Search Results (2,177)

In this paper, we study the time-space truncated M-fractional model of shallow water waves in a weakly nonlinear dispersive media that characterizes the nano-solitons of ionic wave propagation along microtubules in living cells. A fractional wave transformation is applied, reducing the model to a third-order differential equation formulated as a conservative Hamiltonian system. The stability of the equilibrium points is analyzed, and the corresponding phase portraits are constructed, providing valuable insights into the expected types of solutions. Utilizing the dynamical systems approach, a variety of predicted exact fractional solutions are successfully derived, including solitary, periodic and unbounded singular solutions. One of the most notable features of this approach is its ability to identify the real propagation regions of the desired waves from both physical and mathematical perspectives. The impacts of the fractional order and gravitational force variations on the solution profiles are systematically analyzed and graphically illustrated. Moreover, the quasi-periodic dynamics and chaotic behavior of the model are explored. Full article

Low-grade Cu-Ni-PGM concentrators increasingly operate under the combined constraints of declining ore grades, variable process water quality, and the need to optimise reagent suites for sustainable production. This study examines the performance of mixed thiol collectors under controlled inorganic electrolyte conditions representative of modern concentrator water circuits. A comprehensive review of mixed-collector flotation is followed by a bench-scale experimental programme using sodium isobutyl xanthate (SIBX), sodium diethyl dithiophosphate (SEDTP), and their mixtures, tested in synthetic plant water and in CaCl₂ and NaCl solutions at fixed ionic strength. Results show that increasing the SEDTP molar fraction significantly enhances froth stability, water recovery, and solids recovery across all water types, driven by stronger surface activity and the presence of surface-active impurities. Ca²⁺ bearing process water promoted the highest Cu and Ni recoveries but also intensified gangue recoveries at high SEDTP levels, lowering concentrate grades. In contrast, SIBX-rich mixtures yielded superior selectivity, particularly in Na⁺ containing process water. Mechanistic interpretation shows that combined effects of electrical double-layer compression, mineral activation, mixed-collector adsorption, and froth stabilisation behaviour govern the observed grade–recovery trends. Overall, this study demonstrates that thiol-collector synergy is strongly water-chemistry-dependent, and that optimising collector mixtures requires coordinated control of reagent composition and process water quality. The findings provide a mechanistic basis for water-responsive reagent design in Cu-Ni-PGM flotation circuits. Full article

It has been shown for the first time that in the case of a pressure flow of a Newtonian fluid in a circular pipeline, the influence of forces of rheological origin, ion electrostatic and Van der Waals nature on the radius of the undeformed flow core is described by a third-degree polynomial with respect to the thickness of the layer, where the suspension structure is destroyed and its shear flow occurs. In this polynomial, the contributions of rheological forces and the influence of the hydraulic size of the solid-phase particles in the suspension enter as linear terms; ionic electrostatic and Van der Waals forces enter as quadratic and constant terms, respectively. For conditions typical of water–coal fuel, we demonstrate that the hydraulic (size) term is several orders of magnitude smaller than the leading terms and may be neglected, and that the quadratic term is negligible compared with the constant (free) term, so that the limiting value of the undeformed core radius is obtained as the real root of a cubic equation containing cubic, linear and constant terms. At DLVO equilibrium, the constant term vanishes, and the limiting relative core radius reduces to the rheological–hydraulic expression; away from equilibrium, the constant term becomes positive or negative, thereby altering the admissible interval of the relative core radius. Using Cardan’s method, we show analytically that (i) when the cubic discriminant is positive, a single real root exists and physically admissible solutions occur only for a negative constant term; (ii) when the discriminant is negative, three real roots exist and the maximum relative radius at which the suspension structure is preserved shifts above or below the rheological-only radius depending on the sign of the constant term. Numerical evaluation of the proposed lyophobicity model for proportionality coefficients k₁ in the range 1–10 yields a lyophobicity function varying approximately from 0.67 to 1.06, confirming the modest but non-negligible role of interparticle interaction energy in modifying the undeformed core size under water–coal fuel conditions. These results quantify the competing roles of rheology and interparticle forces in determining the stability and extent of the undeformed core in pipeline transport of structured suspensions. Full article

