Introduction:

With the recent advancements in implant technology, the need for novel biocompatible materials is higher than even. This is especially true for the hip joint, which is frequently injured with many patients disappointed from the surgery results.

Methods:

The aim of this work is to provide an extensive assessment of the properties of a porous 3D printed Direct Metal Laser Sintering (DMLS) Ti64 alloy. The assessment was carried out in two parts – experiment and simulation. The experimental part consisted of Tensile Strength mechanical testing of samples with to compute the porosity, density and Young's modulus for two types of samples with varying levels of porosity (0%, 15% and 35%) and with 3 repetitions. Finite element modeling with parameter uncertainty was used to extend mechanical testing of the samples. The paddle sample FE model was solved 128 times based on a Sobol sequence with its parameters treated as random variables.

Results:

The measured values of porosity and density averaged at 27.3 ± 4.9 and 2.72±0.03 [g/m3] for 35% porosity Ti6Al4V and 8.6 ± 0.5 and 3.52 ± 0.16 [g/m3] for 15% porosity Ti6Al4V and 1.9±1.3 and 4.16±0,1 for 0% porosity solid Ti6Al4V alloy. The Young’s modulus in tensile strength varied from 18 018.0 (35%) to 21 149.8 (15%) to 28 826.74 MPa (0%) between the samples.

Conclusions:

This study presents an extensive, two-step assessment of the Ti64 properties. Novel methods are applied both on the experimental side of the study, with tensile strength test and numerical part – with modeling under parameter uncertainty. The results showcase promising material properties of the Alloy for use in implant technology. Future studies will incorporate further experiments and extended modeling under more realistic implant loading conditions.

Acknowledgements:

Bayerische Forschungsallianz BayIntAn_THN_2025_40

Praseodymium-doped antimony–phosphate glasses with the composition 47.5Sb₂O₃–47.5NaPO₃–5WO₃–xPr₆O₁₁ (x = 0.05, 0.1, 0.25, 0.3 mol %) were prepared using the conventional melt-quenching technique to investigate the influence of Pr incorporation on their thermal, structural, physical, elastic, and optical properties. Differential scanning calorimetry (DSC) revealed glass transition temperatures (Tg) between 314.26 and 320.61 °C and thermal stability parameters (ΔT) ranging from 40.12 to 59.07 °C, with the highest stability observed for the undoped glass. FTIR spectra displayed characteristic bands corresponding to P–O–P bending, PO₃²⁻ symmetric stretching, and PO₂⁻ asymmetric stretching, with the intensity of non-bridging oxygen bands increasing with Pr content, indicating network depolymerization induced by Pr₆O₁₁ acting as a network modifier. Density slightly decreased from 4.2735 to 4.2222 g/cm³ with increasing Pr content, while hardness (Hv) showed a steady increase from 254 to 289 Kg/mm². Both molar volume (Vm) and oxygen molar volume (Vo) increased overall with Pr doping, rising from 48.47 to 49.76 cm³/mol and 16.16 to 16.40 cm³/mol respectively. Elastic moduli (longitudinal, shear, bulk, and Young’s) increased with Pr³⁺ content up to 0.25 mol%, indicating improved rigidity and compactness, before decreasing at higher concentrations due to structural relaxation. The optical band gap (Eg) increased slightly from 3.50 to 3.66 eV with doping, while the Urbach energy (E₀₀) remained constant, implying reduced defect states without added disorder. Furthermore, the refractive index increased with Pr content, attributed to greater polarizability and network density. These results suggest that moderate Pr₆O₁₁ doping produces thermally stable, mechanically robust, and optically efficient glasses, making them promising candidates for photonic and optoelectronic applications such as optical amplifiers, lasers, and infrared devices.

