Researcher:
Kulak, Harun

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Harun

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Kulak

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Kulak, Harun

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2019 - 201922020 - 20215

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    PublicationMetadata only
    Towards complete elucidation of structural factors controlling thermal stability of il/mof composites: effects of ligand functionalization on mofs
    (Iop Publishing Ltd, 2020) N/A; Department of Chemical and Biological Engineering; N/A; N/A; Department of Chemical and Biological Engineering; Department of Chemical and Biological Engineering; Durak, Özce; Kulak, Harun; Kavak, Safiyye; Polat, Hüsamettin Mert; Keskin, Seda; Uzun, Alper; Master Student; Researcher; Researcher; Researcher; Faculty Member; Faculty Member; Department of Chemical and Biological Engineering; Koç University Tüpraş Energy Center (KUTEM) / Koç Üniversitesi Tüpraş Enerji Merkezi (KÜTEM); Koç University Surface Science and Technology Center (KUYTAM) / Koç Üniversitesi Yüzey Teknolojileri Araştırmaları Merkezi (KUYTAM); Graduate School of Sciences and Engineering; College of Engineering; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; College of Engineering; College of Engineering; N/A; N/A; N/A; N/A; 40548; 59917
    In this work, we incorporated an ionic liquid (IL), 1-n-butyl-3-methylimidazolium methyl sulfate ([BMIM][MeSO4]) into two different metal organic frameworks (MOFs), UiO-66, and its amino-functionalized counterpart, NH2-UiO-66, to investigate the effects of ligand-functionalization on the thermal stability limits of IL/MOF composites. The as-synthesized IL/MOF composites were characterized in detail by combining x-ray diffraction, scanning electron microscopy, Brunauer-Emmett-Teller analysis, x-ray fluorescence, infrared spectroscopies (FTIR), and their thermal stability limits were determined by thermogravimetric analysis (TGA). Characterization data confirmed the successful incorporation of the IL into each MOF and indicated the presence of direct interactions between them. A comparison of the interactions in [BMIM][MeSO4]-incorporated UiO-66 and NH2-UiO-66 with those in their 1-n-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6])-incorporated counterparts showed that the hydrophilic IL, [BMIM][MeSO4], interacts with the 1,4-benzenedicarboxylate (BDC) ligand of the UiO-66, while the hydrophobic IL, [BMIM][PF6], is interacting with the joints where zirconium metal cluster coordinates with BDC ligand. The TGA data demonstrated that the composite with the ligand-functionalized MOF, NH2-UiO-66, exhibited a lower percentage decrease in the maximum tolerable temperature compared to those of IL/UiO-66 composites. Moreover, it is discovered that when the IL is hydrophilic, its hydrogen bonding ability can be utilized to designate an interaction site on MOF's ligand structure, leads to a lower reduction in thermal stability limits. These results provide insights for the rational design of IL/MOF composites and contribute towards the complete elucidation of structural factors controlling the thermal stability.
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    PublicationOpen Access
    Improving CO2 separation performance of MIL-53(Al) by incorporating 1-N-Butyl-3-methylimidazolium methyl sulfate
    (Wiley, 2019) Department of Chemical and Biological Engineering; N/A; Kulak, Harun; Polat, Hüsamettin Mert; Kavak, Safiyye; Keskin, Seda; Uzun, Alper; Faculty Member; Department of Chemical and Biological Engineering; Koç University Tüpraş Energy Center (KUTEM) / Koç Üniversitesi Tüpraş Enerji Merkezi (KÜTEM); Koç University Surface Science and Technology Center (KUYTAM) / Koç Üniversitesi Yüzey Teknolojileri Araştırmaları Merkezi (KUYTAM); Graduate School of Sciences and Engineering; N/A; N/A; N/A; 40548; 59917
    1-n-Butyl-3-methylimidazolium methyl sulfate is incorporated into MIL-53(Al). Detailed characterization is done by X-ray fluorescence, Brunauer-Emmett-Teller surface area, scanning electron microscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, and thermogravimetric analysis. Results show that ionic liquid (IL) interacts directly with the framework, significantly modifying the electronic environment of MIL-53(Al). Based on the volumetric gas adsorption measurements, CO2, CH4, and N-2 adsorption capacities decreased from 112.0, 46.4, and 19.6 cc (STP) g(MIL-53(Al))(-1) to 42.2, 13.0, and 4.3 cc (STP) g(MIL-53(Al))(-1) at 5 bar, respectively, upon IL incorporation. Data show that this postsynthesis modification leads to more than two and threefold increase in the ideal selectivity for CO2 over CH4 and N-2 separations, respectively, as compared with pristine MIL-53(Al). The isosteric heat of adsorption (Qst) values show that IL incorporation increases CO2 affinity and decreases CH4 and N-2 affinities. Cycling adsorption-desorption measurements show that the composite could be regenerated with almost no decrease in the CO2 adsorption capacity for six cycles and confirm the lack of any significant IL leaching. The results offer MIL-53(Al) as an excellent platform for the development of a new class of IL/MOF composites with exceptional performance for CO2 separation.
