Micro/nano powders are central to functional materials research, yet their behavior is still commonly interpreted through composition, synthesis strategy, or target application alone. Such descriptors are useful initially, but they do not explain why powders with apparently similar chemistry or architecture can exhibit markedly different functional responses under comparable conditions. The underlying difficulty is that the powder state creates a structurally and electronically heterogeneous environment in which reduced dimensions, high surface area, agglomerate porosity, defects, interfaces, and carrier pathways interact across surfaces, grain boundaries, heterointerfaces, and interparticle networks. A solid-state physics framework is developed for interpreting micro/nano powders through three coupled dimensions: defect landscapes, interfacial electrostatics, and charge-transport regimes. Rather than surveying material families descriptively, the analysis examines how defect partitioning, band-edge restructuring, trap states, space-charge formation, and transport-limited charge handling jointly define the active state of powders under operation. Particular attention is given to semiconducting and functional powder systems relevant to photocatalysis and energy conversion. The analysis shows that widely used explanations in powder literature remain incomplete when treated in isolation. On that basis, a variable-centered framework is proposed, together with an evidence hierarchy, application-level mapping, and minimum reporting logic, to support more physically grounded comparison and design of functional powders for energy-conversion technologies.
The hybrid organometallic perovskite CH3NH3PbI3 has attracted significant interest due to its structural properties and potential applications in solar cells, light-emitting diodes (LEDs), and detectors. This material exhibits different crystalline phases that can vary with temperature, humidity, and the presence of the organic cation CH3NH3+, which complicates its structural characterization via transmission electron microscopy (TEM). Analysis of fast Fourier transforms (FFTs) of high-resolution TEM (HRTEM) images indicates the existence of reflections forbidden by the perovskite structure factor. In order to identify their origin, in this work, we present the electron diffraction analysis and diffraction simulation of the most stable tetragonal phase (space group I4cm) of the hybrid perovskite, aimed at identifying and analyzing the predominant characteristics in reciprocal space. The results indicate, in addition to the structure factor allowed reflections, the existence of dynamically excited forbidden reflections associated with multiple diffraction of the sample-electron beam interaction. This combined experimental and simulation approach provides a better interpretation of TEM images and a more reliable structural characterization of beam-sensitive materials under dynamical scattering conditions.
Multifunctional nanoplatforms that can combine diagnosis, imaging and treatment into a single platform are necessary for treating cancers like Triple negative breast cancer (TNBC), as it is a malignant and aggressive subtype with limited treatments available. This study synthesized Copper nanoclusters (CuNCs) and conjugated it with quercetin, a flavonoid, to form quercetin conjugated copper nanoclusters (Que-CuNCs), as a dual functional theranostic system for TNBC. Strong excitation-dependent fluorescence, increased glutathione (GSH) responsive emission, good stability, and sensitive intracellular vision were all demonstrated by the multifunctional nanoplatform. Uniform nanoscale assembly with a high drug loading efficiency (93%) and extended release behaviour upon conjugation, which was validated by structural and surface studies. In vitro tests on MDA-MB-231 cells showed that Que-CuNCs showed decrease in cell viability, than free quercetin, and AO/EtBr staining verified the increased apoptotic induction. The suppression of the PI3K/Akt/mTOR and Wnt/β-catenin pathways was supported by the favourable binding of quercetin to mTOR and β-catenin as demonstrated by molecular docking and 100 ns molecular dynamics simulations. Overall, the Que-CuNCs system showed strong stability, fluorescence, and enhanced therapeutic efficacy, providing a compatible, cost effective nanotheranostic strategy for future clinical applications and TNBC treatment.
