Cellulose acetate (CA) is an attractive and sustainable biopolymer for biomedical applications due to its biocompatibility, tunable physicochemical properties, and compatibility with microfabrication. Mechanical stimuli such as topographical cues are known to profoundly influence stem cell behavior, yet their employment in cellulose acetate systems remains underexplored. In this study, we present a reproducible soft-lithography approach to engineer CA scaffolds with well-defined microstructured topographies and controlled surface roughness. The interfacial characteristics of the resulting biointerfaces were assessed using atomic force microscopy. Mesenchymal stem cells cultured on these microstructured platforms exhibited enhanced adhesion, cytoskeletal organization, and focal adhesion formation compared with flat CA controls. Notably, surfaces with intermediate roughness modulated the nuclear translocation of the mechanosensitive regulator TAZ, relative to flat and high roughness surfaces, in a topography dependent manner, suggesting activation of adhesive and cytoskeletal signaling pathways. Under osteogenic conditions, these biointerfaces further supported elevated alkaline phosphatase activity and osteopontin expression, indicative of enhanced early osteogenic commitment. Overall, this work demonstrates that microstructured CA biointerfaces act as instructive platforms that modulate mesenchymal stem cell response through topography-mediated mechanical cues, highlighting their potential as sustainable platforms for bone tissue engineering applications.

We investigate monolayer MoS_2xSe_2(1-x) alloys across the full composition range using optical spectroscopy. We demonstrate continuous tuning of the optical gap over ∼0.35 eV, accompanied by a systematic reduction of the B–A exciton splitting, in agreement with density functional theory calculations. Temperature-dependent measurements reveal a progressive increase of the average phonon energy from Se-rich to S-rich alloys that follows a simple reduced-mass scaling model. Polarization-resolved spectroscopy further shows a monotonic increase of the circular polarization from nearly zero in MoSe_2 to ∼15% in MoS_2 at 78 K. The observed evolution of the polarization is attributed to alloy-induced modifications of the electronic structure that modify bright–dark exciton mixing and the associated valley depolarization. These findings establish alloy engineering as an effective strategy for controlling excitonic properties in TMD monolayers.

High-performance polymers (HPP) fabricated through material extrusion (MEX) 3D printing, such as polyphenylene sulfide (PPS), are utilized in the production of lightweight and high-quality components. Nonetheless, their mechanical response under varying strain rates has not been thoroughly investigated. This study presents an analysis of the mechanical behavior of MEX 3D printed PPS parts subjected to load rates up to 300 mm/min. Raw PPS was processed into filament and employed to produce tensile testing specimens. A consistent increase in tensile strength, elastic modulus, and toughness was observed with increasing loading rates. At the highest load rate applied, the enhancement in mechanical properties was approximately 20% (around 60% for toughness). This behavior is anticipated due to the strain-rate strengthening characteristic of polymers, which is attributed to the reduced molecular chain flow. The sensitivity index m reached its maximum value at 200 mm/min and its minimum at 100 mm/min. The morphology of the samples was examined using scanning electron microscopy, revealing brittle behavior. Thermal behavior was assessed through thermogravimetric analysis and differential scanning calorimetry. These findings underscore the importance of considering the effect of strain-rate on mechanical properties when designing MEX 3D printed PPS components for use under high load rate conditions.