The development of light-emitting polymers for optoelectronic devices requires the fine tuning of photophysical properties in solution and in the solid state. Poly(N-vinylcarbazole) (PVK) is widely used, but its solid-state emission is limited by aggregation-caused quenching (ACQ). This study investigated the effects of chemical substitution with bromine (PVK-Br) and furanyl (PVK-Fur) groups, focusing on emission spectra, aggregation behavior, and photoluminescence quantum yield (PLQY). PVK, PVK-Br, and PVK-Fur were synthesized and characterized in THF solution, as films (pure and with PMMA), and as powdered material. Under UV excitation (285–320 nm), the emission spectra and PLQY were measured, and the effect of aggregation was evaluated by titration with water. In THF, PVK-Fur showed intense emission with a narrower band (smaller FWHM), indicating greater color purity and less environmental disorder. The presence of the furanyl group promoted greater electronic conjugation and delocalization, shifting the emission to the blue region (hypochromic shift) and narrowing the band gap. The addition of small amounts of water (0.1 eq) increased the PLQY from 12.2% to 13.99%, indicating aggregation-induced emission (AIE), attributed to the restriction of intramolecular movements and the suppression of non-radiative pathways. However, larger volumes of water (>5 eq) caused intense aggregation, π–π stacking, and a sharp drop in PLQY, evidencing ACQ. In the solid state, even with PMMA, PVK-Fur showed low emission due to the strong suppression of excitons by aggregation. Thus, PVK-Fur stands out as a promising candidate for fluorescent sensors in aqueous media or microenvironments, where controlled aggregation favors emission.

The growing demand for sustainable materials has driven the search for biodegradable alternatives to conventional plastics. This study investigates the use of cashew industry waste (Anacardium occidentale), an abundant agro-industrial byproduct, in the production of biodegradable films through the electrospinning technique, in combination with natural polymers such as polylactic acid (PLA) and polycaprolactone (PCL). The objective of this work is to optimize electrospinning parameters for each polymer, including variations in solution concentration, solvent type, flow rate, and applied voltage, as well as the treatment of cellulosic material for incorporation into polymer solutions for film production. The methodology involved preparing PLA and PCL solutions (10 and 15% w/v) using a system of acetic acid and formic acid (9:1 ratio) and in analytical-grade acetone. Electrospinning was carried out under different conditions to determine optimal parameters, and alkaline treatment of the natural raw material was performed with NaOH solutions at 2% and 5% v/v. Film characterization was conducted by Thermogravimetric Analysis (TGA), Derivative Thermogravimetry (DTG), Differential Scanning Calorimetry (DSC), and Scanning Electron Microscopy (SEM). Thermal analysis results allowed classification of the fibers according to thermal stability and confirmed complete solvent evaporation during electrospinning, with single-stage mass loss for both polymers, corresponding to 100% for PLA and 90% for PCL, within their respective degradation temperature ranges (360 °C for PLA and 425 °C for PCL). SEM results enabled the evaluation of the effects of different parameters on surface morphology and revealed the successful production of nanometer-scale fibers for PLA electrospun in acetone and PCL electrospun in acetic acid/formic acid.

Magnets have become significantly important materials due to their high demand in modern technology. However, the use of rare earth elements (REEs) presents significant challenges, including high cost, limited availability, and environmental concerns. M-type hexaferrite (Ba/SrFe₁₉O₁₂) magnets have much smaller magnetic performance than REE magnets, but due to their low cost, they constitute the most produced type of magnets globally. Manufacture as nanostructures or metal-ion substitution in the ferrites constitutes state-of-the-art strategies to improve the magnetic properties of hexaferrites, as part of a shift toward developing cost-effective, rare-earth-free alternatives for permanent magnetic materials. In this work, a comparative study of the structural, morphological, and magnetic properties of Cr-doped Sr-hexaferrite prepared by two synthesis routes, sol–gel (SG) and solid-state methods (SSMs), is performed. The study primarily focuses on multiple aspects of fabricated oxides: Cr doping (SrFe_12-xCr_xO₁₉ with x=0.2, 0.4, 0.6) and the calcination temperature (1000 °C and 1100 °C). We have performed magnetisation studies that include hysteresis loops, Curie temperatures, and the anisotropy field. In general, magnetic studies indicate that the SSM route enables us to obtain a single phase, whereas two magnetic phases are observed in the SG samples. Furthermore, the specific saturation magnetisation of the ferrites made by SG is smaller than that of the SSM oxides. X-ray diffraction analysis and electron dispersive X-ray spectroscopy are performed to investigate differences in the phase formation and composition. The studies demonstrate that the Cr-substitution and temperature calcination weakly affect the properties of the oxides. However, the Cr-substituted ferrites with x=0.6 exhibit the largest specific magnetisation, 70 Am²/kg, and the largest coercive field of 0.56 T, when calcined at 1100 °C and 1000 °C, respectively. The enhanced magnetic moment and coercivity in ferrites prepared by SSM make them a suitable candidate for future permanent magnets.