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    PublicationOpen Access
    CO2 separation from flue gas mixture using [BMIM][BF4]/MOF composites: linking high-throughput computational screening with experiments
    (Elsevier, 2020) N/A; N/A; Polat, Hüsamettin Mert; Kavak, Safiyye; Kulak, Harun; Uzun, Alper; Keskin, Seda; Faculty Member; Koç University Tüpraş Energy Center (KUTEM) / Koç Üniversitesi Tüpraş Enerji Merkezi (KÜTEM); Koç University Surface Science and Technology Center (KUYTAM) / Koç Üniversitesi Yüzey Teknolojileri Araştırmaları Merkezi (KUYTAM); College of Engineering; N/A; N/A; N/A; 59917; 40548
    In this study, we combined experiments with high-throughput molecular simulation methods to unlock CO2/N2 separation performances of 1085 different types of ionic liquid (IL)/metal organic framework (MOF) composites. We first validated the accuracy of our proposed computational methodology by synthesizing and characterizing three different IL/MOF composites composed of [BMIM][BF4] (1-n-butyl-3-methylimidazolium tetrafluoroborate) and by comparing their experimental CO2, N2 adsorption and separation performances with the simulation results. Motivated from the good agreement between experiments and simulations, we performed a high-throughput computational screening of 1085 different types of MOFs and their [BMIM][BF4]-incorporated counterparts to compute adsorption of CO2/N2 mixture in each material. Adsorbent performance evaluation metrics of [BMIM][BF4]/MOF composites including selectivity, working capacity, adsorbent performance score, and regenerability were calculated and compared with those of pristine MOFs to assess adsorption-based CO2/N2 separation performance limits of the composite materials. Our results revealed that [BMIM][BF4] incorporation remarkably increases CO2 selectivity, CO2 working capacity, and adsorption performance score of very large numbers of MOFs, resulting in excellent adsorbent candidates for separation of flue gas mixture. Analysis of the structure-performance relations showed that composites having narrow pore sizes, low porosities, and high IL loadings offer high CO2/N2 selectivities. These results will be useful in guiding and accelerating the design and development of new IL/MOF composites having exceptional CO2 capture performances from flue gas mixtures.
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    PublicationOpen Access
    Fast and selective adsorption of methylene blue from water using [BMIM][PF6]-incorporated UiO-66 and NH2-UiO-66
    (American Chemical Society (ACS), 2020) Department of Chemical and Biological Engineering; N/A; Kulak, Harun; Keskin, Seda; Uzun, Alper; Kavak, Safiyye; Polat, Hüsamettin Mert; Faculty Member; Department of Chemical and Biological Engineering; Koç University Tüpraş Energy Center (KUTEM) / Koç Üniversitesi Tüpraş Enerji Merkezi (KÜTEM); Koç University Surface Science and Technology Center (KUYTAM) / Koç Üniversitesi Yüzey Teknolojileri Araştırmaları Merkezi (KUYTAM); Graduate School of Sciences and Engineering; College of Engineering; N/A; 40548; 59917; N/A; N/A
    Incorporation of ionic liquids (ILs) into metal-organic frameworks (MOFs) offers a broad potential in various applications. However, their applications in wastewater treatment have remained unexplored. Here, we investigate their potential in wastewater treatment and demonstrate a new concept of IL incorporation in ligand-functionalized MOFs, introducing IL/FMOFs. The composites were prepared by incorporating 1-n-butyl-3-methylimidazolium hexafluorophosphate, [BMIM][PF6], into UiO-66 and NH2-UiO-66 and tested for the adsorption of methylene blue (MB) and methyl orange (MO) from aqueous solutions. Data showed that NH2-functionalization and [BMIM][PF6] incorporation improved MB removal performance of UiO-66 by 16- and 48-times, as the capacity increased from 84.8 to 144.7 mg g(-1) and 174.1 mg g(-1), respectively. When considering both modifications together, [BMIM][PF6]/NH2-UiO-66 was almost 300 times faster than that of UiO-66, and the capacity exceeded 200 mg g(-1). Data further suggested that IL incorporation almost doubled MB/MO selectivity because of the strong electrostatic interactions and hydrogen bonding between [PF6](-) and MB, and pi-pi interactions between the [BMIM](+) cation and MB molecules. These results are the first to demonstrate the prospect of combining ligand functionalization with IL incorporation for modifying MOFs, introducing IL/FMOF composites for fast and selective removal of pollutants from wastewater.
