Browsing by Author "Moradi, Ahmadreza"

Now showing 1 - 5 of 5

Access status: Open Access ,
Bridging a Gap in Thermal Conductivity and Heat Transfer in Hybrid Fibers and Yarns via Polyimide and Silicon Nitride Composites
(2023) Moradi, Ahmadreza; Szewczyk, Piotr K.; Stachewicz, Urszula
Wydział Inżynierii Metali i Informatyki Przemysłowej
The pressing issues of the energy crisis and rapid electronics development have sparked a growing interest in the production of highly thermally conductive polymer composites. Due to the challenges related to the poor processability of hybrid materials and filler distribution to achieve high thermal conductivity, electrospinning is employed to create composite nanofibers and yarns using polyimide (PI) and thermally conductive silicon nitride (SiN) nanoparticles. The thermal performance of the individual nanofibers is evaluated using scanning thermal microscopy (SThM), providing significant insights into their heat transfer performance. Next, the nanofibers are applied as coatings on resistance wires to assess the thermal conductivity and insulation properties. Notably, the samples containing 35 wt.% of SiN exhibit a 25% increase in surface temperature. These innovative materials hold great promise as exceptional candidates for smart textiles and thermal management applications, addressing the growing demand for effective heat dissipation and regulation.
Access status: Open Access ,
Controlled therapeutic cholesterol delivery to cells for the proliferation and differentiation of keratinocytes
(2024) Moradi, Ahmadreza; Lichawska-Cieslar, Agata; Szukala, Weronika; Jura, Jolanta; Berniak, Krzysztof; Stachewicz, Urszula
Wydział Inżynierii Metali i Informatyki Przemysłowej
The challenge of enhancing wound healing and skin regeneration, particularly in conditions like burns and diabetic wounds, necessitates innovative solutions. Cholesterol, often associated with cardiovascular diseases, plays vital roles in cellular functions, maintaining skin integrity and preserving the skin barrier. Here, we explore cholesterol's significance, its influence on keratinocytes, and its potential application in skin regeneration. The study utilizes electrospun polyimide (PI) fibers as a cholesterol carrier model and investigates its impact on HaCaT keratinocytes, marking the first time tracked cholesterol delivery from the scaffold into cells. We demonstrate that an optimal concentration of 0.7 mM cholesterol in the medium enhances cell proliferation, while higher concentrations have negative effects. Cholesterol-enriched scaffolds significantly increase cell proliferation and replicative activity, especially in a 3D culture environment. Moreover, cholesterol influences keratinocyte differentiation, promoting early differentiation while inhibiting late differentiation. These findings suggest that cholesterol-loaded scaffolds can have applications in wound healing by promoting cell growth, regulating differentiation, and potentially accelerating wound closure. Further research in this area will lead to innovative wound management and tissue regeneration strategies.
Access status: Open Access ,
Enhanced thermal management of mats and yarns from polystyrene fibers through incorporation of exfoliated graphite
(2025) Das, Madhurima; Knapczyk-Korczak, Joanna; Moradi, Ahmadreza; Pichór, Waldemar; Stachewicz, Urszula
Wydział Inżynierii Metali i Informatyki Przemysłowej
The energy crisis, driven by modern electronics and global warming from population growth, underscores the need for advanced textiles to regulate thermal environments. Researchers stress the need to improve high-performance polymer mats with enhanced thermal conductivity. This report delves into the morphological, mechanical, and thermal properties of exfoliated graphite (EG) when incorporated into polystyrene (PS) fiber mats and yarns through blend electrospinning. The incorporation of EG inside the fibers allowed us to obtain approximately twofold improvement in maximum stress and toughness compared to pristine PS mats. Thermal camera measurement showed significant improvement in heat transport for PS–EG fibers. The heating test showed a temperature increase of ∼2.5 °C for an EG-loaded PS mat, and in the case of a resistance wire coated with a PS fiber yarn, the increase reached 17 °C. The incorporation of EG into electrospun mats enables the recovery of more energy in the form of heat by enhancing the heating of the sample through infrared radiation. The temperature increased by 2 °C for PS and by 27 °C for PS–EG, respectively. The obtained results exhibit a great potential for the application of electrospun hybrid systems with EG in further advancement in the field of next-generation thermal management.
Access status: Open Access ,
Enhancing Thermal Conductivity in Electrospun Polymer Structures for Heat Management Applications
(2025) Moradi, Ahmadreza; Stachewicz, Urszula
WIMiIP
Over the past decade, enhancing the thermal conductivity of polymers has attracted growing attention as an innovative strategy to address the challenges of thermal energy management across diverse sectors. This interest stems not only from the inherent advantages of polymers, such as low weight, flexibility, and ease of processing, but also from their widespread use and established roles in numerous applications. Among available approaches, electrospinning has emerged as a promising method. It offers unique advantages for producing thermally conductive polymer fibers, mats, and yarns, such as enhanced polymer chain alignment, controlled filler distribution, and tunable porosity. Consequently, extensive research has been conducted in this area in recent years. Therefore, this review uniquely focuses on thermally conductive electrospun polymer structures, providing a comprehensive synthesis of advancements in this growing field. It begins with an overview of heat conduction mechanisms in polymers and composites, emphasizing key factors influencing thermal transport. The principles of electrospinning and its advantages for thermal conductivity enhancement are discussed, along with strategies to further improve their thermal performance. Additionally, measurement methods, existing challenges, and recent developments are examined. Finally, the review highlights emerging applications and outlines future research directions to guide continued innovation of high-performance electrospun polymer materials.
Access status: Open Access ,
Unraveling the Impact of Boron Nitride and Silicon Nitride Nanoparticles on Thermoplastic Polyurethane Fibers and Mats for Advanced Heat Management
(2024) Moradi, Ahmadreza; Szewczyk, Piotr K.; Roszko, Aleksandra; Fornalik-Wajs, Elżbieta; Stachewicz, Urszula
WIMiIP
The urgent challenges posed by the energy crisis, alongside the heat dissipation of advanced electronics, have embarked on a rising demand for the development of highly thermally conductive polymer composites. Electrospun composite mats, known for their flexibility, permeability, high concentration and orientational degree of conductive fillers, stand out as one of the prime candidates for addressing this need. This study explores the efficacy of boron nitride (BN) and its potential alternative, silicon nitride (SiN) nanoparticles, in enhancing the thermal performance of the electrospun composite thermoplastic polyurethane (TPU) fibers and mats. The 3D reconstructed models obtained from FIB-SEM imaging provided valuable insights into the morphology of the composite fibers, aiding the interpretation of the measured thermal performance through scanning thermal microscopy for the individual composite fibers and infrared thermography for the composite mats. Notably, we found that TPU–SiN fibers exhibit superior heat conduction compared to TPU–BN fibers, with up to a 6 °C higher surface temperature observed in mats coated on copper pipes. Our results underscore the crucial role of arrangement of nanoparticles and fiber morphology in improving heat conduction in the electrospun composites. Moreover, SiN nanoparticles are introduced as a more suitable filler for heat conduction enhancement of electrospun TPU fibers and mats, suggesting immense potential for smart textiles and thermal management applications.