High-performance polymers (HPPs) operate in demanding environments. Therefore, exploiting their specs to the maximum is critical, considering also their high cost. Investigating Polysulfone (PSU) in material extrusion (MEX) 3D printing is challenging due to processability issues. Therefore, it is still inadequately studied, while the 3D printing parameters are expected to affect its mechanical performance. To examine the influence of critical process variables on the mechanical and thermal properties of HPP PSU samples, a series of test specimens were fabricated using the MEX 3D printing technique. A comprehensive experimental design modeling approach, specifically the Taguchi L16 method, was employed. Five control factors, each at four levels, were considered: raster angle, head speed, nozzle temperature, fill density, and strand width. The mechanical response of the printed specimens was evaluated through measurements of tensile strength, Young's modulus, tensile toughness, and tensile yield strength. The experimental data also facilitated the application of two regression models to interpret the obtained results. The thermal stability and phase transition of PSU were examined using differential scanning calorimetry and thermogravimetric analysis. The microstructural characteristics of the printed parts were evaluated via scanning electron microscopy. Optimization achieved more than 200% improvement in three of the four response metrics (163% in the fourth one). Prediction models achieved less than 10% error in confirmation runs, while R2 was found to be higher than 85% confirming the prediction accuracy. Exploiting the reported findings, the examined mechanical, thermal, and microstructural properties of the MEX-printed PSU can be predicted in real-life applications, enabling future innovations in additive manufacturing processes for high-performance polymers.

Graphene oxide (GO) and reduced graphene oxide (rGO) are widely studied two-dimensional carbon nanomaterials for optoelectronic devices. Because the oxygen content and degree of reduction govern the electronic structure of GO-derived films, controlling the reduction process is essential for tailoring their properties. Laser-induced reduction provides a tunable, contact-free route to transparent and conductive graphene-based layers. In this work, 80 nm spray-coated GO layers were reduced using a KrF excimer laser (248 nm, 20 ns) at a fluence of 20 mJ cm−2, while systematically varying the number of laser pulses (LP) from 1 to 1000. We tuned the degree of GO reduction by stepwise increasing the number of LP and followed the resulting changes in surface composition using X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine-structure (NEXAFS) spectroscopy. The surface composition evolves non-monotonically with the number of laser pulses, revealing a multi-step reduction mechanism. At low laser doses, epoxide groups are preferentially removed or converted, generating a more disordered distribution of hydroxyl-containing sites on the GO sheets. At intermediate laser doses, oxygen-containing groups are depleted, and sp2 conjugation is restored. After extended irradiation in air, however, oxygenated surface species partially re-form. Conductivity measurements show that the sheet resistance reaches a minimum at approximately 300 LP, consistent with efficient chemical reduction and recovery of the conjugated carbon network. These results provide molecular-level guidelines for optimizing laser-induced GO reduction toward graphene-based transparent conductive layers.

The increasing demand for high-performance thermoplastics in functional and engineering applications has led to a rise in the research of their processability through additive manufacturing (AM) methods. Polysulfone (PSU) has emerged as an interesting candidate for use in advanced 3D printed components for its high thermal stability, excellent chemical resistance, and good mechanical strength. However, polysulfone has challenges in material extrusion (MEX) printing due to high processing temperature and melt viscosity. This work aims to improve quality metrics (surface quality, porosity, and dimensional accuracy) of PSU parts through processing the MEX process parameters. The experimental manufacturing and evaluation procedures were conducted based on the Taguchi L16 Robust design experimental model. The toolpath orientation angle (TA), nozzle heat level (NHL), deposition speed (DS), structure density (DS), and line width (LW) were selected as control variables. Their effect was evaluated against the average roughness - Ra, Root Mean Square roughness - Rq, Actual to Nominal Dimensional deviation at 95 % - A2N95, and Computed Tomography Scan porosity- PCT quality responses. TA had a remarkable effect on roughness responses, SD on dimensional deviation, and NHL on porosity. Data processing was implemented with the reduced quadratic regression model (RQRM) and the quadratic regression model (QRM), with RQRM being selected due to the higher F-values (R2 values were sufficient for three metrics, ∼65%, while in porosity they were high, ∼82%). The validity of the prediction functions was confirmed by two additional runs (>10% error), advancing the process understanding of HPPS in MEX AM.

