Güler, Enver

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G.,Enver
Guler, Enver
G., Enver
E., Güler
E.,Güler
Güler,E.
Enver, Güler
E., Guler
Guler,E.
Enver, Guler
Guler E.
Güler E.
Güler, Enver
E.,Guler
Guler, E.
Job Title
Doçent Doktor
Email Address
enver.guler@atilim.edu.tr
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Chemical Engineering
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Website
ORCID ID
0000-0001-9175-0920
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WoS Researcher ID
Scholarly Output

30

Articles

16

Citation Count

167

Supervised Theses

6

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2017 - 201992020 - 202421
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Now showing 1 - 10 of 30
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    Article
    Citation - WoS: 6
    Citation - Scopus: 6
    Effect of Co-Existing Ions on Salinity Gradient Power Generation by Reverse Electrodialysis Using Different Ion Exchange Membrane Pairs
    (Mdpi, 2022) Kaya, Tugce Zeynep; Altiok, Esra; Guler, Enver; Kabay, Nalan; Chemical Engineering
    This study investigates the influence of co-existing ions on the salinity gradient power generation performance of the reverse electrodialysis (RED) using three different commercial ion exchange membrane pairs. The feed solutions, including the mixture of two different salts, were prepared with 90 wt.% of NaCl and 10 wt.% of LiCl, KCl, CaCl2, MgCl2 or Na2SO4 by keeping the salt ratio between high concentrate solution and low concentrate solution constant as 1:30 (g/g) at various flow velocities (50, 125 and 200 mL/min). It was observed that the divalent ions exhibited a negative impact on the performance of the RED system due to their high valence and low ionic mobility depending on their high hydrated radius and low diffusion coefficients compared to those of the monovalent ions. On the other hand, the effect of the monovalent ions differed according to the properties of ion exchange membranes used in the RED stack. When the power generation performances of ion exchange membrane pairs employed in the RED stack were compared, it was considered that Neosepta AMX and CMX membranes provided the highest power density due to their low membrane thicknesses, low electrical resistances, and relatively high ion exchange capacities compared to other two commercial ion exchange membrane pairs.
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    Review
    Citation - Scopus: 5
    Ion Exchange Membranes for Reverse Electrodialysis (red) Applications - Recent Developments
    (Amirkabir University of Technology - Membrane Processes Research Laboratory, 2021) Eti,M.; Othman,N.H.; Guler,E.; Kabay,N.; Chemical Engineering
    The innovative membrane-based technology called reverse electrodialysis (RED) is capable of producing electrical power from the controlled mixing of two aqueous streams of different salinity. There has been tremendous progress so far in the development of RED process in terms of system development, spacer design, membranes properties and operational conditions optimization. Among those, characteristics of the ion exchange membranes are found to be the critical element affecting the performances of RED process. In this respect, a brief overview of the latest developments in ion exchange membranes were presented in this review, focussing on their properties and performances in RED applications. The recent developments of nanocomposite and ion selective membranes, particularly pore filling ion exchange membranes due to their high performances and inexpensive fabrication cost were also summarized. Shortly, fouling problem for the ion exchange membranes employed in the RED system was mentioned. © 2021 Amirkabir University of Technology - Membrane Processes Research Laboratory. All rights reserved.
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    Article
    Citation - WoS: 10
    Citation - Scopus: 12
    Characterization and Fuel Cell Performance of Divinylbenzene Crosslinked Phosphoric Acid Doped Membranes Based on 4-Vinylpyridine Grafting Onto Poly(ethylene-Co Films