Alkaline water electrolysis is a widely researched method for hydrogen generation due to its low cost, scalability and its advantage of being able to produce hydrogen using only renewable energy. Enhancing the efficiency of electrolysis systems relies mainly on the development of high-performance ion-conductive membranes. The incorporation of ceramic fillers into polyvinyl alcohol (PVA) membranes as a composite material has shown considerable promise in enhancing the performance of electrolyzers. In this work, novel composite separator membranes for use in alkaline electrolyzers were developed from aqueous PVA solutions and physically crosslinked through a freeze–thawing process. To enhance the membrane properties, two types of ceramic fillers—titanium dioxide (TiO₂) and zirconium dioxide (ZrO₂)—were incorporated into the starting crosslinking solution. The thermal stability of these membranes was studied by a Differential Scanning Calorimetry (DSC) technique where we can conclude that addition of TiO₂ and ZrO₂ significantly influences the thermal properties of PVA membranes. These metal oxides enhance thermal stability, as shown by the shift in exothermic peaks toward higher temperatures and alterations in the degradation mechanism, evidenced by changes in the intensity and number of DSC peaks. The effect is concentration-dependent for TiO₂, where higher contents produce more pronounced yet increasingly complex thermal behavior. Compared with commercial membrane (Zirfon Perl), these types of membranes exhibit better electrochemical performance at ambient temperature and pressure; however, the process of preparation is simpler, reducing the cost of the hydrogen production process. The polarization curves (U-I curves) indicated a decrease in voltage with the addition of an ionic activator based on cobalt and molybdenum. Conductivity measurements performed using electrochemical impedance spectroscopy utilizing a two-probe method revealed that PVA membranes with TiO₂ exhibit ionic conductivity comparable to that of the commercial membrane. Compared to the commercial membrane, these types of membranes demonstrated similar mechanical properties and improved electrochemical performance at ambient temperature and pressure, along with a simplified production process and lower cost of hydrogen production. Full article

This paper presents the synthesis and characterization of anionic rhodium(I) complexes obtained by the reaction of a homogeneous Wilkinson catalyst or a rhodium cyclooctadiene dimer with ionic liquids as precursors. All newly produced complexes were characterized spectroscopically (NMR, ESI-MS, FT-IR) and their thermal stability was examined (TGA, melting point). Moreover, their catalytic activity was determined in the hydrosilylation of octene or allyl glycidyl ether with 1,1,1,3,3,5-heptamethyltrisiloxane and in the hydroboration reaction of styrene with pinacolborane (HBpin). All catalysts used were insoluble in the reactants, which allowed for their isolation and repeated use. Their activity was compared in subsequent 10 (hydrosilylation) or 5 (hydroboration) catalytic cycles. The obtained results allowed the selection of the most effective catalytic systems, which can be a real alternative to traditional homogeneous catalysts, offering greater ease of recovery and reuse. Full article

Intrinsic optical bi-stability in dense two-level systems is developed for the bad cavity limit where electromagnetic modes are adiabatically eliminated. Each atom interacts via dipole–dipole forces with its nearby spatial distribution of atoms. The theory is developed into two parts, corresponding to the short sample, with dimensions shorter than the wavelength, and the long sample. In both cases, the local field corrections modify the Maxwell–Bloch equations, so that cubic or quartic equations are obtained for the inversion of population as a function of the external light intensity, thus leading to intrinsic bi-stability. The effects of noise sources on intrinsic bi-stability were treated, and I found that while the observability of bi-stability was not obtained experimentally for a simple two-level system, there were many observations of bi-stability obtained through the ‘up-conversion’ of rare earth excited crystals. I show the differences between these two systems. Full article

