Ali Toptaş

Poly Butylene Succinate (PBS) and Poly Butylene Succinate-co-Adipate (PBSA) are biodegradable polyesters that have attracted considerable attention for nanofibre fabrication due to their environmentally friendly characteristics and favourable material properties. PBS nanofibres are known by relatively high rigidity, thermal stability and crystallinity, making them suitable for applications that require structural strength. However, the stiffness of PBS may reduce its flexibility and limit its processing performance in some applications. In contrast, PBSA nanofibres incorporate adipic acid into the polymer chain, which results in lower crystallinity, greater flexibility and reduced melting temperature. These characteristics enhance the elasticity and processability of PBSA-based materials. The differences in mechanical and thermal behaviour between PBS and PBSA arise from the modification of the polymer backbone in PBSA, making it more appropriate for applications that demand adaptable and flexible materials, such as tissue engineering and air filtration. Both nanofibre systems show significant potential for sustainable technologies. In this study, a comparative evaluation of PBS and PBSA nanofibres was conducted to investigate their morphology, crystallinity, mechanical behaviour and filtration performance. The results show that PBS nanofibres exhibit a higher crystallinity of approximately 45%. In contrast, PBSA nanofibres demonstrate a significantly higher strain, reaching nearly twice that of PBS nanofibres. Regarding filtration performance, both materials achieved filtration efficiencies of up to 93%, while maintaining relatively low pressure drops of 210 Pa for PBS and 200 Pa for PBSA. Furthermore, corona discharge treatment was applied to enhance electrostatic capture and maintain filtration efficiency during extended operation for up to seven days.

Polymer-based active packaging systems incorporating natural bioactive agents have attracted growing interest as eco-friendly alternatives to traditional food packaging materials. In this study, Pistacia lentiscus essential oil (PLEO) was incorporated into PCL/gelatin nanofibrous mats fabricated via solution blow spinning (SBS) to develop multifunctional and biodegradable active packaging materials. Neat PCL, gelatin-blended PCL (PCL–G) and PCL–G mats containing 5, 10 and 20 wt.% PLEO were produced and thoroughly analyzed for their morphological, chemical and functional characteristics. Morphological investigation revealed a smooth, bead-free fibrous structure in all samples. The average fiber diameter (AFD) increased from 239 nm to 320 nm with the addition of gelatin to the PCL matrix, while the incorporation of different concentrations of PLEO caused only minor changes. The results showed that as the concentration of PLEO increased, the antioxidant activity of the nanofibrous mats also increased. This enhancement is potentially linked to the rich content of bioactive molecules such as β-pinene, terpineol and verbenol. The 2,2-diphenyl-1-picrylhydrazyl scavenging activity improved from 6.4% (PCL) to 60% (PCL–G–20PLEO), and ABTS activity rose from 8.7% to 72%. In addition, antimicrobial evaluation showed inhibition zones of 12.5 mm against Escherichia coli and 14.2 mm against Staphylococcus aureus for the PCL–G–20PLEO nanofibrous mats. In 14-day storage tests on Kashar cheese, PCL–G–10PLEO and PCL–G–20PLEO mats reduced microbial counts by more than 2 log units compared with the control and effectively slowed yeast and mold growth. These findings confirm the potential of the PCL–G–PLEO nanofibrous mat as novel active packaging materials for preserving dairy products such as Kashar cheese.

The increasing demand for sustainable, antibacterial, and eco-friendly food packaging materials has intensified research into biodegradable biopolymers with enhanced functional properties. In this study, gelatin–chitosan-based nanofibers were fabricated via electro-blowing and reinforced with cellulose microcrystals (CMC) extracted from corn cobs via acid hydrolysis. The formulation (12% gelatin and 3% chitosan) and electro-blowing parameters were optimized based on previous literature and preliminary trials to ensure uniform fiber morphology. CMC was incorporated at concentrations of 1, 3, and 5% (w/w), and the resulting nanofibers were characterized using FE-SEM, ATR-FTIR, XRD, TGA, and air permeability tests. SEM analysis revealed smooth, bead-free fibers with average diameters ranging from 642.19 ± 40.36 nm (control) to 760.05 ± 32.64 nm (3% CMC), confirming the impact of filler loading. XRD results demonstrated an increase in crystallinity from 21.3% in the control to 27.8% with 5% CMC. At the same time, TGA indicated enhanced thermal stability at low CMC concentrations, with a maximum decomposition temperature of 326 °C for 1% CMC compared to 315 °C in the control. However, higher loadings (5% CMC) led to slight thermal deterioration, likely due to disruptions in polymer chains. These results confirm that corncob-derived CMC can be successfully integrated into gelatin–chitosan nanofibers to improve structural and thermal properties, positioning them as promising candidates for active food packaging. Future studies will focus on mechanical and antibacterial performance to further validate their practical application.

