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Abstract In this study, Wood Plastic Composites (WPCs) were produced from post-consumer bulky wastes of recycled plastic and wood in order to minimize waste, decrease environmental effects of plastics, reserve natural resources, and support circular economy for sustainable production and consumption. Five different types of polypropylene (PP) or polyethylene (PE) based recycled plastics and wood obtained from urban household bulky wastes were used in the production of recycled WPC composites, r-WPCs. Virgin WPC (v-WPC) and r-WPC compounds were prepared with wood flour (WF) and maleic anhydride grafted compatibilizer (MAPP or MAPE) to evaluate the effect of recycled polymer type and compatibilizer on the mechanical properties. It was found that tensile strength properties of r-WPCs produced from recycled PP (r-PP) were higher than that of the r-WPCs produced from mixed polyolefins and recycled PE. r-WPCs containing anti-oxidants, UV stabilizers, and compatibilizer with different WF compositions were produced from only recycled garden fraction PP (PPFGF) to determine the optimum composition and processing temperature for pilot scale manufacturing of r-WPCs. Based on tensile, impact, flexural, and water sorption properties of r-WPC compounds with different formulations, the optimum conditions of r-WPC compounds for industrial manufacturing process were determined. Surface morphology of fractured surfaces as well as tensile, flexural and density results of r-WPC compounds revealed the enhancement effect of MAPP on interfacial adhesion in r-WPCs. r-WPC products (crates and table/chair legs) based on bulky wastes were produced using an injection molding process at industrial scale by using 30 wt% WF-filled r-WPC compound. This study demonstrated that r-WPC compounds from recycled bulky plastic and wood wastes can be used as a potential raw material in plastic as well as WPC industry, contributing to circular economy. Graphic Abstract

In this study, we present the ethyl esters biodiesel production from Nannochloropsis oculata and Spirulina sp. microalgal lipids on 60 wt% CaO on Al2O3 catalyst at 50 degrees C and 1.0 atm. The activity of the catalyst was studied as a function of ethanol:lipid molar ratios, catalyst amounts and reaction times. It was found that 6 wt% of the lipids as catalyst amount resulted in 59% biodiesel yield in 30 min at 12 of ethanol:lipid molar ratio whereas 90-99% biodiesel yield was obtained at 24 and 48 of ethanol:lipid molar ratios. In order to achieve 90-99% yields, the basic strength was found to be weak and to be in the form of bi-carbonate, whereas high basicity was not necessary. Besides, pure CaO and Al2O3 were not active under the same reaction conditions. We found that the glycerolysis of triacylglyceride occurred in series with the reverse of the transesterification of the triacylglyceride when the catalyst amount was 6 wt% of the lipids and the ethanol:lipid molar ratio was 24 and 48 and the reaction time was 60 min. (C) 2019 Elsevier Ltd. All rights reserved.

PubMed: 31622724, POSS, regarded as the smallest silica particle, is widely used as nanofiller in polymer systems. POSS-based nanocomposites are deduced as novel materials having potency for biomedical applications owing to the enhanced biocompatibility and physicochemical characteristics. The aim of this work was to integrate the beneficial features of chitosan (CS) and OctaTMA-POSS nanoparticle to design nanocomposite for bone tissue regeneration. The nanocomposite scaffolds were fabricated by freeze-drying. The effects of POSS incorporation on morphology and structure of CS matrix were examined. Bioactivity and osteogenic effects of the POSS nanoparticles were investigated with cytocompatibility, cell proliferation, alkaline phosphatase activity, osteocalcin production and biomineralization assays. PUSS incorporation altered the surface morphology by increasing surface roughness. Nanocomposite scaffolds with 82-90% porosity exhibited an increase in compression modulus of scaffolds (78-107 kPa) compared to control CS group (56 kPa). Results indicated that CS-POSS scaffolds were found cytocompatible with 3T3, MG-63 and Saos-2 cell lines. POSS incorporation showed promising effects on osteoblast adhesion and proliferation as well as increasing ALP activity, octeocalcin secretion and biomineralization of cells. (C) 2019 Elsevier B.V. All rights reserved.

The effect of temperature on stability of lipid microbubble shell containing polyethyleneoxide-40-stearate (PEG40St) as emulsifier was investigated. Microbubbles at 4 °C were subjected to different temperatures up to 48 ºC (down-to-up) and it was found that both the number and the size of microbubbles remained unchanged in the population up to a certain time, so called “onset time”. The onset time was about 6 hours at 10 °C, 2 hours at 20 °C and shorter at elevated temperatures, exhibiting an exponential decrease with increasing temperature. Once the onset time was reached, the number of microbubbles started to decrease and the average size of the population started to increase. Observation of single microbubbles on a constant temperature heating stage exhibited that each microbubble had its own onset time, with the smaller microbubbles vanishing earlier than the larger ones. The Langmuir monolayer studies showed that hydration degree of the emulsifier PEG chains decreased with temperature, causing them go through conformational changes and subsequently destabilization of the shell. By subjecting the freshly produced microbubbles directly to the desired temperatures in up-to-down fashion, more stable microbubbles were able to be produced, with their onset time increased 40% at 10 °C to 500% at 38 °C. Overall, the results suggest that the new strategies need to be developed to control the collapse process in the microbubble shell resulting from the conformational changes in the PEG chains of the emulsifier for the design of more stable microbubbles. © 2019, Turkish Chemical Society. All rights reserved.

Thesis (Doctoral)--Izmir Institute of Technology, Chemical Engineering, Izmir, 2020, Includes bibliographical references (leaves: 68-76), Text in English; Abstract: Turkish and English, The target of this study was the investigation of biofuel and/or biochemical production from microalgae in growth medium or its lipids over heterogenous catalyst. The primary aim was to study the conversion of 6 wt. % N. Oculata into biofuels without harvesting and dewatering over Ni-Al2O3-SiO2 catalyst at 80oC and 1 atm for 24 h. Solgel method was used to synthesize the catalyst by using the acids of H2SO4, HCl, and HNO3 to investigate the effect of acid type on catalytic activity. The catalyst prepared with H2SO4 yielded the highest conversion. The treatment of the catalyst prepared by H2SO4, with NaCl increased the conversion from 74 % to 91.5 % under same reaction conditions. The products included poly- or monosaccharides, esters and fatty acids. To achieve this conversion, Ni presence was significant beside total acidity of 25 μmol per gram of catalyst, and acidic strength ranging between 130-380oC. A new industrial application was proposed for direct conversion of 6 wt. % N. Oculata into biofuels at 80oC and 1 atm. The capacity of the plant was 1669 liters biofuel per year from 1064 liters microalgae solution per hour. The catalyst prepared with H2SO4 was used to coat either inner surface of tubes or 1-meter pluggable monoliths in tubular reactor having 20 m length and 1000 tubes each of which had 4 cm diameter. The microalgae solution was heated with Therminol®66 heated via parabolic troughs. For operation continuity, ~46000 kg of oil was stored in the tank at 120 o C for 12 h. The production of ethyl ester biodiesel from Spirulina sp. and N. Oculata lipids over 60 % CaO/Al2O3 was studied at 50oC and 1 atm. Ethanol: lipid molar ratio, catalyst amount and reaction time were investigated parameters to identify their effects on catalytic activity. The study showed that ~59 % biodiesel yield was obtained in the presence of the catalyst which was 6 wt. % of lipids, in 30 min. at ethanol: lipid molar ratio of 12 while 90 %-99 % yield was acquired at ethanol: lipid molar ratios of 24 and 48. To achieve these yields, weak basic strength in the form of bicarbonate was necessary while high basicity was not essential. Pure alumina and CaO did not yield any lipid conversion. Glycerolysis of triacylglycerol took place in series with reverse transesterification of triacylglycerol at catalyst amount which was 6 wt. % of lipids, ethanol: lipid molar ratio of 24 and 48, and 60 min. reaction time., Bu çalışmanın amacı mikroalglerden katı katalizörler üzerinde biyoyakıt ve biyokimyasalların elde edilmesidir. Yapılan çalışmada mikroalglerin biyoyakıta dönüştürülmesi üç ayrı kısımda incelenmiştir. İlk bölümde büyüme ortamında kütlece 6% olan N.Oculata mikroalginin hasatlama ve kurutma olmadan katı katalizör üzerinde direkt biyoyakıt ve biyokimyasallara dönüştürülmesi 80oC ve 1 atm çalışma koşullarında ve 24 saat reaksiyon süresinde gerçekleştirilmiştir. Bu amaçla katalizörlerin asitlik ve asit bölgelerinin kuvvetlerinin reaksiyon üzerindeki etkilerini incelemek amacıyla sol-jel yöntemi kullanılarak farklı asitler (H2SO4, HCl ve HNO3) ile alümina-silika destekli nikel katalizörleri sentezlenmiştir. Yapılan reaksiyon çalışmaları sonucunda en yüksek mikroalg dönüşümü sülfürik asit ile sentezlenen katalizör üzerinde elde edilmiştir. Ayrıca bu katalizör NaCl ile muamele edilmiş ve elde edilen katalizör kullanılarak aynı koşullarda gerçekleştirilen reaksiyonların sonucunda mikroalg dönüşümünün %74 'den %91,5'e yükseldiği gözlemlenmiştir. Reaksiyon sonucunda elde edilen ürün dağılımının içerisinde yağ asidi, polisakkarit, monosakkarit ve esterlerin olduğu görülmüştür. Yüksek mikroalg dönüşümünün elde edilmesi için nikel varlığının yanı sıra toplam katalizör asitliğinin gram katalizör başına 25 μmol olması ve asitlik kuvvetinin 130-380 oC arasında olması gerektiği bulunmuştur. Bunun yanı sıra, büyüme ortamındaki N.Oculata mikroalginin hasatlama ve kurutma olmadan direkt olarak biyoyakıtlara çevrilmesinin endüstriyel uygulanma yöntemi ile ilgili bir öneri sunulmuştur. Bu önerinin temelinde reaktörde bulunan tüplerin veya monolitlerin sentezlenen katalizörler ile kaplanması prensibi yatmaktadır. Bir diğer yapılan çalışmada ise Spirulina sp. ve N.Oculata mikroalg lipitlerinden 60 % CaO/Al2O3 katalizörü üzerinde etil ester biyodizel üretimi gerçekleştirilmiştir. Yapılan çalışmalarda 12 etanol: lipit oranında ve lipidin kütlece 6%'sı kadar katalizör miktarında, %59 biyodizel verimi 30 dakikalık reaksiyon sonucunda elde edilirken 90- 99% biyodizel verimi 24 ve 48 etanol: lipit oranlarında elde edilmiştir. Yüksek verimleri elde edebilmek için katalizör üzerinde bikarbonat fazında düşük bazik kuvvetinin olması gerektiği bulunmuştur. Ayrıca saf alümina ve ticari kalsiyum oksit katalizörleri üzerinde herhangi bir lipit dönüşümü elde edilmemiştir.