Deep eutectic solvents (DES) have emerged as a versatile and sustainable medium for the green synthesis of nanomaterials, offering a viable alternative to conventional organic solvents and ionic liquids. Nanomaterials can be synthesised in DESs via multiple routes, including chemical reduction, solvothermal, and electrochemical methods. Among the different pathways, this review focuses on the electrochemical synthesis of nanomaterials in DESs, as it offers several advantages: low cost, scalability for large-scale production, and low-temperature processing. The size, shape, and morphology (e.g., nanoparticles, nanoflowers, nanowires) of the resulting nanostructures can be tuned by adjusting the concentration of the electroactive species, the applied potential, the current density, mechanical agitation, and the electrolyte temperature. The use of DES as an electrolytic medium represents an environmentally friendly alternative. From an electrochemical perspective, it exhibits high electrochemical stability, good solubility for a wide range of precursors, and a broad electrochemical window. Furthermore, their low surface tensions promote high nucleation rates, and their high ionic strengths induce structural effects such as templating, capping and stabilisation, that play a crucial role in controlling particle morphology, size distribution and aggregation. Despite significant progress, key challenges persist, including incomplete mechanistic understanding, limited recyclability, and difficulties in scaling up synthesis while maintaining structural precision. This review highlights recent advances in the development of metal, alloy, oxide, and carbon-based composite nanomaterials obtained by electrochemical routes from DESs, along with their applications. Full article

Polyampholytes combine cationic and anionic groups in one macromolecular platform and are emerging as versatile components for energy storage and conversion. This review synthesizes how their charge balance, hydration, and architecture can be engineered to address ionic transport, interfacial stability, and safety across batteries, supercapacitors, solar cells, and fuel cells. We classify annealed, quenched, and zwitterionic systems, outline molecular design strategies that tune charge ratio, distribution, and crosslinking, and compare device roles as gel or solid electrolytes, eutectogels, ionogels, binders, separator coatings, and interlayers. Comparative tables summarize ionic conductivity, cation transference number, electrochemical window, mechanical robustness, and temperature tolerance. Across Li and Zn batteries, polyampholytes promote ion dissociation, homogenize interfacial fields, suppress dendrites, and stabilize interphases. In supercapacitors, antifreeze hydrogels and poly(ionic liquid) networks maintain conductivity and elasticity under strain and at subzero temperature. In solar cells, zwitterionic interlayers improve work function alignment and charge extraction, while ordered networks in fuel cell membranes enable selective ion transport with reduced crossover. Design rules emerge that couple charge neutrality with controlled hydration and dynamic crosslinking to balance conductivity and mechanics. Key gaps include brittleness, ion pairing with multivalent salts, and scale-up. Opportunities include soft segment copolymerization, ionic liquid and DES plasticization, side-chain engineering, and operando studies to guide translation. Full article

Designing ionic liquids (ILs) where a single functional group orchestrates a suite of enhanced properties remains a key challenge in materials science. Here, we introduce 1-butyl-3-methylimidazolium mandelate, [Bmim][Man], a novel IL where the hydroxyl group on the mandelate anion simultaneously enhances hydrogen bonding, thermal stability, antimicrobial activity, and extraction selectivity. The structure-property relationships of [Bmim][Man] were investigated through measurements of density, viscosity, and conductivity and were compared with analogous ILs. The presence of the hydroxyl group on the mandelate anion resulted in the highest density and viscosity among the series, attributed to strong hydrogen bonding and efficient ion packing. Notably, [Bmim][Man] exhibited a high molar conductivity that decouples from its high viscosity, suggesting an unusual degree of ion dissociation facilitated by the hydroxyl group. Thermogravimetric analysis revealed superior thermal stability. Furthermore, the investigated ionic liquid demonstrated a low critical aggregation concentration (CAC = 0.01982 mol·dm⁻³) in water, indicating a strong propensity for self-aggregation. [Bmim][Man] showed synergistic, enhanced antibacterial activity against E. coli and P. aeruginosa. Finally, the functional utility of this designed liquid was demonstrated in separation science, where [Bmim][Man]-based aqueous biphasic systems showed selective extraction capabilities for transition metals, a process driven by the same hydrogen-bonding and coordination interactions that define its bulk properties. These findings establish [Bmim][Man] as a promising multifunctional material where the mandelate anion concurrently dictates liquid microstructure, thermal resilience, antimicrobial performance, and application in extraction. Full article

