Ura, Daniel Paweł
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inżynieria materiałowa
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Item type:Article, Access status: Open Access , Thermally insulating mats based on electrospun fibers with bioinspired nano-groove surface structure(2025) Ura, Daniel Paweł; Szewczyk, Piotr K.; Parisi, Gregory; Osak, Andrzej; Puzio, Bartosz; Wrona, Jan; Kim, Il-Doo; Stachewicz, Urszula
Wydział Inżynierii Metali i Informatyki PrzemysłowejHeating and heat retention in buildings account for over 50 % of total energy costs, emphasizing the urgent need not only for advanced thermal insulation materials but also for nature-inspired design strategies to enhance energy efficiency and address the global energy crisis. In this study, we present a one-step fabrication method that improves both thermal insulation efficiency and the mechanical performance of polymer fiber mats. By leveraging bioinspired design, we successfully fabricate nanogroove fibers by precisely controlling humidity during in-situ electrospinning. This approach mimics the nanogroove topography of Old Man Cactus hair, enabling a simple yet effective method to regulate the nanoscale morphology of fibers. The resulting nanogroove fibers exhibit a substantial ~10 % reduction in surface temperature compared to conventional insulation coatings when applied to hot water pipes. Remarkably, our nanogroove fibrous coatings achieve 25 % higher energy savings per unit area and approximately 29 times higher per gram of material mass than commercial rubber insulation materials. This study highlights the critical role of nanoscale surface morphology engineering, particularly in the facile fabrication of nanogroove structures, in mitigating energy and heat loss during thermal transport processes. Based on the unique advantages of humidity-controlled polymer fiber architectures, this approach enables the development of flexible, high-performance thermal insulation materials, opening new avenues for versatile applications across various fields.Item type:Article, Access status: Open Access , Direct electrospinning of short polymer fibers: factors affecting size and quality(2024) Ura, Daniel Paweł; Stachewicz, Urszula
Wydział Inżynierii Metali i Informatyki PrzemysłowejThe growing demand for lightweight and robust materials drives the development of polymer-based and fiber-reinforced composites. Here, using short fibers offers several advantages; however, currently employed methods for producing short fibers, such as homogenization, result in a wide dispersion of dimensions in the produced fibers, which is an undesirable effect in composite materials. In this study, electrospinning is used to produce polymer short fibers directly. This research highlights, for the first time, the differences in the electrospinning process dynamics between short and continuous fibers. By adjusting parameters: voltage and distance, we control dimensions of short fibers below 1 µm in diameter and around 4 µm in length to a few microns in diameter and approximately 14 µm in length. Direct electrospinning of short fibers offers significant advantages, including a narrow size distribution and reproducibility compared to chopped continuous fibers with homogenization.Item type:Article, Access status: Open Access , Interfacial blending in co-axially electrospun polymer core-shell fibers and their interaction with cells via focal adhesion point analysis(2024) Polak, Martyna; Ura, Daniel Paweł; Berniak, Krzysztof; Szewczyk, Piotr K.; Marzec, Mateusz M.; Stachewicz, Urszula
Wydział Inżynierii Metali i Informatyki PrzemysłowejElectrospun polymer scaffolds have gained prominence in biomedical applications, including tissue engineering, drug delivery, and wound dressings, due to their customizable properties. As the interplay between cells and materials assumes fundamental significance in biomaterials research, understanding the relationship between fiber properties and cell behaviour is imperative. Nevertheless, altering fiber properties introduces complexity by intertwining mechanical and surface chemistry effects, challenging the differentiation of their individual impacts on cell behaviour. Core-shell fibers present an appealing solution, enabling the control of mechanical properties of scaffolds, flexibility in material and drug selection, efficient encapsulation, strong protection of bioactive drugs against harsh environments, and controlled, prolonged drug release. This study addresses a key challenge in core-shell fiber design related to the blending effect between core and shell polymers. Two types of fibers, PMMA and core-shell PC-PMMA, were electrospun, and thorough analyses confirmed the desired core-shell structure in PC-PMMA fibers. Surface chemistry analysis revealed PC diffusion to the PMMA shell of the core-shell fiber during electrospinning, subsequently prompting an investigation of the fiber’s surface potential. Conducting cellular studies on osteoblasts by super-resolution confocal microscopy provided insights into the direct influence of interfacial polymer blending and, consequently, altered fiber surface and mechanical properties on cell focal adhesion points, bridging the gap between material attributes and cell responses in core-shell fibers.Item type:Article, Access status: Open Access , Direct electrospinning of short polymer fibers: factors affecting size and quality(2024) Ura, Daniel Paweł; Stachewicz, Urszula
