Lead-free ferroelectric ceramics have gained widespread interest as alternatives to toxic lead-based dielectrics. In this work, Ba₀.₉₅Ca₀.₀₅TiO₃ (BCT) ceramics were synthesized via the conventional solid-state reaction route and evaluated for their structural and dielectric characteristics. X-ray diffraction combined with Rietveld refinement confirmed the formation of dense ceramics with a tetragonal perovskite structure (P4mm) after calcination at 850 °C and sintering at 950 °C, with refined lattice parameters a = 3.9895 Å, c = 4.0114 Å and c/a = 1.0055. The nanocrystalline microstructure remained stable, with an average crystallite size of ~26 nm and minimal lattice strain, demonstrating uniformity of the phase. Raman spectroscopy further supported the tetragonal symmetry through distinct E(TO) and A₁ vibrational modes, underlining the structural robustness of the synthesized ceramics. Dielectric investigations revealed a high permittivity of ~600 at 100 Hz and 50 °C, while a stable dielectric response was maintained between 10 kHz and 1 MHz across 100–450 °C. Importantly, dielectric loss remained below 0.1 throughout this operational range, confirming excellent thermal–frequency stability and low energy dissipation. Impedance and electric modulus analyses highlighted the presence of non-Debye type relaxation, defect-mediated hopping conduction, and clear distinction between grain and grain boundary contributions. The combination of phase purity, nanocrystalline stability, and superior dielectric response demonstrates the potential of BCT ceramics as environmentally benign candidates for next-generation capacitors, high-temperature sensors, actuators, and energy-storage devices.

Photoelectrocatalysis (PEC) is a promising solar-driven strategy that integrates photocatalysis and electrocatalysis for both solar fuel generation and water remediation. Among emerging contaminants, antibiotics and non-steroidal anti-inflammatory drugs are of particular concern due to their persistence and ecological risks. Tungsten trioxide (WO₃) is a benchmark n-type photoanode owing to its suitable band gap (~2.7 eV), strong oxidative potential, and acid stability. However, its relatively positive conduction band (~0.5 V vs. NHE) hampers O₂ reduction, limiting PEC degradation efficiency for pharmaceutical pollutants. Defect engineering via oxygen vacancies is an effective route to extend light absorption, enhance carrier mobility, and activate surface sites without complex modifications. In parallel, structuring metal oxides into three-dimensional inverse opals (IOs) produces ordered macroporous photonic crystals with tunable photonic band gaps (PBGs), where slow-photon effects can be integrated with suitable compositional modifications to improve light trapping and charge separation.

Here, we combine these two strategies in oxygen-deficient WO_3-x IO photoanodes for the PEC degradation of tetracycline (TC) and ibuprofen (IBU). PBG engineering was first optimized by tuning IO lattice constants relative to the absorption edge, as confirmed by photoelectrochemical tests and TC degradation performance. The best-performing IOs were subsequently reduced under H₂, introducing oxygen vacancies and W⁵⁺ defect states. The resulting WO_3-x IOs showed more than twofold photocurrent enhancement, extended visible–NIR absorption, and increased donor density. These oxygen-deficient IOs achieved significantly higher PEC degradation rates for both pollutants, validating the synergistic role of vacancy engineering and photonic structuring. This study highlights the potential of WO_3-x IOs as efficient photoanodes for solar-driven pharmaceutical degradation and establishes defect–photon coupling as a general strategy to advance PEC water treatment technologies.

Acknowledgements

The research work was supported by the Hellenic Foundation for Research and Innovation (HFRI) under the 3rd Call for HFRI PhD Fellowships (Fellowship Number: 5570).