Thesis (Doctoral)--Izmir Institute of Technology, Chemical Engineering, Izmir, 2020, Includes bibliographical references (leaves: 70-87), Text in English; Abstract: Turkish and English, The aim of this work was to develop Localized Surface Plasmon Resonance (LSPR) surfaces for quantitative detection of exosomes from different sources. For this aim, gold nanorods (AuNRs) with a mean diameter of 40 nm with an aspect ratio of 2.9 were first synthesized and characterized. The self-assembly of AuNRs on glass wafers were optimized through several experiments. In parallel, PEGylation of cetrimonium bromide (CTAB) stabilized AuNRs was investigated using PEGs with three different molecular weights via LSPR, zeta potential and XPS techniques. PEGylated AuNRs were further self-assembled on silanized microscope slides as confirmed. Surface functionalization of AuNR patterned slides was performed using alkane thiol molecules having carboxylic acid and hydroxyl functional groups and confirmed via XPS, FTIR and zeta potential. Specific antibodies (Ab) were conjugated to the surface following two different methods, i.e. click and NHS/EDC chemistry. To perform click chemistry strategy, ImmuneLink® molecules were conjugated with Abs and the final conjugate was used to functionalize surfaces prepared beforehand using azide bearing molecules. The functionalization procedure was confirmed via XPS FTIR and LSPR spectroscopy. The orientation of the antibodies on the AuNRs patterned surfaces was investigated with LSPR in comparison with conventional EDC/NHS chemistry. The click-chemistry strategy proved to provide conjugation of antibodies through their Fc regions exposing Fab regions better for antigen recognition. Finally, surfaces functionalized with a variety of antibodies were used to detect first a pregnancy-associated protein, PLAP, and then exosomes obtained from human semen samples with pre-determined exosome concentrations. The LoD of the biosensor surfaces was found to be between 103-104 exosomes/mL and 5 ng/mL (0.3 pM) PLAP. Human breast cancer cell culture samples having an unknown concentration of exosomes were further analyzed using the newly developed LSPR biochips and the exosome concentration was determined as 108 exosomes/mL for MCF-7 cell line and 107 exosomes/mL for MDA-MB-231 cell line., Bu çalışmanın amacı, farklı kaynaklardan eksozom tespiti için lokalize yüzey plazmon rezonans (LSPR) yüzeyleri geliştirmektir. Bu amaçla, ortalama 40 nm çapında 2.9'luk en-boy oranına sahip altın nanoçubuklar sentezlenmiş ve karakterizasyonları tamamlanmıştır. Ardından, altın nanoçubukların cam yüzeyler üzerinde kendiliğinden organizasyonları çeşitli deneyler ile optimize edilmiştir. Paralelinde, CTAB stabilize altın nanoçubukların üç farklı molekül ağırlığındaki PEGler ile PEGilasyonu ayrıntılı olarak incelenmiş ve altın nanoçubukların PEGilasyonu için optimum koşullar LSPR, yüzey yükü testi ve XPS kullanılarak belirlenmiştir. PEGilasyona uğramış altın nanoçubukların silanlanmış mikroskop lamları üzerinde kendiliğinden organizasyonu sağlanmış ve sonuçlar LSPR, XPS ve yüzey yükü testi ile onaylanmıştır. Altın nanoçubukların yüzey fonksiyonelleştirmesi, fonksiyonel karboksilik asit ve hidroksi gruplarını içeren aynı zamanda tiyol bağlı küçük alkan tiyol molekülleri kullanılarak elde edilmiştir ve bu, XPS, FTIR ve yüzey yükü testi ile doğrulanmıştır. İlgili spesifik antibodiler EDC/NHS kimyası ve klik kimyası kullanılarak yüzeylere bağlanmıştır. Klik kimyası için, ImmuneLink ® molekülü spesifik antibodiler ile konjuge edilmiş ve bu konjugatlar önceden azid ile fonksiyonelleştirilmiş yüzeylere bağlanmıştır. Bu fonksiyonelleştirme XPS, LSPR ve FTIR ile gösterilmiştir. Altın nanoçubuk desenine sahip yüzeyler üzerindeki antibodilerin oryantasyonu, EDC/NHS kimyası ile fonksiyonelleştirilmiş yüzeylerle karşılaştırılarak LSPR ile kontrol edilmiştir. Klik kimyası ile hazırlanmış yüzeylerde antibodilerin Fc bölgelerinden bağlanma sağlayarak antijen tanımaya yönelik Fab bölgelerini açıkta bırakacak şekilde oryantasyon sağladığı kanıtlanmıştır. Son olarak yüzeyler farklı antibodiler ile modifiye edilerek, hamilelik sırasında ortaya çıkan protein, PLAP, ve konsantrasyonu önceden belirlenmiş olan insan sperm eksozomları ile kullanılmıştır. Yüzeylerin eksozom tanıma limiti 103 -104 eksozom/mL ve 5 ng/mL (58 pM) PLAP protein cevabı olarak bulunmuştur. Hazırlanan LSPR biyoçipler, bilinmeyen eksozom konsantrasyonundaki insan meme kanseri hücre hatları kullanılarak test edilmiş ve eksozom konsantrasyonları MCF-7 hücre hattı için 108 eksozom/mL ve MDA-MB-231 hücre hattı için 107 eksozom/mL olarak bulunmuştur., NIH grants NIBIB P41 EB002027 and NIH Grant# 61-1140 (Placentomics)

Thesis (Doctoral)--Izmir Institute of Technology, Chemical Engineering, Izmir, 2020, Includes bibliographical references (leaves: 170-177), Text in English; Abstract: Turkish and English, Chitosan is a preferred bio-foam material used in many research fields such as tissue engineering and drug delivery due to its unique structural features (wide pH stability, nontoxic-biocompatible-biodegradable, anti-inflammatory, antimicrobial). However, chitosan foams are mechanically too weak to maintain the desired shape until newly formed tissue natures. A wound infection and serious tissue necrosis, endanger human's lives. So, a dressing is required to protect loss of fluids and proteins from the wound area and prevents any bacterial invasion replacing the function of skin temporarily. Therefore controlled drug release from a wound dressing is necessary with a biocompatibility and enough mechanical strength. The aim of this study was the synthesis of mechanically durable - dual porosity chitosan bio-foams to provide a controlled drug release. For this purpose, oil droplets formed in a chitosan solution were used as templates to produce micropores that also contain vancomycin (a model antibiotic-hydrophylic) and curcumin (a model anti-inflammatory-hydrophobic) in the walls of the chitosan matrix with large structural voids. An anionic surfactant, sodium dodecyl sulfate (SDS) alone, was used as a crosslinking agent which was a new approach. Then the structures were characterized by SEM, FTIR, mechanical tests and BET analysis. The chitosan foams have dual pore structures. 1) The intrinsic micro pores that the walls of chitosan matrix have with different morphology that depends on the oil phase. 2) The structural voids that the chitosan matrix have, present even in the absence of an oil phase that depends on the experimental conditions. The mechanical strength of the foams were found to be much higher (up to 250 kPa) compare to the foams produced in literature and suggested to be suitable to use for wound dressing applications. The drug release mechanism of foams were found to depend on the conditions used for foam development and the released kinetics were presented with a mathematical model., Kitosan, eşsiz yapısal özellikleri (geniş pH stabilitesine sahip olmak, toksik olmamak, biyouyumlu, biyobozunur, antiinflamatuar ve antimikrobiyal olmak) nedeniyle doku mühendisliği ve ilaç salım sistemleri gibi birçok alanda biyo-köpük üretmek için kullanılan bir malzemedir. Bununla birlikte, kitosan köpükler, dokunun yeniden oluşması ya da iyileşmesine kadar geçen sürede istenen şeklini koruması açısından mekanik olarak çok zayıftır. Yara enfeksiyonu ve ciddi doku ölümü, insanların hayatını tehlikeye sokar. Bu nedenle, yara bölgesinden sıvı ve protein kaybını önlemek ayrıca cildin işlevini geçici olarak değiştiren bakteri istilasını engellemek için bir yara örtüsü gereklidir. Bununla birlikte, biyouyumluluğa ve yeterli mekanik mukavemete sahip yara örtülerinden kontrollü ilaç salınımı, yaraların tedavisi için önemlidir. Bu çalışmanın amacı, kontrollü bir ilaç salımı sağlamak için mekanik olarak dayanıklı ve iki farklı tip gözenek yapısına sahip kitosan biyo-köpüklerin sentezidir. Bu amaçla, kitosan çözeltisinde oluşturulan yağ damlacıkları, büyük yapısal boşluklara sahip kitosan matrisinin duvarlarında vankomisin (model antibiyotik-hidrofilik) ve curcumin (model antiinflamatuar-hidrofobik) içeren mikro gözenekler üretmek için şablon olarak kullanılmıştır. Yeni bir fikir olarak, anyonik bir yüzey aktif madde olan sodyum dodesil sülfat (SDS) çapraz bağlama maddesi olarak kullanılmıştır. Yapılar SEM, FTIR, BET analizi ve mekanik test ile karakterize edilmiştir. Kitosan köpükler iki farklı tip gözenek içeren yapıya sahiptir. Bunlar, 1) Kitosan matrisinin duvarlarında bulunan ve yağ fazına bağlı olarak farklı morfolojiye sahip olan gerçek mikro gözeneklerdir. 2) Kitosan matrisinin yağ fazı olmasa bile deney koşullarına bağlı olarak sahip olduğu yapısal boşluklardır. Köpüklerin mekanik mukavemetinin, literatürde üretilen köpüklere kıyasla çok daha yüksek (250 kPa 'a kadar) olduğu ve yara sargısı uygulamalarında kullanılmaya uygun olduğu görülmüştür. Köpüklerin ilaç salım mekanizmasının, köpük üretimi için kullanılan koşullara bağlı olduğu bulunmuştur ve salım kinetikleri, matematiksel bir modelle sunulmuştur.

Thesis (Master)--Izmir Institute of Technology, Chemical Engineering, Izmir, 2020, Includes bibliographical references (leaves: 48-53), Text in English; Abstract: Turkish and English, The purpose of this study was to develop mesoporous solid acid catalyst for glycosidation reaction of butanol. Therefore, Zr incorporated SBA-15 silica materials with two different amount of zirconia loadings were prepared by hydrothermal synthesis. In addition to them, sulfate modified forms (SO/Zr-SBA-15) were prepared by treating Zr-SBA-15 catalysts in 0.5 M and 1.0 M H2SO4 solutions respectively. These 6 catalysts were tested in the glycosidation of butanol and as product butyl glucosides were produced. The reaction tests were carried out in a 100 ml glass reactor at 117°C. Catalysts properties were determined by different characterization techniques. The analysis showed that mesoporous, acidic catalysts were obtained and zirconium was incorporated into SBA-15 structure. While the surface area and pore diameter decreased by higher zirconium loading and sulfonation, acidity of the catalysts increased. The highest acidity was observed in 1.0 SO/Zr-SBA-15-(1.0) catalyst. The formation of butyl glucosides was determined by HPLC analysis. Results showed that activity of the catalysts were different for the glycosidation reaction of butanol. The highest butyl glucoside yield was obtained with 1.0 SO/Zr-SBA-15-(1.0) catalyst, while the lowest yield was obtained with Zr-SBA-15-(1.0) catalyst. This was attributed to the higher acidity (2.35 mmol NH3/g cat.) and B/L ratio (1.97) of 1.0 SO/Zr-SBA-15-(1.0) catalyst with respect to the others. The reusability tests were performed up to 2 times for the catalyst with the best results. There was no major decrease (7%) in the product yields and this confirmed the stability and reusability of the catalysts., Bu çalışmanın amacı, bütil glikozit sentezi reaksiyonu için mezogözenekli katı asit katalizörler geliştirmektir. Bunun için; Zr-SBA-15 silika katalizörleri iki farklı miktarda zirkonyanın yapıya dahil edilmesiyle, hidrotermal sentez ile hazırlanmıştır. Bunlara ek olarak, Zr-SBA-15 katalizörlerinin sırasıyla 0.5 M ve 1.0 M H2S04 çözeltilerinde kimyasal işleme tutulmasıyla sülfat modifiye formları (SO/Zr-SBA-15) üretilmiştir. Bu 6 katalizör, bütil glikozit sentezi reaksiyonunda test edilmiş ve ürün olarak bütil glikozitler elde edilmiştir. Reaksiyon testleri, 117 °C'de 100 ml'lik bir cam reaktörde gerçekleştirilmiştir. Katalizörlerin özellikleri, farklı karakterizasyon teknikleri ile belirlenmiştir. Analiz sonuçları, mezogözenekli, asidik katalizörlerin elde edildiğini ve Zr'nin SBA-15 yapısına başarıyla eklendiğini göstermiştir. Daha fazla zirkonyum yüklemesi ve sülfatlama ile yüzey alanı ve gözenek çapı azalırken, katalizörlerin asitliği artmıştır. En yüksek asitlik değeri 1.0 SO/Zr-SBA-15-(1.0) katalizöründe gözlemlenmiştir. Bütil glikozitlerin oluşumu HPLC analizi ile belirlenmiştir. Bütil glikozit sentezi reaksiyonunda test edilen katalizörler farklı aktiviteler göstermiştir. En yüksek bütil glikozit verimi 1.0 SO/Zr-SBA-15-(1.0) katalizörü ile elde edilirken, en düşük verim Zr-SBA-15-(1.0) katalizörü ile elde edilmiştir. Bu durum diğer katalizörlere nispeten 1.0 SO/Zr-SBA-15-(1.0) katalizörünün daha yüksek asitlik değerine (2.35 mmol NH3/g cat.) ve B/L oranına (1.97) sahip olmasına bağlanmıştır. Yeniden kullanılabilirlik testleri, en iyi sonuçların elde edildiği katalizör ile 2 defaya kadar gerçekleştirilmiştir. Ürün veriminde önemli bir azalış (%7) gözlemlenmemiştir ve bu sonuç katalizörlerin dayanıklılığını ve tekrar kullanılabilirliğini doğrulamıştır., TUBITAK (MAG/117M160)