This study investigates femtosecond laser pre-patterning of silicon substrates for subsequent Ti/Zr/Ti thin-film deposition. Conical microspikes were fabricated on silicon using femtosecond pulses in an SF6 atmosphere, yielding uniform high-aspect-ratio features with an average height of 2 & micro;m, an opening angle of 40 degrees, and a density of 1.3 & times; 10(7) cm(-2). A nanocomposite Ti thin film with a Zr (10 nm) sublayer was deposited onto the structured surfaces by ion sputtering. The resulting Ti/Zr/Ti films were systematically characterised in terms of morphology, chemical composition, wettability, and reflectance. Predominantly oxidised surface components formed globular agglomerates (similar to 1 & micro;m) within the interspike regions. The designed surface morphology exhibited hydrophilic behaviour and enhanced optical performance, resulting in a 20% increase in reflectivity compared to the pre-patterned silicon. It has been demonstrated that wettability and reflectivity can be controlled through UV irradiation and thermal annealing.

There is currently a strong need for functional polymer components with tailored mechanical properties. The performance of these materials in Material Extrusion (MEX) 3D printing can be enhanced through effective optimization of the parameter values. This is important for semi-crystalline high-performance polymers (HPPs), such as polyvinylidene fluoride (PVDF), because they are more sensitive to the 3D printing settings utilized. This investigation was designed to optimize the MEX printed tensile strength of PVDF through the optimization of six critical variables (five levels of each): Raster Deposition Angle, Nozzle Temperature, Print Speed, Infill Density, Layer Thickness, and Build Bed Temperature. Filaments were produced from the raw materials, and standard specimens were created for testing purposes. Thermal, morphological, and structural characteristics of each sample were studied. The L25 Taguchi design was used to analyze the impact of these parameters on strength (tensile and yield), modulus of elasticity, toughness, specimen weight, and tensile strength per weight. The properties were influenced the most by Raster deposition angle (Young's modulus improved by similar to 30%, other properties considerably improved, too). Infill density was found to be statistically insignificant within the highly dense 80-100% regime examined. Reduced quadratic regression model quantified main effects, enabling the development of predictive equations. Confirmation runs revealed less than 10% value deviation for the models. R-2 values remained around 70%, indicating an intrinsic process variability. This study provides a statistically sound framework to optimize the processing of PVDF in MEX 3D printing and thus contributes to the production of robust HPP components.

In three-dimensional (3D) printing, the produced components quality in terms of their surface roughness, porosity, and dimensional inaccuracy is a weak point, affecting also their performance. This is critical for Polyvinylidene fluoride (PVDF), a high-performance thermoplastic, which is capable of functional parts production, due to its high chemical and thermal resistance. This study investigates how six key process parameters, i.e., raster deposition angle, nozzle temperature, bed temperature, infill density, print speed, and layer height, affect the quality of PVDF MEX 3D‑printed components. A Taguchi L25 design of experiments combined with a regression model (reduced quadratic) was employed for the analysis of the experimental data. Through the optimization process followed, surface roughness and dimensional accuracy improved by roughly 30

Although high-performance thermoplastics are increasingly in demand for advanced manufacturing, there are still no optimized guidelines for obtaining reliable mechanical properties in MEX-printed polyphenylsulfone (PPSU). Herein, PPSU was extruded in filament form and then additively manufactured as coupons via material extrusion (MEX) for mechanical testing and microscopic evaluation. The optimization was assigned to the Taguchi L16 design of the experiment, which was operated with five control parameters (infill angle, extrusion temperature, print speed, fill percentage, track width) and four response metrics (tensile strength, tensile yield strength, Young’s modulus, and tensile toughness). Reduced Quadratic (RQRM) and linear (LRM) regression models were evaluated, with RQRM being more efficient. The fill percentage was the most influential of all responses, while raster orientation had the minimum impact on them. Overall, the optimization process led to a remarkable improvement of the investigated mechanical properties for PPSU, which ranged from 164% - 274% enhancement (maximum tensile strength 70.65MPa, yield strength 60.75MPa, Young’s modulus 221.55MPa, toughness 18.6MJ/m3). The study presents knowledge for industry and predictive tools for researchers, designers, and engineers to utilize to improve the structural performance of PPSU components.

