Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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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: 21Citation - Scopus: 24Modification of Electrospun Pva/Paa Scaffolds by Cold Atmospheric Plasma: Alignment, Antibacterial Activity, and Biocompatibility(Springer Verlag, 2019) Arik, Nehir; İnan, Alper; İbiş, Fatma; Demirci, Emine A.; Karaman, Ozan; Ercan, Utku K.; Horzum, NesrinThe ongoing search for better antibacterial wound care dressings has led to the design and fabrication of advanced functional nanomaterials. Taking advantage of electrospinning and cold atmospheric plasma (CAP), free-standing nanofibrous scaffolds are promising for use in novel biomedical applications. Random and aligned polyvinyl alcohol (PVA)/polyacrylic acid (PAA) nanofiber scaffolds are fabricated by electrospinning and treated with CAP. In this study, we investigate the effects of CAP treatment on alignment, hydrophilicity, antibacterial activity, and biocompatibility in determining the surface properties of the nanofibrous scaffolds. The results of vibrational polarization spectroscopy analysis indicate that CAP treatment changes the degree of alignment of the nanofibers. Furthermore, both random and aligned CAP-treated nanofibrous scaffolds show significant antibacterial activity against the E. coli strain. The results of an in vitro scratch assay reveal that CAP treatment of PVA/PAA nanofibers has no toxic effect.Article Citation - WoS: 10Citation - Scopus: 12Li-Ion Battery Cathode Performance From the Electrospun Binary Licoo2 To Ternary Li2coti3o8(Springer Verlag, 2020) Kap, Özlem; İnan, Alper; Er, Mesut; Horzum, NesrinMetal oxide nanofibers are prepared by electrospinning and are developed to be the electrodes for lithium-ion batteries (LIBs). The effect of calcination temperature and the Li:Co mole ratio of LiCoO2 nanofibers was investigated on the electrochemical cathode performance in a coin cell battery. The higher temperature calcination and Li:Co mole ratio have improved the electrochemical performance of the nanofibers. Lithium cobalt oxide (LiCoO2) nanofibers obtained at 400 and 700 degrees C retain 65% and 90% of the initial capacity, respectively, after the high-current test and the C-rate reverted to 0.1 C. When doubling the mole ratio of Li:Co (2:1), an increase in specific capacity values from 78 to 148 mAh g(-1) has been provided. Additionally, colloidal titania nanoparticles (TiO2 NPs)-doped LiCoO2 nanofibers were obtained and investigated as a cathode material. While the increment in calcination temperature results in higher crystallinity and stability of the LiCoO2 phase, in the presence of the TiO2 NPs causes a transformation of binary (LiCoO2/TiO2) to ternary Li-based transition metal oxide (Li2CoTi3O8/TiO2). An initial discharge capacity of 82 mAh g(-1) was found at 0.1 C for the Li2CoTi3O8/TiO2 nanoparticles and the capacity retention was 83% when returned to 0.1 C after 25 cycles.Article Citation - WoS: 24Citation - Scopus: 30Solution Electrospinning of Polypropylene-Based Fibers and Their Application in Catalysis(Korean Fiber Society, 2016) Berber, Emine; Horzum, Nesrin; Hazer, Bakí; Demir, Mustafa MuammerSince the dissolution of polyolefins is a chronic problem, melt processing has been tacitly accepted as an obligation. In this work, polypropylene (PP) was modified on molecular level incorporating poly(ethylene glycol) (PEG) as graft segment (PP-g-PEG) in a range of 6 to 9 mol%. Gold nanoparticles were nucleated in the presence of the copolymer chains via redox reaction. The dissolution of the amphiphilic comb-type graft copolymers containing gold nanoparticles (80 nm in diameter) was achieved in toluene and successfully electrospun from its solution. The diameter of composite fibers was in the range from 0.3 to 2.5 μm. The design of the structurally organized copolymer fiber mats provided a support medium for the nanoparticles enhancing the active surface area for the catalytic applications. The resulting composite fibers exhibited rapid catalytic reduction of methylene blue (MB) dye in the presence of sodium borohydride (NaBH4) compared to corresponding composite cast film.Article Citation - WoS: 6Citation - Scopus: 7Utilization of Electrospun Polystyrene Membranes as a Preliminary Step for Rapid Diagnosis(John Wiley and Sons Inc., 2016) Işık, Tuğba; Horzum, Nesrin; Yıldız, Ümit Hakan; Liedberg, Bo; Demir, Mustafa MuammerRecent advances in clinical practice drive deoxyribonucleic acid (DNA) as an important class of biomarker. Monitoring the change in their concentration suggests the initiation and/or progression of various disorders. However, low quantity of DNA biomarkers in body fluids requires a delicate isolation methodology that provides efficient separation and easy handling. This study describes a newer-generation separation technology relying on electrospun fibers of sub-micrometer diameter of a commodity polymer for DNA biomarkers in simulative serum. Fibrous polystyrene membranes are prepared by electrospinning and they are subjected to post-modification with Au. The composite membranes may provide a convenient environment for the removal of bovine serum albumin (BSA) from BSA and DNA mixtures. The eluent can be used as an efficient tool for detection of DNA biomarkers associated with diagnosis of numerous life-threatening diseases.Article Citation - WoS: 16Citation - Scopus: 17Electrospun Amino-Functionalized Pdms as a Novel Spme Sorbent for the Speciation of Inorganic and Organometallic Arsenic Species†(Royal Society of Chemistry, 2013) Boyacı, Ezel; Horzum, Nesrin; Çağır, Ali; Demir, Mustafa Muammer; Eroğlu, Ahmet EminSol–gel based amine-functionalized SPME fibers (PDMS-weak anion exchanger) were prepared and used for direct mode extraction of dimethylarsinic acid (DMA), monomethylarsonic acid (MMA), and arsenate (As(V)) from aqueous solutions followed by HPLC-ICPMS determination. Two different methods of coating were employed: (i) electrospinning and (ii) dip coating. Electrospinning was used for the first time for preparation of sol–gel based SPME fibers and was found to be superior in terms of extracted amount of arsenicals, coating homogeneity, accessibility of amine groups on the surface, and preparation time for a single fiber. Various parameters such as solution pH, extraction time, agitation speed, extraction temperature, and ionic strength were studied. Optimum extraction conditions were determined as pH of 5.0, extraction time of 30 min, agitation speed of 700 rpm, and extraction temperature of 20 C. Extraction ability of the novel coating decreased by the addition of NaCl as a consequence of the competition between anionic arsenic species and chloride ions for active sites of the weak anion exchanger. This novel sol–gel coating prepared by electrospinning was found to be promising for SPME applications. Vibrational spectroscopy revealed the alignment of PDMS chains by elongational force under electrospinning process. The chain alignment accordingly orients the pendant amino functional groups perpendicular to the fiber surface, which may develop the free active functional groups available to the medium and lead to the enhancement of the extraction performance. Moreover, the proposed coating strategy through electrospinning might be able to break new ground for various applications in analytical chemistry as well as other disciplines.