Polyethylene terephthalate–derived fluorescent carbon quantum dots (PET-FCQDs) have emerged as promising nanomaterials for environmental sensing and potential biomedical applications. However, their biological safety profile remains underexplored, particularly when modified through metal doping for enhanced performance. In this study, we present a comprehensive in silico biocompatibility and safety evaluation of pristine and dual-site metal-doped PET-FCQDs (Ca, Mg, Zn, Fe) using multi-target molecular docking against key human proteins—Human Serum Albumin (HSA), Cytochrome P450 3A4 (CYP3A4), Hemoglobin, Transferrin, Caspase-3, Glutathione S-Transferase (GST), Estrogen Receptor alpha (ERα), and inflammatory markers (TNF-α, IL-6). The docking analysis revealed moderate to strong binding affinities, with variations in interaction profiles suggesting different implications for distribution, metabolism, and potential toxicity. Additionally, ADMET analysis indicated that all variants possessed high gastrointestinal absorption, low skin permeability, favorable blood-brain barrier penetration, and non-mutagenic, non-carcinogenic profiles. Metal doping enhanced aqueous solubility (up to ~18.6 mg/mL for Ca-O and Mg-O variants) but generally reduced lipophilicity (Log P: 0.38–0.64 vs. pristine: 1.13). All CQDs complied with major drug-likeness rules (Lipinski, Veber, Egan, Muegge) and displayed minimal CYP450 inhibition risk, indicating low potential for drug–drug interactions. Toxicity predictions classified all as low acute toxicity (Class III, LD₅₀ = 500–5000 mg/kg), with biodegradability dependent on doping site. These findings provide novel computational insights into the biocompatibility and pharmacokinetic behavior of PET-FCQDs and their doped analogues, supporting their safe integration in biomedical and environmental applications while highlighting site- and metal-dependent variations in safety profiles.

Stable high-spin organic radicals (S ≥ 1) are attractive objects for organic materials with potential applications in fields such as organic magnets, spintronics, spin filters, and memory devices [1]. However, the synthesis of thermally stable di- and polyradicals is a challenging task, especially when ferromagnetic exchange interactions between multiple paramagnetic centers are desired. The report discusses methods for obtaining promising synthetic blocks for the synthesis of functionally substituted di-nitronyl nitroxyl radicals and their complexes with Cu(hfac)2 based on m-xylene. Using the strategy of Pd-catalyzed cross-coupling reactions of active aryl halides based on 4,6-dibromoiso-phthalaldehyde, an approach to obtaining a new type of polyhetero-radicals is proposed. The structural features of the obtained paramagnets and their EPR spectra are considered. Recently, the bifunctional substituted nitronyl nitroxide (NNR) diradical which was synthesized by cross coupling reaction such as 1 which was successfully used as a working body in a molecular heat engine in the study of spin phase transitions between superconducting electrodes [2].

In this presentation and graphical abstract , various synthetic approaches to previously unknown types
of functionally substituted (X, Y = Br, NO2, COOR) diradicals 2, 3 with meta-positioning of the NHR fragments will be discussed. Special attention will be paid to methods of introducing reactive groups into the diradical molecule by using cross coupling reaction and the possibility of obtaining various complexes with copper salts.

References:
[1] E. V. Tretyakov, I. A. Zayakin, A. A. Dmitriev, M. V. Fedin et al. Chem. Eur. J. 2024, 30, e202303456.
[2] S. Volosheniuk, D. Bouwmeester, D. Vogel, H.S.J. van der Zant et al. Nat. Commun., 2025, 16, 3279.

Caffeine is one of the most popular bioactive substances and psychoactive agents in the world. Due to its stimulating properties and cognitive-enhancing abilities, it is a formulation staple in many beverages. Additionally, this alkaloid is known to support metabolic health. However, caffeine is rapidly absorbed and metabolized, which can limit its effectiveness throughout the body and increase the risk of side effects, including tachycardia, dependence, insomnia, and migraines, especially in highly sensitive individuals or when consumed in high doses. Materials science proves essential for this purpose. Following PRISMA guidelines, this systematic review discusses the latest advances in using nanomaterials to encapsulate caffeine in functional drinks. Results have shown that a feasible strategy to increase bioavailability, protect against gastric degradation, and enable controlled release in the intestine is to encapsulate caffeine in nano/microcarriers. These nanomaterials optimize absorption, preventing acute energy spikes and subsequent sharp declines. Furthermore, the liquid matrix of functional drinks, composed of macronutrients and micronutrients, can modulate the stability and release profile of nanosystems. The matrix also affects the interaction between the nanoparticles and the liquid environment, thereby influencing caffeine's final bioaccessibility. Therefore, understanding these interactions is essential to designing functional drinks that modulate caffeine release at the intestinal level. This approach increases the safety of caffeine intake and minimizes adverse effects caused by sudden spikes in plasma levels. Finally, using nanocarrier systems in liquid formulations can facilitate incorporating caffeine into sustained-release matrices with an improved sensory profile. This reduces the perceived bitterness by activating taste receptors in the oral mucosa, thereby enhancing consumer acceptance of the final product.