The properties of acrylonitrile styrene acrylate (ASA) are similar to acrylonitrile butadiene styrene. However, it is more robust against environmental phenomena. Therefore, it is capable of use in outdoor applications. Its behavior under different strain rates in 3D printing is still insufficiently investigated. The aim herein was to report the 3D printed ASA parts' mechanical performance for test speeds varying from 10 to 300mm/sec. The mechanical performance is affected by the viscoelastic behavior of the material and the 3D printing structure. ASA was sourced in raw form. It was then extruded into filament and finally into tensile specimens. Thermal examinations included thermogravimetric analysis and differential scanning calorimetry. Scanning electron microscopy on the lateral and fractured surfaces contributed to the samples’ morphological evaluation. The ultimate strength, yield strength, stiffness, and toughness were assessed from the performed tensile experiments. To investigate the material’s deformation mechanisms, the strain rate sensitivity index m was determined. The samples subjected to higher strain rates had higher strength (∼47MPa, compared to 41MPa at the standard test speed, ∼13% increase), stiffness (∼510MPa, compared to ∼470MPa at the standard test speed, ∼8% increase), and toughness (∼7.42MJ/m3 at 250mm/min, compared to ∼4.67MJ/m3 at 75mm/min, ∼37% increase). Toughness was higher at low and high strain rates and lower at median values. Ductility increased at higher strain rates, contributing to the toughness increase. The strain rate sensitivity index was higher at low speeds (∼0.06 at 75mm/min, compared to ∼0.018 at 250mm/min). Samples were more brittle at medium strain rates. These findings provide valuable information for the design of ASA 3D printed components operating under high-speed loads.

In structural and biomedical applications, where high-speed loading is a major concern for mechanical reliability, high-performance polymers (HPP) are increasingly required. Still, their thermomechanical response produced by additive manufacturing methods has not been fully characterized. In this study, the strain-rate-dependent compressive behavior of specimens, 3D printed by the material extrusion (MEX) method with the polyether ether ketone (PEEK) biopolymer, has been investigated. Simultaneously, the evolution of specimen temperature has been monitored using an infrared camera. Compression testing was performed over a range of test speeds up to 200 mm/min. The aim was to quantify the mechanical performance under compression loads and concurrently thermal self-heating phenomena as a function of applied strain rate. Results show that the compressive strength of the MEX-processed PEEK had a positive strain-rate sensitivity of 14.1% at higher strain rates. The strain-rate sensitivity index had higher values at lower test velocities, suggesting that viscoelastic effects play a larger role in the deformation mechanism. At the same time, the maximum specimen temperature increased by 33% as the strain rate increased (63 to 85 °C) (thermomechanical self-heating), which can affect material response at elevated strain rates. This work offers fundamental insights into the mechanical response of MEX-fabricated PEEK biopolymer under loads applied at various speeds and has direct merit for the design of additively manufactured biomedical components which are often subjected to such loading conditions.

This study presents a comparative analysis of short and ultrashort-pulsed laser-induced reduction of graphene oxide (GO) films, placing emphasis on the critical influence of laser pulse duration on the reduction process and material properties. Through systematic experiments, using femtosecond (170 fs), picosecond (150 ps) and nanosecond (1 ns) infrared laser pulses on GO films of 100 and 200 nm thickness, we demonstrate that pulse duration plays a significant role in the GO reduction process and the resulting electrical conductivity of laserreduced graphene oxide (LrGO). Optimal laser parameters, including pulse duration and energy, are identified for achieving a highly conductive LrGO surface, with the best performing films reaching sheet resistance values below 140 Omega sq-1. The interplay between pulse duration, GO film thickness and reduction efficiency has been investigated and discussed. Notably, the best reduced LrGO layer exhibits superior performance as a metal-free electrocatalyst for hydrogen production. In electrochemical tests for hydrogen evolution reaction, LrGO produced under optimal reduction conditions, specifically under femtosecond irradiation, shows significantly enhanced catalytic activity, achieving a current density of 381 mu A cm- 2, attributed to its high conductivity and the beneficial defect structures introduced during laser reduction. Our results establish that all three factors, including the reduction level, film thickness, and laser pulse duration, synergistically determine the catalytic activity of LrGO. By tuning such parameters, we achieve substantial enhancements in hydrogen generation performance, indicating the strong potential of laser-engineered GO films for efficient hydrogen production.

