Person: FINDIKÇI, Ilknur Eruçar
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Ilknur Eruçar
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FINDIKÇI
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ArticlePublication Metadata only Zinc(II) and cadmium(II) coordination polymers containing phenylenediacetate and 4,4′-azobis(pyridine) ligands: Syntheses, structures, dye adsorption properties and molecular dynamics simulations(Elsevier, 2017) Sezer, G. G.; Arıcı, M.; Fındıkçı, İlknur Eruçar; Yeşilel, O. Z.; Özel, H. U.; Gemici, B. T.; Erer, H.; Mechanical Engineering; FINDIKÇI, Ilknur EruçarTwo new coordination polymers (CPs) – [Zn(µ4-ppda)(µ-abpy)0.5]n(1) and [Cd(μ3-opda)(µ-abpy)0.5(H2O)]n(2) (o/ppda = 1,2/1,4-phenylenediacetate, abpy = 4,4′-azobis(pyridine)) – have been synthesized by using Zn(II)/Cd(II) salts in the presence of o- and p-phenylenediacetic acid and abpy under hydrothermal conditions. Their structures have been characterized by FT-IR spectroscopy, elemental analysis, X-ray powder diffraction and single crystal X-ray diffraction techniques. The structural diversities were observed depending on anionic ligands and metal centers in the synthesized complexes. Complex 1 consists of a 2-fold interpenetrated 3D+3D→3D framework with pcu topology while complex 2 has a 2D structure with sql topology. The adsorption of methylene blue (MB) was studied to examine the potential of the title CPs for removal of dyes from aqueous solution. Molecular dynamics (MD) simulations were also performed to examine diffusion of MB in 1 and 2. Thermal and optical properties of two complexes were also discussed.ArticlePublication Open Access Unlocking the effect of H2O on CO2 separation performance of promising MOFs using atomically detailed simulations(ACS Publications, 2020-02-19) Fındıkçı, İlknur Eruçar; Keskin, S.; Mechanical Engineering; FINDIKÇI, Ilknur EruçarMetal organic frameworks (MOFs) have been considered as potential adsorbents for adsorption-based CO2/CH4 and CO2/N-2 separations because of their high CO2 selectivities and high working capacities. H2O in flue gas and natural gas streams affects the gas uptake capacities of MOFs. However, the presence of H2O is commonly neglected in high-throughput computational screening studies while assessing the CO2 separation performances of MOFs. In this study, the impact of the presence of H2O on the CO2 separation performances of 13 MOFs that were previously identified as the best adsorbent candidates among several thousands of MOFs was examined. Molecular simulations were used to compute selectivity, working capacity, regenerability, and adsorbent performance score (APS) of MOFs considering separation of binary CO2/CH4, CO2/N-2, and ternary CO2/CH4/H2O and CO2/N-2/H2O mixtures. The results showed that introduction of H2O as the third component into binary CO2/CH4 and CO2/N-2 mixtures significantly affected the adsorbent evaluation metrics of MOFs that have strong affinity toward H2O because of the presence of specific functional groups and/or extra framework anions in the framework. Remarkable increases in CO2/N-2 selectivities of MOFs were observed in the presence of H2O. On the other hand, simulations performed using MOFs that are preloaded with H2O to mimic the exposure of MOFs to humidity prior to gas adsorption revealed drastic decreases in CO2 working capacities and APSs of MOFs both for CO2/CH4 and CO2/N-2 separations. These results will be useful for the design and development of efficient MOF adsorbents for CO2 capture under humid conditions.ArticlePublication Open Access Database for CO2 separation performances of MOFs based on computational materials screening(American Chemical Society, 2018-05-23) Altintas, C.; Avci, G.; Daglar, H.; Azar, A. N. V.; Velioglu, S.; Fındıkçı, İlknur Eruçar; Keskin, S.; Mechanical Engineering; FINDIKÇI, Ilknur EruçarMetal-organic frameworks (MOFs) are potential adsorbents for CO2 capture. Because thousands of MOFs exist, computational studies become very useful in identifying the top performing materials for target applications in a time-effective manner. In this study, molecular simulations were performed to screen the MOF database to identify the best materials for CO2 separation from flue gas (CO2/N-2) and landfill gas (CO2/CH4) under realistic operating conditions. We validated the accuracy of our computational approach by comparing the simulation results for the CO2 uptakes, CO2/N-2 and CO2/CH4 selectivities of various types of MOFs with the available experimental data. Binary CO2/N-2 and CO2/CH4 mixture adsorption data were then calculated for the entire MOF database. These