Browsing by Author "Canlier, Ali"

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Development of highly transparent Pd-coated Ag nanowire electrode for display and catalysis applications
(ELSEVIER, 2015) Canlier, Ali; Ucak, Umit Volkan; Usta, Hakan; Cho, Changsoon; Lee, Jung-Yong; Sen, Unal; Citir, Murat; 0000-0002-0618-1979; 0000-0003-3736-5049; 0000-0002-6666-4980; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü; Canlier, Ali; Ucak, Umit Volkan; Usta, Hakan; Sen, Unal; Citir, Murat
Ag nanowire transparent electrode has excellent transmittance (90%) and sheet resistance (20 Omega/sq), yet there are slight drawbacks such as optical haze and chemical instability against aerial oxidation. Chemical stability of Ag nanowires needs to be improved in order for it to be suitable for electrode applications. In our recent article, we demonstrated that coating Ag nanowires with a thin layer of Au through galvanic exchange reactions enhances the chemical stability of Ag nanowire films highly and also helps to obtain lower haze. In this study, coating of a thin Pd layer has been applied successfully onto the surface of Ag nanowires. A mild Pd complex oxidant [Pd(en)(2)](NO3)(2) was prepared in order to oxidize Ag atoms partially on the surface via galvanic displacement. The mild galvanic exchange allowed for a thin layer (1-2 nm) of Pd coating on the Ag nanowires with minimal truncation of the nanowire, where the average length and the diameter were 12.5 mu m and 59 nm, respectively. The Pd-coated Ag nanowires were suspended in methanol and then electrostatically sprayed on flexible polycarbonate substrates. It has been revealed that average total transmittance remain around 95% within visible spectrum region (400-800 nm) whereas sheet resistance rises up to 175 Omega/sq. To the best of our knowledge, for the first time in the literature, Pd coating was employed on Ag nanowires in order to design transparent electrodes for high transparency and strong chemical resistivity against nanowire oxidation. The current Pd-coated Ag nanowires may render an excellent catalyst system for fuel cell applications, as well as in organic synthesis with relatively low costs since our approach enables the fabrication of these nanowires with a very thin layer of Pd. We believe that mesh form of Pd-coated Ag nanowires will coin a new catalyst concept to the related areas since their sheet conductivity is high enough, and also little amount of Pd displays a large surface area as thin layers. (C) 2015 Elsevier B.V. All rights reserved.
An efficient and facile method of grafting Allyl groups to chemically resistant polyketone membranes
(ELSEVIER SCI LTD, THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND, 2018) Jung, Youn Seo; Canlier, Ali; Hwang, Taek Sung; 0000-0002-5462-6039; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü
Polyketone is a thermoplastic polymer known for its strong mechanical properties and chemical resistance. Such superiorities make it difficult to process and chemically modify for further functionalizations and applications. In this work, we introduce a novel method for functionalizing the alpha carbon of polyketone. We succeeded to attach allyl groups to the backbone of polyketone by a heterogeneous reaction between polyketone enolate and allyl bromide. Allylated polyketone is not soluble in common solvents. Since we started with a membrane of polyketone, there is no need to cast again. Further functionalization is possible through pending allyl groups via alkene addition reactions and ionic or radicalic polymerization. FTIR, elemental analysis, solid NMR, FT-Raman, SEM and XPS methods were employed to confirm the elemental composition, molecular structure and morphology. In addition, X-ray diffractometer (XRD), UVeVisible spectroscopy and thermal analysis were used to investigate the crystal structure, physical and electronic properties. (c) 2018 Elsevier Ltd. All rights reserved.