Air pollution has emerged as one of the most pressing environmental challenges, primarily driven by rapid industrialization and climate-related phenomena. Within this context, nanofiber-based filter materials offering high particle capture efficiency and low pressure drop (ΔP) play a crucial role in ensuring access to clean air. In this study, nanofibrous filter surfaces based on thermoplastic polyurethane (TPU) were fabricated via the melt-blowing (MB) technique a solvent-free and high-throughput production method. The experimental design was structured using a Taguchi L9 orthogonal array, considering three processing parameters at three levels each: feeding rate (1, 5, and 10 rpm), die (nozzle) temperature (220, 240, and 260 °C), and air pressure (1, 2, and 3 bar). The morphological characteristics of the produced nanofibers were examined through scanning electron microscopy (SEM). Their AFDs, filtration efficiencies, pressure drops (ΔP), air permeabilities, and quality factors (QFs) were systematically compared. The sample produced under the optimal conditions -1 rpm feeding rate, 260 °C die temperature, and 3 bar air pressure- demonstrated the best performance, achieving a filtration efficiency of 82.12% and a ΔP of 95 Pa, with an average fiber diameter (AFD) of 423 ± 47 nm. Moreover, this optimal sample was subjected to mechanical strain levels of 5%, 10%, and 20%, and successfully preserved its functional integrity, maintaining a filtration efficiency of 71.44% even at 20% elongation. These findings highlight the potential of the melt-blown process as an environmentally friendly, rapid, scalable, and solvent-free method to produce high-performance TPU based nanofibrous air filters.

Oil mist filtration is essential for reducing environmental pollution and extending equipment lifespan. This study explores the fabrication of nano/microfibrous filter mats from acrylic fiber wastes using solution blowing (SB) and centrifugal spinning (CS) techniques, offering a sustainable approach to advanced oil filtration. The effects of neat, oleophobic‐coated single‐layer, and multilayer structures on filtration performance were analyzed. While SB mats exhibited finer fibers and a denser structure, CS mats had a more porous and fluffy morphology. To enhance oleophobicity, SB mats were coated with a modified perfluoroalkyl silane (mFAS) by spraying. The coating increased the paraffin oil contact angle by 120° but also led to higher pressure drops (ΔP) due to the altered pore structure and surface characteristics. A multilayered design incorporating CS mats as the top layer and mFAS as an intermediated layer created asymmetric wettability and a bimodal structure, achieving over 99% filtration efficiency. The 5S/2.5 M/5C (×2) configuration in the multilayered designs demonstrated superior performance, (filtration efficiency (η) over 99%, lower ΔP, and slower clogging). These results indicate that the acrylic waste‐based bimodal structured fibrous mats produced can be used as an effective and sustainable oil mist filtration media.

This study investigates the effects of temperature of pressurized blown air on fiber morphology, porosity, phase structure, and filtration performance of PVDF nanofibers produced via the electro‐blowing method for the first time. The blown air heated to 20, 40, 60, and 80°C was utilized during production. Increasing air temperature resulted in more homogeneous distribution of fibers and defect‐free fibrous mats, accompanied by a significant reduction in fiber diameter. A linear relationship between fiber diameter and pore size was observed; as fiber diameter decreased, reducing air permeability due to smaller pore sizes. FTIR measurements revealed the highest β‐phase content (82%) in the PVDF‐80C sample produced at 80°C. The rise in temperature lowered solution viscosity and surface tension, contributing to improved drawing effect and therefore higher β‐phase content in the PVDF polymer. Corona discharge treatment further enhanced the surface potential, with the finest fibers exhibiting the highest surface charge. The PVDF‐80C sample demonstrated the best performance during filtration tests against NaCl aerosols (PM_0.3) at a flow rate of 95 L/min, achieving a filtration efficiency of 98.68% with a pressure drop of 153 Pa. These findings highlight the critical role of temperature in influencing nanofiber properties and filtration performance.Highlights: Finer fibers and defect‐free mats achieved with increased air temperature. PVDF‐80C showed 82% β‐phase content, the highest among all samples. Smaller fiber diameter led to reduced pore size and lower air permeability. Corona discharge enhanced surface potential, boosting fiber charge. PVDF‐80C achieved 98.68% filtration efficiency with 153 Pa pressure drop.

