Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Book Part Citation - Scopus: 1A Recycling Route of Plastics Via Electrospinning: From Daily Wastes To Functional Fibers(Walter de Gruyter GmbH, 2019) Isık, Tuğba; Horzum,N.; Demir, Mustafa MuammerSince large-scale plastic production has begun in the 1940s, plastics have been produced and used globally, bringing many advantages to modern life. The consumption of plastics has increased exponentially due to their low cost, chemical resistance, lightness, durability and ability to combine with other materials. However, plastic materials represent high tonnage in urban wastes, and it is known that these plastics discarded at the end of their useful life by filling the landfill sites. Electrospinning is a well-established and versatile technique for the fabrication of submicron fibers. In addition, it is a promising approach for the recycling of waste polymers without using complex methodologies. In this chapter, utilization of electrospinning approach for the recycling of daily wastes will be discussed. The literature about the daily wastes of both synthetic materials and natural/agricultural materials will be analyzed, and the applications of these materials will be given in detail. © 2019 Walter de Gruyter GmbH, Berlin/Boston. All rights reserved.Article Citation - WoS: 49Citation - Scopus: 52Advances in Electrospun Fiber-Based Flexible Nanogenerators for Wearable Applications(Wiley-VCH Verlag, 2021) Arıca, Tuğçe Aybüke; Isık, Tuğba; Güner, Tuğrul; Horzum, Nesrin; Demir, Mustafa M.In today's digital age, the need and interest in personal and portable electronics shows a dramatic growth trend in daily life parallel to the developments in sensors technologies and the internet. Wearable electronics that can be attached to clothing, accessories, and the human body are one of the most promising subfields. The energy requirement for the devices considering the reduction in device sizes and the necessity of being flexible and light, the existing batteries are insufficient and nanogenerators have been recognized a suitable energy source in the last decade. The mechanical energy created by the daily activities of the human body is an accessible and natural energy source for nanogenerators. Fiber-structured functional materials contribute to the increase in energy efficiency due to their effective surface to volume ratio while providing the necessary compatibility and comfort for the movements in daily life with its flexibility and lightness. Among the potential solutions, electrospinning stands out as a promising technique that can meet these requirements, allowing for simple, versatile, and continuous fabrication. Herein, wearable electronics and their future potential, electrospinning, and its place in energy applications are overviewed. Moreover, piezoelectric, triboelectric, and hybrid nanogenerators fabricated or associated with electrospun fibrous materials are presented.Article Citation - WoS: 22Citation - Scopus: 25Cryopreservation of a Cell-Based Biosensor Chip Modified With Elastic Polymer Fibers Enabling Ready-To On-Site Applications(Elsevier, 2021) Özsoylu, Dua; Isık, Tuğba; Demir, Mustafa M.; Schoning, Michael J.; Wagner, TorstenAn efficient preservation of a cell-based biosensor chip to achieve a ready-to-use on-site system is still very challenging as the chip contains a living component such as adherent mammalian cells. Herein, we propose a strategy called on-sensor cryopreservation (OSC), which enables the adherent cells to be preserved by freezing (-80 degrees C) on a biosensor surface, such as the light-addressable potentiometric sensor (LAPS). Adherent cells on rigid surfaces are prone to cryo-injury; thus, the surface was modified to enhance the cell recovery for OSC. It relies on i) the integration of elastic electrospun fibers composed of polyethylene vinyl acetate (PEVA), which has a high thermal expansion coefficient and low glass-transition temperature, and ii) the treatment with O-2 plasma. The modified sensor is integrated into a microfluidic chip system not only to decrease the thermal mass, which is critical for fast thawing, but also to provide a precisely controlled micro-environment. This novel cryo-chip system is effective for keeping cells viable during OSC. As a proof-of-concept for the applicability of a ready-to-use format, the extracellular acidification of cancer cells (CHO-K1) was evaluated by differential LAPS measurements after thawing. Results show, for the first time, that the OSC strategy using the cryo-chip allows label-free and quantitative measurements directly after thawing, which eliminates additional post-thaw culturing steps. The freezing of the chips containing cells at the manufacturing stage and sending them via a cold-chain transport could open up a new possibility for a ready-to-use on-site system.Article Citation - WoS: 63Citation - Scopus: 65Amidoxime Functionalized Polymers of Intrinsic Microporosity (pim-1) Electrospun Ultrafine Fibers for Rapid Removal of Uranyl Ions From Water(Elsevier Ltd., 2019) Satılmış, Bekir; Isık, Tuğba; Demir, Mustafa Muammer; Uyar, TamerThe Polymers of Intrinsic Microporosity (PIM-1) is considered as one of the most promising polymer candidates for adsorption applications owing to its high surface area and the ability to tailor the functionality for the targeted species. This study reports a facile method for the preparation of amidoxime functionalized PIM-1 fibrous membrane (AF-PIM-FM) by electrospinning technique and its practical use for the extraction of U(VI) ions from aqueous systems via column sorption under continuous flow. Fibrous membrane form of amidoxime functionalized PIM-1 (AF-PIM-FM) was prepared by electrospinning method owing to its excellent processability in dimethylformamide. Bead-free and uniform fibers were obtained as confirmed by SEM imaging and average fiber diameter was 1.69 +/- 0.34 mu m for AF-PIM-FM. In addition, electrospun PIM-1 fibrous membrane (PIM-FM) was prepared as a control group. Structural and thermal characterization of powder and membrane forms of the materials were performed using FT-IR, H-1 NMR, XPS, Elemental analyses, TGA, and DSC. The porosity of the samples was measured by N-2 sorption isotherms confirming amidoxime PIM-1 still maintain their porosity after functionalization. Amidoxime functionality along with membrane structure makes AF-PIM-FM a promising material for uranyl adsorption. First, a comparison between powder and membrane form of amidoxime functionalized PIM-1 was investigated using batch adsorption process. Although membrane form has shown slightly lower adsorption performance in the batch adsorption process, the advantage of using the membrane in column adsorption processes makes membrane form more feasible for real applications. In addition, amidoxime modification enhanced the uranium adsorption ability of PIM-FM up to 20 times. The effect of initial concentration and pH were investigated along with regeneration of the adsorbents. AF-PIM-FM was successfully used for five adsorption-desorption cycles without having any damage on the fibrous structure.