Ekran uygulamaları için bulanıklı azaltıcı metal nanotel saydam elektrotlar
(TUBİTAK, 2015) Çıtır, Murat; Şen, Ünal; Kılıç, Ahmet; Canlier, Ali; Ata, Ali; 0000-0002-5009-5197; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü; Çıtır, Murat; Şen, Ünal; Kılıç, Ahmet; Canlier, Ali; Ata, Ali
Günümüzde kullanılmakta olan İndiyum Kalay Oksit (ITO) saydam elektrotnunun indiyum elementinin doğada az bulunması, malzemelerin ve prosesin pahalı olması, esnek ve dokunmatik ekranlarda ölümcül olabilecek mekanik kırılganlığının olması gibi özellikleri kullanımını sınırlamaktadır. ITO’nun yerine geçebilecek karbon nanotüp, grafen ve metal nanotel elektrotlar gibi gelecek vaat eden saydam iletken malzemeler çalışılmaktadır. Bunlar arasında metal nanoteller, ITO’nun sayılan dezavantajlarını gidermesine ek olarak optik ve elektriksel özelliklerinin en az ITO kadar iyi olmasından dolayı özellikle gelecek vaat etmektedir. Metal nanoteller çözelti sentezi yöntemiyle yüksek verimde üretilebilir ve çözeltiye dağıtılmış nanoteller spin-coating veya sprey yöntemiyle geniş subtratlara kolayca kaplanabilir. Bu devrim niteliğindeki teknoloji özellikle mekanik esneklik isteyen ürünlerde kullanılmak üzere ekran endüstrisine büyük etkisi olacaktır. Önerilen proje kapsamında, hedef geçirgenlik başına nanotel elektrotların iletkenliği iki yöntemle geliştirilmesi amaçlanmaktadır: 1) daha ince ve daha uzun nanoteller sentezleyip kesişim nokta (junction) sayısını azaltmak ve 2) nanoteller üzerindeki oksit tabakasını gidererek ve nanotelleri iletkenliği yüksek altın (veya inert metal) tabakasıyla kaplayarak junction direncini azaltmak. Böylece bu çalışmayla ekran uygulamaları için hedeflenen levha direncine daha az nanotel kullanılarak ulaşılacaktır. Bu durum toplam geçirgenliğin iyileşmesini ve bulanıklık seviyesinin düşmesini sağlayacaktır. Son çalışmalara göre bulanıklık seviyesi 8 ohm/sq levha direnç ve %80 diffusive geçirgenlikte %15 seviyesindedir. Bulanıklık seviyesinin yüksek olması güneş pilleri için bir avantaj iken, yüksek-teknolojik ve askeri uygulamalarda kullanılacak ekranlar için düşük bulanıklık (<5%) seviyesine ihtiyaç vardır. Önerilen projede nanotellerin enboy oranını küçülterek ve junction direncini azaltarak toplam bulanıklığın azaltılmasıyla bu teknolojinin ekranlar için uygun hale gelmesi amaçlanmaktadır.
Enhancement of Anhydrous Proton Conductivity of Poly(vinylphosphonic acid)-Poly(2,5-benzimidazole) Membranes via In Situ Polymerization
(WILEY-V C H VERLAG GMBH, 2015) Sen, Unal; Usta, Hakan; Acar, Oktay; Citir, Murat; Canlier, Ali; Bozkurt, Ayhan; Ata, Ali; 0000-0002-6666-4980; 0000-0003-3736-5049; 0000-0002-0618-1979; 0000-0001-6055-2817; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü; Sen, Unal; Usta, Hakan; Canlier, Ali; Citir, Murat
Polymer electrolyte membranes (PEMs) are synthesized via in situ polymerization of vinylphosphonic acid (VPA) within a poly(2,5-benzimidazole) (ABPBI) matrix. The characterization of the membranes is carried out by using Fourier transform infrared (FTIR) spectroscopy for the interpolymer interactions, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) for the thermal properties, and scanning electron microscopy (SEM) for the morphological properties. The physicochemical characterizations suggest the complexation between ABPBI and PVPA and the formation of homogeneous polymer blends. Proton conductivities in the anhydrous state (150 degrees C) measured by using impedance spectroscopy are considerable, at up to 0.001 and 0.002 S cm(-1) for (1: 1) and (1: 2) molar ratios, respectively. These conductivities indicate signifi cant improvements (> 1000x) over the physically blended samples. The results shown here demonstrate the great potential of in situ preparation for the realization of new PEM materials in future high-temperature and non-humidified polymer electrolyte membrane fuel cell (PEMFC) applications.