    (Pergamon-elsevier Science Ltd, 2018) Guler, Enver; Sadeghi, Sahl; Gursel, Selmiye Alkan; Chemical Engineering
    The effect of divinylbenzene (DVB) as crosslinker on the graft polymerization of 4-vinylpyridine (4VP) from poly(ethylene-co-tetrafluoroethylene) (ETFE) films was studied. The resulted films were doped with phosphoric acid (PA) and characterized for mechanical, surface, thermal properties, and fuel cell performance. The crosslinked membrane obtained from grafting a mixture of 4VP with 1% DVB improved the polymerization kinetics and resulted in about 50% graft level depending on graft conditions. The crosslinked membranes were also found to have better mechanical properties compared to its non-crosslinked counterpart. The resulted membrane exhibited proton conductivity as high as 75 mS/cm under 50% relative humidity (RH) at 120 degrees C, besides almost doubling the power output of fuel cell compared to a non-crosslinked membrane. To the best of our knowledge, DVB crosslinked 4VP based ETFE membranes were, for the first time, tested in practical fuel cell test station correlating their performance to operating temperature. Furthermore, surface properties of produced membranes were additionally correlated to the degree of crosslinking. Humidity dependence is less pronounced in the produced membranes resulting in strong potential for testing at intermediate temperature (80-120 degrees C) polymer electrolyte membrane fuel cells. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
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    Master Thesis
    Alkali Yakıt Hücreleri için Yarı-iç İçe Geçen Polietersülfon Kuaternize Nişasta Polimer Ağına Dayalı Anyon Değişim Membranı
    (2021) Almurumudhe, Osamah Kadhım Hılal; Güler, Enver; Chemical Engineering
    Zehirli emisyonlar olmadan güç üretmeye yönelik birçok etkili cihaz ortaya çıkmış ve geliştirilmiştir. Proton değişim membranlı yakıt hücresi (PEMFC) bu etkili cihazlardan biridir. Elektrokatalizör olarak platine tamamen bağımlı olması son derece rekabetçi olan pazardaki uygulamasını sınırlandırmıştır. Değerli olmayan metal katalizörün potansiyel kullanımı, anyon değişim membranlı yakıt hücresinin (AEMFC) yeniden dikkati çekmesini sağlamıştır. Anyon değişim membranı (AEM), AEMFC'nin kalbi olarak kabul edilir ve aynı zamanda AEM´lerin hazırlanması, bu yakıt hücrelerin geliştirilmesindeki en büyük zorluk olarak kabul edilmiştir. Yüksek iletkenliğe ve yüksek alkali direncine sahip anyon değişim membranların üretimi, bu alanda aktif bir araştırma alanı haline gelmiştir. Bu çalışmada, alkali yakıt hücreleri için iki tür anyon değişim membranı, basit ve yeni bir stratejiye göre tek aşamalı kuaternizasyon yöntemi ile üretilmiştir, Nişastanin kolin klorür ve epiklorohidrin ile kuaternizasyonu ̸ çapraz bağlanması ve ardından polietersülfon (PES) ile karıştırılması, iç içe geçen bir polimer ağıyla (IPN) sonuçlanmıştır. Birinci tip, 133.33 μm kalınlığa sahip gözenekli polieter sülfon AEM, % 376.7 su alımı ve % 5.3 şişmevi oranı sergilemiştir. İkinci tip ise, 55.48 μm ile yoğun polieter sülfon AEM, % 69.9 su alımı ve % 7.5 şişme oranı sergilemiştir. Karakterizasyon sonuçları, üretim rotamızın çok başarılı olduğunu ve üretilen anyon değiştirici membranlarımızın alkali yakıt hücresi uygulamaları için umut verici olduğunu doğrulamıştır.
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    Book Part
    Citation - Scopus: 2
    Ion Exchange Membranes in Electrodialysis Process for Wastewater Treatment
    (Elsevier, 2023) Altıok,E.; Cihanoğlu,A.; Güler,E.; Kabay,N.; Chemical Engineering