Zirconia (ZrO₂) is a ceramic oxide known for its properties such as inertness and biocompatibility, making it attractive for biomedical and protective coating applications.

In this study, Zirconia (ZrO₂) thin films were deposited using a radio-frequency magnetron sputtering (RFMS) system. A pure zirconium target was sputtered in an Ar–O₂ gas mixture. The sputtering power was systematically varied from 100 W to 400 W in order to investigate its influence on the film’s properties.

The structural, morphological and surface characteristics of the deposited films were analyzed using X-ray Diffraction, contact angle measurements and Atomic Force Microscopy. XRD results show that the monoclinic phase is predominant in lower sputtering power, and the increase in the power induces a notable change in the films' crystallinity and the preferred orientation. Higher sputtering power also led to a significance increase in the surface roughness (from 0.46 nm at 100 W to 14.77 nm at 400 W). In line with our previous work [1], in this study, the contact angle measurement showed that a sputtering power of 250 W produced the most hydrophobic films. In addition. The electrochemical behavior of the films was assessed trough potentiodynamic polarization tests in Hank’s solution. Compare to the uncoated sample, the films presented a better corrosion resistance. The results also showed that the Zirconia films exhibited a protective anti-corrosion performance.

In conclusion, the results demonstrate that the sputtering power is a key deposing parameter for tailoring different properties of zirconia thin films, confirming their potential as a protective coating for biomedical metals.

[1] H.Zegtouf et al , Influence of oxygen percentage on in vitro bioactivity of zirconia thin films obtained by RF magnetron sputtering, Applied Surface Science, V532, 2020, 147403, ISSN 0169-4332

Classical effective-medium models (e.g., Maxwell, Hamilton–Crosser) systematically underpredict thermal-conductivity enhancements in nanofluids and cannot reproduce the characteristic sublinear growth and early saturation seen across metal-oxide, graphene, and carbon-nanotube (CNT) dispersions. I present a compact mesoscale correction that augments a baseline effective-medium estimate with a single compound parameter representing interfacial layering and collective micro-scale coupling. In its simplest closed form:

κₑff / κₘ = 1 + α √φ

where κₑff is the effective thermal conductivity, κₘ the base-fluid conductivity, φ the particle volume fraction, and α one system-level parameter that can be estimated once from lightweight characterization proxies (e.g., viscosity ratio, ζ-potential, dynamic light scattering size) and then held fixed for prediction across concentrations. The √φ shape encodes two bundled effects: (i) a density-linked screening length in the interfacial layer that weakens with concentration, and (ii) a narrow resonance-like coupling window that briefly boosts transport before saturation.

Using small, public datasets (Al₂O₃/water, graphene/water, CNT/water, 20–40 °C, φ ≤ 6%), the one-parameter law reproduces curvature and saturation that classical models miss, while remaining falsifiable: once α is fixed from a single calibration point, all remaining concentrations are blind predictions. I provide a predict-then-make workflow—measure 2–3 proxies → estimate α → forecast κₑff before formulation—and a design chart linking target gain to particle size, volume fraction, and surfactant level.

The talk covers (i) derivation and physical interpretation; (ii) validation on held-out concentrations and particle types; (iii) a falsifier specifying data patterns that would refute the model; and (iv) guidance for synthesis/processing to hit required conductivity gains without extensive trial-and-error.

Alkaline earth copper silicates, with the general formula ACuSi4​O₁₀​ (A: Ca²⁺, Ba²⁺), are materials of historical relevance, known since ancient times. Notable examples are CaCuSi4​O₁₀​ (Egyptian Blue) and BaCuSi4​O₁₀​ (Han Blue), dating back to 2500 BC and 1200 BC respectively, both valued for their vibrant blue color and remarkable resistance to wear over time. In addition to their historical value, their unique layered crystalline structure and their ability to emit light in the NIR region make them promising candidates for optoelectronics. Their intense pigmentation is due to a chromophore center with a square planar [CuO₄​] group, surrounded by [SiO₄​] tetrahedra.

