Fibrous Structures Produced Using the Solution Blow-Spinning Technique for Advanced Air Filtration Process

Production and Characterization of Plant Extract-Based Cell-Friendly and High Mechanical Strength Nanofiber Wound Dressings by Electrospinning Technique

This study focused on the development of wound dressings. Plant active ingredients such as clover, chickweed, chamomile, garlic, liverwort, bitter melon, pine resin, marigold (Calendula officinalis), and St. John's Wort (Hypericum perforatum L.) were reinforced with polyethylene oxide (PEO) and polyvinyl alcohol (PVA) polymers, and nanofiber membranes were produced by electrospinning. As a result of the analyses, FTIR confirmed the presence of polymer and active ingredient functional groups in the composite membranes; softening and shifting were observed in the peaks. In the FEGSEM analysis, a thin and regular nanofiber structure was obtained in the S12 membrane in the range of 150-500 nm. In the tensile test, the tensile strength of the S12 sample was measured as 25.89 MPa, and this strength was associated with the homogeneous distribution and thinning of the fibers. In the mesenchymal stem cell analysis, cell viability was determined as 98%, and cell death was determined as 2% for the S12 membrane at the end of 72 h. The results show that the S12 composite membrane can be used as a biomaterial with ideal properties in wound healing applications.

Biodegradable Electret Filters Based on Beeswax-Modified Fibers: A Novel Production Strategy

This research aims to create a high-efficiency, low-resistance biodegradable air-filter structure containing beeswax as a result of the simultaneous production of fibers by solution-blowing and melt-blowing. The melt-blowing method is effective for producing micrometer fibers on an industrial scale. In turn, the solution-blowing method allows for the production of fibers with a nanometric diameter from solutions containing temperature-sensitive additives such as beeswax. Combining these two methods is a promising perspective for producing high-performance, functional air-filter materials. Beeswax is a natural material capable of accumulating an electrical charge. When an external electric field is applied, the presence of beeswax in the filter structure facilitates charge retention on the fiber surface. This results in a fully biodegradable filter material with high efficiency and low resistance.

Electret Nonwoven Structures for High-Efficiency Air Filtration, Produced Using the Blow Spinning Technique

This study explores the fabrication of electret nonwoven structures for high-efficiency air filtration, utilizing the blow spinning technique. In response to the growing need for effective filtration systems, we aimed to develop biodegradable materials capable of capturing fine particulate matter (PM2.5) without compromising environmental sustainability. Polylactic acid (PLA) was used as the primary polymer, with the addition of SiO2 and MoS2 to enhance the fibers' charge retention and filtration performance. The fibers were charged electrostatically to improve particle capture efficiency. The experimental results showed that fibers containing 5% MoS2 exhibited the highest filtration efficiency, surpassing those with SiO2, despite MoS2 being a semiconductor and SiO2 a dielectric. Furthermore, the addition of MoS2 improved the filtration efficiency across a range of particle sizes (0.2-1 µm) while maintaining a manageable pressure drop. These findings suggest that incorporating MoS2 in electret nonwoven structures can significantly improve filtration performance, making it a promising material for advanced air filtration applications. This study contributes to the development of eco-friendly filtration materials with high performance, essential in reducing exposure to airborne pollutants.

Effect of Collector Rotational Speed on the Morphology and Structure of Solution Blow Spun Polylactic Acid (PLA)

Apart from structure and composition, morphology plays a significant role in influencing the performance of materials in terms of both bulk and surface behavior. In this work, polylactic acid (PLA) constituted by submicrometric fibers is prepared. Using a modified electrospinning (ES) device to carry out solution blow spinning (SBS), the fibrillar morphology is modified, with the aim to induce variations in the properties of the material. The modification of the ES device consists of the incorporation of a source of pressurized gas (air) and a 3D-printed nozzle of our own design. For this work, the morphology of the PLA submicrometric fibers is modified by varying the rotational speed of the collector in order to understand its influence on different properties and, consequently, on the performance of the material. The rotational speed of a cylindrical collector (250, 500, 1000 and 2000 rpm) is considered as variable for changing the morphology. Morphological study of the materials was performed using scanning electron microscopy and image analysis carried out with ImageJ 1.54f software. Besides a morphology study, structural characterization by Fourier transformed infrared spectroscopy using attenuated total reflectance of prepared materials is carried out. Finally, the morphology and structure of produced PLA fibrous mats were correlated with the analysis of mechanical properties, wettability behavior and adhesion of DH5-α E. coli bacteria. It is of interest to highlight how small morphological and chemical structure variations can lead to important changes in materials' performance. These changes include, for example, those above 30% in some mechanical parameters and clear variations in bacterial adhesion capacity.

Preparation and Characterization of Calcium Carbonate Masterbatch-Alkali Soluble Polyester/Polyester Porous Fiber via Melt Spinning

Porous fibers have gained significant attention for their lightweight and high porosity properties in applications such as insulation and filtration. However, the challenge remains in the development of cost-effective, high-performance, and industrially viable porous fibers. In this paper, porous fibers were fabricated through the melt spinning of an alkali soluble polyester (COPET)- CaCO3 masterbatch and PET slice. Controlled alkali and acid post-treatment techniques were employed to create porous structures within the fibers. The effects on the morphology, mechanical, thermodynamic, crystallinity, pore size, and thermal stability were investigated. The results indicate that the uniform dispersion of CaCO3 particles within the fiber matrix acts as nucleating agents during the granulation process, improving the thermal resistance and strength of the porous fiber. In addition, the porous fiber prepared by COPET/CaCO3 to PET with an 85/15 ratio and post-treated on 4% NaOH and 3% HCl exhibits a "spongy body" with uniformly small pores, favorable strength (2.71 cN/dtex), and elongation at break (47%).