data were then used to predict selectivity, working capacity, regenerability, and separation potential of MOFs. The top performing MOF adsorbents that can separate CO2/N-2 and CO2/CH4 with high performance were identified. Molecular simulations for the adsorption of a ternary CO2/N-2/CH4 mixture were performed for these top materials to provide a more realistic performance assessment of MOF adsorbents. The structure-performance analysis showed that MOFs with Delta Q(st)(0) > 30 kJ/mol, 3.8 angstrom < pore-limiting diameter < 5 angstrom, 5 angstrom < largest cavity diameter < 7.5 angstrom, 0.5 < phi < 0.75, surface area < 1000 m(2)/g, and rho > 1 g/cm(3) are the best candidates for selective separation of CO2 from flue gas and landfill gas. This information will be very useful to design novel MOFs exhibiting high CO2 separation potentials. Finally, an online, freely accessible database https://cosmoserc.ku.edu.tr was established, for the first time in the literature, which reports all of the computed adsorbent metrics of 3816 MOFs for CO2/N-2, CO2/CH4, and CO2/N-2/CH4 separations in addition to various structural properties of MOFs.Book ChapterPublication Metadata only Metal-organic frameworks for biomedical applications(Elsevier, 2020) Gülçay, Ezgi; Fındıkçı, İlknur Eruçar; Mechanical Engineering; FINDIKÇI, Ilknur Eruçar; Gülçay, EzgiMetal-organic frameworks (MOFs) have received significant interest in the recent years as promising candidates for biomedical applications due to their high porosities and tunable surface characteristics. The rational design and synthesis of MOFs provide unique physical and chemical structures that make them potential materials for drug storage and drug delivery; biologically important gas storage such as nitric oxide, hydrogen sulfide, and oxygen; imaging; and sensing. The aim of this chapter is to outline the recent progress in biomedical applications of MOFs, mainly focusing on drug storage and drug delivery applications. First, MOFs were briefly introduced and then both experimental and computational studies with emphasis on their potential applications in drug storage, biomedical gas storage, and drug delivery were reviewed. Critical issues such as toxicity, size, shape, and biological stability were also discussed. Finally, current opportunities and challenges of using MOFs in biomedicine were addressed and some future trends were suggested.ArticlePublication Metadata only Molecular simulations of COFs, IRMOFs and ZIFs for adsorption-based separation of carbon tetrachloride from air(Elsevier, 2019-01) Gülçay, Ezgi; Fındıkçı, İlknur Eruçar; Mechanical Engineering; FINDIKÇI, Ilknur Eruçar; Gülçay, EzgiCovalent organic frameworks (COFs), metal organic frameworks (MOFs) and zeolitic imidazolate frameworks (ZIFs) have been widely studied gas separation applications due to their large surface areas, high pore volumes, tunable pore sizes and chemical stabilities. In this study, separation performances of 153 COFs, 14 IRMOFs and 8 ZIFs were assessed for efficient removal of carbon tetrachloride (CCl4) from CCl4/Ar, CCl4/N-2, CCl4/O-2 mixtures at 298 K and infinite dilution. The top performing three materials in each group, namely, borazine-linked polymer (BLP-2H-AA), IRMOF-11 and ZIF-6 were identified. Single-component, binary mixture and quaternary mixture adsorption isotherms of argon (Ar), CCl4, nitrogen (N-2) and oxygen (O-2) in these materials were computed at 298 K and various total pressures from 10(-3) to 1.5 x 10(4) kPa. Mixture adsorption selectivities and separation potentials were then calculated and the effect of relative humidity on the performance of adsorption-based CCl4 separation was examined. Single-component and quaternary mixture diffusion coefficients of Ar, CCl4, N-2 and O-2 were finally computed. Our results showed that ZIF-6 exhibits the highest adsorption selectivity and the highest separation potential for CCl4/Ar, CCl4/N-2 and CCl4/O-2 mixtures, followed by IRMOF-11 and BLP-2H-AA. Results of this computational study will be highly useful to identify the promising materials for removal of CCl4 from air.ArticlePublication Metadata only Combining tensile test results with atomistic predictions of elastic modulus of graphene/polyamide-6,6 nanocomposites(Elsevier, 2023-06) Batyrov, Merdan; Dericiler, K.; Palabıyık, Büşra Akkoca; Okan, B. S.; Öztürk, Hande; Fındıkçı, İlknur Eruçar; Mechanical Engineering; KAYMAKSÜT, Hande Öztürk; FINDIKÇI, Ilknur Eruçar; Batyrov, Merdan; Palabıyık, Büşra AkkocaIn this work, we combined tensile test results with atomistic simulations to investigate the effect of filler parameters including