Although these are excellent optoelectronic materials, the literature lacks procedures for synthesizing a nanomaterial with good dimensional homogeneity. Current studies focus on exfoliating pre-formed bulk materials. A further advantage is their very low toxicity and biocompatibility, a rare quality for materials used in solar-to-electricity conversion, IR light-emitting devices, and telecommunications.

In this work, we present our recent results on the synthesis of 2D nanosheets of these two compounds and of SrCuSi4​O₁₀​. By modifying the reagents of the hydrothermal synthesis and the exfoliation conditions, it was possible to alter the final compounds obtained. Varied morphologies have been obtained: nanosheets, rolled nanosheets, and spheres. Depending on the different solvents used to exfoliate the samples, they undergo preferential exfoliation along different planes, resulting in a consequent variation in the relative intensity of the XRD pattern. The study on the influence of these multiple factors on NIR emission is currently underway.

Our study focuses on persistent luminescence (PeL) halide double perovskites (HDPs), both bulk and nano. PeL materials, or glow-in-the-dark materials, can temporarily store the excitation energy in metastable traps and release it as photons after a certain time. Given the same stoichiometry (Cs₂Na₁₋ₓAgₓInCl₆:Mn²⁺), at room temperature (RT) bulk shows PeL, but nano does not. The mechanism behind this behaviour is still unknown. To understand what causes the PeL annihilation at nano size at RT, we performed thermally stimulated luminescence measurements across a broad temperature range (10 K – 450 K) and PeL decay measurements (at RT and 15 K) after X-ray charge. These measurements enabled us to determine at which temperatures the materials exhibit PeL. At 15 K, even nano materials have PeL. So, to find out what causes the PeL behaviour change with T, we analysed electronic structure with T, using X-ray Absorption Near Edge Structure (XANES) spectroscopy at the K-edge of Mn (the emissive centre) at three different temperatures: 15 K (nano and bulk have PeL), 290 K (bulk has PeL) and 430 K (no PeL). The XANES analysis suggests that Mn is present in the bulk sample in both 2⁺ and 3⁺ oxidation states, but in the nano sample only 2⁺, so the PeL arising could be associated with the presence of the 3⁺ oxidation state.

The rise of antimicrobial resistance (AMR) poses a critical challenge to global health as conventional antibacterial drugs increasingly lose their efficacy. The administration of conventional antibacterial drugs often suffers from incomplete absorption, resulting in reduced efficacy and the need for higher or more frequent dosing. To counteract this limitation, a zinc-aluminium double hydroxide-palmitic acid nanocomposite (ZnAl-LDH-PA) was developed as a pH-reactive carrier for controlled drug delivery. The ZnAl-LDH-PA nanocomposite was synthesised using the co-precipitation method. Structural characterisation confirmed the successful intercalation: Powder X-ray diffraction (PXRD) showed an increase in the basal spacing from 8.6 Å to 14.35 Å, while Fourier transform infrared spectroscopy (FTIR) confirmed the intercalation by the disappearance of the nitrate band at 1344 cm-¹, the appearance of a COO band at 1535 cm^-¹ and the appearance of symmetric and asymmetric alkane stretching peaks at 2915 cm^-¹ and 2847 cm^-¹. Energy dispersive X-ray analysis (EDX) confirmed the incorporation of PA, with nitrogen absent and carbon making up 71.90% of the elemental composition. In addition, Brunauer–Emmett–Teller (BET) surface area measurements increased from 4.82 m²/g for the LDH host to 21.35 m²/g after intercalation, indicating improved porosity. Drug release studies showed a pH-dependent behaviour, with the highest release efficiency (68%) observed at a pH of 4.8, while a slower sustained release behaviour was observed at a pH of 7.4. The ZnAl-LDH-PA nanocomposite exhibited remarkable antimicrobial activity and retained the efficacy of palmitic acid against Escherichia coli, Klebsiella pneumoniae and Staphylococcus aureus. Overall, the results show that ZnAl-LDH-PA nanocomposites are promising candidates for smart pH-responsive drug delivery systems. This work contributes to the further development of nanostructured carriers in pharmaceutical applications and provides a basis for further research into drug delivery.