Extra virgin olive oil (EVOO) oil-in-water nanoemulsions were successfully developed using an ultrasonic-assisted emulsification method. The study investigated the influence of surfactant combinations with different hydrophilic–lipophilic balance (HLB) values on the physicochemical properties and stability of the nanoemulsion systems. Five surfactant blends (C1–C5), with HLB values ranging from 6.4 to 12.5, were evaluated under different ultrasonic processing conditions. The results demonstrated that both surfactant composition and ultrasonic parameters significantly affected droplet size distribution, polydispersity index (PDI), zeta potential, and storage stability of the formulations. Among the investigated systems, the nanoemulsion formulated with the Montane 60/Triton X-100 blend (C2, HLB = 9.1) and processed at 40% amplitude for 10 min exhibited the best overall physicochemical performance, characterized by the smallest droplet size, a narrow size distribution, and good physical stability during storage, particularly at 4 °C. The antibacterial activity of the optimized nanoemulsion (C2) was evaluated against representative Gram-positive and Gram-negative bacterial strains. While pure EVOO showed no measurable inhibitory effect under the tested conditions, the nanoemulsion exhibited a moderate antibacterial activity. Comparison with the corresponding surfactant control indicated that the observed antibacterial effect resulted from the combined contribution of the nanoemulsion components rather than EVOO alone. These findings provide useful insights for the optimization of stable EVOO nanoemulsions through appropriate surfactant selection and ultrasonication conditions, with potential applications in food, nutraceutical, and pharmaceutical fields.
The present work concentrates on the influence of nano and micro SiO2 particles in the cement mortar. The potential additives usage offers enhanced mechanical properties and better surface morphology. The study on the effect of nano SiO2 and ZrO2 particles in geopolymer mortar with fly ash is carried out. The detailed study on behavior of cement mortars for the different composition of nano + micro size SiO2 particles and nano SiO2 + nano ZrO2 particles mixtures is highlighted. The behavior of each sample was determined by the water absorption, normal consistency(NC), compressive and tensile strength. The results shows that the micro and nano SiO2 particles were successfully blended into the cement mortar with uniform distribution of the particles. They samples were also shown better mechanical properties for 3.0 wt percentage of micro and nano SiO2 particles. The higher strength is achieved at the period of 28 days of curing. Further, the morphological study was carried out by SEM analysis, which reveals the homogeneous distribution of nano SiO2 and ZrO2 particles in the cement mortar. In both the cases the increase in the secondary particles in the cement mortar has shown increase in the compressive and tensile strength. The significant improvement in the compressive strength by 33.58% and tensile strength by 63.30% were reported for the 3.0% of ZrO2 and SiO2 nano particles. The increase in the strength is resulted by the pozzolanic and filling effect higher surface area of the nano particles. Hence, the outcome of this research helps for the future applications of nano and micro sized secondary particles in the cement-based composition for the next generation of the multi-functional construction materials.
The rise of antibiotic-resistant pathogens demands innovative antimicrobial solutions, and green-synthesized nanoparticles offer a promising alternative. Here, chitosan-coated tellurium-gallate nanoparticles (Chi@Ga-TeNPs) were developed using gallic acid, and their broad-spectrum activity was evaluated against bacteria, including Gram-positive (Staphylococcus aureus, Bacillus cereus) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa) types, as well as fungal strains (Candida albicans, Aspergillus niger). Characterization of the nanoparticles was performed using UV-Vis spectroscopy, transmission electron microscopy (TEM), and X-ray diffraction (XRD), confirming spherical morphology with an average size of 98 ± 55 nm and high stability. In vitro safety was demonstrated through low cytotoxicity up to 128 µg/mL (viability >70%) and minimal hemolysis (<2% at 512 µg/mL). Potent antimicrobial activity was observed, with MIC values of 16 µg/mL being recorded for C. albicans and A. niger, while values of 16–32 µg/mL and 64–256 µg/mL were obtained for Gram-positive and Gram-negative bacteria, respectively. Concentration-dependent efficacy was further validated through time-kill assays, with particularly strong effects being shown against fungal strains. These findings highlight Chi@Ga-TeNPs as a promising eco-friendly antimicrobial platform for combating resistant infections.