Highly Transparent Au-Coated Ag Nanowire Transparent Electrode with Reduction in Haze
(AMER CHEMICAL SOC, 2014) Kim, Taegeon; Canlier, Ali; Lee, Jung-Yong; Rozyyev, Vepa; Han, Seung Min; Cho, Changsoon; 0000-0003-2488-1167; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü; Canlier, Ali
Ag nanowire transparent electrode has excellent transmittance and sheet resistance, yet its optical haze still needs to be improved in order for it to be suitable for display applications. Ag nanowires are known to have high haze because of the geometry of the nanowire and the high light scattering characteristic of the Ag. In this study, a Au-coated Ag nanowire structure was proposed to reduce the haze, where a thin layer of Au was coated on the surface of the Ag nanowires using a mild [Au(en)2]Cl3 galvanic displacement reaction. The mild galvanic exchange allowed for a thin layer of Au coating on the Ag nanowires with minimal truncation of the nanowire, where the average length and the diameter were 13.0 μm and 60 nm, respectively. The Au-coated Ag nanowires were suspended in methanol and then electrostatically sprayed on a flexible polycarbonate substrate that revealed a clear reduction in haze with a 2–4% increase in total transmittance, sheet resistance ranges of 80–90%, and 8.8–36.8 Ohm/sq. Finite difference time domain simulations were conducted for Au-coated Ag nanowires that indicated a significant reduction in the average scattering from 1 to 0.69 for Au layer thicknesses of 0–10 nm.
Insights of CO2 adsorption performance of amine impregnated mesoporous silica (SBA-15) at wide range pressure and temperature conditions
(ELSEVIER SCI LTD, THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND, 2015) Ullah, Ruh; Atilhan, Mert; Aparicio, Santiago; Canlier, Ali; Yavuz, Cafer T.; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü;
Beside IGCC, efficient storage and transportation of CO2 and other gases require pressurize conditions. CO2 and other gases adsorption on solid sorbents at high pressure and various temperatures are extremely important as long as the environmental purification via gas capture and separation and gas transpiration are concern. The main objective of the present research was to investigate the effect of amine impregnation on the CO2, methane and nitrogen adsorption capacity of mesoporous silica (SBA-15). Ordered mesoporous silica (SBA-15) was prepared and modified with ammonium hydroxide solution to introduce NH2 functional groups within the pores of materials to produce modified SBA-15 (MSBA-15). The newly prepared materials were characterized with X-ray diffraction analysis, thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) analysis were performed to measure pore volume as well as the surface area of both the unmodified and modified samples. Results revealed that the crystal structures of SBA-15 were matched with that of MSBA15; yet, pore volume of the modified material was almost reduced to 50% of the pristine material indicating amine loading into the pore channels. Importantly, gas sorption capacity was investigated at 200 bars and three different temperatures of 318 K, 328 K, and 338 K by using state-of-the-art gravimetric Rubotherm(R) magnetic suspension sorption apparatus. Gas sorption experiments showed that modified mesoporous silica adsorbed 1.6164 mmol/g of CO2 at 1 bar which is almost double than that of 0.6462 mmol/g adsorbed by unmodified material. Quantitative selectivity of both the materials varied as CO2 > CH4 > N-2. (C) 2015 Elsevier Ltd. All rights reserved.
