Search Results (1,567)

Nanoparticle superlattices—periodic assemblies of uniformly spaced nanocrystals—bridge the nanoscale precision of individual particles with emergent collective properties akin to those of bulk materials. Recent advances demonstrate that multivalent ions and charged polymers can guide the co-assembly of nanoparticles, imparting electrostatic gating and enabling semiconductor-like behavior. However, the specific roles of anion geometry, valency, and charge density in mediating ion transport remain unclear. Here, we employ coarse-grained molecular dynamics simulations to investigate how applied electric fields (0–0.40 V/nm) modulate ionic conductivity and spatial distribution in trimethylammonium-functionalized gold nanoparticle superlattices assembled with four phosphate anions of distinct geometries and charges. Our results reveal that linear anions outperform ring-shaped analogues in conductivity due to higher charge densities and weaker interfacial binding. Notably, charge density exerts a greater influence on ion mobility than size alone. Under strong fields, anions accumulate at nanoparticle interfaces, where interfacial adsorption and steric constraints suppress transport. In contrast, local migration is governed by geometrical confinement and field strength. Analyses of transition probability and residence time further indicate that the rigidity and delocalized charge of cyclic anions act as mobility barriers. These findings provide mechanistic insights into the structure–function relationship governing ion transport in superlattices, offering guidance for designing next-generation ion conductors, electrochemical sensors, and energy storage materials through anion engineering. Full article

Currently, there is a growing interest in biomedical research in the use of inorganic nanoparticles for targeted drug delivery, as biosensors, and in theranostic applications. This review examines the interaction of inorganic nanoparticles with protein molecules depending on the chemical nature, size, and surface charge of the nanoparticles. The effect of protein and nanoparticle concentration, as well as their incubation time, is analyzed. The work focuses on the influence of parameters such as pH, ionic strength, and temperature on the interaction of nanoparticles with protein molecules. The following dependencies were studied in detail: the thickness of the protein corona as a function of nanoparticle size; the size of nanoparticles after interaction with protein as a function of protein and nanoparticle concentration; the distribution of zeta potentials in colloids of nanoparticles, proteins, and their mixtures. It has been shown that proteins and nanoparticles can influence each other’s physicochemical properties. This can lead to the emergence of new biological properties in the system. Therefore, the adsorption of proteins onto nanoparticle surfaces can induce conformational changes. The probability of changing the protein structure increases when a covalent bond is formed between the nanoparticle and the protein molecule. Studies demonstrate that protein structure remains more stable with spherical nanoparticles than with rod-shaped or other high-curvature nanostructures. The results presented in the review demonstrate the possibility of adapting physiological responses to nanomaterials by changing the chemical composition of the surface of nanoparticles and their size and charge. Full article

In response to the increasing demand for environmentally friendly and cost-effective adsorbents in wastewater treatment, this study reports the green synthesis, characterization, and application of a magnetic epichlorohydrin Rosa canina (m-ECH-RC) nanocomposite for removing Safranin O (SO), a commonly used cationic dye in textile effluents. The synthesized material was characterized using Brunauer–Emmett–Teller (BET), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), X-ray diffraction (XRD), and zeta potential analyses to reveal its surface morphology, pore structure, functional groups, crystallinity, and colloidal stability. Adsorption performance was systematically tested under various conditions, including pH, adsorbent dose, contact time, ionic strength, and initial dye concentration. Kinetic analyses revealed that the adsorption process of Safranin O dye mainly obeys pseudo-second-order kinetics, but intraparticle and film diffusion also contribute to the process. As a result of the Isotherm analysis, it was found that the adsorption process conformed to the Langmuir model. Testing on real textile wastewater samples demonstrated a removal efficiency of 75.09% under optimized conditions. Reusability experiments further revealed that the material maintained high adsorption–desorption performance for up to five cycles, emphasizing its potential for practical use. These findings suggest that m-ECH-RC is a viable and sustainable adsorbent for treating dye-laden industrial effluents. Full article

Ionic rare earths are extracted from primary sources by the in situ chemical leaching method, where the type and concentration of leaching agents significantly affect the mechanical properties and microstructure of the ore body. In this study, MgSO₄ and Al₂(SO₄)₃ solutions of varying concentrations were used as leaching agents to investigate the evolution of shear strength, the characteristics of Duncan–Chang hyperbolic model parameters, and the changes in microstructural pore characteristics of rare earth samples under different leaching conditions. The results show that the stress–strain curves of all samples consistently exhibit strain-hardening behavior under all leaching conditions, and shear strength is jointly influenced by confining pressure and the chemical interaction between the leaching solution and the soil. The samples leached with MgSO₄ exhibited higher shear strength than those treated with water. The samples leached with 3% and 6% Al₂(SO₄)₃ showed increased strength, while 9% Al₂(SO₄)₃ caused a slight decrease. With increasing leaching agent concentration, the cohesion of the samples significantly declined, whereas the internal friction angle remained relatively stable. The Duncan–Chang model accurately described the nonlinear deformation behavior of the rare earth samples, with the model parameter b markedly decreasing as confining pressure increased, indicating that confining stress plays a dominant role in governing the nonlinear response. Under the coupled effects of chemical leaching and mechanical stress, the number and size distribution of pores of the rare earth samples underwent a complex multiscale co-evolution. These results provide theoretical support for the green, efficient, and safe exploitation of ionic rare earth ores. Full article