distribution, stacking, loading and lateral graphene size on elastic moduli of graphene/PA-6,6 nanocomposites. Stacked and randomly distributed atomistic models were adapted in Molecular Dynamics (MD) simulations to establish the limits of stiffness enhancement in graphene reinforced PA-6,6 nanocomposites with loading ratios changing from 0 to 1 wt%. Experimental results showed that incorporating of 0.3–0.4 wt% graphene loading improved the elastic modulus of the neat polymer by 41.7%−43.5%. While the test sample behaved close to the computational results of the stacked atomistic model at low graphene loadings up to 0.4 wt%, it overshot the predictions of the randomly distributed model at all considered loadings up to 1 wt%. Elastic moduli of graphene-based PA-6,6 nanocomposites increased linearly with graphene loading in the stacked model, however, no such relation was detected in the randomly distributed model. The lower stiffness enhancement provided by the randomly distributed model compared to the stacked model was revealed as the small lateral size of graphene plates in PA-6,6 matrix. As the graphene size increased, the elastic modulus of the graphene dramatically increased, directly improving the elastic modulus of the nanocomposite. The developed computational approach is highly useful to estimate the boundaries of stiffness enhancement provided by graphene dispersions in macroscale nanocomposite samples.ArticlePublication Open Access Exploring covalent organic frameworks for H2S+CO2 separation from natural gas using efficient computational approaches(Elsevier, 2022-08) Aksu, G. Ö.; Fındıkçı, İlknur Eruçar; Haslak, Z. P.; Keskin, S.; Mechanical Engineering; FINDIKÇI, Ilknur EruçarCovalent organic frameworks (COFs) are emerged as strong adsorbent candidates for industrial gas separation applications due to their highly porous structures. In this work, we explored H2S+CO2 capture potentials of synthesized and computer-generated COFs from a natural gas mixture using an efficient, multi-level computational screening approach. We computed the adsorption data of a six-component natural gas mixture, CH4/C2H6/CO2/C3H8/H2S/H2O, for 580 synthesized COFs by performing Grand Canonical Monte Carlo (GCMC) simulations under industrially relevant conditions. H2S+CO2 selectivities and working capacities of COFs were computed to be 0.4-12.4 (0.2-8.5) and 0.01-5.36 (0.04-2.5) mol/kg at pressure-swing adsorption (vacuum-swing adsorption) condition. NPN-3 was identified as the best performing COF due to the competitive adsorption of H2S+CO2 over C2H6 and C3H8 as revealed by density functional theory (DFT) calculations. Structural (pore sizes, porosities, and topologies) and chemical properties (linker units and heats of gas adsorption) of the best-performing synthesized COFs were used to efficiently screen the very large number of hypothetical COFs (hypoCOFs). Results showed that isosteric heats of adsorption can be used to discover high performing hypoCOFs for H2S+CO2 separation from natural gas. Finally, we compared COFs, hypoCOFs, zeolites, carbon nanotubes, metal organic frameworks (MOFs) and concluded that several synthesized and computer-generated COFs can outperform traditional adsorbents in terms of H2S+CO2 selectivities. Our results provide molecular-level insights about the potential of COFs for natural gas purification and direct the design and development of new COF materials with high H2S+CO2 selectivities.ArticlePublication Open Access Computational investigation of dual filler-incorporated polymer membranes for efficient CO2 and H2 separation: MOF/COF/Polymer mixed matrix membranes(American Chemical Society, 2023-01-26) Aydın, S.; Altintas, C.; Fındıkçı, İlknur Eruçar; Keskin, S.; Mechanical Engineering; FINDIKÇI, Ilknur EruçarMixed matrix membranes (MMMs) composed of two different fillers such as metal-organic frameworks (MOFs) and covalent-organic frameworks (COFs) embedded into polymers provide enhanced gas separation performance. Since it is not possible to experimentally consider all possible combinations of MOFs, COFs, and polymers, developing computational methods is urgent to identify the best performing MOF-COF pairs to be used as dual fillers in polymer membranes for target gas separations. With this motivation, we combined molecular simulations of gas adsorption and diffusion in MOFs and COFs with theoretical permeation models to calculate H2, N2, CH4, and CO2 permeabilities of almost a million types of MOF/COF/polymer MMMs. We focused on COF/polymer MMMs located below the upper bound due to their low gas selectivity for five industrially important gas