Thesis (Doctoral)--Izmir Institute of Technology, Chemical Engineering, Izmir, 2020, Includes bibliographical references (leaves: 63-66), Text in English; Abstract: Turkish and English, In this study, it was pursued to develop acidic mesoporous catalysts for the synthesis of octyl glucosides. Butyl glucoside synthesis was used for catalyst screening. Tungstophosphoric acid (TPA) incorporated mesoporous silica (TPA-SBA-15), sulfated La incorporated titania-silica (SO4/La-TiO2-SiO2), organosulfonic acid functionalized mesoporous silica (Propyl-SO3-SBA-15), and sulfated mesoporous carbon (SO4/CMK-3) catalysts were prepared for this purpose. The effects of the active species (sulfates, tungstophosphoric acid and organosulfonic acid) and promoter (La) on the catalyst properties and activity were investigated. All the catalysts had mesoporous structure and high surface area. The acidity and acid site character varied depending on the catalyst type and amount of the active sites. La promoter was found effective to enhance the sulfation performance and to improve the stability of sulfates. The TPA-SBA-15 catalysts provided high glucose conversions (over 99%) and butyl glucoside yields (over 95%) due to their acidity, Keggin ion structure and pore size. The SO4/La-TiO2-SiO2 catalysts and SO4/CMK-3 catalysts were also active with glucose conversions of 74.4 % and 70 % respectively. The reaction parameters such as the reaction temperature (117 and 100 oC) and catalyst amount (20 and 30 wt% wrt. glucose) were studied in butyl glucoside synthesis over TPA-SBA-15 and SO4/La-TiO2-SiO2 which were the most active catalysts. These catalysts were found to be reusable in glycosidation with 1-butanol. Octyl glucoside synthesis was carried out via direct glycosidation. The octyl glucoside yields obtained over TPA-SBA-15 and SO4/La-TiO2-SiO2 catalysts were above 55 % and 43 % respectively. The catalysts were found promising for further investigations., Bu çalışmada, glikozun 1-oktanol ile glikozidasyonu yoluyla oktil glukozitlerin sentezlenmesi için asidik mezo-gözenekli katalizörler geliştirilmesi amaçlanmıştır. Katalizör tarama testleri bütil glukozit sentezinde yaplmıştır. Tungstofosforik asit (TPA) katkılı mezo-gözenekli silika (TPA-SBA-15), sülfatlı La katkılı titanya-silikat (SO4/La-TiO2-Si02), organosülfonik asit ile fonksiyonelize edilen mezo-gözenekli silika (Propyl-SO3-SBA-15) ve sülfatlı mezo-gözenekli karbon (SO4 /CMK-3) katalizörleri hazırlanmıştır. Aktif malzemelerin (sülfatlar, tungstofosforik asit ve organosülfonik asit) ve katkı malzemesinin (La) katalizör özellikleri ve aktivitesi üzerindeki etkileri ayrıntılı karakterizasyonlarla araştırılmıştır. Tüm katalizörler mezo-gözenekli yapıya ve yüksek yüzey alanına sahiptir. Asitlik ve asit bölgesi karakteri, katalizör tipine ve aktif malzemenin miktarına bağlı olarak değişmiştir. La katkısının sülfatlama performansını arttırmak ve sülfatların kararlılıklarını geliştirmek için etkili olduğu bulunmuştur. TPA-SBA-15 katalizörleri yüksek glikoz dönüşümleri (% 99 'un üzerinde) ve bütil glukozit verimleri (% 95'in üzerinde) sağlamıştır. Bu katalizörlerin aktiviteleri, yüksek asitlikleri ve Keggin iyon yapısından kaynaklanmaktadır. SO4/La-TiO2-SiO2 katalizörleri ve SO4/CMK-3 katalizörleri de sırasıyla % 74.4 ve% 70 glikoz dönüşümleri ile aktif bulunmuştur. TPA-SBA-15 ve SO4/La-TiO2-SiO2 katalizörleri üzerinde, reaksiyon sıcaklığı (117 ve 100 oC) ve katalizör miktarı (glikoza göre kütlece % 20 ve % 30) gibi reaksiyon parametreleri incelenmiştir. Bu katalizörlerin 1-butanol ile glikozidasyonda tekrar kullanılabilir oldukları tespit edilmiştir. Oktil glukozit sentezi, glukozun 1-oktanol ile doğrudan glikozidasyonu yoluyla gerçekleştirilmiştir. TPA-SBA-15 ve SO4/La-TiO2-SiO2 katalizörleri üzerinde elde edilen oktil glukozit verimleri sırasıyla % 55 ve % 43'ün üzerindedir. Katalizörler ilerideki araştırmalar için umut verici bulunmuştur., TUBITAK (117M160)

Thesis (Master)--Izmir Institute of Technology, Chemical Engineering, İzmir, 2020, Text in English; Abstract: Turkish and English, Includes bibliographical references (leaves: 61-66), Organic coil coated aluminum substrates are one of the most widely used materials for construction industry. These coated substrates typically consist of 4 separate layers, the aluminum substrate, the inorganic conversion coating (resulting from the pretreatment application), and the organic coating layers that are called the primer and the topcoat. From industrial experience, it is not clearly and quantitatively determined how these layers contribute to the different processes that occur during corrosion, such as water uptake (diffusion of water through the coating) and the corrosion reactions that take place on the substrate. In this thesis, the formation of the inorganic conversion coating as a function of the pretreatment application parameters, immersion time, temperature and pH, and the individual effects of inorganic and organic coating layers on corrosion are investigated. The structure of the various surfaces formed after coating application and after corrosion testing by Neutral Salt Spray Test (NSST) is investigated by Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX), X-ray Fluorensence Spectrometer (XRF) and Atomic Force Microscopy (AFM) analysis, while their anticorrosive properties are determined by Electrochemical Impedance Spectroscopy (EIS). The results indicate that the formation of the pretreatment layer is enhanced continuously as function of temperature and immersion time, within the values investigated, while for pH an optimum is observed. The investigation of the corrosion resistance of substrates coated with different coating layers reveal that without organic coating layers, the substrates corrode much faster, indicating the importance of water diffusion on the corrosion reactions., Organik bobin kaplamalı alüminyum substratlar inşaat sektöründe oldukça yaygın kullanılan malzemelerdir. Bobin kaplama sistemi, alüminyum metali, önişlem uygulaması sonucunda oluşan dönüşüm kaplaması (inorganik kaplama), astar ve sonkat (organik kaplama) olarak adlandırılan kaplama katmanlarından oluşur. Endüstriyel çalışmalardan, bu katmanların, su alımı (suyun kaplamadan difüzyonu) ve substrat üzerinde meydana gelen korozyon reaksiyonları gibi korozyon sırasında meydana gelen farklı proseslere nasıl katkıda bulunduğu açıkça ve niceliksel olarak belirlenmemiştir. Bu tezde, önişlem uygulama parametreleri olan daldırma süresi, sıcaklık ve pH değerinin bir fonksiyonu olarak inorganik dönüşüm kaplamasının oluşumu ve inorganik ve organik kaplama katmanlarının korozyon üzerindeki bireysel etkileri araştırılmıştır. Kaplama uygulamasından ve tuzlu sis korozyon testinden (NSST) sonra oluşan çeşitli yüzeylerin yapısı, Atomik Kuvvet Mikroskobu (AFM), Taramalı Elektron Mikroskobu (SEM), Elektron Dispersif X-Işını Spektroskopisi (EDX) ve X-Işını Flüoresans Spektroskopisi (XRF) kullanılarak, korozyon önleyici özellikleri ise Elektrokimyasal Empedans Spektroskopisi (EIS) kullanılarak belirlendi. Sonuçlar, önişlem katmanının oluşumunun, sıcaklık ve daldırma süresinin fonksiyonu olarak, araştırılan değerler dahilinde sürekli olarak geliştirildiğini, pH için ise bir optimum değerin gözlemlendiğini göstermektedir. Farklı kaplama katmanları ile kaplanmış substratların korozyon direncinin araştırılması, organik kaplama katmanları olmadan, substratların çok daha hızlı korozyona uğradığını ve korozyon reaksiyonlarında su difüzyonunun önemini göstermektedir.

Text in English; Abstract: Turkish and English., Thesis (Master)--Izmir Institute of Technology, Chemical Engineering, Izmir, 2020, Includes bibliographical references (leaves: 55-61), The goal of this study was to add high value to cellulose as the most abundant source of biomass and glucose by producing a building-block chemical-Sorbitol-, which is not produced in our country and has very large market share. In this manner, the effect of reaction time (1-2 h), catalyst amount (1-2 g) and catalyst type on conversion of cellulose and glucose and yield of sorbitol with presence of various catalysts in subcritical water environment were investigated. The hydrogenation of both glucose and cellulose over Ruthenium based catalysts (Ru/AC, Ru/SiO2, Ru-SBA15 and Ru-SBA15/SO3), using a high pressure-high temperature reactor (Parr 5500 High Pressure Compact Reactor) at a reaction pressure of 5 bar and reaction temperature of 150°C were studied. Ruthenium based catalysts were prepared by wet impregnation method. The synthesized Ru based catalysts with various metal based were characterized by various characterization tools such as Scanning Electron Microscope (SEM), Fouirer Transform Infrared Spektrofotometre (FT-IR) and Brunauer-Emmett-Teller (BET). The catalytic performances were evaluated in hydrogenation of cellulose and also glucose to produce sorbitol under subcritical water conditions. As a result of these analyzes, the highest sorbitol yield and cellulose conversion were found to be 234.98 ppm and 28.64%, respectively for 2 gram of Ru-SiO2 catalyst for 2 hours. For glucose conversion, the catalyst of Ru-SBA15/SO3 showed better catalytic performance than other catalysts., Bu çalışmanın amacı, ülkemizde üretilmeyen ve çok büyük pazar payına sahip bir kimyasal yapı taşı olan sorbitol üreterek, en çok bulunan biyokütle kaynağı olan selüloza ve glikoza yüksek değer katmaktır. Bu şekilde, reaksiyon süresi (1-2 saat), katalizör miktarı (1-2 gram) ve katalizör tipinin selülozun ve glikozun dönüşümü ve sorbitol veriminin kritik altı su ortamında çeşitli katalizörlerin varlığı üzerindeki etkisi araştırıldı. Hem glikoz hem de selülozun hidrojenasyonu Rutenyum bazlı katalizörler üzerinde (Ru/AC, Ru/SiO2, Ru-SBA15 and Ru-SBA15/SO3), yüksek basınç-yüksek sıcaklık reaktörü kullanarak (Parr 5500 Yüksek Basınçlı Kompakt Reaktör) 5 bar reaksiyon basıncında ve 150°C reaksiyon sıcaklığında çalışıldı. Rutenyum bazlı katalizörler ıslak emprenye yöntemi ile hazırlandı. Çeşitli metaller ile sentezlenmiş Ru bazlı katalizörler, Taramalı Elektron Mikroskobu (SEM), Fourier Dönüşümlü Kızılötesi Spektroskopisi (FT-IR) ve Brunauer-Emmett-Teller (BET) gibi çeşitli karakterizasyon araçları ile karakterize edildi. Katalitik performanslar, kritik altı su koşulları altında sorbitol üretmek için selüloz ve ayrıca glikozun hidrojenasyonunda değerlendirildi. Bu analizler sonucunda, en yüksek sorbitol verimi ve selüloz dönüşümü 2 saat boyunca 2 gram Ru-Si02 katalizörü için sırasıyla 234.98 ppm ve 28.64% olduğu bulunmuştur. Glikoz dönüşümü için Ru-SBA15/SO3 katalizörü, diğer katalizörlerden daha iyi katalitik performans gösterdi.

Brushite forming calcium phosphate cements (CPCs) have received growing interest for scaffold applications due to their high surface area and high bioresorbability. The dehydrated form of brushite, monetite, has a finer microstructure with higher surface area, higher strength and bioresorbability comparable to brushite, making it a viable alternative phase in CPCs. The increase in monetite content of the β-tricalcium phosphate (β-TCP)–monocalcium phosphate monohydrate (MCPM) cement system due to the reduction in its supersaturation upon addition of NaCl to excess setting liquid was investigated kinetically. The relaxation period was monitored by pH-stat titration of the cement solution by 0.1 M NaOH. Monetite growth was achieved in shorter periods at higher NaCl concentrations where the supersaturation gap between brushite and monetite is thought to be narrowed due to high ionic strength in accord with Pitzer's ion interaction model. The brushite/monetite ratio decreased consistently with increasing NaCl concentration in the 3–6 M range.

WOS:000520534400001, Supercritical fluid-based technologies are increasingly being used to develop novel functional nanostructured materials or improve the properties of existing ones. Among these, supercritical deposition (SCD) is an emerging technique to incorporate metals on supports. It has been used to deposit a wide variety of single or multi-metallic morphologies such as highly dispersed species, nanoparticles, nanorods and conformal films on high surface area supports, polymers and crystalline substrates. SCD is also attracting increasing attention for preparation of micro or nano-architectured functional materials in a highly controllable manner for electrochemical energy conversion and storage systems. Increasing number of studies in the literature demonstrates that materials synthesized using SCD are comparable or superior in performance as compared to their conventional counterparts. In this review, an overview of the fundamentals of the SCD technique is presented. Properties of a wide variety of nanostructured functional materials such as supported nanoparticles and films prepared using SCD for electrochemical applications are summarized. The electrochemical performance of these materials in electrochemical tests and also in fuel cells, electrolyzers and Li-ion batteries are also presented. (C) 2020 The Author(s). Published on behalf of The Electrochemical Society by IOP Publishing Limited.

