Scopus İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/395
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Article Citation - WoS: 7Citation - Scopus: 7Unveiling the Multifaceted Properties of a 3D Covalent-Organic Framework: Pressure-Induced Phase Transition, Negative Linear Compressibility and Auxeticity(Elsevier, 2023-08) Erkartal, MustafaHigh-pressure behavior and mechanical properties of a three-dimensional covalent-organic framework (NPN-1) were investigated by using different types of first principles molecular simulations. An irreversible pressureinduced first-order isosymmetric phase transition was predicted at 0.14 GPa. The subunit of NPN-1 retains its rigidity under pressure thanks to the strong covalent bonds. However, compression leads to significant tilting of the nitrophenyl groups. The mechanical properties of frameworks are highly anisotropic. Remarkably, both phases exhibit not only negative linear compressibility along the c-axis but also negative Poisson's ratio in certain directions. Detailed structural analysis revealed that the origin of the phase transition and anomalous mechanical properties of both phases are the wine-rack motif and strut-hinge mechanism. To the best of our knowledge, this study is the first report of such behavior in COFs, opening up new avenues for the exploration of COFs as materials for many promising applications.Article Citation - WoS: 29Citation - Scopus: 31Pressure-Induced Amorphization, Mechanical and Electronic Properties of Zeolitic Imidazolate Framework (ZIF-8)(Elsevier Science SA, 2020-01) Erkartal, Mustafa; Durandurdu, MuratAb initio molecular dynamics (AIMD) simulations are carried out to probe the high-pressure behavior of ZIF-8 over wide pressure-range. Under compression, the enormous distortions in the ZnN4 tetrahedral units lead to a crystal-to-amorphous phase transition at around 3 GPa. During the amorphization process, the Zn-N coordination is retained. No other phase change but a possible fracture of the system is proposed above 10 GPa. Depending on released pressures, amorphous states with different densities are recovered. Yet when the applied pressure is released just before the amorphization, the rotations of imidazolate linkers (swing effect) cause an isostructural crystal-to-crystal phase transition, in agreement with experiments. In the tensile regime, no phase transition is perceived up to -2.75 GPa at which point the structural failure is observed. The crystal-amorphous phase transitions are also discovered at around 4 GPa under uniaxial compressions. The amorphous structures formed under uniaxial stress are about 20% denser than the one formed under the hydrostatic pressure. The average Young's modulus and Poisson's ratio of ZIF-8 are estimated to be around 5.6 GPa and 0.4, respectively. Interestingly, the tensile strength of ZIF-8 is found to be about 50% greater than its compressive strength. This paper shows that the experimentally observed phase transitions can be successfully reproduced with a clear explanation about the transition mechanism(s) at the atomistic level and all mechanical properties can be accurately calculated for a given ZIF structure by using AIMD simulations.Article Citation - WoS: 18Citation - Scopus: 21Poly(Lauryl Methacrylate)-Grafted Amino-Functionalized Zirconium-Terephthalate Metal-Organic Framework: Efficient Adsorbent for Extraction of Polycyclic Aromatic Hydrocarbons from Water Samples(Amer Chemical Soc, 2020-05-20) Tabatabaii, Maryam; Khajeh, Mostafa; Oveisi, Ali Reza; Erkartal, Mustafa; Sen, UnalIn this study, a novel porous hybrid material, poly(lauryl methacrylate) polymer-grafted UiO-66-NH2 (UiO = University of Oslo), was synthesized for efficient extraction of polycyclic aromatic hydrocarbons (PAHs) from aqueous samples. The polymer end-tethered covalently to the MOF's surface was synthesized by surface-initiated atom transfer radical polymerization, revealing a distinct type of morphology. The adsorbent was characterized by scanning electron microscopy, energy-dispersive spectroscopy, transmission electron microscopy, powder X-ray diffraction, N-2 adsorption-desorption analysis, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The analyses were carried out by gas chromatography-mass spectrometry. Parameters including the type and volume of the eluent, the amount of the adsorbent, and adsorption and desorption times were investigated and optimized. Under optimal conditions, the limit of detection, intraday precision, and interday precision were in the range of 3-8 ng L-1, 1.4-3.1, and 4.1-6.5%, respectively. The procedure was used for analysis of PAHs from natural water samples.Article Citation - WoS: 75Citation - Scopus: 80From 2-Methylimidazole to 1,2,3-Triazole: A Topological Transformation of ZIF-8 and ZIF-67 by Post-Synthetic Modification(Royal Soc