Fibers with electrostatic capture properties and bimodal structures, combining fibers of different diameters, offer innovative filtration approaches with low‐pressure drop and high efficiency. In this study, PA6 and dielectric PVDF nanofibrous mats, positioned differently in the triboelectric series, are produced via the electro‐blowing technique. To identify the most effective factors influencing filter performance, four groups are prepared: unimodal single‐layer filters, group X (fibers with the same diameters but different polymers for triboelectric effect), group Y (fibers with different diameters and polymers for bimodal + triboelectric effects), and group Z (fibers with only different diameters for only bimodal effect). The unimodal PVDF mats show 100% higher surface potential and the highest filtration efficiency (99.233%) among single‐layered samples. Multi‐layered samples perform better, with the four‐layered bimodal PA6/PVDF showing the greatest efficiency improvement due to both bimodal structure and triboelectric effect. After corona charging, sample Y3's filtration efficiency increases from 99.886% to 99.997%, with minimal change in pressure drop. After one month and IPA treatment, it retains a surface potential of −0.26 kV and 99.829% efficiency. The higher surface potential of group Y confirms the triboelectric effect, while its superior performance highlights the advantages of bimodal and electret effects. Trial Registration: Not applicable, as this study does not involve a clinical trial.

In this study, a novel active food packaging hybrid nanofibrous mats were fabricated from gelatin (G), chitosan (Ch), polyamide-6 (PA6), and Cedrus atlantica essential oil (CAEO) via an electroblowing technique. The G-Ch-PA6 nanofibrous mats containing varying concentrations (0, 1, 3, and 5%, m/m) of CAEO were produced and thermally crosslinked. These hybrid mats underwent comprehensive characterization, including morphology assessment, surface wetting analysis, thermal stability examination, antioxidant evaluation, bioactivity testing, and more. Morphological investigation revealed that the incorporation of different CAEO concentrations influenced the average diameter of the nanofibers, which ranged from 335.09 to 541.90 nm. Moreover, the antioxidant properties of nanofibrous mats were assessed using DPPH and ABTS methods, revealing a linear relationship between antioxidant activity and the loading amount of CAEO. These findings underscore the potential of the G-Ch-PA6-CAEO5 nanofibrous mat as a multifunctional active packaging material, promising in the preservation and freshness monitoring of fruits such as tangerines. Graphical Abstract

Air pollution is a significant global health concern, causing respiratory diseases, cardiovascular disorders, and various cancers. The increasing population, industrial activities, fuel emissions, and construction activities contribute to the formation of particulate matter, leading to air pollution. The inhalation of fine particulate matter (PM2.5) and various toxic gases substantially exacerbates these health risks. Traditional air filtration systems, while relatively effective at capturing larger particles, fall short in capturing nanoscale pollutants. To address these deficiencies, nanofibrous air filters have emerged as a significant innovation. Due to their large surface area and high porosity, nanofibrous filters can effectively capture smaller particles and harmful gases. Research has demonstrated that nanofibrous filters exhibit high efficiency in filtering PM2.5 and smaller particles, as well as bacteria, and viruses. Furthermore, the long-term use of these filters presents a significant potential to reduce health risks associated with air pollution. This study emphasizes the critical importance of developing and implementing nanofibrous filter technology and the innovative research in this field to improve air quality and protect public health. The widespread adoption of this technology is viewed as an effective strategy to mitigate the adverse health effects of air pollution and create healthier living environments. In this context, the study presents insights into the current and future applications of nanofibrous air filters.