Text in English; Abstract: Turkish and English., Thesis (Master)--Izmir Institute of Technology, Chemical Engineering, Izmir, 2020, Includes bibliographical references (leaves: 80-86), Industrial observations indicate that sulfur acts a poison for Fischer-Tropsch Synthesis (FTS) and surface science studies show that sulfur blocks the adsorption sites for reactants on cobalt surfaces. However, various experimental studies have indicated conflicting results about the effect of sulfur on cobalt FTS catalyst activity and selectivity. This study aims to clarify the effect of sulfur on cobalt FTS catalysts by molecular modelling of the elementary reactions of FTS on surfaces that are present on sulfur covered cobalt surfaces that are present in fcc-Co nanoparticles, using Density Functional Theory (DFT). For 0.25 ML sulfur coverage, it is found that on bare, C and O covered surfaces, S is the main dissociation product, while HS can be present on low coverages. Atomic sulfur decreases the adsorption energies of all species investigated, while the decrease is more pronounced for CO compared to H2. The effect of S on the elementary FTS reactions direct and H-assisted CO dissociation, carbon hydrogenation, carbon coupling and oxygen removal are also investigated. The results indicate that S inhibits mainly the oxygen removal reaction, in terms of both H2O and CO2. CO dissociation is not inhibited but rather slowed down, due to increasing activation barriers. It is also found that carbon hydrogenation barriers are significantly decreased, while carbon coupling barriers are unaffected. These results indicate that the intrinsic effect of sulfur poisoning would be to increase methane selectivity, while decreasing the selectivity to long chain hydrocarbons., Endüstriyel gözlemlerin sonucunda, sülfürün Fischer-Tropsch Sentezi (FTS) için zehirleyici bir etkiye sahip olduğu ve yüzey bilimi çalışmaları, sülfürün kobalt yüzeyindeki reaktantların adsorpsiyon bölgelerini blokladığını göstermektedir. Öte yandan, çeşitli deneysel çalışmalar sülfürün kobalt FTS katalizörlerinin aktivite ve ürün seçilimi üzerinde çelişen sonuçlar göstermektedir. Bu çalışma, sülfürün kobalt bazlı FTS katalizörleri üzerindeki etkisini anlamak için, fcc-Co nanoparçacığı üzerindeki temel reaksiyonları, moleküler modelleme yöntemi ile yoğunluk fonksiyoneli teorisi kullanarak incelemeyi amaçlamaktadır. 0.25 ML sülfür kaplı yüzey için, sülfür yalın, C ve O kaplı yüzeylerde ana parçalanma ürünü iken düşük kaplı yüzeylerde HS de olabilmektedir. Atomik sülfürün tüm türlerin adsorpsiyon enerjilerini düşürdüğü gözlemlenirken, CO adsorpsiyon enerjisindeki düşüş H2’ye kıyasla daha fazladır. Sülfürün etkisi FTS ana reaksiyonları, direkt ve h-destekli CO parçanlaması, karbon hidrojenleşmesi, karbon eşleşmesi ve oksijen giderme reaksiyonları üzerinde incelenmiştir. Bu sonuçlara göre, oksijen giderme reaksiyonu hem H2O hem de CO2 formunda, sülfür tarafından engellemektedir. CO parçalanması ise engellenmemiş, ancak aktivasyon bariyerleri yükseldiği için yavaşlamıştır. Karbon hidrojenleşme bariyerleri ciddi miktarda düşerken, karbon eşleşme bariyerlerinde bir değişim gözlemlenmemiştir. Bu çalışma sülfür zehirlenmesinin esas nedeni olarak, sülfürün metan seçilimini artırırken uzun zincirli hidrokarbon seçilimini azaltması olarak göstermektedir.

Phase behaviors of 1,2-Distearoyl-sn-glycero-3-phosphocholine (DSPC) and polyoxyethylene(40)stearate (PEG40St) were investigated with Langmuir monolayer isotherms and Brewster angle microscopy (BAM) imaging at DSPC/PEG40St molar ratios ranging from 9:1 to 5:5. Two plateaus were found in the Langmuir isotherms which were relatively shorter for the 9:1 mixture and extended significantly by increasing the PEG40St content, indicating that the PEG40St squeezed out whereas more emulsifier retained in the monolayer at higher PEG40St contents. A strong hysteresis was observed when the mixed monolayers were subjected to compression-expansion cycles. The degree of hysteresis for the first cycles also increased with increasing PEG40St content in the monolayer. Gray scale intensities in the Brewster angle microscopy images were determined for pure DSPC and pure PEG40St and a scale was established to better interpret the morphologies for the mixtures. Bud and vessels formed during the PEG40St squeezed out upon compression. Upon expansion, PEG40St and DSPC is reappeared on the monolayer. When considered BAM images together with the Langmuir isotherm, PEG40St molecules were found to be well distributed within the DSPC molecules at lower DSPC/PEG40St mole ratios and mostly phase separated at higher mole ratios. It was concluded that higher PEG40St content would be advantageous for the design of an efficient and cheaper ultrasound contrast agents., TUBITAK (113M270)

Sofuoglu, Sait C/0000-0001-6990-0275; Ozturk, Fatma/0000-0001-5179-8444, WOS: 000432475300003, PubMed: 29573689, Cancer has become the primary reason of deaths in Dilovasi probably due to its location with unique topography under the influence of heavy industrialization and traffic. In this study, possible sources and carcinogenic health risks of PAHs and PCBs were investigated in Dilovasi region by Positive Matrix Factorization ( PMF) and the USEPA approach, respectively. PAHs and PCBs were measured monthly for a whole year at 23 sampling sites using PUF disk passive samplers. Average ambient air concentrations were found as 285 +/- 431 ng/m(3) and 4152 +/- 6072 pg/m(3), for Sigma(15)PAH and Sigma 41PCB, respectively. PAH concentrations increased with decreasing temperature especially at urban sites, indicating the impact of residential heating in addition to industrial activities and traffic. On the other hand, PCB concentrations mostly increased with temperature probably due to enhanced volatilization from their sources. Possible sources of PAHs were found as emissions of diesel and gasoline vehicles, biomass and coal combustion, iron and steel industry, and unburned petroleum/petroleum products, whereas iron-steel production, coal and biomass burning, technical PCB mixtures, and industrial emissions were identified for PCBs. The mean carcinogenic risk associated with inhalation exposure to PAHs and PCBs were estimated to be >10(-6) and >10(-5), respectively, at all sampling points, while the 95th percentile was >10(-5) at 15 of 23 and >10(-4) at 8 of 23 sampling locations, respectively. Probabilistic assessment showed, especially for PCBs, that a majority of Dilovasi population face significant health risks. The higher risks due to PCBs further indicated that PCBs and possibly other pollutants originating from the same sources such as PBDEs and PCNs may be an important issue for the region. (c) 2018 Elsevier B.V. All rights reserved.

The present article aims to show how work function measurements (WF) can be applied in the study of elementary surface reaction steps on metallic single crystal surfaces. The work function itself can in many cases not be interpreted directly, as it lacks direct information on structural and chemical nature of the surface and adsorbates, but it can be a powerful tool when used together with other surface science techniques which provide information on the chemical nature of the adsorbed species. We here, illustrate the usefulness of work function measurements using Rh(100) as our model catalyst. The examples presented include work function measurements during adsorption, surface reaction, and desorption of a variety of molecules relevant for heterogeneous catalysis. Surface coverage of adsorbates, isosteric heat of adsorption, and kinetic parameters for desorption, desorption/decomposition temperatures of surface species, different reaction regimes were determined by WF with the aid of other surface science techniques.

Lubricants consist of base oils and chemical additives such as dispersants, surfactants, oxidation inhibitors, and antiwear agents. Organic and inorganic boron-based additives increase wear resistance and decreases friction. Hexagonal boron nitride and metal borates are used for this purpose. Zinc borate is a synthetic hydrated metal borate. The production techniques of zinc borate generally include the reaction between zinc source materials (zinc oxide, zinc salts, zinc hydroxide) and the boron source materials (boric acid and borax). The nano zinc borate particles were prepared from zinc nitrate and borax in the present study by using low initial zinc and borate concentrations and low temperature to prevent particle growth. The templates span 60 and PEG 4000 were used to control the particle size. The particles were separated from mother liquor by centrifugation, washed with ethanol, dried and ground and used as additive to base oil. The particles have H2O and B(3)-O vibrations in their FTIR spectra. The empirical formula of the nanoparticles was approximately 3ZnO.2B2O3.4H2O from EDX and TGA analysis. X-ray diffraction diagram indicated the particles were in amorphous state. When the nanoparticles were added to light neutral oil the wear scar diameter and friction coefficient was lowered 50% and 20% respectively.

In this study the effect of ultrasound of the cerium exchange was studied. The results were compared to those obtained from traditional batch exchange method. Contact time, initial cation concentration (fold equivalent excess) and the types of the ultrasound were studied. Ultrasonic probe, which is the most effective method, enhanced the replacement of Na+ ion with Ce3+ ion in the extra-framework of zeolite up to 73 % by applying 5 consecutive ion exchanges. The cerium in the solution caused to be formed cerium oxides on the crystal surface occluding the pores. Thus the specific surface area of cerium exchanged zeolite was decreased due to formation of cerium complexes on the surface and into the pores. © 2018, Turkish Chemical Society. All rights reserved., Izmir Institute of Technology (Project number: 2006IYTE31) and State Planning Organization of Turkey (DPT)

In this study, natural silica source, diatomite, incorporated novel chitosan based composite membranes were fabricated and characterized for bone tissue engineering applications as possible bone regeneration membrane. The effect of diatomite loading on the mechanical, morphological, chemical, thermal and surface properties, wettability and in vitro cytotoxicity and cell proliferation on of composite membranes were investigated and observed by tensile test, atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), protein adsorption assay, air/water contact angle analysis and WST-1 respectively. Swelling studies were also performed by water absorption capacity determination. Results showed that incorporation of diatomite to the chitosan matrix increased the surface roughness, swelling capacity and tensile modulus of membranes. An increase of about 52% in Young's modulus was achieved for 10 wt% diatomite composite membranes compared with chitosan membranes. High cell viability results were obtained with indirect extraction method. Besides, in vitro cell proliferation and ALP activity results showed that diatom incorporation significantly increased the ALP activity of Saos-2 cells cultured on chitosan membranes. The novel composite membranes prepared in the present study with tunable properties can be considered as a potential candidate as a scaffold in view of its enhanced physical & chemical properties as well as biological activities for bone tissue engineering applications., Scientific Research Project of Izmir Institute of Technology (2011 IYTE02)

The SAOS and LAOS behavior of tomato paste were investigated in this study. SAOS rheology was well predicted by the semi-empirical Bird-Carreau constitutive model. The LAOS (Large amplitude oscillatory shear) behavior of tomato paste was also investigated in depth in this study and non-linear rheological properties were obtained by utilizing Ewoldt-McKinley theory. These parameters offer new insights into the rheology of tomato paste and help understand structural changes which occur at different deformations (strain) and time scales (frequency). We plotted the intracycle normalized stress vs. normalized strain in the linear and non-linear regions offered new intracycle insights and observations. Tomato paste showed an irreversible structural change in LAOS evidenced by strain softening (in the mid-oscillatory region) followed by strain hardening (in the large oscillatory region). The nonlinear flow behavior simulated by the single mode Giesekus model gave good results up to moderate strains and frequencies. These results help gain better insights at large deformations, which occur during processing and consumption.

Boron industrial solid waste is used as reinforcement for preparing composite materials. This waste has boron trioxide which holds unique properties may affect the surface or interface of the composite. The prepared composites are characterized in order to determine the dispersion and the structure by means of inverse gas chromatography (IGC), Fourier transform infrared spectroscopy, thermal gravimetric analysis, scanning electron microscopy (SEM) and X-ray diffraction (XRD). There is a strong relation between the dispersion of reinforcement and the properties of newly formed composite. The dispersive component of the surface energies of the composites and components are determined by IGC. This parameter is difficult to measure by other methods and it is related to the wettability and adhesive characters of solid materials. The effect of compounding ratios of reinforcement is also examined. Furthermore, XRD diffractograms and SEM images of composites showed well dispersion. Thermal analysis revealed that the addition of the boron industrial solid waste to the polymer increased the thermal stability of pure polymer. Infrared spectra of the composites indicated that the composites were formed from the waste reinforcement and the polymer matrix., The Scientific Research Fund of Eskişehir Osmangazi University [grant number 201015040]

Polymer nanocomposites, based on bacterial biodegradable thermoplastic polyester, poly(hydroxy-butyrate) (PHB), poly(hydroxyl-butyrate-co-hydroxy-valerate) (PHBHV), and commercial organo-modified montmorillonite (OMMT-Cloisite 10A) were prepared by solution casting method. This work aims to investigate the effect of Cloisite 10A type clay addition on the water vapour permeability properties of PHB/OMMT, and PHBHV/OMMT nanobiocomposite films. Temperature dependence of water vapor permeabilities of the films were also evaluated at various temperatures, and semi empirical permeability models were used to predict the permeability of polymer systems as a function of clay concentration and aspect ratio of nanoplates. Moreover, thermal, optical, and mechanical properties of the composites were examined by using varieties of techniques including differential scanning calorimeter (DSC), thermogravimetric analyzer (TGA), scanning electron microscope (SEM), and thin-film X-ray diffractometer (TF-XRD) respectively. Test results indicated that addition of highly intergallery swollen Cloisite 10A to the PHB/PHBHV, reduced the water vapor permeability up to 41 and 25% compared to native PHB and PHBHV films, respectively. Regarding the all mechanical properties measured, the maximum improvement was achieved for 3 wt% clay loaded samples for both PHB and PHBHV polymer composites. An increase of about 152 and 73% in tensile strength and of 77 and 18% in strain at break was achieved for PHB and PHBHV polymers, respectively. As a result of X-ray diffraction analysis, exfoliated structure was achieved at low clay loaded sample (1% w/w), however at higher concentration (3% w/w) the structure found as intercalated. Therefore, it is an evident that enhancement of characteristic properties highly depend on the dispersion level of clay particles in polymer matrix. The results obtained in this study show the feasibility of improvement of the properties of PHB based polymers with incorporation of nanoclay., National Research Council of Turkey (TUBITAK 108M335)

Predicting loaf volume development of gluten free baked products to have similar properties to wheat products remains a challenge and there is no good marker for loaf volume. Large Amplitude Oscillatory Shear (LAOS) flow experiments and baking tests were conducted on rice, buckwheat, quinoa, and soy flour doughs to understand if there is any correlation between the non-linear rheological properties and loaf volume. The challenging water absorption capacities were determined by matching the η* vs. frequency data of the gluten free flours with that of the soft wheat flour dough with moisture content at 500 BU. 110%, 90%, 85%, and 160% water levels were found as optimal for rice, buckwheat, quinoa, and soy flour, respectively. The comparison of elastic Lissajous-Bowditch curves showed that the stronger non-linearities were seen at low frequencies and the wider the loop, the weaker the structure and the more structural breakdown with an order of soft wheat, soy, buckwheat, quinoa and rice flour doughs. Secondary loops have been observed in viscous Lissajous-Bowditch curves which are related to the strong non-linearities in elastic stress. The distributions of elastic and viscous LAOS parameters showed that soy dough has the closest rheological performance to wheat dough among other dough samples, which has the highest protein content. G L ′ and G M ′ values at 10 rad/s and 200% strain showed the best correlation among all LAOS parameters with the loaf volume. The strain stiffening/softening property e3/e1 complemented the mechanistic explanations which were offered using G L ′ and G M ′ values.