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    PublicationOpen Access
    MIL-53(Al) as a versatile platform for ionic-liquid/MOF composites to enhance CO2 selectivity over CH4 and N2
    (Wiley, 2019) N/A; Department of Chemical and Biological Engineering; Kavak, Safiyye; Polat, Hüsamettin Mert; Kulak, Harun; Keskin, Seda; Uzun, Alper; Faculty Member; Department of Chemical and Biological Engineering; Koç University Surface Science and Technology Center (KUYTAM) / Koç Üniversitesi Yüzey Teknolojileri Araştırmaları Merkezi (KUYTAM); Koç University Tüpraş Energy Center (KUTEM) / Koç Üniversitesi Tüpraş Enerji Merkezi (KÜTEM); College of Engineering; N/A; N/A; N/A; 40548; 59917
    Five different imidazolium-based ionic liquids (ILs) were incorporated into a metal–organic framework (MOF), MIL-53(Al), to investigate the effect of IL incorporation on the CO2 separation performance of MIL-53(Al). CO2, CH4, and N2 adsorption isotherms of the IL/MIL-53(Al) composites and pristine MIL-53(Al) were measured to evaluate the effect of the ILs on the CO2/CH4 and CO2/N2 selectivities of the MOF. Of the composite materials that were tested, [BMIM][PF6]/MIL-53(Al) exhibited the largest increase in CO2/CH4 selectivity, 2.8-times higher than that of pristine MIL-53(Al), whilst [BMIM][MeSO4]/MIL-53(Al) exhibited the largest increase in CO2/N2 selectivity, 3.3-times higher than that of pristine MIL-53(Al). A comparison of the CO2 separation potentials of the IL/MOF composites showed that the [BMIM][BF4]- and [BMIM][PF6]-incorporated MIL-53(Al) composites both showed enhanced CO2/N2 and CO2/CH4 selectivities at pressures of 1–5 bar compared to composites of CuBTC and ZIF-8 with the same ILs. These results demonstrate that MIL-53(Al) is a versatile platform for IL/MOF composites and could help to guide the rational design of new composites for target gas-separation applications.
