₄³⁻-P and 36.86% for NH₄⁺-N, thereby confirming its potential application value in wastewater treatment. Full article

Background/Objective: Staphylococcus aureus (S. aureus) is a clinically significant pathogenic bacterium. Daptomycin (DAP) is a cyclic lipopeptide antibiotic used to treat infections caused by multidrug-resistant Gram-positive bacteria, including S. aureus. However, DAP currently faces clinical limitations due to its short half-life, toxic side effects, and increasingly severe drug resistance issues. This study aimed to develop a biomimetic nano-drug delivery system to enhance targeting ability, prolong blood circulation, and mitigate resistance of DAP. Methods: DAP-loaded chitosan nanocomposite particles (DAP-CS) were prepared by electrostatic self-assembly. Macrophage membrane vesicles (MM) were prepared by fusion of M1-type macrophage membranes with 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC). A biomimetic nano-drug delivery system (DAP-CS@MM) was constructed by the coextrusion process of DAP-CS and MM. Key physicochemical parameters, including particle diameter, zeta potential, encapsulation efficiency, and membrane protein retention, were systematically characterized. In vitro immune escape studies and in vivo zebrafish infection models were employed to assess the ability of immune escape and antibacterial performance, respectively. Results: The particle size of DAP-CS@MM was 110.9 ± 13.72 nm, with zeta potential +11.90 ± 1.90 mV, and encapsulation efficiency 70.43 ± 1.29%. DAP-CS@MM retained macrophage membrane proteins, including functional TLR2 receptors. In vitro immune escape assays, DAP-CS@MM demonstrated significantly enhanced immune escape compared with DAP-CS (p < 0.05). In the zebrafish infection model, DAP-CS@MM showed superior antibacterial efficacy over both DAP and DAP-CS (p < 0.05). Conclusions: The DAP-CS@MM biomimetic nano-drug delivery system exhibits excellent immune evasion and antibacterial performance, offering a novel strategy to overcome the clinical limitations of DAP. Full article

Poly(organo)phosphazenes (PPZs) are increasingly recognized as versatile biomaterials for drug delivery applications in nanomedicine. Their unique hybrid structure—featuring an inorganic backbone and highly tunable organic side chains—confers exceptional biocompatibility and adaptability. Through precise synthetic methodologies, PPZs can be engineered to exhibit a wide spectrum of functional properties, including the formation of multifunctional nanostructures tailored for specific therapeutic needs. These attributes enable PPZs to address several critical challenges associated with conventional drug delivery systems, such as poor pharmacokinetics and pharmacodynamics. By modulating solubility profiles, enhancing drug stability, enabling targeted delivery, and supporting controlled release, PPZs offer a robust platform for improving therapeutic efficacy and patient outcomes. This review explores the fundamental chemistry, biopharmaceutical characteristics, and biomedical applications of PPZs, particularly emphasizing their role in zero-dimensional nanotherapeutic systems, including various nanoparticle formulations. PPZ-based nanotherapeutics are further examined based on their drug-loading mechanisms, which include electrostatic complexation in polyelectrolytic systems, self-assembly in amphiphilic constructs, and covalent conjugation with active pharmaceutical agents. Together, these strategies underscore the potential of PPZs as a next-generation material for advanced drug delivery platforms. Full article

Quinoa protein isolate (QPI) and sodium alginate (SA) have excellent biocompatibility and functional properties, making them promising candidates for food-grade delivery systems. In this study, we developed, for the first time, a QPI/SA complex-stabilized Pickering emulsion for curcumin encapsulation. The coacervation behavior of QPI and SA was investigated from pH 1.6 to 7.5, and the structural and interfacial characteristics of the complexes were analyzed using zeta potential measurements, Fourier-transform infrared spectroscopy, scanning electron microscopy, and contact angle analysis. The results showed that the formation of QPI/SA complexes was primarily driven by electrostatic interactions, hydrogen bonding, and hydrophobic interactions, with enhanced amphiphilicity observed under optimal conditions (QPI/SA = 5:1, pH 5). The QPI/SA-stabilized Pickering emulsions demonstrated excellent emulsification performance and storage stability, maintaining an emulsification index above 90% after 7 d when prepared with 60% oil phase. In vitro digestion studies revealed stage-specific curcumin release, with sustained release in simulated gastric fluid (21.13%) and enhanced release in intestinal fluid (88.21%). Cytotoxicity assays using HeLa cells confirmed the biocompatibility of QPI/SA complexes (≤500 μg/mL), while curcumin-loaded emulsions exhibited dose-dependent anticancer activity. These findings suggest that QPI/SA holds significant potential for applications in functional foods and oral delivery systems. Full article

Electrostatic adsorption plays a crucial role in nanoparticle-based drug delivery, enabling the targeted and reversible loading of biomolecules onto nanoparticles. This review explores the fundamental mechanisms governing nanoparticle–biomolecule interactions, with a focus on electrostatics, van der Waals forces, hydrogen bonding, and protein corona formation. Various functionalization strategies—including covalent modification, polymer coatings, and layer-by-layer assembly—have been employed to enhance electrostatic binding; however, each presents trade-offs in terms of stability, complexity, and specificity. Emerging irradiation-based techniques offer potential for direct modulation of surface charge without the addition of chemical groups, yet they remain underexplored. Accurate characterization of biomolecule adsorption is equally critical; however, the limitations of individual techniques also pose challenges to this endeavor. Spectroscopic, microscopic, and electrokinetic methods each contribute unique insights but require integration for a comprehensive understanding. Overall, a multimodal approach to both functionalization and characterization is essential for advancing nanoparticle systems toward clinical drug delivery applications. Full article