A novel bio-gelatin fiber-reinforced composite (BFRC) was first developed by incorporating industrial bone glue/gelatin as the matrix, magnesium oxide (MgO) as an additive, and natural or synthetic fibers as reinforcement. Systematic tests evaluated mechanical, impact, and thermal performance, alongside microstructural mechanisms. Results showed that polyethylene (PE) fiber-reinforced composites achieved a tensile strength of 3.40 MPa and tensile strain of 10.77%, with notable improvements in compressive and flexural strength. PE-based composites also showed excellent impact energy absorption, while bamboo fiber-reinforced composites exhibited higher thermal conductivity. Microstructural analysis revealed that coordination between Mg²⁺ ions and amino acids in gelatin formed a stable cross-linked network, densifying the matrix and improving structural integrity. A multi-criteria evaluation using the TOPSIS model identified the BC-PE formulation as the most balanced system, combining strength, toughness, and thermal regulation. These findings demonstrate that ionic coordination and fiber reinforcement can overcome inherent weaknesses of gelatin matrices, offering a sustainable pathway for building insulation and cushioning packaging applications. Full article

Background/Objectives: Polybia-MP1 (MP1) exhibits antimicrobial and anticancer properties. To improve selectivity toward acidic tumor microenvironments, we designed HMP1, a histidine-substituted analog of MP1, aiming to introduce pH-responsive behavior within physiological and pathological pH ranges. Methods: HMP1 was synthesized by replacing all lysine residues in MP1 with histidines. We characterized its surfactant properties and interactions with lipid monolayers composed of DPPC under varying pH and ionic strength conditions. Langmuir monolayer experiments were used to evaluate peptide-induced morphological changes and lipid packing effects at physiologically relevant lateral pressures. Results: HMP1 displayed pH-dependent activity between pH 5.5 and 7.5, inducing significant morphological reorganization of lipid domains without reducing the condensed phase area. Ionic strength modulated these effects, with distinct behaviors observed at low and physiological saline conditions. HMP1 preferentially interacted with cholesterol-enriched membranes, while MP1 did not induce comparable effects under the same conditions, as previously reported, at physiological lateral pressures. HMP1 also exhibited non-hemolytic properties and lower cytotoxicity compared to MP1. Conclusions: The lysine-to-histidine substitution conferred pH sensitivity to HMP1, enabling selective modulation of membrane organization based on lipid composition, packing, pH, and ionic environment. These findings highlight HMP1’s potential in targeted therapeutics and pH-responsive drug delivery systems. Full article

Sulfate minerals (SMs), such as BaSO₄, SrSO₄, and CaSO₄, precipitate when incompatible solutions from the oil industry, such as seawater (SW) and high-salinity brine solutions (HSBSs), are mixed during the oil production process. To investigate the potentiality to extract SM by mixing three different brine solutions, such as HSBS-1, -2, and -3, with SW, at different temperatures and pressures, a practical simple model was used to predict the saturation index (SI), the quantity of precipitated minerals (Y), and the induction time (t_ind) required for precipitation. From the results, it was found that CaSO₄ hemihydrate and SrSO₄ yield lower amounts of precipitate. BaSO₄ precipitation ranges from 20 to 60 mg/L and 1500 mg/L of CaSO₄ anhydrous under ambient conditions. These findings suggest that recovering low-solubility minerals is technically feasible and environmentally preferable to direct disposal. Full article

This study addresses the issues of the reduced strength and increased brittleness of non-autoclaved aerated concrete by introducing an ionic modifying additive (MIA) derived from lignin-rich softwood sawdust. The additive is intended to reduce internal stresses during hydration and enhance the stability of the pore structure. Concrete samples containing 10%, 20%, and 30% additive are tested for compressive strength, wear resistance, water absorption, frost resistance, thermal conductivity, and mineral composition. Optimising the MIA content to 20% increases compressive strength by 19%, improves wear resistance by 15%, reduces water absorption by 22%, and achieves a frost resistance class of F50 versus F30 for the control sample. An X-ray diffraction analysis shows a reduction in the portlandite content from 52% to 31%, as well as increased calcite and hatrurite formation. These results confirm that the MIA optimises hydration, enhances microstructural homogeneity, and significantly extends the service life of non-autoclaved aerated concrete under cyclic freeze–thaw conditions. Full article