Fungal infections caused by Fusarium solani demand sustainable alternatives to conventional fungicides and free nanoparticles, which often show poor stability and rapid release. This study developed zinc-crosslinked alginate microparticles containing silver (AgNPs), zinc oxide (ZnONPs), or both to improve nanoparticle stability, sustain release, and enhance antifungal efficacy. Microparticles were produced by ionic gelation and characterized by FTIR, microscopy, swelling analysis, encapsulation efficiency, and kinetic modeling. AgNPs weakened hydrogen bonding within alginate, yielding rough, porous structures, whereas ZnONPs strengthened COO⁻–Zn²⁺ interactions, forming smoother surfaces with smaller pores; co-loaded particles combined both characteristics. Encapsulation efficiencies were 77.9% (AgNPs) and 98.6% (ZnONPs), with co-loaded systems retaining 64.0% and 98.9%, respectively. Swelling was highest in AgNP-loaded microparticles (63.8%) and lowest in ZnONP and co-loaded systems (≈42%). AgNPs followed anomalous transport (n = 0.65), while ZnONPs transitioned from Fickian diffusion (n ≈ 0.36–0.38) to zero-order release (K₀ = 1.00 for ZnONPs alone; 0.80 co-loaded). Antifungal tests showed strong inhibition: 80.7% for AgNPs, 91.4% for ZnONPs, and 99.7% for co-loaded formulations. Microscopy confirmed membrane disruption, hyphal collapse, and ROS-mediated damage, with the strongest effects in co-loaded samples. These results demonstrate a tunable, synergistic, sustained-release platform that outperforms single nanoparticles and offers a promising strategy for sustainable crop protection. Full article

Curcumin is a phenolic compound with antioxidant and anti-inflammatory properties; however, due to its low bioavailability, the use of encapsulation systems is recommended. Chitosan-based polymeric nanoparticles produced via ionic gelation offer controlled release, though their storage stability remains limited. In this work, the incorporation of collagen-derived peptides, NaCl, and Tween^® 80 was evaluated as a strategy to enhance physicochemical performance. A 2³ factorial design was used to identify the most relevant formulation components, resulting in four stable systems capable of retaining curcumin and preserving its antioxidant and anti-inflammatory activity during storage. These findings highlight the potential of chitosan-based systems for improving the functional performance of curcumin and suspension stability. Full article

Eutectogels, obtained from the combination of deep eutectic systems (DESs) or natural deep eutectic systems (NADESs) with polymers, represent a new class of sustainable soft materials. Combining the tunable properties of DESs, such as low volatility, ionic conductivity, and biocompatibility, with the structural integrity of gels, these materials can be designed to have improved mechanical flexibility, self-healing ability, and environmental stability. Recent research focused on understanding how the composition of DESs, polymer type, or crosslinking mechanisms influence the physicochemical behavior and performance of eutectogels. Advances in this field enabled their use in diverse biotechnological applications, particularly in drug delivery, transdermal systems, wound healing, and tissue engineering, where they demonstrate improved biofunctionality and adaptability compared to traditional hydrogels. Nevertheless, challenges related to scalability, reproducibility, long-term stability, and toxicity must be addressed to reach their full potential. Progress in this area relies on multidisciplinary efforts between green chemistry, materials science, and bioengineering. Overcoming these hurdles could allow eutectogels to evolve from academic concepts into a new generation of sustainable, high-performance soft materials with broad applicability in the biotechnology field. Full article