separations, CO2/N2, CO2/CH4, H2/N2, H2/CH4, and H2/CO2. We further investigated whether these MMMs could exceed the upper bound when a second type of filler, a MOF, was introduced into the polymer. Many MOF/COF/polymer MMMs were found to exceed the upper bounds showing the promise of using two different fillers in polymers. Results showed that for polymers having a relatively high gas permeability (≥104 barrer) but low selectivity (≤2.5) such as PTMSP, addition of the MOF as the second filler can have a dramatic effect on the final gas permeability and selectivity of the MMM. Property-performance relations were analyzed to understand how the structural and chemical properties of the fillers affect the permeability of the resulting MMMs, and MOFs having Zn, Cu, and Cd metals were found to lead to the highest increase in gas permeability of MMMs. This work highlights the significant potential of using COF and MOF fillers in MMMs to achieve better gas separation performances than MMMs with one type of filler, especially for H2 purification and CO2 capture applications.ArticlePublication Metadata only Computational investigations of Bio-MOF membranes for uremic toxin separation(Elsevier, 2022-01-15) Palabıyık, Büşra Akkoca; Batyrov, Merdan; Fındıkçı, İlknur Eruçar; Mechanical Engineering; FINDIKÇI, Ilknur Eruçar; Palabıyık, Büşra Akkoca; Batyrov, MerdanDeveloping new and efficient methods as an alternative to hemodialysis is important due to the challenges associated with poor efficiency of membranes and long dialysis sessions. Recently, metal organic frameworks (MOFs) have attracted interest in the membrane community due to their tunable physical and chemical properties. However, their potential in uremic toxin separations is still unknown and it is not practical to test each synthesized MOF for uremic toxin separations. The main objective of this study is to computationally assess membrane-based uremic toxin separation performances of 60 bio-compatible MOFs (bio-MOFs). Combining grand canonical Monte Carlo (GCMC) and equilibrium molecular dynamics (EMD) simulations, we predicted urea, creatinine, and water permeabilities of bio-MOFs and their membrane selectivities for urea/water and creatinine/water separations. Results showed that OREZES, a carboxylate-based MOF exhibited the highest membrane selectivity (347.94) for urea/water separation whereas BEPPIX, an amino-based MOF gave the highest creatinine/water selectivity (1.5 × 105) at infinite dilution and 310 K. Guest-guest and host–guest interaction energies for uremic toxins were also computed during EMD simulations and van der Waals interactions were found to be much stronger than the coulombic interactions. We finally examined the effect of MOF's flexibility on the predicted membrane performance and membrane selectivities of bio-MOFs for urea/water separation significantly enhanced when the structural flexibility was considered in simulations. Our results will be a guide for further studies to design novel bio-MOF membranes for uremic toxin separations.Book ChapterPublication Metadata only Computational screening of MOFs for CO2 capture(Springer, 2021-03-30) Altıntaş, Ç.; Fındıkçı, İlknur Eruçar; Keskin, S.; Mechanical Engineering; FINDIKÇI, Ilknur EruçarThe capture of CO2 (carbon dioxide) is an urgent environmental issue due to global warming. Adsorption-based CO2 capture using a new family of porous materials, metal-organic frameworks (MOFs), has been considered as a promising alternative to conventional methods. The rapid increase in the number of synthesized MOFs offers various materials for efficient CO2 capture, but assessing the performance of each MOF material using purely experimental methods is challenging. Recent progress in computational tools, high-throughput molecular simulations, and machine learning algorithms provide great opportunities for effective computational screening of MOFs with the aim of identifying the most promising adsorbents for CO2 capture prior to experimental studies. In this chapter, we focused on the recent advances in high-throughput screening of MOFs for CO2 capture and separation. We first reviewed the details of molecular simulation methods to compute CO2 adsorption properties of MOFs and adsorbent performance evaluation metrics that have been used to assess the CO2 separation potential of MOFs. Large-scale computational screening studies and quantitative structure-performance relationships obtained from molecular simulations were then discussed. Finally, opportunities and challenges of using computational tools to reveal the potential of MOFs for CO2 capture and separation were addressed.