The development of a better understanding of the low temperature nanophase evolution of high surface area titania (TiO2) based powders is essential for their use in photocatalytic applications. A series of rare earth (RE) element doped TiO2 powders were prepared by sol-gel processing. The effects of RE doping level, ionic size and heat treatment temperature on the nanophase structure evolution and the dopant ion location in TiO2 main matrix were investigated. Anatase was determined to be the main phase up to 900 °C at all doping levels for all REs. Anatase to rutile phase transformation was inhibited by RE doping. The inhibitory effect of REs increased with increasing ionic radius. Oxide phases of La, Nd, Pr, Sm were not present up to 5% and Nd4Ti9O24 phase was formed at 10% doping level at 800 °C. The formation of RE2Ti2O7 phases were determined for the REs with relatively lower ionic radii at 800 °C., Scientific and Technological Research Council of Turkey (TUBITAK 10M739)

Clinoptilolite supported rutile TiO2 composites were synthesized for the enhancement of its photocatalytic performance in the degradation of the aqueous terephthalic acid solution under UVC illumination by the increase in its surface area and to simplify its recovery from the treated solution after use. The XRD spectra of the composites revealed the formation of pure rutile TiO2 on the surface of the clinoptilolite. The SEM images showed the formation of the spherical TiO2 clusters were composed of nano fibers on the surface of the clinoptilolite. For all composites synthesized, the dispersion of the TiO2 particles on the clinoptilolite led to a surface area larger than that of the bare TiO2 and clinoptilolite. The materials synthesized in the present study exhibited higher catalytic activity compared with the commercial Degussa P25 and anatase. Among the catalysts synthesized the TiO2/clinoptilolite with a weight ratio of 0.5 was found to be the most photoactive catalyst even though it contains a lesser amount of active TiO2. The kinetic of the reactions for different catalyst was found to be consistent with the pseudo-first order kinetic model. The results of the Langmuir-Hinshelwood model showed the slight contribution of the adsorption on the degradation. The activity of the TiO2/clinoptilolite with a weight ratio of 0.5 decreased after repetitive use due to the accumulation of the TPA molecules on the surface of the catalyst., Scientific and Technological Research Council of Turkey (TUBITAK 104M255-110M451); Science, Technology Application, and Research Center of Ege University (EBILTEM) (2012/BIL/027); Scientific Research Council of Ege University (13MUH031)

WOS: 000395353600090, PubMed ID: 27939936, Atmospheric and concurrent soil samples were collected during winter and summer of 2014 at 41 sites in Kutahya, Turkey to investigate spatial and seasonal variations, sources, air-soil exchange, and associated carcinogenic risks of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs). The highest atmospheric and soil concentrations were observed near power plants and residential areas, and the wintertime concentrations were generally higher than ones measured in summer. Spatial distribution of measured ambient concentrations and results of the factor analysis showed that the major contributing PAH sources in Kutahya region were the coal combustion for power generation and residential heating (48.9%), and diesel and gasoline exhaust emissions (473%) while the major PCB sources were the coal (thermal power plants and residential heating) and wood combustion (residential heating) (45.4%), and evaporative emissions from previously used technical PCB mixtures (34.7%). Results of fugacity fraction calculations indicated that the soil and atmosphere were not in equilibrium for most of the PAHs (88.0% in winter, 87.4% in summer) and PCBs (76.8% in winter, 83.8% in summer). For PAHs, deposition to the soil was the dominant mechanism in winter while in summer volatilization was equally important. For PCBs, volatilization dominated in summer while deposition was higher in winter. Cancer risks associated with inhalation and accidental soil ingestion of soil were also estimated. Generally, the estimated carcinogenic risks were below the acceptable risk level of 10-6. The percentage of the population exceeding the acceptable risk level ranged from 10-6, Scientific and Technological Research Council of Turkey [TUB/112Y305]; Anadolu University research fund for scientific projects [1306F272]; Gizem Tuna Tuygun and Hasan Altiok (Dokuz Eylul University), This study was supported by The Scientific and Technological Research Council of Turkey (project no: TUB/112Y305) and by Anadolu University research fund for scientific projects (project no: 1306F272). We would like to thank Gizem Tuna Tuygun and Hasan Altiok (Dokuz Eylul University) for their support during the study.

Polyurethane foam (PUF) passive samplers were employed to assess air concentrations of polychlorinated biphenyls (PCBs) in background, agricultural, semi-urban, urban and industrial sites in Bursa, Turkey. Samplers were deployed for approximately 2-month periods from February to December 2014 in five sampling campaign. Results showed a clear rural-agricultural-semi-urban-urban-industrial PCBs concentration gradient. Considering all sampling periods, ambient air concentrations of Σ43PCBs ranged from 9.6 to 1240 pg/m3at all sites with an average of 24.1 ± 8.2, 43.8 ± 24.4, 140 ± 190, 42.8 ± 24.6, 160 ± 280, 84.1 ± 105, 170 ± 150 and 280 ± 540 pg/m3for Mount Uludag, Uludag University Campus, Camlica, Bursa Technical University Osmangazi Campus, Hamitler, Agakoy, Kestel Organised Industrial District and Demirtas Organised Industrial District sampling sites, respectively. The ambient air PCB concentrations increased along a gradient from background to industrial areas by a factor of 1.7–11.4. 4-Cl PCBs (31.50–81.60%) was the most dominant homologue group at all sampling sites followed by 3-Cl, 7-Cl, 6-Cl and 5-Cl homologue groups. Sampling locations and potential sources grouped in principal component analysis. Results of PCA plots highlighted a large variability of the PCB mixture in air, hence possible related sources, in Bursa area. Calculated inhalation risk levels in this study indicated no serious adverse health effects. This study is one of few efforts to characterize PCB composition in ambient air seasonally and spatially for urban and industrial areas of Turkey by using passive samplers as an alternative sampling method for concurrent monitoring at multiple sites., Scientific and Technological Research Council of Turkey (21514107-221.01-8290); TUBITAK (112Y315)

Thesis (Master)--Izmir Institute of Technology, Chemical Engineering, Izmir, 2019, Includes bibliographical references (leaves: 95-99), Text in English; Abstract: Turkish and English, Market share of the can coating industry was 2 billion dollars in 2018 globally. A large portion of this market is focused on protecting valuable goods such as foods and cosmetics. Recent bans on the Bisphenol A(BPA) created a BPA-free coating demand due to the high portion of BPA based coatings in the industry such as epoxy. A conventional epoxy based (EP) can coating was compared with a new design of BPAfree polyester coating(PE). Atomic Force Microscopy(AFM), Scanning Electron Microscopy(SEM), Electron Dispersive Spectroscopy(EDX), Electrochemical Impedance Spectroscopy(EIS), Direct Current(DC) Polarization were used to investigate degradation. Industrial and model tinplate samples are compared with surface investigation methods. AFM results indicate the surface composition difference. To investigate bare tinplate corrosion, a mixture of acidic electrolyte was prepared and compared with other conventional aging electrolytes, containing mono acids. The electrolyte prepared from mixed acids was found to have the highest detinning abilities. Therefore, coated samples were aged with this mixed acid solution electrolyte. EIS results indicated that the type of electrolyte alters the corrosion mechanism, indicated by the observance of different time constants at different time scales. During immersion tests, EP based coatings showed better corrosion resistance as shown by higher impedance at low frequency, higher coating resistance and lower capacitance values. However, after sterilization, polyester coated samples showed better corrosion protective abilities (indicated by lower amount of corrosion products and higher impedance values) compared to the epoxy sample even though AFM measurements indicated that it had larger pore sizes after aging compared to epoxy sample. These results are attributed to the larger electrochemical area and higher diffusion properties of EP coatings, obtained after modelling of EIS data., Dünya genelinde metal ambalaj kaplamalarının pazar payı, 2018 yılında 2 milyar olarak raporlanmıştır. Bu pazarın büyük bir kısmı gıda ve kozmetik gibi değerli ürünlerin korunmasına odaklanmaktadır. Kullanılan kaplamaların büyük bir kısmı Bisfenol A (BPA) ile üretilen epoksi bazlı reçineler içermektedir. BPA ile ilgili geçtiğimiz yıllarda getirilen yasal kısıtlamalar, BPA içermeyen kaplamalara yönelik yeni bir talep yaratmıştır. Bu tezde, epoksi (EP) ve polyester bazlı (PE) reçinelerle üretilen iki farklı kaplama karşılaştırılmıştır. Atomik Kuvvet Mikroskobu (AFM), Taramalı Elektron Mikroskobu (SEM), Elektron Dispersif Spektroskopisi (EDX), Elektrokimyasal Empedans Spektroskopisi (EIS) ve DC Polarizasyon testleri, kaplamaların bozunma düzeyini incelemek için kullanılmıştır. Endüstriyel ve model kalay kaplı çelik(tinplate) numuneleri, yapılan yüzey analizleri ile karşılaştırılmıştır. Alınan AFM sonuçları, yüzey kompozisyonunda farklılıklar olduğunu göstermektedir. Kaplanmamış tinplate korozyonu incelemek için, asidik bir elektrolit, endüstride sık kullanılan mono asit çözeltileri ile karşılaştırılmıştır. En yüksek kalay çözme hızı, karışık asitlerden hazırlanan elektrolit ile gözlemlenmiştir. Bu nedenle, kaplanmış yüzeyler bu karışık asit çözeltisi ile yaşlandırılmıştır. EIS sonuçları, elektrolit tipinin, korozyon mekanizmasını etkilediğini göstermektedir. Elektrolitte bekletme sırasında, EP numunelerinde, düşük frekansta daha yüksek empedans, daha yüksek kaplama direnci ve düşük kapasitans değerleri gözlemlenmiştir. Sterilizasyondan sonra gerçekleştirilen AFM ölçümleri, PE’in yüzeyinde EP’ye göre daha büyük porlar oluştuğunu göstermektedir. Buna rağmen EP’ye kıyasla daha iyi korozyon koruyucu özellikler (daha düşük korozyon ürünleri ve daha yüksek empedans değerleri) gözlemlenmiştir. EIS verilerinin modellenmesinden sonra elde edilen bu sonuçlar EP sisteminin, daha geniş elektrokimyasal aktif alana ve düşük difüzyon direncine atfedilmiştir.

Thesis (Doctoral)--Izmir Institute of Technology, Chemical Engineering, Izmir, 2019, Includes bibliographical references (leaves: 108-120), Text in English; Abstract: Turkish and English, Silica nanoparticles (SNPs) which can be synthesized with high surface area, controllable morphology and desired particle size have gained significant interests in high-end applications such as catalysis, chemical sensors, cosmetics and drug delivery applications. The sol-gel technique is the most commonly applied method for manufacturing these particles owing to its simplicity and suitability for allowing surface modifications to the final product. Though monodisperse amorphous SNPs have been studied extensively, how their formation proceeds through nucleation and growth is still a topic of debate. Over the years, a number of mathematical models have been suggested for the nucleation and growth of SNPs; some suggesting that silica growth occurred through monomer addition while some arguing that aggregation of nuclei/subparticles were the dominant mechanism. Nevertheless, a clear understanding of the nucleation and growth sub-processes is extremely important in control on the size and shape of SNPs for those industrial applications which demand specific morphology and surface properties. The need for a simple, robust and generalized model, both conceptually and mathematically, to understand formation and growth of Stöber silica particles has been the main driving force for this thesis. In this study, silica synthesis was carried out under a wide variety of experimental conditions while determining the size distributions of the formed particles kinetically during different stages of the synthesis in-situ through SEM analysis using an image analysis software. The outcome of the extensive synthesis work was to obtain a clear understanding of how the formation and growth of the silica particles proceed during synthesis. This conceptual understanding of the nucleation and growth processes was then translated into a mathematical model to predict the size of the particles as a function of synthesis time., Yüksek yüzey alanları, ayarlanabilir morfolojileri ve istenilen boyutlarda üretilebilmeleri nedeniyle, silika nanotaneler katalizörler, sensörler, kozmetik ürünler ve ilaç taşıyıcılar gibi pek çok yüksek teknoloji uygulamalarında dikkate değer bir ilgi görmektedir. Soljel tekniği, bu tanelerin üretiminde, kolay uygulanabilirliği ve sonuç ürünün niteliklerinin modifikasyonuna olanak vermesi nedeniyle en yaygın kullanılan yöntemdir. Her ne kadar amorf silika taneler sıklıkla çalışılsa da, tanelerin oluşumlarının çekirdeklenme ve büyüme prosesleri ile nasıl ilerlediği sentezin kontrolü ve tekrarlanabilirliği açısından hala bir tartışma konusudur. Yıllar boyunca, sol-jel silika tanelerin çekirdeklenme ve büyüme prosesleri için bir takım matematiksel modeller önerilmiş; kimi silika büyümesinin monomer ilavesi ile olduğunu öne sürmüş kimisi de çekirdek/alt parçacıkların agregasyonun dominant mekanizma olduğunu tartışmıştır. Yine de, çekirdeklenme ve büyüme alt proseslerinin açık bir şekilde anlaşılması, spesifik morfoloji ve yüzey özellikleri gerektiren endüstriyel uygulamalar için silika tanelerin boyut ve morfoloji kontrolü açısıdan son derece önemlidir. Stöber silika tanelerin oluşum ve büyüme mekanizmalarının anlaşılması için konsept ve matematik olarak, basit, sağlam ve genel bir modele olan gereksinim bu tezin temel itici gücüdür. Bu çalışmada, silika sentezi geniş deneysel koşulları altında uygulanmış, oluşan tanelerin boyut dağılımları kinetik olarak sentezin farklı basamaklarında, bir görüntü analiz programı kullanılarak SEM analizlerinden elde edilmiştir. Yoğun sentez çalışmalarının neticesi silika tanelerin sentez esnasında oluşum ve büyüme proseslerinin net bir şekilde anlaşılırlığının sağlanmasıdır. Çekirdeklenme ve büyüme proseslerinin konsept olarak anlaşılması ayrıca sentez zamanına karşı tanelerin boyutunun tahmin edilebilmesine olanak sağlayan bir matematiksel modele aktarılmıştır.