Mixed Cellulose Ester (MCE) membranes have received little attention in the growing field of hybrid membranes for water treatment, despite the extensive work done on materials such as Polyvinylidene Fluoride (PVDF) and Polyethersulfone (PES). Our bibliometric analysis shows that the number of studies on MCE membranes remains low, and comprehensive reviews on the topic are lacking, even though MCE offers high hydrophilicity, a uniform porous structure, low cost, and ease of nanomaterial integration. This review examines MCE-based hybrid membranes modified with functional nanomaterials, including graphene oxide, MXenes, TiO₂, and Metal-Organic Frameworks (MOFs), which give the membranes antifouling, photocatalytic, self-cleaning, and high-flux properties. These MCE-based hybrids have achieved separation efficiencies above 99% in applications such as oil emulsion separation, organic dye removal, solar desalination, and pharmaceutical pollutant removal. The review also evaluates key challenges, including long-term chemical stability, the mechanisms by which nanomaterials are anchored to the membrane, industrial scalability, and the use of machine learning tools for fouling prediction and process optimization. Overall, combining nanomaterial modification with these analytical approaches positions MCE as a promising platform for future water purification technologies.
Enhancing heat and mass transfer using advanced tri-hybrid nanofluids has become essential for high-performance cooling, drilling, and electromagnetic energy systems. This study investigates the slip-induced three-dimensional flow and transport characteristics of an electromagnetic tri-hybrid nanofluid composed of ZnO–Fe₂O₃–MoS₂ nanoparticles dispersed in an Apheron base fluid over a rotating disk. The governing steady, laminar, incompressible flow equations are reduced using similarity transformations and solved numerically via MATLAB’s bvp4c solver. The results reveal that introducing velocity slip reduces radial and tangential velocities by 18–23%, while the surface temperature decreases by approximately 15% due to weakened shear-driven heating. Heat and mass transfer rates are significantly enhanced: the local Nusselt number increases by 12–17% with rising Prandtl number, whereas the Sherwood number improves by 14–19% for higher Schmidt numbers. A stronger magnetic field (higher Hartmann number) suppresses fluid motion, thickens the thermal boundary layer (BL) by nearly 11%, and increases temperature gradients. Comparative assessment demonstrates that the proposed tri-hybrid formulation outperforms mono and hybrid nanofluids, achieving up to 22% higher heat-transfer enhancement owing to the synergistic interaction of metal, metal-oxide, and sulfide nanoparticles. These findings provide a robust computational foundation for optimizing rotating disk cooling systems, drilling fluids, and micro-thermal devices operating under electromagnetic and slip-dependent conditions.
Post-synthetic modification of inorganic nanoparticles (NPs) is an unprecedented synthetically facile platform to access unique nanomaterials. Trivalent lanthanide (Ln3+) doped semiconductor NPs offer several advantages from material perspective, which particularly often are associated with their emission properties. Intrinsic challenges related to inefficient direct excitation and environmental quenching, however, need to be circumvented to access the potential uses of these luminophores. Co-sensitization of Ln3+ by another metal ion (Mn+) along with the optical antenna of the host semiconductor NPs provides an efficient way to overcome the intrinsic challenges by establishing a favorable Ln3+−Mn+ co-dopant electronic interaction. This study summarizes our current findings on post-synthetic modification of terbium doped zinc sulfide [Zn(Tb)S] NPs by various metal ions (Mn+), particularly focusing on the pre-cation exchange reaction conditions. Special attention is devoted to post-synthetic addition of Pb2+, where these cations can act as co-sensitizer for Tb3+ emission in ZnS NPs. Important mechanistic insights with regard to (a) spatial proximity of co-dopants and (b) host dependence are discussed. Density functional theory (DFT) calculations identify important energy level criterion in achieving this co-sensitization. The strategy of using the pre-cation exchange reactions and thus accessing lower concentration of Mn+ is demonstrated to detect (a) Pb2+ and (b) Sn redox states in aqueous media, with a limit of detection (LOD) in the range of sub 5 ppb level, in each case. Finally, future perspectives in this research direction towards predictive development of these materials are envisioned.