    Water is the most important natural resource on earth. Survival without water is impossible and industries cannot operate without water as well. Availability of safe and reliable source of water is therefore essential. Different practical solutions are needed for sustainable preservation of water resources as freshwater resources are limited in terms of technical and economical aspects. Membrane technologies can be applied to water and wastewater treatment for removal of various unwanted substances from water. Recently, the utilization of membrane technologies in the water purification sector has grown exponentially. Compared to conventional reclamation methods, membrane technologies are much more efficient for removal of various contaminants and they are able to overcome more stringent water regulations. Membrane separation processes employed for water treatment include reverse osmosis, nanofiltration, ultrafiltration, microfiltration, and electrodialysis (ED). In this chapter, we reviewed the basic principles of electromembrane processes, such as ED, electrodeionization, electrodialysis reversal, and bipolar membrane ED based on ion exchange membranes (IEMs) along with few examples of the use of these processes in water and wastewater treatment. In addition, fouling of IEMs is also discussed. © 2024 Elsevier Inc. All rights reserved.
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    Article
    Citation - WoS: 4
    Citation - Scopus: 4
    Salinity Gradient Energy Conversion by Custom-Made Interpolymer Ion Exchange Membranes Utilized in Reverse Electrodialysis System
    (Elsevier Sci Ltd, 2023) Altiok, Esra; Kaya, Tugce Zeynep; Smolinska-Kempisty, Katarzyna; Guler, Enver; Kabay, Nalan; Tomaszewska, Barbara; Bryjak, Marek; Chemical Engineering
    Reverse electrodialysis (RED) is one of methods to extract salinity gradient energy between two aqueous solu-tions with different salt concentrations. In this work, custom-made interpolymer ion exchange membranes were employed in the RED stack. The effects of divalent (Mg2+, Ca2+ , SO42-) and monovalent (Li+, K+ and Cl-) ions in the feed solutions prepared from NaCl salt as a function of such process parameters as number of membrane pairs, flow rate , salinity ratio on power generation by the RED method were studied. It was shown that the maximum power density of 0.561 W/m2 was reached by using three membrane pairs using 1:45 of salt ratio with a feed flow rate of 120 mL/min using only NaCl salt in the feed solutions. The maximum power density was 0.398 W/m2 at 120 mL/min of the flow rate of the feed solutions composed of 90 wt% NaCl and 10 wt% KCl by using a salt ratio of 1:30 while the lowest power density of 0.246 W/m2 was obtained with a feed flow rate of 30 mL/min in the presence of SO42-ions with a similar salt ratio. Consequently, it was seen that while the presence of divalent ions in NaCl solutions had negative impact on power generation by RED system, the addition of monovalent ions having smaller hydrated radius than that of the Na+ ions contributed positively to the power generation.
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    Article
    Citation - WoS: 3
    Citation - Scopus: 3
    Further Development of Polyepichlorohydrin Based Anion Exchange Membranes for Reverse Electrodialysis by Tuning Cast Solution Properties
    (Mdpi, 2022) Eti, Mine; Cihanoglu, Aydin; Guler, Enver; Gomez-Coma, Lucia; Altiok, Esra; Arda, Muserref; Kabay, Nalan; Chemical Engineering
    Recently, there have been several studies done regarding anion exchange membranes (AEMs) based on polyepichlorohydrin (PECH), an attractive polymer enabling safe membrane fabrication due to its inherent chloromethyl groups. However, there are still undiscovered properties of these membranes emerging from different compositions of cast solutions. Thus, it is vital to explore new membrane properties for sustainable energy generation by reverse electrodialysis (RED). In this study, the cast solution composition was easily tuned by varying the ratio of active polymer (i.e., blend ratio) and quaternary agent (i.e., excess diamine ratio) in the range of 1.07-2.00, and 1.00-4.00, respectively. The membrane synthesized with excess diamine ratio of 4.00 and blend ratio of 1.07 provided the best results in terms of ion exchange capacity, 3.47 mmol/g, with satisfactory conductive properties (area resistance: 2.4 omega center dot cm(2), electrical conductivity: 6.44 mS/cm) and high hydrophilicity. RED tests were performed by AEMs coupled with the commercially available Neosepta CMX cation exchange membrane (CEMs).