Purpose This paper aims to present a novel and cost-effective optical biosensor design by simple preparation method for detection of “parathion-methyl,” which is a model pesticide pose to public health and the environment. Design/methodology/approach The optical enzyme biosensor (TCA) for detection of pesticide “parathion-methyl” was developed on the basis of immobilization of tyrosinase enzyme on chitosan film by adsorption technique. The analytic performance of TCA was investigated by measuring its activity with Ultraviolet (UV) visible spectrophotometer. Findings Uniform porous network structure and protonated groups of chitosan film provided a microenvironment for tyrosinase immobilization evident from Fourier transform infrared (FTIR) spectroscopy and Atomic Force Microscopy analysis. TCA has a wide linear detection range (0-1.03 µM) with high correlation coefficient and it can detect the parathion-methyl concentration as low as 159 nM by noncompetitive inhibition kinetics. Using the TCA sensor both for ten times and at least 45 days without a significant loss in its activity are the indicators of its good operational and storage stability. Moreover, TCA can be applicable to tap water, providing a promising tool for pesticides detection. Originality/value This is the first time to use the in situ analytical technique that can improve the performance of optical enzyme sensor provided to control the pesticide residue better with respect to traditional techniques. The effect of organic solvents on the performance of optical enzyme biosensor was investigated. Inhibition kinetic of the solvents rarely encountered in literature was also studied besides the pH and temperature tolerance of the optical biosensor.

Thesis (Master)--Izmir Institute of Technology, Chemical Engineering, Izmir, 2019, Includes bibliographical references ( leaves: 58-64), Text in English; Abstract: Turkish and English, The objective of this study was to develop a method to synthesize CaCO3 nanoparticles from a chemical precipitation reaction under ambient and high supersaturation conditions. Equimolar CaCl2 and Na2CO3 solutions were reacted in a tubular reactor at a constant rate. The particles growth inhibition was attempted by dispersing the reaction mixture in a continuously stirred Ca(OH)2 solution. This procedure separated the nucleation phase from the growth inhibition process, and was conducted without pH and composition control. The possibility of impeding the CaCO3 particles overgrowth was explored at different precipitants and Ca(OH)2 concentrations. Their effects on the particles morphology, colloidal stability and specific surface area were studied. Although rapidlysettling particles were produced at precipitants concentration of 100 mM, colloidally stable CaCO3 nanoparticles were obtained at concentrations ≤75 mM. Additive Ca2+ ions, provided by the Ca(OH)2 solutions, inhibited the crystals growth by adsorbing irreversibly on the growth sites. The synthesized particles were as much as 95% smaller than those obtained when pure H2O was used instead. Ca2+ ions concentration and amount of precipitated particles were observed to be important factors for monodispersity and high growth inhibition. Monodisperse and stable nanoparticles were synthesized at low reactants concentration and/or precipitates volume. Vaterite phase was observed in the particles obtained when pure H2O was used as the growth-inhibiting solution. However, the presence of additive Ca2+ ions effected the crystallization of pure calcite, regardless of Ca(OH)2 or precipitants concentration, reaction mixtures retention time in the tubular reactor, volume of precipitates, and the growth-inhibiting solutions initial pH., Bu çalışmanın amacı, yüksek aşırı doyma ve normal ortam koşullarındaki bir çöktürme reaksiyonundan, CaCO3 nanotaneciklerini üretmeye yönelik metod geliştirmekti. Eşdeğer molar CaCl2 ve Na2CO3 çözeltileri sabit hızla, tüp şeklinde bir reaktörde reaksiyona sokulmuştur. Yeni oluşan partiküllerin fazla büyümesini engellemek için, reaksiyon karışımı devamlı karıştırılan Ca(OH)2 çözeltisine dağıtılmıştır. Bu yöntem, çekirdeklenme basamağını, kristal büyümesini engelleme prosesinden ayırmıştır. Kimyasal bileşim ve pH ayarlanmadan tamamlanmıştır. Üretilen taneciklerin aşırı büyümesinin engelleme olasılığı, farklı Ca(OH)2 çözeltisi ve tepkenlerin konsantrasyonlarında incelenmiştir. Partiküllerin morfolojisi, koloidal stabilitesi ve özgül yüzey alanı üzerindeki etkiler araştırılmıştır. 100 mM tepken konsantrasyonunda, hızlıca çöken partiküller üretilmesine rağmen, ≤75 mM konsantrasyonlarında kararlı CaCO3 nanotanecikleri elde edilmiştir. Ca(OH)2 çözeltisinden sağlanan katkı Ca2+ iyonları, kristallerin yüzeyine geri dönülemez bir şekilde tutunarak aşırı büyümelerini engellemiştir. Sentezlenen tanecikler, Ca(OH)2 yerine saf H2O kullanıldığında elde edilenlerden %95’e kadar daha küçüktür. Partiküllerin fazla büyümesinin engellemesi ve homojen boyut dağılımında üretilmesinde, katkı Ca2+ iyon konsantrasyonu ve Ca(OH)2 çözeltisine giren çökeltinin miktarı önemli faktörlerdir. Homojen dağılımlı ve koloidal kararlı kalsit nanotanecikleri düşük çökelti hacmi ve tepkenler konsantrasyonunda üretilmiştir. Ca(OH)2 yerine saf H2O kullanıldığında, taneciklerde vaterit polimorfu elde edilmiştir. Ancak, Ca(OH)2 veya tepkenlerin konsantrasyonuna, reaksiyon karışımını reaktörde tutma süresine, Ca(OH)2 çözeltisinin başlangıç pH’ına ve çökelti hacmine bakmaksızın, katkı Ca2+ iyonlarının varlığı saf kalsit fazlarının kristallenmesine etki etmiştir.

Thesis (Master)--Izmir Institute of Technology, Chemical Engineering, Izmir, 2019, Includes bibliographical references (leaves: 40-50), Text in English; Abstract: Turkish and English, In this study, peptides with sequences and notations as KLELKLELKLEL (KLEL), KLDVKLDVKLDV (KLDV), KLDVKLDVKLKV (KLKV1), KLKVKLDVKLKV (KLKV2), KLKVKLKVKLKV (KLKV3) were synthesized using solid phase peptide synthesis (SPPS) method based on Fmoc chemistry. Reverse phase HPLC and MALDI-TOF mass spectroscopy characterization methods were used to assess the purity of the peptides. Three different synthesis procedures were tested, and it was found that employing DMF:DMSO at 1:1 ratio as a solvent increased purity of the resultant peptide. FTIR results indicated the presence of expected β-sheet secondary structure, as well as an interference band from TFA salts for all of the peptides. All the peptides formed hydrogels at pH 7.4 with 1 wt% concentration in deionized water (DIW). AFM results of these hydrogels indicated that KLKV1 and KLKV2 had fibrous morphology with a width of 5-20 nm and 7-18 nm respectively. KLDV and KLKV3 peptide hydrogels, on the other hand, exhibited globular structures, having sizes with 15-50 nm and 8-15 nm, respectively. Storage moduli (G’) of these hydrogels in DIW were obtained as ~860 ± 150 Pa, ~260 ± 60 Pa, ~210 ± 30 Pa and ~1850 ± 200 Pa for KLDV, KLKV1, KLKV2 and KLKV3 respectively. Of these peptides, only HCl salt of KLDV and KLKV1 peptides more readily formed hydrogels in PBS but at 1.5 wt% concentration. G’ values of these KLDV and KLKV1 hydrogels were determined as ~1810 ± 850 Pa and ~700 ± 230 Pa, respectively. Cell proliferation tests (CCK-8 assay) of KLDV and KLKV1 hydrogels were performed by using L929 mouse fibroblast cells. Empty wells (TCPS) were used as a control group. Cell proliferation was observed to be comparable for both select hydrogels and empty wells, suggesting possible applications of these hydrogels in tissue engineering., Bu çalışmada KLELKLELKLEL (KLEL), KLDVKLDVKLDV (KLDV), KLDVKLDVKLKV (KLKV1), KLKVKLDVKLKV (KLKV2), KLKVKLKVKLKV (KLKV3) dizinleri ve kısaltmalarına sahip peptidler, f-moc kimyası temelli katı faz peptid sentez yöntemi (SPPS) kullanılarak sentezlenmiştir. Peptidlerin saflığını değerlendirmek için ters faz HPLC ve MALDI-TOF kütle spektroskopisi karakterizasyon yöntemleri kullanılmıştır. 3 farklı sentez prosedürü test edilmiştir ve çözgen olarak 1:1 oranda DMF:DMSO kullanılmasının, elde edilen peptidin saflığını artırdığı bulunmuştur. FTIR sonuçları, tüm peptidler için beklenen β-sheet ikincil yapısıyla birlikte, TFA tuzlarından gelen girişim bandını göstermiştir. Bütün peptidler, ağırlıkça 1% derişim, pH 7.4 ve deiyonize su içerisinde hidrojel oluşturmuştur. Bu hidrojellerin AFM sonuçları, KLKV1 ve KLKV2’nin, sırasıyla 5-20 nm ve 7-18 nm genişlikte lifli morfolojiye sahip olduğunu göstermiştir. Diğer taraftan, KLDV ve KLKV3 peptid hidrojelleri, sırasıyla, 15-50 nm ve 8-15 nm boyutları arasında küresel yapılar sergilemiştir. Deiyonize suda hazırlanan bu hidrojellerin, saklama modülleri, KLDV, KLKV1, KLKV2 ve KLKV3 için, sırasıyla, ~860 ± 150 Pa, ~260 ± 60 Pa, ~210 ± 30 Pa ve ~1850 ± 200 Pa olarak elde edilmiştir. Bu peptidlerden, sadece KLDV ve KLKV1 peptidlerinin HCl tuzları, PBS içerisinde, ağırlıkça 1.5% derişimde hidrojel oluşturmuştur. Bu KLDV ve KLKV1 hidrojellerinin G’ değerleri, sırasıyla ~1810 ± 850 Pa ve ~700 ± 230 Pa olarak belirlenmiştir. KLDV ve KLKV1 hidrojellerinin hücre çoğalma testleri (CCK-8 analizi) L929 fare fibroblast hücreleri kullanılarak yapılmıştır. Boş kuyucuklar (TCPS) control grubu olarak kullanılmıştır. Her iki seçilmiş hidrojel ve boş kuyucuklar için hücre çoğalması karşılaştırabilir olarak gözlenmiş ve sonuç olarak bu hidrojellerin doku mühendisliğinde muhtemel uygulamaları olabileceğini önermektedir.

Polycyclic aromatic hydrocarbons (PAHs) and some of their nitrated derivatives, NPAHs, are seemingly ubiquitous in the atmospheric environment. Atmospheric lifetimes may nevertheless vary within a wide range, and be as short as a few hours. The sources and sinks of NPAH in the atmosphere are not well understood. With a Lagrangian field experiment and modeling, we studied the conversion of the semivolatile PAHs fluoranthene and pyrene into the 2-nitro derivatives 2-nitrofluoranthene and 2-nitropyrene in a cloud-free marine atmosphere on the time scale of hours to 1 day between a coastal and an island site. Chemistry and transport during several episodes was simulated by a Lagrangian box model i.e., a box model coupled to a Lagrangian particle dispersion model, FLEXPART-WRF. It is found that the chemical kinetic data do capture photochemical degradation of the 4-ring PAHs under ambient conditions on the time scale of hours to 1 day, while the production of the corresponding NPAH, which sustained 2-nitrofluoranthene/fluoranthene and 2-nitropyrene/pyrene yields of (3.7 ± 0.2) and (1.5 ± 0.1)%, respectively, is by far underestimated. Predicted levels of NPAH come close to observed ones, when kinetic data describing the reactivity of the OH-adduct were explored by means of theoretically based estimates. Predictions are also underestimated by 1-2 orders of magnitude, when NPAH/PAH yields reported from laboratory experiments conducted under high NOx conditions are adopted for the simulations. It is concluded that NPAH sources effective under low NOx conditions, are largely underestimated., Grant Agency of the Czech Republic (P503 16-115375); Izmir Institute of Technology Research Fund (2013IYTE-14); Max Planck Society; European Union (262254); Ministry of Education, Youth & Sports - Czech Republic (LM2015051/CZ.02.1.01/0.0/0.0/16_013/0001761)

Olive mill wastewater (OMW) is highly dangerous for land and aquatic environments because of its high phenolic content, acidity, and salinity. Hence, hydrothermal degradation of OMW in subcritical water medium with and without using external oxidizer (H2O2) was studied to decrease its total organic carbon (TOC), total phenolic content (TPC), and color. Effects of reaction temperature (150 degrees C-250 degrees C), reaction time (30-120 min), and H2O2 content (0-100 mM) on TOC and TPC of OMW were investigated. Box-Behnken-type experimental design and statistical analysis (analysis of variance) were practiced by Design Expert 11. According to statistical analysis, effect of reaction temperature significantly affected TOC removal efficiency. The best TOC reduction (31.65%) was achieved without using H2O2 at 250 degrees C for 120 min.