Synthesis of L-Cysteine Capped Silver Nanoparticles in Acidic Media at Room Temperature and Detailed Characterization
(SPRINGER, VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS, 2018) Panhwar, Sallahuddin; Hassan, Syeda Sara; Mahar, Rasool Bux; Canlier, Ali; Sirajuddin; Arain, Munazza; 0000-0002-1966-0397; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü
This work reports a simple and one pot synthesis of water dispersible l-cysteine stabilized silver nanoparticles (l-CYS-AgNPs) in an acidic media. Silver nanoparticles were synthesized within few minutes of reaction time (< 5 min) at room temperature without needing to heat and use of any hazardous organic solvents. Prepared nanoparticles were characterized by UV-Visible spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscopy, atomic force microscopy, X-ray diffraction and zeta potential analysis, respectively. Surface plasmon resonance band of AgNPs which was observed at 392 nm by UV-Visible spectroscopy indicated successful formation of l-CYS-AgNPs in acidic media. Imaging techniques showed that AgNPs possess spherical morphology and average size of 25 nm. Nanoparticles were stable for more than 2 months when stored at ambient temperature. This approach is a facile and rapid one pot synthesis which can be stored as a homogenous aqueous dispersion for more than 2 months. Being stabilized by a sulfur-containing amino acid (l-cysteine) and the synthesis carried out in a moderately acidic media (pH 5.3) are distinctive aspect of this work. These stable l-CYS-AgNPs could be used as a catalyst and sensor applications for advanced perspective against water pollution and industrial effluents.
Synthesis of polyketone-g-sodium styrene sulfonate cation exchange membrane via irradiation and its desalination properties
(POLYMER SOC KOREAROOM 601, HATCHON BUILDING, 831 YEOKSAM-DONG, KANGNAM-KU, SEOUL 135-792, SOUTH KOREA, 2017) Kim, In Sik; Hwang, Chi Won; Kim, Young Joong; Canlier, Ali; Jeong, Kyung Seok; Hwang, Taek Sung; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü
Using the radiation grafting technique, polyketone membranes were graft copolymerized with sodium styrene sulfonate (SSS) in the presence of additives such as Mohr's salt and H2SO4. Fourier-transform infrared (FT-IR) spectroscopy was used to characterize the grafted membranes. Water uptake (WU), ion exchange capacity (IEC) and electrical resistance (ER) of the prepared membranes were measured in order to evaluate their physical properties The prepared membranes were applied to the membrane capacitive deionization (MCDI) process, in which their salt removal rates were evaluated and compared to those of CDI (capacitive deionization) process. The degree of grafting rose from 14.4% to 81.4% as the irradiation dose and the monomer concentration were increased. The water uptake ranged from 7.9% to 34.2%. The ionexchange capacity was observed between 0.43 meq/g and 1.1 meq/g, and the electrical resistance had values ranging from 12.2 Omega center dot cm(2) to 2.1 Omega center dot cm(2). The electrical resistance decreased as the ion-exchange capacity was extended. When the prepared cation exchange membrane was used in the MCDI process, the salt removal rate reached 87.6%, which was much higher than 28.8% of CDI process.
Synthesis of polyketone-g-vinylbenzyl chloride anion exchange membrane via irradiation and its properties
(POLYMER SOC KOREAROOM 601, HATCHON BUILDING, 831 YEOKSAM-DONG, KANGNAM-KU, SEOUL 135-792, SOUTH KOREA, 2017) Kim, Young Joong; Hwang, Chi Won; Hyeon, Seung Mi; Canlier, Ali; Hwang, Taek Sung; 0000-0002-5462-6039; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü
A novel anion exchange membrane composed of aminated polyketone-g-vinylbenzyl chloride was synthesized via Co-60 gamma-ray irradiation grafting technique. Total irradiation dose and concentration of monomers were set as variables to determine degree of grafting. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy equipped with energy dispersive X-ray spectrometer (SEM-EDS) were used to characterize the grafted membranes. Water uptake (WU) and swelling ratio (SR) were measured with a gravimetric method. A titration method was used to detect ion exchange capacity (IEC), whereas electrical resistance (ER) and ion conductivity (IC) were measured with a LCR meter. Our method has boosted the degree of grafting up to 97.6% from 3.7% as total irradiation dose and monomer concentration have been increased. WU and SR were in the ranges 1.5%-35.6% and 0.35%-20.9%, respectively. Also, IEC has taken values ranging between 0.2 and 1.19 meq/g. IC has varied within the range 0.01-0.3 S cm(-1), and it has shown a rising trend as IEC increased. In this study, the optimum synthesis conditions have been 70 kGy of total irradiation dose and 50wt% of monomers. The membrane synthesized here is potentially superior to Nafion membrane in terms of several properties.
