Scopus İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/395
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Article Citation - WoS: 104Citation - Scopus: 109Proton Conducting Poly(Vinyl Alcohol) (PVA)/Poly (2-Acrylamido Sulfonic Acid) (PAMPS)/Zeolitic Imidazolate Framework (ZIF) Ternary Composite Membrane(Elsevier, 2016-02) Erkartal, Mustafa; Usta, Hakan; Citir, Murat; Sen, UnalThe design, synthesis and characterization of novel proton exchange membranes (PEMs) are of significant scientific and technological importance for the realization of fuel cells, actuators, and sensors. Here, we demonstrate a novel ternary composite membrane consisting of poly(vinyl alcohol) (PVA), poly (2-acrylamido-2-methylpropane sulfonic acid) (PAMPS), zeolitic imidazolate framework-8 (ZIF-8), which is prepared by physical blending and casting methods. To enhance the water management of the membranes, in situ chemical cross-linking is carried out by glutaraldehyde (GA). During the characterization of the new membranes, FT-IR is used for intermolecular and inter-polymer interactions between different components of the membrane, SEM is used to identify morphology, XRD is used to prove the presence of ZIF-8 nanoparticles, and finally TGA is used for thermal stability. The proton conductivity of the membranes is found to increase with temperature and also with the increasing content of PAMPS. The highest proton conductivity under fully hydrated state at 80 degrees C is measured as 0.134 S cm(-1) for PVA: PAMPS: ZIF-8 (55:40:5) composition. In this study, it is clearly shown that ZIF-8 nanoparticles contribute to the proton conductivity by forming hydrogen bonds with the polymer network in the membrane. The water uptake (WU) and ion exchange capacity (IEC) values are 3.28 (gig) and 1.52 meq g(-1), respectively for the same membrane. To the best our knowledge, this study shows one of the first example of a MOFcontaining membrane with truly high proton conductivities, and both values of proton conductivity and electrochemical properties are comparable to those of well-studied membrane, Nation. (C) 2015 Elsevier B.V. All rights reserved.Book Part Citation - Scopus: 2Paper-Based Substrates for Sustainable (OPTO)Electronic Devices(Elsevier, 2022) Usta, Hakan; Facchetti, A. F.Cellulose-based paper has been a convenient eco-friendly platform for storing and exchanging information for thousands of years. Amazingly, the studies and advancements in the past decade have demonstrated that paper and nanocellulose-based substrates are also attractive for fabricating flexible electronic circuits as well as optoelectronic components and devices. Paper and nanocellulose-based substrates have been considered for use in new generation green devices and optoelectronic applications based on their sustainable and inexpensive source, lightweight, and superior mechanical/optical properties, all factors that could also reduce manufacturing costs for producing these devices. In this chapter, we review functional materials and optoelectronic devices fabricated on paper or nanocellulose-based substrates including transistors and circuits, solar cells, light-emitting diodes, and other devices, such as sensors/actuators, batteries, supercapacitors/energy-harvesters, and breathalyzer/diagnosis devices. We also thoroughly discuss remaining challenges and promising research directions with paper-based substrates for future advancements in green optoelectronics. © 2022 Elsevier B.V., All rights reserved.Article Citation - WoS: 18Citation - Scopus: 20Electrochemical Polymerization of Ambipolar Carbonyl-Functionalized Indenofluorene With Memristive Properties(Elsevier, 2019-08) Figa, Viviana; Usta, Hakan; Macaluso, Roberto; Salzner, Ulrike; Ozdemir, Mehmet; Kulyk, Bohdan; Bruno, MaurizioCarbonyl-functionalized indenofluorene was electropolymerized with a high faradaic efficiency of 85% and the solid state properties of the resulting polymeric thin films were investigated. They displayed modular optical properties depending on their oxidation state. The approach used for inorganic semiconductors was applied to polyindeonofluorene derivative. Mott-Schottky analysis evidenced a switching from p-type to n-type electrical conduction, suggesting an ambipolar behaviour of the polymer. As an application, flexible organic memristors were fabricated and resistive switching properties were observed.