WOS: 000456637900023, PubMed: 30445350, The aim of this study is to prepare high flux, stable, antifouling nanofiltration membranes through single bilayer polyelectrolyte deposition. To this end, a tight ultrafiltration support membrane was prepared from a polysulfone/sulfonated polyethersulfone blend. Deposition of a polyethyleneimine and alginate pair on this support has reduced the molecular weight cut off from 6 kDa to below 1 kDa. The pure water permeability and polyethylene glycol 1000 rejection of the coated membrane were found to be 15.5 +/- 0.3 L/m(2).h.bar and 90 +/- 0.6%, respectively, by setting the deposition pH for each layer to 8 and the ionic strengths to 0.5 M and 0 M. This membrane has exhibited significantly higher permeability than commercial membranes with the same molecular weight cut off, retaining 98% of the initial flux during 15 h filtration of bovine serum albumine. In addition, the membrane has been able to completely remove anionic dyes from aqueous solution by showing 99.9% retentions to Reactive red 141, Brilliant blue G and Congo red with a 2 bar transmembrane pressure. High flux and membrane stability in acidic and salty environments have been achieved when deposition conditions favor high adsorption levels for the first layer and strong ionic cross-linking between the carboxyl group on the alginate and the amine groups on the polyethyleneimine. (C) 2018 Elsevier Inc. All rights reserved.

Titania is one of the most preferable ceramic membrane materials of superior durability (as zirconia) when compared to that of other ceramics, e.g. alumina or silica. The surface charge of the membrane top layer is an important parameter of the separation performance of the multilayer ceramic membrane due to the Donnan exclusion mechanisms. In this study, the change of the surface charge of unsupported nano-structured titania top layer is investigated with calcination temperature variation. The effect observed indicates the possibility of preparation of tailor-made top layers for multilayer ceramic membranes. © 2019, University of Chemical Technology and Metallurgy.

Thesis (Master)--Izmir Institute of Technology, Chemical Engineering, Izmir, 2019, Includes bibliographical references (leaves: 46-48), Text in English; Abstract: Turkish and English, Nickel (Ni) and zinc (Zn) based organic frameworks were synthesized on the synthetic zeolite (5A and 13X), natural zeolite mineral clinoptilolite, -Alumina. Initially the zeolite surface was modified or seeded with metal organic framework (MOF). MOF-zeolite composite materials were characterized with XRD, SEM and ATR-IR to understand whether surface processes was achieved successfully or not. Additionally, band gap energies were evaluated to understand these composite materials were used as photocatalyst. Surface modification with APTES was not affect surface of the zeolites. In spite of that seeding created a layer on the surface of zeolite. Nickel based organic framework was coated onto the surface of modified 5A surface. Hydrothermal ZIF8 (ZIF8(1)) and solvothermal ZIF8 (ZIF8(2)) were synthesized successfully as MOF crystals. Besides ZIF8(2) was coated onto the surface of natural zeolite. Additionally, ZIF8/CuBTC sample were synthesized, seeded and coated onto the surface of natural zeolite. Band gap energies of the MOFs and composite materials were calculated with Tauc plot. Results showed that UV light can be used as light source for photocatalytic reactions of these photocatalysts. Also increasing photocatalyst amount increased dye degredation under UV light., Nikel ve çinko temelli organic ağ yapıları, zeolit 5A ve 13X, doğal zeolite ve alüminyum oksit’in yüzey işlemleri ve doğrudan sentez ve kaplama metotları ile yapılan metal organik ağ yapıları ile zeolitlerin oluşturduğu birleşik maddeler araştırılmıştır. Bu maddeler yüzey işlemlerinin başarılı olup olmadığını anlayabilmek için XRD, SEM ve ATR-IR ile analiz edilmiştir. Ayrıca bu birleşik maddelerin fotokatalizör olarak kullanılabileceği bant aralığı enerjileri incelenerek anlaşılmıştır. Yüzey modifikasyon işlemlerinden APTES isimli kimyasal ile yapılanın zeolite yüzeyine bir etkisi görülmemiştir. Buna karşın MOF kaplama işlemini kolaylaştırması için yapılan tutunma yüzeyi oluşturma işlemi başarı ile sonuçlanmıştır. Nikel temelli metal organic ağ yapısı yüzeyine modifikasyon işlemi uygulanmış zeolite 5A’nın yüzeyine başarı ile kaplanmıştır. ZIF8 isimli metal organic ağ yapısı iki farklı metot ile sentezlenmiş olup sentez sırasında çözücü olarak metil alkol kullanılan ürün ayrıca doğal zeolite üzerine de kaplanmıştır. Kaplama işlemi başarı ile gerçekleştirilmiştir. Buna ek olarak, ZIF8 ve bakır içeren metal organic ağ yapısı kompozit ürün olarak sentezlenmiş olup, bu ürün doğal zeolitin üzerine de sentezlenmiştir. Bu fotokatalizörlerin bant aralığı enerjileri incelenmiş olup UV ışık kaynağı ile fotokataliz reaksiyonlarının gerçekleştirilebileceği görülmüştür. Ayrıca yapılan UV ışığı kaynaklı deneyler sonucunda artan fotokatalizör miktarının solüsyondaki Rhodamine-B isimli boyayı bozundurduğu gözlemlenmiştir

Symposium on Legacy and Emerging Flame Retardants - Occurrence, Human Exposure and Toxicokinetics (DIOXIN) -- 2018 -- Krakow, POLAND WOS:000472694200025 PubMed ID: 31129402 Brominated flame retardants (BFRs) are found in multi-media indoors, therefore, may pose serious risks to human health. This study investigated the occurrence of BFRs in particulate matter (PM1 and PM10 and gas phase by active and passive sampling, and settled dust to estimate potential exposure in a computer technical service. Polybrominated diphenyl ethers (PBDEs) and their alternatives (novel BFRs, NBFRs) were studied. PM and gas phase were collected on glass fiber filters and polyurethane foam plugs, respectively, and analyzed with a GC/MS after extraction, clean-up, and concentration. Inhalation exposure of the staff was estimated based on the measured concentrations using Monte Carlo simulation. BDE-209 was the dominating PBDE congener in all media while bis(2-ethylhexyl)-3,4,5,6-tetrabromophthalate and 1,2-bis(2,4,6-tribromophenoxy)ethane were those of NBFRs. Submicron particulate matter (PM1) BFR levels constituted about one half of the PM10-associated concentrations, while average PM10 mass concentration (69.9 mu g m(-3)) was nine times that of PM1 (7.73 mu g m(-3)). Calculated log(10) dust-gas and PM-gas partitioning coefficients ranged from -5.03 to -2.10, -2.21 to -0.55, and -2.26 to -1.04 for settled dust, PM10, and PM1, respectively. The indoor/outdoor concentration ratios were >1 for all compounds indicating the strength of indoor sources in the service. The estimated potential inhalation exposures, for future chronic-toxic and carcinogenic risk assessments, indicated that the levels of gas-phase and PM1-associated exposures were similar at approximately one half of PM10-associated levels. Results of this study indicate that the occurrence of BFRs in all studied media should be taken into consideration for occupational health mitigation efforts. (C) 2019 Elsevier Ltd. All rights reserved.

Thesis (Master)--Izmir Institute of Technology, Chemical Engineering, Izmir, 2019, Includes bibliographical references (leaves: 56-60), Text in English; Abstract: Turkish and English, Soybean oil is an abundant, cheap and nontoxic biomass source and contains triglycerides with unsaturated fatty acids which can be easily modified by epoxidation. In this study, mesoporous Ti-SBA-15 with two different Si/Ti molar ratios, MoO3/Ti-SBA-15 with two different MoO3 mass ratios and Nb-SBA-15 with two different Si/Nb molar ratios were prepared as catalysts for soybean oil epoxidation reactions. Tertbutanol and ethyl acetate was used as solvent and H2O2 was utilized as oxidant. BET analysis indicated existence of high surface area of the catalysts which ranged between 650 and 950 m2/g. XRD analysis indicated successful incorporation of Nb and Ti into SBA-15 structure. Epoxidation reactions were carried out successfully using Ti-SBA-15 and Nb-SBA-15 catalysts in tertbutanol at 75 ºC for 6 h. Utilizing ethyl acetate as solvent was caused undesired catalyst behaviour such as precipitation, gelation and aggradation. No further investigations were carried out with ethyl acetate. Epoxidation products were analysed with H-NMR, FTIR and analytic methods. Ti-SBA-15 catalysts provided only 10 % double bond conversion and 49 % epoxide selectivity. They were not very active. Nb-SBA-15 catalysts exhibited high acidity. They provided 28 % double bond conversion and 31 % epoxide selectivity. Best yield was obtained with Nb-SBA-15 (10) catalyst as 6.49 %. Stability tests of catalysts indicated that Nb and Ti did not leach whereas severe leaching was observed with Mo. Also, homogenous epoxidation reaction with H2SO4 was carried out for comparison with heterogenous catalysts. Results indicated that, heterogenous catalysts were not competitive with homogenous catalyst., Soya yağı, ucuz, bol bulunan ve toksik olmayan bir biyokütle kaynağıdır ve doymamış yağ asitlerini ihtiva eden trigliseritleri içerir, bu doymamış yağlar epoksidasyonla kolayca modifiye edilebilirler. Bu çalışmada, farklı Si/Ti mol oranı olan iki Ti-SBA-15, farklı MoO3 kütle oranı olan iki MoO3/Ti-SBA-15 ve farklı Si/Nb mol oranı olan iki Nb-SBA-15 katalizörleri soya yağı epoksidasyonu için hazırlandı. H2O2 oksidant olarak ve tertbütanol ve etil asetat çözücü olarak kullanıldı. BET analiziyle katalizörlerin yüzey alanın yüksek olduğunu ve 650 ile 950 m2/g arasında değiştiği belirlendi. Nb ve Ti’un SBA-15 yapısına başarılı bir şekilde yerleştirildiği XRD analiziyle belirlendi. Epoksidasyon reaksiyonları Ti-SBA-15 ve Nb-SBA-15 katalizörleri kullanılarak tertbütanol’de 75 ºC de 6 sa olarak başarılı şekilde gerçekleştirildi. Etil asetat’ın çözücü olarak kullanılması katalizörlerde pelteleşme, dibe çökme ve tabakalaşma gibi istenmeyen davranışlara sebep oldu. Bu yüzden etil asetat’ın çözücü olarak kullanımana devam edilmemiştir. Epoksidasyon ürünleri H-NMR, FTIR ve analitik metotlarla analiz edildi. Ti-SBA-15 katalizörleri sadece 10 % çift bağ dönüşümü ve 49 % epoksi seçiciliği sağladı. Katalizörlerin çok aktif olmadığı bulundu. Nb-SBA-15 katalizörlerinin daha yüksek asitliğe sahip olduğu bulunmuştur. Nb-SBA-15 katalizörleri 28 % çift bağ dönüşümü ve 31 % epoksi seçiciliği sağladı. En iyi epoksit verimi Nb-SBA-15 (10) katalizörüyle 6.49 % olarak elde edildi. Kararlılık testlerinden Mo’un yüksek miktarda sıvıya geçtiği bulunurken, Ti ve Nb’un kararlı olduğu bulunmuştur. Ayrıca, heterojen katalizörlerle karşılaştırmak için homojen epoksidasyon reaksiyonu H2SO4 ile gerçekleştirildi. Sonuçlardan, heterojen katalizörlerin homojen katalizörle rekabet edecek düzeyde olmadığı belirlendi