The stability of all-inorganic metal halide perovskite anodes is critically dependent on the electrode fabrication method, a factor often overlooked. This work compares the structural and electrochemical performance of slurry-cast versus solvent-free dry-processed anodes using CsPbBr3 (lead-based) and Cs2AgBiBr6 (lead-free) perovskites. We find that the conventional slurry process induces a catastrophic degradation of the CsPbBr3 structure into its constituent products before cycling, whereas the dry-processing method successfully preserves the pristine perovskite phase. Consequently, the dry-fabricated CsPbBr3 electrode exhibits excellent cycling stability driven by a reversible Li-Pb alloying mechanism, significantly outperforming the rapidly fading Cs2AgBiBr6 anode. These findings demonstrate that for this class of materials, optimizing the fabrication process to prevent chemical degradation is a primary and critical step toward achieving stable electrochemical performance.

In an effort to keep up with the rapidly growing needs of society, manufacturing processes and materials need to be constantly developed. Additive manufacturing (AM) exploits different materials and enables reinforcing them with additives. Acrylonitrile styrene acrylate (ASA) is a thermoplastic with high UV and weather conditions resistance. Herein, it was reinforced with ceramic titanium carbide (TiC) nanoparticles. Nanocomposites were developed and evaluated utilizing material extrusion (MEX) AM. TiC loadings ranged between 0 and 12 wt%. Standard specimens for testing were produced with these loadings. The effect of filler content on mechanical, dynamic mechanical, thermal, rheological, and microstructural properties of the 3D printed coupons was studied. The maximum tensile properties were achieved by the 8 wt% nanocomposite (13.9% tensile strength and 20.0% Young's modulus improvement). Overall, considering also the filler cost, the 6 wt% should be considered the optimum loading in the nanocomposites. Higher loadings resulted in higher porosity, increased microhardness (24.3% increase with 12 wt% TiC content), and better dimensional accuracy, making nanocomposites suitable for wear-related applications. The impact strength decreased, suggesting that the nanocomposites are not effective for such applications. Overall, this work establishes ASA/TiC as a promising nanocomposite system for outdoor applications and provides design guidelines for optimizing filler content for robust MEX components manufacturing.

In this study, the influence of incorporating Antimony Tin Oxide (ATO) filler into the Acrylonitrile Styrene Acrylate (ASA) pure polymer matrix was investigated, focusing on the mechanical, thermomechanical/thermochemical, and overall quality of 3D printed ASA/ATO nanocomposites. The aim was to introduce novel ceramic-based nanocomposites in material extrusion 3D printing, expanding its use and performance in outdoor applications. The influence of adding small to moderate to high ATO loading on the properties of the various ASA/ATO composites was closely monitored. The compositional range of the ATO filler content in the pure ASA polymer matrix was between 2 wt. % and 12 wt. % in 2 wt. % intervals. The results showed that the incorporation of ATO into the ASA pure polymer matrix enhanced the overall mechanical properties (by more than 15%) and characteristics of the ASA/ATO composites produced (quality, porosity, and geometrical accuracy improved by more than 15%, thermal stability, etc.). They also aimed to shed more light on the overall behavior of ASA composites bearing inorganic (ceramic) filler loadings. This study provides a thorough investigation of ASA/ATO composites and elucidates their overall quality and performance.