Thin films of inert metal nanowires for display applications
(TANGER LTD, 2015) Citir, Murat; Sen, Unal; Usta, Hakan; Canlier, Ali; 0000-0002-6666-4980; 0000-0002-0618-1979; 0000-0003-3736-5049; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü; Citir, Murat; Sen, Unal; Usta, Hakan; Canlier, Ali
Ag nanowire transparent electrode has excellent transmittance (90%) and sheet resistance (20 Ohm/sq), yet there are slight drawbacks such as optical haze and chemical instability against aerial oxidation. Chemical stability of Ag nanowires needs to be improved in order for it to be suitable for electrode applications. Coating Ag nanowires with a thin layer of inert metals such as Au and Pd through galvanic exchange reactions may enhance the chemical stability of Ag nanowire films highly and also helps to obtain lower haze. In this study, coating of thin Au and Pd layers has been applied successfully onto the surface of Ag nanowires. Usually coatings are carried out by salts such as HAuCl4 and K2PdCl4 in order to make nanotubes. In this study, novel ethylenediamine(en) complexes of inert metal cations with mild oxidation power were prepared in order to oxidize Ag atoms partially on the surface through galvanic displacement. The mild galvanic exchange allowed for a thin layer (1-4 nm) of inert metal coating on the Ag nanowires with minimal truncation of the nanowire, where the average lengths and the diameters were between 10 similar to 14 mu m and 55 similar to 65 nm, respectively. The crystalline structure of the shell was formed epitaxially on the surface. The new Ag nanowires were suspended in methanol and then electrostatically sprayed on glass and flexible substrates. It was revealed that average total transmittance remain around 90% within visible spectrum region (400-800 nm) whereas sheet resistance rises up to 175 Ohm/sq. Very thin layer of inert metal costs low, though this may render an excellent catalyst for applications such as fuel cell and organic synthesis, whereas transparent films of inert metal-coated Ag nanowire can be utilized as working electrodes for spectro-electrochemical cells as well.
Ultra-rapid catalytic degradation of 4-nitrophenol with ionic liquid recoverable and reusable ibuprofen derived silver nanoparticles
(ELSEVIER SCI LTD, THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND, 2018) Hassan, Syeda Sara; Carlson, Krista; Mohanty, Swomitra Kumar; Sirajuddin; Canlier, Ali; 0000-0002-4288-2641; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü
This study reports a one-pot and eco-friendly method for the synthesis of spherical ibuprofen derived silver nanoparticles (IBU-AgNPs) in aqueous media using ibuprofen analgesics drug as capping as well as reducing agent. Formation of AgNPs occurred within a few min (less than 5 min) at room temperature without resorting to any harsh conditions and hazardous organic solvents. Synthesized AgNPs were characterized with common analytical techniques. Transmission electron microscope (TEM) images confirmed the formation of spherical particles having a size distribution in the range of 12.5 +/- 1.5 nm. Employment of IBU analgesic aided the control of better size distribution and prevented agglomeration of particles. Such AgNPs solution was highly stable for more than two months when stored at ambient temperature. The IBU-AgNPs solution showed excellent ultra-rapid catalytic activity for the complete degradation of toxic 4-nitrophenol (4-NPh) into non-toxic 4-aminophenol (4-APh) within 40 s. AgNPs were recovered with the help of water insoluble-room temperature ionic liquid and reused with enhanced catalytic potential. This method provides a novel, rapid and economical alternative for the treatment of toxic organic pollutants to maintain water quality and environmental safety against water pollution. It is extendable for the control of other reducible contaminants in water as well. Furthermore, this catalytic activity for an effective degradation of organic toxins is expected to play a crucial role for achieving the Sustainable Development Goal 6 set by United Nations. (C) 2017 Elsevier Ltd. All rights reserved.