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    Master Thesis
    Etilen Oksidasyonuyla Asetik Asit Üretiminin Aspen Plus Kullanılarak Modellenmesi
    (2018) Maıuf, Abır Abdelftah Alı; Güler, Enver; Chemical Engineering
    Bu çalışmada etilenin oksidasyonu ile asetik asit üretiminin tasarım ve optimizasyon modeli Aspen Plus yazılımı kullanılarak incelenmiştir. Simülasyon işleminde girdi alt akış olarak CO2, N2 ile gaz fazı besleme akışı, üst girdi akışı olarak ise H2O'dur. Araştırma, asetik asit üretim sürecini anlamayı ve incelemeyi ve buna ek olarak operasyonel değişkenleri ve bunların üretim üzerindeki etkilerini incelemeyi amaçlamaktadır. Simülasyon modeline göre, asetik asit absorber içinde altı aşamadan sonra alt akışta sıvı olarak üretilmiştir. Ayrıca akış hızı, sıcaklık ve basınç kontrol edilmiş ve hassasiyet parametreleri olarak analiz edilmiştir. Elde edilen temel ürün, 30.3 °C sıcaklıkta ve 10 bar basınçta mol akışı yaklaşık 0.6 kmol/saat ve mol oranı yaklaşık 0.004 olan asetik asittir.
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    Article
    Az Bilinen Fakat Potansiyeli Yüksek Sürdürülebilir Bir Enerji Türü: Mavi Enerji
    (Herkese Bilim Teknoloji, 2017) Güler, Enver; Chemical Engineering
    21. yüzyılda insanoğlunun karşılaştığı ve ileride ziyadesiyle sözkonusu olacak en temel durum enerji, su ve gıdaya olan taleptir. Bu talebin karşılanmasında ise sürdürülebilirlik şimdiki ve gelecek kuşakların temel sorunu olmaya devam edecektir. Su, enerji ve gıda arasındaki sıkı bağ açıkça gösteriyor ki; su ve enerji gıda üretiminde, su enerji üretiminde ve enerji su temini ve üretiminde en temel faktörlerdir [1]. Bunun neticesinde bu üçlü bağlam, 2035 yılında enerjiye olan talebin en fazla değer olarak % 50 olacağını öngörmektedir (Şekil 1). Enerjiye olan bu yüksek talebin yakın gelecekte fosil yakıtlar ile sürdürülebilir şekilde karşılanamayacağı aşikardır. Bu durum, enerjinin sürdürülebilir olarak üretimini sağlayacak alternatif teknikler geliştirilmesini bir öncelik haline getirmiştir.
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    Article
    Citation - Scopus: 8
    New generation radiation-grafted PVDF-g-VBC based dual-fiber electrospun anion exchange membranes
    (Elsevier Ltd, 2024) Kırlıoğlu,A.C.; Rajabalizadeh Mojarrad,N.; Alkan Gürsel,S.; Güler,E.; Yarar Kaplan,B.; Chemical Engineering
    Anion Exchange Membranes (AEM) have the potential to solve the cost issues of fuel cell technologies due to their basic environment that can allow the use of cheaper components. However, there is still a need to develop an ideal inexpensive, mechanically robust AEM with high ionic conductivity and ion exchange capacity (IEC). In this work, we present various dual-fiber electrospun membranes based on a novel radiation-grafted copolymer. First, the synthesis route of radiation-induced grafting of vinyl benzyl chloride (VBC) onto poly (vinylidene fluoride) (PVDF) to prepare PVDF-g-VBC was optimized. Then, PVDF-g-VBC powders were used to fabricate dual-fiber electrospun mats with inert PVDF and commercial Fumion-FAA-3 ionomer. Dual-fiber electrospun mats were hot-pressed and then quaternized with trimethylamine. Finally, mechanical properties, ion exchange capacity, ionic conductivity, and morphology of these prepared dual-fiber electrospun membranes were investigated. The dual-fiber membrane prepared with PVDF-g-VBC (88% of the total weight of the membrane) and PVDF: Fumion-FAA-3 (1:2) mix (12 wt%) realized ionic conductivity of 4.67 mS/cm at 25 °C, high ion exchange capacity of 1.35 mmol/g with Young's Modulus of 761 MPa. The membrane based on the combination of radiation grafting and dual-fiber electrospinning was prepared for the first time in literature and offers the prospect of tuning and fine-control of mechanical and physicochemical properties of AEMs. © 2023 Hydrogen Energy Publications LLC