Wydział Inżynierii Metali i Informatyki PrzemysłowejThe growing demand for lightweight and robust materials drives the development of polymer-based and fiber-reinforced composites. Here, using short fibers offers several advantages; however, currently employed methods for producing short fibers, such as homogenization, result in a wide dispersion of dimensions in the produced fibers, which is an undesirable effect in composite materials. In this study, electrospinning is used to produce polymer short fibers directly. This research highlights, for the first time, the differences in the electrospinning process dynamics between short and continuous fibers. By adjusting parameters: voltage and distance, we control dimensions of short fibers below 1 µm in diameter and around 4 µm in length to a few microns in diameter and approximately 14 µm in length. Direct electrospinning of short fibers offers significant advantages, including a narrow size distribution and reproducibility compared to chopped continuous fibers with homogenization.Item type:Article, Access status: Open Access , Multifunctional piezoelectric yarns and meshes for efficient fog water collection, energy harvesting, and sensing(2024) Parisi, Gregory; Szewczyk, Piotr K.; Narayan, Shankar; Ura, Daniel Paweł; Knapczyk-Korczak, Joanna; Stachewicz, Urszula
Wydział Inżynierii Metali i Informatyki PrzemysłowejGiven global water scarcity and the quest for sustainable energy, there's a pressing need for integrated approaches addressing water-energy interdependence worldwide. A practical approach for this challenge involves the implementation of fog water collectors. Herein, a polyvinylidene fluoride (PVDF) multifunctional device capable of harvesting water and electricity from wind is developed and tested, collecting up to 365 mg cm−2 h−1 of fog water. Due to the piezoelectric nature of electrospun PVDF, these yarns and meshes not only serve as piezoelectric sensors, enabling the detection of incoming fog flow and determination of its speed and, bust also harvest electricity by charging a capacitor, making it a green and renewable power source. In this study, promising insights are offered into developing efficient fog water collection methods and utilizing piezoelectric fiber-based yarns and meshes for multifunctional applications in sustainable water management, energy harvesting, and sensing in a single device.Item type:Article, Access status: Open Access , Nanoparticles distribution and agglomeration analysis in electrospun fiber based composites for desired mechanical performance of poly(3-hydroxybuty-rate-co-3-hydroxyvalerate (PHBV) scaffolds with hydroxyapatite (HA) and titanium dioxide (TiO2) towards medical applications(2022) Karbowniczek, Joanna; Ura, Daniel Paweł; Stachewicz, Urszula
Wydział Inżynierii Metali i Informatyki PrzemysłowejScaffolds designed for tissue engineering must meet multiple criteria, including mechanical performance matching particular tissue properties. One of the strategies to improve electrospun scaffolds strength is the incorporation of ceramic nanoparticles. In this work, the effect of the addition of hydroxyapatite (HA) and titanium dioxide ($TiO_{2}$) nanoparticles on tensile strength, elongation and toughness of poly (3-hydroxybuty-rate-co-3-hydroxyvalerate (PHBV) based fibers was tested. Samples morphology along with chemical composition and particles distribution were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and Fourier transform infrared spectroscopy (FTIR). Mechanical properties of PHBV-based electrospun scaffolds were correlated with the nanoparticles' distributions examined via microscopy analysis to understand the failure mechanism of composite fibers. We observed a significant improvement of mechanical properties of composites containing HA nanoparticles compared with solely PHBV fibers. Notably, 3 times higher tensile strength and strain at failure, followed by 16 times improved toughness, was correlated with homogenous distribution of HA nanoparticles with an average area of aggregates reaching 0.11 μm2. At the same time, two times larger $TiO_{2}$ aggregates were irregularly formed along PHBV fibers and caused deterioration of their mechanical properties. We showed the relevant strategy of particle distribution in fibers that are able to tailor mechanical properties by controlling the size and distribution of ceramic fillers in hybrid scaffolds.