An extensive study on the interactions between O-phosphorylethanolamine (PEA) and O-phosphorylcholine (PPC), Cu²⁺ and Zn²⁺, is thoroughly described. The formation constants were determined at different temperatures (15 ≤ t/°C ≤ 37) and ionic strengths (0.15 ≤ I/mol L⁻¹ ≤ 0.97) by potentiometric titrations. For the Zn²⁺-PEA/-PPC systems, speciation models were also confirmed by ¹H NMR titrations at t = 25 °C and I = 0.15 mol L⁻¹ in NaCl. Sequestering abilities were calculated under different temperatures and physiological conditions. Density Functional Theory (DFT) calculations along with enhanced sampling of the conformational space were performed aimed to better elucidate the Cu²⁺-, Zn²⁺- PEA/PPC molecular interactions and their relative stabilities. Overall, both experiments and computer simulations showed that the complex species involved in the Cu²⁺–PEA system exhibited a significant and selective stability, particularly in conditions simulating cerebrospinal fluid. While the binding molecular mechanisms were elucidated via DFT supplemented by automized conformational search, the computational binding energies trend qualitatively follows the experimental logK behavior across the Cu²⁺-, Zn²⁺- PEA/PPC complexes. These results highlight the potential physiological role of PEA in modulating free copper levels and regulating its redox activity in pathological conditions, such as Wilson’s Disease (WD). Full article

Intrinsically stretchable polymer ionic conductors (PICs) hold significant application prospects in fields such as flexible sensors, energy storage devices, and wearable electronic devices, serving as promising solutions to prevent mechanical failure in flexible electronics. However, the development of PICs is hindered by an inherent trade-off between mechanical robust and electrical properties. Cellulose, renowned for its high mechanical strength, tunable chemical groups, abundant resources, excellent biocompatibility, and remarkable recyclability and biodegradability, offers a powerful strategy to decouple and enhance mechanical and electrical properties. This review presents recent advances in cellulose-based polymer ionic conductors (CPICs), which exhibit exceptional design versatility for flexible electrodes and strain sensors. We systematically discuss optimization strategies to improve their mechanical properties, electrical conductivity, and environmental stability while analyzing the key factors such as sensitivity, gauge factor, strain range, response time, and cyclic stability, where strain sensing refers to a technique that converts tiny deformations (i.e., strain) of materials or structures under external forces into measurable physical signals (e.g., electrical signals) for real-time monitoring of their deformation degree or stress state. Full article

Poly(carboxybetaine methacrylate)s (PCBMA) belongs to a class of zwitterionic polymers that offer promising alternatives to polyethylene glycol (PEG) in biomedical applications. This review highlights how the unique zwitterionic structure of PCBMA dictates its strong antifouling behavior, low immunogenicity, and sensitivity to environmental stimuli such as pH and ionic strength. These features make PCBMA promising for designing advanced systems suited for complex biological environments. This review describes PCBMA-based materials—ranging from hydrogels, nanogels, and surface coatings to drug carriers and protein conjugates—and critically evaluates their performance in drug delivery, tissue engineering, diagnostics, and implantable devices. Comparative studies demonstrated that PCBMA consistently outperformed other zwitterionic polymers and PEG in resisting protein adsorption, maintaining bioactivity of conjugated molecules, and ensuring long circulation times in vivo. Molecular dynamics simulations provide additional information into the hydration shells and conformational behaviors of PCBMA in aqueous dispersions. These insights underscore PCBMA’s broad potential as a promising high-performance material for next generation healthcare technologies. Full article

Sludge electro-dewatering technology is an attractive dewatering technology, but its application is limited by high energy consumption and filter cloth clogging caused by the dissolution of extracellular polymeric substances (EPSs). Thus, the addition of inorganic coagulants is expected to enhance the electro-dewatering efficiency of waste activated sludge (WAS). In this study, we evaluated the effects of the three typical inorganic coagulants (HPAC, PAC, and FeCl₃) on sludge electro-dewatering behavior. The results show that the electro-dewatering rate at the cathode was increased with the raising of the inorganic coagulants dosage, and FeCl₃ exhibited the best effect on the improvement of sludge electro-dewatering among the three inorganic coagulants. The zeta potential of the sludge flocs and the electro-osmotic effect were raised with the increasing of the inorganic coagulants dosage. The sludge floc conditioned by FeCl₃ is more compact than HPAC and PAC. Moreover, the dissolved EPS content reduced in the sludge electro-dewatering process when inorganic coagulant was added. In comparison to increasing ionic strength, the compression of extracellular polymeric substances (EPSs) plays a more critical role in enhancing the electro-dewatering process of sludge. The addition of inorganic coagulants also reduced the energy consumption during water removal in the electro-dewatering process. Full article