Improving electronic and ionic transport and the structural stability of electrode materials is essential for the development of advanced lithium-ion batteries. Despite its great potential as a high-power anode, Ti₂Nb₁₀O₂₉ (TNO) still underperforms due to its unsatisfactory electronic and ionic conductivity. Here, a TNO/carbon microtube (TNO@CMT) composite is constructed via an ethanol-assisted solvothermal process and controlled annealing. The hollow carbon framework derived from kapok fibers provides a lightweight conductive skeleton and abundant nucleation sites for uniform TNO growth. By tuning precursor concentration, the interfacial structure and loading are precisely regulated, optimizing electron/ion transport. The optimized TNO@CMT-2 exhibits uniformly dispersed TNO nanoparticles anchored on both inner and outer CMT surfaces, enabling rapid electron transfer, short Li⁺ diffusion paths, and high structural stability. Consequently, it delivers a reversible capacity of 314.9 mAh g⁻¹ at 0.5 C, retains 75.8% capacity after 1000 cycles at 10 C, and maintains 147.96 mAh g⁻¹ at 40 C. Furthermore, the Li⁺ diffusion coefficient of TNO/CMT-2 is 5.4 × 10⁻¹¹ cm² s⁻¹, which is nearly four times higher than that of pure TNO. This work presents a promising approach to designing multi-cation oxide/carbon heterostructures that synergistically enhance charge and ion transport, offering valuable insights for next-generation high-rate lithium-ion batteries. Full article

Recent botulinum neurotoxin type A (BoNT/A) formulations have shifted towards the use of polysorbate 20 (PS20) and polysorbate 80 (PS80) as a non-human-derived excipient to enhance product stability. Polysorbates are a distinct class of synthetic non-ionic surfactants with high heterogeneity in chemical structure and properties. Accumulating mechanistic and clinical evidence suggests that they may trigger immunological reactions, including hypersensitivity and immunogenicity. Such risks are largely associated with their susceptibility to degradation via hydrolysis and oxidation, forming reactive byproducts that can interact with proteins and immune pathways. Despite these mechanistic insights, data on the association between polysorbate excipients and observed immune outcomes in practice is relatively sparse and excipient-related immunogenicity and hypersensitivity is often underrecognized in practice. This review provides a summary of polysorbate excipients in BoNT/A formulations, focusing on their chemical properties and degradation pathways, characterizing downstream immune effects and appraising available clinical data of polysorbate-containing BoNT/A formulations. Finally, we discuss potential risk mitigation strategies including process modifications that could prevent degradation, and consideration of alternative excipients, such as human serum albumin, that has been shown to be immunologically inert and has an established safety profile. By integrating chemical, mechanistic, and clinical perspectives, this review seeks to clarify the implications of polysorbate use in BoNT/A formulations and inform both clinical practice and future formulation strategies. Full article

The promise of lithium–oxygen batteries lie not merely in their record-breaking theoretical energy density, but in the challenge of making such energy truly reversible. Rising as the key obstacle is the lithium metal anode, whose remarkable capacity and low potential come at the cost of dendritic growth, unstable solid electrolyte interphases, and relentless reactions with oxygen species. These instabilities, once overshadowed by cathode-related limitations, now define the frontier of research as current densities and energy demands approach practical levels. This review highlights recent progress in two complementary directions for anode protection: physical approaches, such as artificial protective layers, solid or functional separators, and oxygen-blocking interlayers that isolate and stabilize the surface; and chemical strategies, including electrolyte and additive design that enable in situ formation of LiF- and Li₃N-rich interfaces with high ionic conductivity and chemical robustness. Together, these approaches establish a unified framework for achieving dendrite-free and oxygen-resistant lithium interfaces. Mastering solid electrolyte interfacial stability rather than only cathode catalysis will ultimately determine whether lithium oxygen battery can evolve from laboratory prototypes to truly viable high-energy systems. Full article