The development of sustainable biomaterials for skincare applications is gaining attention due to growing consumer demand for eco-friendly products. This study explores the potential of sugarcane bagasse-based activated carbon as a sustainable alternative, emphasizing both its functional skincare performance and underlying materials science. Sugarcane bagasse, an abundant agro-industrial byproduct, was converted into activated carbon using a two-step process: pyrolysis at 500 °C for two hours, followed by chemical activation with potassium hydroxide (KOH) at 800 °C for one hour. This approach offers a cost-effective and environmentally conscious alternative to conventional activation methods, while enabling the fine-tuning of pore structure and surface chemistry to suit cosmetic applications, thereby representing a novel application of this well-established activation method to generate biomaterials specifically tailored for cosmetic use. This method yielded a high-performance material while supporting waste valorization and circular economy goals. Comprehensive physicochemical characterization was conducted using BET surface area analysis, scanning electron microscopy (SEM), and Fourier-transform infrared spectroscopy (FTIR). The resulting activated carbon exhibited a high specific surface area, well-developed pore structure, and surface functional groups conducive to adsorption. These structural features enabled effective removal of biologically relevant substances such as sebum analogs and model toxins, evaluated using a silicon skin model. Comparative analysis with commercial activated carbon showed that the sugarcane bagasse-derived variant demonstrated equivalent or superior adsorption capacity. The findings validate its potential for deep skin cleansing applications and broader use in eco-friendly formulations. Moreover, the synthesis approach highlights a sustainable route for transforming agricultural waste into valuable biomaterials. By integrating green synthesis principles with detailed materials characterization, this research positions sugarcane bagasse-based activated carbon as a viable candidate for sustainable skincare applications and contributes to the advancement of biodegradable and high-performance biomaterials in the cosmetics industry.

Recent advances in nanoscience increasingly focus on simple and cost-effective strategies for assembling well-defined nanomaterials. Designing hybrid nanostructures that synergistically combine different nanoscale components to achieve enhanced or novel functionalities remains a significant challenge. Carbon Dots (CDs), a class of small (<10 nm) luminescent carbon nanoparticles, are particularly suited for such applications due to their strong light-harvesting and emission properties, coupled with high surface chemical versatility. These features make CDs ideal building blocks for functional nanohybrids.

Here, we investigate how the fluorescence of green-emitting CDs is modulated when coupled with plasmonic metallic nanoparticles (MNPs) featuring controlled surface charges. We examine the photophysical and photochemical response of binary CD–MNP hybrids both when the components are in close contact and when a polymeric spacer separates them. Nitrogen-doped CDs with strong visible-range absorption and emission were synthesized via a simple bottom-up approach. These CDs were self-assembled in solution with silver (AgNPs) or gold nanoparticles (AuNPs) engineered to bear either positive or negative surface charges. Steady-state and time-resolved optical measurements confirm successful CD–MNP coupling, revealing that the optical response critically depends on the interparticle separation. Close contact between CDs and MNPs leads to emission quenching via efficient photoinduced charge transfer, triggering emergent photocatalytic activity due to interfacial charge separation. In contrast, the presence of a polymeric spacer enhances CD emission, with the nature of plasmonic interactions determined by the metal type: AgNPs plasmonically couple to the CD absorption, while AuNPs couple to the CD emission band.

These findings highlight versatile strategies to tune CD optical properties through MNP coupling, opening avenues for novel applications in photonics and photochemistry.

Nanoscale, 2025, 17, 9380

Nanographenes (NGs) are a class of two dimensional nanomaterials based on graphene laterally confined to a spatial scale of a few nanometers. They have attracted significant interest in the recent literature [1] due to the possibility of controlling their chemical structure with atomic precision, and due to their remarkable optical properties and potential applications in various fields. On the other hand, the fundamental photophysics of NGs is still poorly understood, and some NGs are known to display non-standard photophysical behaviour [2], deviating from the optical response of typical molecular dyes.

In this study, a pyrene-based nanographene (NG) is investigated by means of various spectroscopic techniques capable of providing a comprehensive view of the optical response of the NG initiated by photoexcitation. We employed steady-state absorption and fluorescence spectroscopy to analyze the basic optical properties as well as time-resolved nanosecond spectroscopy to observe the excited-state depopulation. To delve deeper into the ultrafast dynamics of pyrene, we then conducted femtosecond transient absorption (FTA) spectroscopy, which was capable of reconstructing the earliest stages of the photocycle.