We investigated coherent electronic transport in all-carbon two-terminal junctions formed by semi-infinite carbyne electrodes bridged by phenyl-terminated alkyne oligomers (n = 1–10 repeat units). Using self-consistent DFT (GGA-PBE) and NEGF as implemented in SIESTA/TranSIESTA (DZP-like localized basis, real-space mesh ≈200–300 Ry and dense k-sampling along the transport axis), we computed zero-bias transmission, I–V and G–V curves, projected DOS and full T(E,V) landscapes up to 1.0. V. At low bias all devices lie in an off-resonant tunneling regime: zero-bias conductance decreases strongly with bridge length, from conductances on the order of ∼20 μS for the shortest bridges to below ∼0.3 μS for the longest, corresponding to transmission at EF that falls from ∼0.26 G0 to ∼4×10−3 G0 (with G0= 2e2/h). At 1.0 V the current similarly spans microampere to sub-microampere ranges (≈22 μA → ≲0.3 μA) across the series. Superposed on this dominant exponential attenuation we find reproducible odd-even (parity) modulations of conductance (tens-of-percent scale) that reflect orbital- symmetry changes when a single repeat unit is added. Finite-bias behavior is governed by discrete resonant channels: T(E,V) maps show HOMO/LUMO-derived bands entering the bias window and producing pronounced nonlinearity and conductance peaks; resonance widths decrease and spacing narrows with increasing chain length, consistent with reduced level broadening and smaller HOMO-LUMO gaps. Taken together, these results demonstrate clear design knobs, bridge length, parity, and contact matching, that tune transport from deep tunneling to resonance-dominated regimes, suggesting applications in nanoscale interconnects, bias-triggered switches and chemically sensitive molecular sensors.
In this study, the adsorption behavior of glucose on pure and systematically doped graphene nanosheets was explored by density functional theory (DFT) calculations and molecular dynamics (MD) simulations. Impurities of S, Ni and Ru atoms were incorporated into the electronic structure and adsorption properties of the graphene. The energy gap, density of states (DOS), HOMO-LUMO energies and Fermi level were calculated to analyze the electronic behavior of the studied systems. The obtained adsorption energies showed the stability of the glucose adsorption on the pure graphene systems and doped graphene systems. Doping was shown to significantly influence the electronic response and adsorption behavior of glucose molecules on graphene. Nickel-doped graphene exhibited a remarkable electronic response following glucose adsorption, along with relatively more balanced adsorption-de-adsorption behavior. Molecular dynamics simulations also confirmed the thermal and structural stability of the adsorption systems during the simulation process. The results obtained indicate that graphene-doped systems, particularly nickel-doped graphene, may represent promising materials for glucose-related sensing applications.
The rapid escalation of antimicrobial resistance (AMR) poses a severe threat to global public health, necessitating the development of alternative therapeutic strategies beyond conventional antibiotics. Antimicrobial peptides (AMPs) represent promising candidates due to their broad-spectrum activity and reduced susceptibility to classical resistance mechanisms; however, their clinical translation is hindered by poor stability, short half-life, and potential cytotoxicity. In this review, we report the rational design, synthesis, and nanoformulation of two AMP mimics, Stig-I and Stig-II, derived from the scorpion venom peptide Stigmurin. Both analogues exhibited markedly enhanced antimicrobial activity against Bacillus subtilis, with minimum inhibitory concentrations (MICs) of 3.5 µM, compared to the weak activity of the parent peptide. Stig-II demonstrated superior bactericidal efficacy, while both peptides maintained minimal haemolysis at bacteriologically relevant concentrations. To overcome peptide-associated limitations, the mimics were encapsulated within biocompatible PLA-PEG (Polylactic acid-poly(ethylene glycol)) polymeric nanoparticles, achieving high entrapment efficiencies (>95%), low polydispersity, and stable physicochemical profiles. Nanoparticle encapsulation offers protection from degradation and the potential for controlled release and improved bioavailability. Integrating peptide engineering with nanotechnology boosts AMP efficacy and safety. It offers a strong strategy for next-generation antimicrobial therapies against AMR.