Chemistry, 2017) Erkartal, Mustafa; Erkilic, Ufuk; Tam, Benjamin; Usta, Hakan; Yazaydin, Ozgur; Hupp, Joseph T.; Sen, UnalBridging ligand replacement in zeolitic imidazolate frameworks, ZIF-8 and ZIF-67, by 1,2,3-triazole was investigated. A complete substitution of 2-methylimidazole by 1,2,3-triazole resulted in a topological transformation of the parent framework from a sodalite (SOD) network to a diamond (DIA) network.Article Citation - WoS: 6Citation - Scopus: 7Extreme Flexibility and Unusual Piezomechanical Properties of Zinc-Alkyl Metal-Organic Frameworks: A First Principles Study(Elsevier, 2023-06) Erkartal, MustafaThe behavior of three Zn-alkyl-based MOFs, ZnGA (Zn-Glutarate), ZnAA (Zn-Adipate), and ZAG-4 (Zinc Alky Gate), under hydrostatic compression has been investigated using first-principles DFT simulation, which has proven its reliability in previous studies. Due to the lack of the high pressure experimental data for ZnGA and ZnAA, the reliability of the simulation parameters was tested by taking ZAG-4, whose structural flexibility has been previously reported experimentally and computationally, as a benchmark. All three structures were found to exhibit elastic deformation under pressure up to 15 GPa, due to the flexibility of the alkyl chains that allow the structures to move without disrupting the metal-ligand coordination. Interestingly, the structures exhibit different mechanical properties, with ZAG-4 showing negative linear compressibility (NLC), ZnGA showing positive linear compressibility (PLC), and ZnAA showing zero linear compressibility (ZLC). The NLC in ZAG-4 is attributed to the proton transfer between phosphonate oxygen and water in the structure as previously reported, while the ZLC in ZnAA is due to a dumbbell-like structural motif formed by substructures displaying both NLC and PLC.Article Citation - WoS: 17Citation - Scopus: 20Basalt Fiber Reinforced Polymers: A Recent Approach to Electromagnetic Interference (EMI) Shielding(Wiley, 2024-10-09) Fareez, Umar Naseef Mohamed; Loudiy, Aymen; Erkartal, Mustafa; Yilmaz, CagatayElectromagnetic wave (EMW) radiation pollution is getting more severe as result of the advancement of electronic technology. Researching shielding materials with superior EMI (electromagnetic interference) shielding characteristics is therefore crucial. Basalt fibers (BFs) have been an emerging candidate in the fiber-reinforced polymer (FRP) category due to their favorable mechanical and chemical properties, along with being favorites in sustainability and having low production costs. Therefore, due to the rising need for cheaper and efficient alternatives in the EMI shielding industry, the EMI shielding is covered in terms of BF composite materials and their properties in this review, starting with the EMI shielding mechanism and followed by how BF composites affect the EMI properties. This review then covers the post-treatments of BF composites and, finally, the factors of the composites that affect the EMI properties. Moreover, the EMI shielding applications in which BFRPs are used are comprehensively discussed as well. This review aspires to bridge an understanding between EMI shielding as a material property and the BF composites that are developed to aid in the EMI shielding application.Article Citation - WoS: 3Citation - Scopus: 4An In-Depth Investigation of Mg-Zn Metallic Glasses: A First Principles Study(Elsevier, 2018-10) Erkartal, Mustafa; Durandurdu, MuratThe atomic structures, glass forming evolutions, mechanical properties and high pressure behavior of Mg75Zn20Ca5 and Mg60Zn35Ca5 bulk metallic glasses, which are promising candidates for biomedical implants, have been examined by using ab initio molecular dynamics simulations. The pair-distribution function and coordination number analyses show that increasing Zn content in the alloy results in a decrease in several bond distances and an increase in the total coordination number of each species due to the atomic size difference between Mg and Zn atoms. According to the Voronoi tessellation, bond pair and bond angle distribution analyzes, the fivefold geometrical arrangements (pentagonal-bipyramid) are the most predominant in the first coordination shell, indicating the stability of the amorphous states and their dense atomic packing. The most striking result emerged from the calculations of mechanical properties is that an increase of Zn (>= 30%) content in the alloy yields embrittlement in the alloys. Under uniaxial compressions, both compositions undergo structural failure between 6 and 8 GPa. Under hydrostatic pressure, a diminishing in fcc/hcp ordering and an enlargement of the ideal icosahedral ordering may indicate a more disordered structure. In our view, these results represent a good step toward understanding the atomic structures Mg-Zn-Ca bulk metallic glasses.