The absorption and emission spectra of the NG were found to vary depending on whether the compound was in solution or solid state, and these environmental variations significantly affect its optical properties and relaxation dynamics. The FTA measurements provided insight into the excited-state dynamics and revealed interesting features both in solution and solid state. In particular, one of the most intriguing findings was the observation of coherent nuclear oscillations launched in the NG by excitation with femtosecond pulses. The observation of coherent oscillations in the femtosecond transient absorption signal, rarely observed in nanographenes or other carbon-based compounds, adds a new dimension to our understanding of the excited-state dynamics of nanographenes and opens up new possibilities for their application in advanced photonic and optoelectronic devices.

[1] Drummer et al. Photosynth Res 151, 163–184 (2022)

[2] M. Reale et al. Carbon 206, 45 (2023)

Introduction
Controlled surface topographies on soft polymer substrates are of great interest for applications in microfluidics, optics, sensors, and flexible electronics. Wrinkling via plasma oxidation offers a lithography-free route to generate such patterns. This work systematically investigates the formation and tunability of plasma-induced wrinkles on uncross-linked polydimethylsiloxane (PDMS) thin films.

Methods
Uncured PDMS films were exposed to oxygen plasma to create a stiff silica-like (SiOx) surface layer atop a compliant elastomer substrate. This bilayer system, upon cooling, developed compressive stresses that triggered buckling instability. Wrinkle evolution was monitored using optical microscopy, and topographical features were quantified using atomic force microscopy (AFM). Plasma exposure duration and power were varied to study their influence on wrinkle morphology. Additional post-treatment thermal annealing and sequential short-duration plasma exposures were performed to explore secondary tuning strategies.

Results
Wrinkle wavelength and amplitude increased with prolonged plasma treatment, correlating with greater oxidized layer thickness and mechanical contrast. Sequential short plasma exposures and thermal annealing further enhanced compressive strain, leading to reduced wrinkle wavelengths and improved pattern uniformity. The process demonstrated high reproducibility and tunability, with feature sizes controlled by simple adjustments of plasma parameters.

Conclusions
Oxygen plasma treatment provides a scalable, metal-free method to engineer wrinkle morphologies on PDMS. By controlling plasma parameters and applying secondary treatments, nanoscale topographies with tailored periodicity can be achieved without complex lithography. This approach offers a reliable framework for designing functional surfaces with tunable wettability, adhesion, and optical properties, advancing the development of soft material interfaces for emerging technologies.

The increasing need for energy-efficient and tunable photonic materials drives the investigation of hybrid systems that integrate the distinctive properties of carbon nanotubes with liquid crystals. Composites made from single-walled carbon nanotubes (SWCNTs) and nematic liquid crystals (NLCs) exhibit multifunctional behaviors that make them highly promising for photonic and electro-optic device applications. This study explores these hybrids and proposes their potential role as adaptive materials for future neuromorphic photonic technologies, based on their enhanced electro-optic and optical characteristics.

SWCNTs were dispersed at low concentrations in a nematic liquid crystal matrix to fabricate hybrid materials. Electro-optic characteristics were assessed by measuring threshold voltage and switching times. Optical behavior was analyzed via UV–Vis absorption spectroscopy, while dielectric spectroscopy was used to investigate conductive percolation networks within the composites.

Compared to pure NLC, the hybrids exhibited an 82% reduction in electro-optic threshold voltage and a 63% acceleration in switching time, indicating improved molecular alignment and reduced energy consumption. UV–Vis spectra showed tunable optical bandgaps with redshifted absorption peaks, evidencing enhanced electronic transitions and ordering. Dielectric studies confirmed the formation of conductive percolation networks above critical SWCNT loadings, significantly increasing charge transport and dielectric permittivity. The observed tunable electro-optic and dielectric responses may be influenced by quantum confinement and charge transport phenomena intrinsic to SWCNTs, supporting their multifunctionality.

SWCNT–NLC hybrids demonstrate ultra-efficient photonic switching and modulation capabilities. Based on their multifunctional electro-optic, optical, and dielectric properties—coupled with their potential quantum mechanical effects—these materials are proposed as promising adaptive platforms for future neuromorphic photonic devices. Their fast responses, low power requirements, and tunability provide a solid scientific foundation for integration into brain-inspired photonic architectures.