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    PublicationOpen Access
    Influence of anion size and electronic structure on the gas separation performance of ionic liquid/ZIF-8 composites
    (Elsevier, 2020) Department of Chemical and Biological Engineering; N/A; Zeeshan, Muhammad; Kulak, Harun; Kavak, Safiyye; Polat, Hüsamettin Mert; Durak, Özce; Keskin, Seda; Uzun, Alper; PhD Student; Faculty Member; Department of Chemical and Biological Engineering; Koç University Surface Science and Technology Center (KUYTAM) / Koç Üniversitesi Yüzey Teknolojileri Araştırmaları Merkezi (KUYTAM); Koç University Tüpraş Energy Center (KUTEM) / Koç Üniversitesi Tüpraş Enerji Merkezi (KÜTEM); N/A; N/A; N/A; N/A; N/A; 40548; 59917
    We investigated the influences of the changes in the electronic structure and size of the anion of an imidazolium ionic liquid (IL) on gas adsorption and separation performance of the IL/ZIF-8 (zeolitic imidazolate framework) composites. We studied four different imidazolium ILs having the same cation, 1-n-butyl-3-methylimidazolium, [BMIM]+, with anions having structures allowing a systematic comparison of the changes in the electronic structure and size. To examine the influence of changes in the electronic structure, we considered anions representing the fluorination on the anion, methanesulfonate, [MeSO3]−, and trifluoromethanesulfonate, [CF3SO3]−. To investigate the change in the anion size, methyl sulfate, [MeSO4]−, and octyl sulfate, [OcSO4]−, were studied. Characterization of IL/ZIF-8 composites demonstrated successful incorporation of each IL in ZIF-8 without causing any detectable changes in the crystal structure and morphology of ZIF-8. Thermogravimetric analysis and infrared (IR) spectroscopy indicated the presence of direct interactions between ILs and ZIF-8, which directly control gas separation performance of the composite. Gas adsorption measurements illustrated that incorporation of ILs significantly improves the gas separation performance of the pristine ZIF-8. [BMIM][MeSO4]/ZIF-8 composite had 3.3- and 1.8-times higher CO2/N2 and CH4/N2 selectivities compared to ZIF-8, respectively, at 1 bar. When the IL has a fluorinated anion, CO2/CH4 selectivity improved 3-times compared to its non-fluorinated counterpart. Upon the incorporation of IL with a small anion, IL/ZIF-8 composite showed higher CO2/N2 and CH4/N2 selectivities compared to the composite having an IL with a bulky anion. These results will contribute in guiding rational design of IL/MOF composites for different gas separations.
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    PublicationOpen Access
    Enhanced water purification performance of ionic liquid impregnated metal-organic framework: dye removal by [BMIM][PF6]/MIL-53(Al) composite
    (Frontiers, 2021) N/A; Department of Chemical and Biological Engineering; Kavak, Safiyye; Durak, Özce; Kulak, Harun; Polat, Hüsamettin Mert; Keskin, Seda; Uzun, Alper; Faculty Member; Department of Chemical and Biological Engineering; Koç University Tüpraş Energy Center (KUTEM) / Koç Üniversitesi Tüpraş Enerji Merkezi (KÜTEM); Koç University Surface Science and Technology Center (KUYTAM) / Koç Üniversitesi Yüzey Teknolojileri Araştırmaları Merkezi (KUYTAM); Graduate School of Sciences and Engineering; College of Engineering; N/A; N/A; N/A; N/A; 40548; 59917
    We incorporated a water-stable ionic liquid (IL), 1-butyl-3-methylimidazolium hexafluorophosphate, [BMIM][PF6], into a water-stable metal-organic framework (MOF), MIL-53(Al), to generate the [BMIM][PF6]/MIL-53(Al) composite. This composite was examined for water purification by studying its capacity for methylene blue (MB) and methyl orange (MO) removal from aqueous solutions having either single dye or a mixture of both. Data illustrated that the removal efficiency and the maximum adsorption capacity of MIL-53(Al) were increased several times upon [BMIM][PF6] incorporation. For instance, within 1 min, 10 mg of pristine MIL-53(Al) adsorbed 23.3% MB from 10 mg/L of MB solution, while [BMIM][PF6]/MIL-53(Al) composite was adsorbed 82.3% MB in an identical solution. In the case of MO, 10 mg of pristine MIL-53(Al) achieved 27.8 and 53.6% MO removal from 10 mg/L of MO solution, while [BMIM][PF6]/MIL-53(Al) composite removed 61.4 and 99.2% within 5 min and 3 h, respectively. Moreover, upon [BMIM][PF6] incorporation, the maximum MB and MO adsorption capacities of the pristine MOF were increased from 84.5 to 44 mg/g to 204.9 to 60 mg/g, respectively. The adsorption of dyes in pristine MIL-53(Al) and [BMIM][PF6]/MIL-53(Al) followed a pseudo-second-order kinetic model and a Langmuir isotherm model. In a mixture of both dyes, the IL/MOF composite showed a doubled MB selectivity after the IL incorporation. The composite was successfully regenerated at least two times after its use in water purification to remove MB, MO, and their mixtures. Infrared (IR) spectra indicated that the MB/MO adsorption occurs on [BMIM][PF6]/MIL-53(Al) by electrostatic interactions, hydrogen bonding, and pi-pi interactions. These results showed that [BMIM][PF6]/MIL-53(Al) composite is a highly promising material for efficient water purification.