Trimetallic magnesium–zirconium–aluminium mixed metal oxide (MZAO) nanocomposites were synthesised via a solution combustion route and calcined at 500 °C, 600 °C, and 700 °C to elucidate the influence of thermal treatment on fluoride adsorption. The samples were abbreviated as MZAO-500, MZAO-600, and MZAO-700 respectively. Calcination temperature played a decisive role in regulating surface hydroxyl density, surface charge, and the combined interaction among Mg, Zr, and Al active sites. Lower calcination temperature (MZAO-500) preserved a higher density of surface hydroxyl groups and a more favourable positive surface charge, as evidenced by zeta potential analysis, thereby enhancing electrostatic attraction and ion-exchange interactions with fluoride ions. Consequently, MZAO-500 exhibited superior adsorption performance. As estimated from the Langmuir model the maximum fluoride uptake capacities of MZAO-500, MZAO-600, and MZAO-700 58.37, 36.27, and 24.11 mg/g respectively. Equilibrium data were better described by the Freundlich isotherm, indicating heterogeneous adsorption arising from likely distributed surface sites. Adsorption kinetics followed a pseudo-second-order model, suggesting chemisorption-dominated fluoride capture. Thermogravimetric analysis confirmed excellent thermal stability of the nanocomposites above 800 °C. Efficient fluoride removal was achieved within a pH range of 5–8, with high selectivity retained in the presence of competing anions such as chloride, sulphate, and nitrate. X-ray photoelectron spectroscopy supporting the adsorption mechanism governed by surface hydroxyl group and electrostatic effects. These findings demonstrate that calcination-driven tuning of surface chemistry is critical for maximizing the fluoride adsorption efficiency of trimetallic oxide nanocomposites.
Hard/soft (H/S) CoCexFe2-xO4/Ni0.3Cu0.3Zn0.4Fe2O4 (x ≤ 0.025) spinel nanocomposites (H/S Ce→CFO/NCZFO (x ≤ 0.025) SNCs) were obtained via ultrasonic irradiation route. X-ray diffraction (XRD) patterns confirmed the formation of a single-phase cubic spinel structure for all compositions, with the average crystallite size (Dp) ranging between 10.8 and 19.8 nm. Electron microscopy images revealed clusters of spherical nanoparticles, while energy-dispersive X-ray (EDX) mapping verified the homogeneous distribution of all constituent elements. Vibrating sample magnetometry revealed that the nanocomposites exhibit superparamagnetism at ambient temperature. This was characterized by smooth M-H curves and single-peak in their demagnetization differential curves, which indicate an effective exchange coupling between the two ferrite components. At 20 K, the combinations revealed ferrimagnetic behaviors. While the pristine H/S (x = 0.00) displayed a smooth M-H curve and maintained a single-phase-like switching behavior, the Ce-doped H/S ferrite-based samples (x ≥ 0.010) exhibited kinks in their M-H curves and multiple peaks in their demagnetization differential curves, indicating a weakening of the exchange coupling at low temperatures. Substitution with Ce ions led to a systematic decrease in saturation magnetization (Ms) and magnetic moment (nB), while the coercivity (Hc) increased significantly at low temperatures, reflecting enhanced magnetocrystalline anisotropy. The measurements of magnetization versus temperature confirmed the transition from a superparamagnetic state to a ferrimagnetic state, with blocking temperatures (TB) observed to increase from 149.1 K (x = 0.015) to 162.2 K (x = 0.025). These results highlight the role of Cerium in tailoring the magnetic hardness and thermal stability of hard/soft ferrite systems.
Electrochemical exfoliation of graphene is emerging as an efficient process owing to its high scalability. However, most studies are conducted at high voltages, resulting in multi-layer graphene with high defect concentrations. In this study, multilayer graphene was synthesized via electrochemical exfoliation of graphite foil using KOH solution at various processing conditions. The effects of various process parameters, including molarity, electrode spacing, electrolyte temperature, current density, and stirring speed, on the kinetics of graphene exfoliation were studied. The as-synthesized graphene was characterized using various techniques. TEM, AFM, and Raman spectroscopy confirmed the synthesis of multilayer graphene with relatively low defect concentrations. A proof-of-concept study showed that tungsten oxide nanopowder exhibits improved NO2 gas-sensing performance when mixed with graphene. The minimum concentration of NO2 detected at room temperature using tungsten oxide mixed with graphene nanoplatelets was 0.75 ppm.