The application of organic amendments and humic acids (HA) often ameliorates saline soils, but the mechanisms responsible for their positive action have never been fully clarified. HA from four different origins (Elliott soil—EHA, peat—PHA, leonardite—LHA and compost—CHA) and polyacrylic acid (PAA) were characterized by acid–base titrations and ¹H-NMR spectroscopy and tested in laboratory experiments by measuring changes in electric conductivity (EC) and pH following micro-additions of Na₂CO₃ or NaCl. The effective salinity amelioration potential (SAP_eff) of HA, which expresses the amount of Na₂CO₃ neutralized per unit weight of HA at a given pH, was calculated. PAA had the highest capacity of mitigation, corresponding to 49.9 mg Na₂CO₃ g⁻¹, followed by LHA, EHA and PHA, whose SAP_eff values were similar and only slightly lower, and with CHA having the lowest value (25.1 mg Na₂CO₃ g⁻¹ HA). All substances failed to display any effect at constant pH when NaCl was the only salt present. The dissociation of acid groups, when HA become exposed to a more alkaline pH, produces an excess of negative charges that attracts more cations within the diffuse double layer. Because of the slower diffusion of HA and their tendency to aggregate at high ionic strengths, this action reduces the osmolarity of the soil solution and therefore mitigates salinity stress. Full article

Composite anion exchange membranes (AEMs) based on poly(terphenylene piperidinium) (PTPiQA) and impregnated with varying loadings of quaternized graphene oxide (QGO) as filler were developed, and their properties as anion exchange membranes for use in water electrolysis (AEMWEs) and fuel cells (AEMFCs) were explored. This study investigates the trade-off between mechanical robustness, ionic conductivity, and alkaline stability in QGO-reinforced twisted polymer backbones. QGO synthesized by functionalization with ethylenediamine (EDA), followed by quaternization with glycidyl trimethylammonium chloride (GTMAC), was used as a filler for PTPiQA, and the properties of the resulting composites PTPiQA-QGO-X investigated as a function of QGO loading for X between 0.1 and 0.7 wt%. Among all compositions, PTPiQA-QGO-0.3% exhibited the highest OH⁻ conductivity of 71.56 mS cm⁻¹ at room temperature, attributed to enhanced ionic connectivity and water uptake. However, this increase in conductivity was accompanied by a slight decrease in ion exchange capacity (IEC) retention (91.8%) during an alkaline stability test in 1 M KOH at 60 °C for 336 h due to localized cation degradation. Mechanical testing revealed that PTPiQA-QGO-0.3% offered optimal dry and wet tensile strength (dry TS of 42.77 MPa and wet TS of 30.20 MPa), whereas higher QGO loadings yielded low mechanical strength. These findings highlight that 0.3 wt% QGO balances ion transport efficiency and mechanical strength, while higher loadings improve alkaline durability, compromising mechanical durability and guiding the rational design of AEMs for AEMWEs and AEMFCs. Full article

This study investigates the impacts of the gas environment, water matrix, and reactive species on the TiO₂-mediated photocatalytic degradation of safranin O (SO), a dye commonly found in wastewater. A slurry reactor (UVA, 365 nm) was used to quantify SO oxidation while systematically varying the SO concentration (5–40 mg/L), the TiO₂ loading (0–3 g/L), the temperature (15–45 °C), and the pH (2–12). The dissolved gases (air, nitrogen, and argon) and matrices (deionized water, mineral water, and seawater) were also examined. Eight mechanistic probes (ascorbic acid, methanol, azide, nitrite, benzoquinone, oxalate, sucrose, and phenol) were used to identify active oxidants. UVA/TiO₂ achieved rapid decolorization in approximately 90 min at 10 mg/L of SO and 0.4 g/L of TiO₂. Decolorization rates decreased with increasing SO concentration due to active-site competition and inner-filter effects. Rates also exhibited a bell-shaped dependence on TiO₂ loading due to light scattering and aggregation at high solids concentrations. Temperature exhibited a non-monotonic profile with an optimum around 25 °C, and the pH displayed an optimum range with maximal removal occurring around pH 10 and declining at pH 12. Air saturation outperformed N₂ and Ar, indicating that O₂ is the terminal electron acceptor. Photocatalytic performance decreased in the order deionized water > mineral water > seawater, owing to bicarbonate/chloride scavenging and ionic-strength effects. Scavenger tests converged on ^•OH dominance, with measurable contributions from superoxide/hydrogen peroxide (O₂^•−/H₂O₂) and valence-band holes (h⁺); singlet oxygen (¹O₂) played a minor role. These findings underscore the critical interplay between operational and environmental factors and offer a practical framework for scaling TiO₂-based SO abatement in real waters. Full article