Water contamination by synthetic dyes, such as methylene blue (MB), poses a significant environmental challenge due to their chemical stability and resistance to conventional waste water treatments. In this study, a series of silver-doped phosphate and borate glasses were synthesized via typical melt-quenching methods and evaluated for their photocatalytic efficiency in MB degradation under UV and visible light. The most significant result is the superior performance of silver metaphosphate (AgPO3), which achieved 86% MB removal under visible LED irradiation and 64% removal in the dark within 60 min, outperforming all other investigated compositions, including silver-free sodium phosphate, silver-rich iodide-phosphate, and silver borate glasses. This confirms its dual catalytic activity under both light-assisted and non-irradiated conditions. Characterization results indicate that this enhanced performance is directly associated with the formation and homogeneous dispersion of Ag0 nanoparticles within the phosphate glass matrix, which promotes strong plasmonic activation and efficient generation of reactive oxygen species (ROS), leading to accelerated dye degradation. Furthermore, comparative analysis clearly demonstrates that the phosphate network provides the most favourable environment for nanoparticle stabilization and catalytic activity among the studied systems. The AgPO3 glass also maintained stable photocatalytic efficiency over multiple reuse cycles, confirming its structural and functional durability. Overall, AgPO3 exhibits the highest quantified degradation efficiency, combined with strong activity in both dark and illuminated conditions and excellent reusability, highlighting its potential as an effective and stable photocatalyst for wastewater treatment applications.

The use of 3D printed components often requires materials with good resistance to weather conditions, which is usually a weak point of thermoplastics. Acrylonitrile styrene acrylate (ASA) is a thermoplastic capable of withstanding extreme environmental conditions. Thus, its investigation is of great importance, especially when it comes to being processed by additive manufacturing (AM). Herein, novel ceramic nanocomposites loaded with silicon carbide (SiC) in five (5) different filler quantities (2.0–10.0 wt%) were prepared and characterized, aiming to be used in lightweight automotive interior and exterior parts, customized aerospace, electrical and electronic housing, or tooling and fixtures. Matrix-filler mixtures were extruded into filaments to 3D print a series of specimens. The samples underwent tests for their performance during thermal, rheological, (thermo-) mechanical, structural, and morphological examinations. 6.0 wt% was distinguished overall for its performance over ASA pure, showing improvement in tensile strength (15.1%), modulus of elasticity (14.1%), flexural strength (16.8%), and modulus of elasticity (19.1%). 8.0 wt% had the highest tensile toughness (13.8%) and flexural toughness (10.6%). Porosity was reduced by the addition of the SiC filler (10.0 wt% loading improved porosity by 36.5%). In total, the ASA/ SiC nanocomposites have great potential to be utilized for outdoor applications requiring 3D printed components with reinforced mechanical performance.

As additive manufacturing (AM) continues to expand, the demand for durable components for outdoor applications is increasing. Acrylonitrile styrene acrylate (ASA), a weather-resistant polymer, is widely used in these applications, and improving its performance could broaden its range of applications. In this study, ceramic aluminum oxide (Al2O3) nanoparticles, known for their hardness and insulating properties, were added to ASA to produce enhanced nanocomposites for AM. Five filler loadings (2.0-10.0 wt%) were evaluated and compared with neat ASA. The resulting materials were characterized through thermomechanical, mechanical, thermal, morphological, rheological, structural, and quality assessments. Aluminum oxide improved the mechanical performance by 13.1% to 16.8% and structural metrics by 13.1% for tensile and flexural strength and up to 45.6% for porosity reduction. The nanoparticles also affected the morphology of the samples, which may be critical for specific applications. Among the formulations, the 6 wt% composite performed best, indicating that intermediate filler levels offer the best balance of reinforcement, quality, and processability. These results provide new insights into ASA/Al2O3 ceramic nanocomposites produced by AM.