Thesis (Master)--Izmir Institute of Technology, Chemical Engineering, Izmir, 2019, Includes bibliographical references (leaves: 58-63), Text in English; Abstract: Turkish and English, In this study, it was aimed to develop a drug carrier system including a TAT-derived cell penetrating peptide in order to provide fast transport of anticancer drugs from endosomal compartments to nucleus. The drug delivery system, denoted as mPEGpeptide- oxime-DOX, was based on polyethylene glycol, endosome disruptive peptide (G2RQR3QR3G2S), and doxorubicin (DOX) conjugate. Control drug delivery system, lack of the peptide (mPEG-oxime-DOX) was also synthesized to assess the effect of the peptide on the physiochemical and drug release properties of the drug carrier. As the first synthesis step, mPEG-OH was converted to mPEG-aldehyde form using DMSO-acetic anhydride oxidation reaction and aldehyde functionalization was determined by using FTIR and NMR spectroscopy. The peptide and mPEG-peptide were synthesized using solid phase synthesis protocol, and their purities were confirmed using HPLC and MALDI-TOF mass spectroscopy analyses. Prior to DOX conjugation, hydroxyl group of serine residue in the mPEG-peptide system was oxidized to aldehyde. The anticancer drug was attached to the carrier molecules via amine-aldehyde reaction forming an acid cleavable oxime bond. Drug release, size distribution, and stability of the PEG-peptideoxime- DOX system were evaluated and compared with those results of the control drug delivery system. For mPEG-oxime-DOX, a pH programmed DOX release with the respective % DOX release values of ~68 % and ~28 % at pH 5.0 and pH 7.4 was observed. For mPEG-peptide-oxime-DOX, on the other hand, quite low DOX release (~10-15 %) was obtained for both pH values suggesting possible interaction between DOX and the peptide. Mean size value of the mPEG-oxime-DOX was measured as ~24 nm. However, mPEG-peptide-oxime-DOX, had quite lower hydrodynamic diameter values (~3nm and ~6 nm at pH 5.0 and pH 7.4, respectively) possibly due to repulsions between the arginines in the peptide domain. Observation of the morphology and evaluation of the cytotoxicity of these drug delivery systems are underway., Bu çalışmada, antikanser ilaçların endozomal bölmelerden çekirdeğe hızlı transferini sağlamak için TAT türevi bir hücre delici peptid içeren ilaç taşıyıcı sisteminin geliştirilmesi amaçlanmıştır. mPEG-peptid-oksim-DOX olarak adlandırılan ilaç taşıyıcı sistemi, polietilen glikol, endozom parçalayıcı peptid (G2RQR3QR3G2S) ve doksorubisin (DOX) konjugatı temellidir. Peptidin, ilaç taşıyıcının fizikokimyasal ve ilaç salım özelliklerine etkisini değerlendirmek için peptid içermeyen kontrol ilaç taşıyıcı sistemi de (mPEG-oksim-DOX) sentezlenmiştir. İlk sentez adımı olarak mPEG-OH, mPEGaldehit formuna DMSO-asetik anhidrit oksidasyon reaksiyonu ile dönüştürülmüş ve aldehit işlevselleştirilmesi, FTIR ve NMR spektroskopisi kullanılarak belirlenmiştir. Peptid ve mPEG-peptid katı faz sentez protokolü ile sentezlenmiş ve HPLC ve MALDITOF kütle spektroskopi analizleri kullanılarak saflıkları teyit edilmiştir. DOX konjugasyonu öncesinde, mPEG-peptid sisteminde bulunan serin amino asitinin hidroksil grubu aldehite oksitlenmiştir. Antikanser ilaç, taşıyıcı moleküllere asit parçalanabilir oksim bağı ile bağlanmıştır. PEG-peptid-oksim-DOX sisteminin ilaç salımı, boyut dağılımı ve stabilitesi değerlendirilmiş ve kontrol sisteminin sonuçlarıyla karşılaştırılmıştır. mPEG-oksim-DOX için, pH 5.0 ve pH 7.4’te sırasıyla yaklaşık % 68 ve % 28 DOX salım değerleri ile pH programlı bir DOX salımı elde edilmiştir. Diğer taraftan, mPEG-peptid-oksim-DOX için her iki pH değerinde de oldukça düşük DOX salımı (yaklasık % 10-15) elde edilmiş ve DOX ile peptid arasındaki muhtemel etkileşimi sebebiyle olduğu düşünülmüştür. mPEG-oksim-DOX’un ortalama boyut değeri yaklaşık 24 nm olarak ölçülmüştür. Buna karşın, mPEG-peptid-oksim-DOX, muhtemelen peptid kısmındaki arjininler arasındaki itmeler nedeniyle, oldukça düşük hidrodinamik çap değerlerine (pH 5.0 ve pH 7.4 için sırasıyla yaklaşık 3 nm ve 6 nm) sahip olmuştur. Bu ilaç taşıyıcı sistemlerinin morfolojilerinin gözlenmesi ve sitotoksisitelerinin değerlendirmesine yönelik çalışmalar devam etmektedir., TUBİTAK-Münir Birsel Foundation and İzmir Institute of Technology Scientific Research Projects Coordination Unit (BAP Project Number = 2017İYTE53)

Despite the advancements in bone transplantation operations, inflammation is still a serious problem that threatens human health at the post-implantation period. Conventional antibiotic therapy methods may lead to some side effects such as ototoxicity and nephrotoxicity, especially when applied in high doses. Therefore, local drug delivery systems play a vital role in bone disorders due to the elimination of the disadvantages introduced by conventional methods. In the presented study, it was aimed to develop Vancomycin (VC) and Gentamicin (GC) loaded chitosan-montmorillonite nanoclay composites (CS/MMT) to provide required antibiotic doses to combat post-implantation infection. CS/MMT nanocomposite formation was supplied by microfluidizer homogenization and spherical drug carrier nanoparticles were obtained by electrospraying technique. Three factors; voltage, distance and flowrate were varied to fabricate spherical nanoparticles with uniform size. Emprical model was developed to predict nanosphere size by altering process variables. Nanospheres were characterized in terms of morphology, hydrodynamic size, zeta potential, drug encapsulation efficiency and release profile. Drug loaded nanospheres have been successfully produced with a size range of 180-350 nm. Nanocomposite drug carriers showed high encapsulation efficiency (80%-95%) and prolonged release period when compared to bare chitosan nanospheres. The drug release from nanocomposite carriers was monitored by diffusion mechanism up to 30 d. The in vitro release medium of nanospheres showed strong antimicrobial activity against gram-positive S. aureus and gram-negative E. coli bacteria. Furthermore, it was found that the nanospheres did not show any cytotoxic effect to fibroblast (NIH/3T3) and osteoblast (SaOS-2) cell lines. The results demonstrated that the prepared composite nanospheres can be a promising option for bone infection prevention at the post implantation period., TUBITAK (116M096)

Thesis (Master)--Izmir Institute of Technology, Chemical Engineering, Izmir, 2019, Includes bibliographical references (leaves: 89-94), Text in English; Abstract: Turkish and English, Doxorubicin (DOX) is one of the most commonly used hydrophilic anticancer drug in cancer treatment. However, when it is used in free form, it can attack not only cancer cells but also healthy cells. So as to prevent entering of DOX to the healthy cells, the encapsulation method is employed. Liposomes are suitable for encapsulation of DOX but the most important problems with the use of liposome are hand-foot syndrome and stomatitis. Encapsulation method is not enough because of these reasons, thus delivery of DOX to the desired site by targeted therapy has gained interest in recent years. In this study, DOX was encapsulated into liposomes and the DOX loaded liposomes (LipoDOX) was attached to microbubbles (MBs). MBs as ultrasound contrast agents are widely used in medical imaging. Use of MBs in combination of DOX loaded liposomes facilitates the uptake of the drug because ultrasound cavitation results in opening of transient pores in cell membrane via a process named sonoporation. Herein, MB-LipoDOX complex was engineered to optimize the size of the complex as well as the loaded DOX content. For this purpose, determination of incubation temperature and time for DOX loading into liposome and optimization of liposome formulation for maximum DOX loading were studied. Ratios of Lipid/Cholesterol/PEGylated lipid, PEG chain length and PEG molar ratio in liposome were determined. Also, determination of Strept Avidin (StAv) to Biotin ratio in LipoDOX and the amount of LipoDOX in LipoDOX-MB complex were studied. For characterization, Dynamic Light Scattering (DLS) method, Fluorescence Spectrometry method and Coulter Counter device were used. Lipoosme size was found to be associated with the pore size of polycarbonate membrane (200nm) resulting in liposomes at around 190±5 nm in size . When the PEGylated lipid with PEG chain of 2000 was used in liposome structure, particle size distribution is more monodispersed than the others. The maximum amount of DOX loaded liposomes was obtained at 32% Cholesterol, 5% DSPE-PEG2000, after 90 min. incubation at 65oC incubation. Optimum StAv to Biotin ratio in LipoDOX was determined as 1.0. The optimum molar ratio of Biotinylated lipids in LipoDOX was determined as 0.05% and the optimum molar ratio of Biotinylated lipids in MBs was determined as 8%., Doksorubisin (DOX), kanser tedavisinde en yaygın kullanılan hidrofilik antikanser ilacıdır. Ancak serbest formda kullanıldığında, sadece kanser hücrelerine değil aynı zamanda sağlıklı hücrelere de zarar verir. DOX'un sağlıklı hücrelere zarar vermesini önlemek için, kapsülleme yöntemi kullanılır. Lipozomlar, DOX'un kapsüllenmesi için uygundur, ancak el-ayak sendromu ve ağız içi yaralarına sebep olmaktadır. Bu sebeple DOX'un hedeflenmiş tedavi yöntemi ile istenen bölgeye verilmesi son yıllarda oldukça ilgi kazanmıştır. Bu çalışmada, DOX lipozomların içine enkapsüle edilmiş ve DOX yüklü lipozomlar (LipoDOX) mikro-kabarcıklara (MB) bağlanmıştır. Ultrason kontrast maddeleri olarak MB'lar, tıbbi görüntülemede yaygın olarak kullanılmaktadır. MB'lar ultrason yardımıyla ilacın hedef hücre içine alımını kolaylaştırır. Çünkü ultrasonun yarattığı kavitasyon, sonoporasyona yani hücre zarındaki geçici gözeneklerin açılmasına, hücre geçirgenliğinin artmasına neden olur. MB-LipoDOX kompleksi, boyutunun yanı sıra, içeriğindeki DOX miktarının optimize edilmesi için tasarlanmıştır. Bu amaçla, optimum LipoDOX inkübasyon sıcaklığı, süresi ve liposozom formülasyonu incelenmiştir. Lipozomdaki Lipid / Kolesterol / PEGile lipit, PEG zincir uzunluğu ve PEG molar oranı belirlenmiştir. Ayrıca, LipoDOX'taki StAv/Biotin oranı belirlenmiş ve LipoDOX-MB kompleksi içindeki optimum LipoDOX miktarı incelenmiştir. Çalışmalarda, karakterizasyon için Dinamik Işık Saçılımı (DLS) yöntemi, Floresan Spektrometresi yöntemi ve Coulter Counter cihazı kullanılmıştır. Lipozom büyüklüğü 200 nm olarak belirlenmiştir. Lipozom yapısında PEG2000 kullanıldığında, partikül büyüklüğü dağılımının diğerlerinden daha monodispers olduğu gözlenmiştir. Maksimum DOX yüklü lipozomlar, lipozom formulasyonunda %32 Kolesterol ve %5 DSPE-PEG2000 kullanıldığında ve DOX ile lipozomlar 65oC’de 90 dakika inkübe edildiğinde elde edilmiştir. LipoDOX'taki StAv/Biotin oranı 1.0 olarak; LipoDOX'taki Biotinli lipid mol oranı %0,05 ve MB'daki Biotinli lipid mol oranı %8 olarak belirlenmiştir.

Computational modeling of membrane materials is a rapidly growing field to investigate the properties of membrane materials beyond the limits of experimental techniques and to complement the experimental membrane studies by providing insights at the atomic-level. In this study, we first reviewed the fundamental approaches employed to describe the gas permeability/selectivity trade-off of polymer membranes and then addressed the great promise of mixed matrix membranes (MMMs) to overcome this trade-off. We then reviewed the current approaches for predicting the gas permeation through MMMs and specifically focused on MMMs composed of metal organic frameworks (MOFs). Computational tools such as atomically-detailed molecular simulations that can predict the gas separation performances of MOF-based MMMs prior to experimental investigation have been reviewed and the new computational methods that can provide information about the compatibility between the MOF and the polymer of the MMM have been discussed. We finally addressed the opportunities and challenges of using computational studies to analyze the barriers that must be overcome to advance the application of MOF-based membranes.

Thesis (Master)--Izmir Institute of Technology, Chemical Engineering, Izmir, 2019, Includes bibliographical references (leaves: 97-104), Text in English; Abstract: Turkish and English, Fuel oxygenate additives have been used as an alternative method to reduce the combustion emissions. The effects of methanol addition on n-heptane oxidation were investigated for one-dimensional, atmospheric pressure, laminar, premixed, fuel-rich flame at an equivalence ratio of 2.10. The Detailed Chemical Kinetic Modeling approach has been used to obtain information about the combustion characteristics of n-heptane and n-heptane/methanol flames. A detailed chemical kinetic mechanism was generated by merging two mechanisms of n-heptane (with the formation of polycyclic aromatic hydrocarbons (PAHs)) and methanol. The Master Mechanism consists of 4480 reactions and 945 species. Model validation was carried out using the experimental data available in the literature for different combustion systems. The Master Mechanism was investigated for the combustion of n-heptane and n-heptane/methanol flames using reaction sensitivity, rate of production, and reaction pathway analyses. The mole fraction profiles of low-molecular-weight stable species, single ring aromatics, and PAHs have been predicted by the model. Good agreements between the modeling and experimental results of species mole fractions for both flames have been achieved. The mole fractions of low-molecular-weight species, aromatics, and PAHs were reduced as the methanol was added to n-heptane flame. Acetylene, propargyl radical, and vinylacetylene have been found as important species for the formation of the first aromatic ring and PAH species. Model reduction was also carried out using directed relation graph method. The Reduced Mechanism consists of 1113 reactions and 156 species. The Reduced Mechanism was in a good agreement with the Master Mechanism in terms of the species mole fraction predictions of the n-heptane/methanol flame., Oksijenli yakıt katkı maddeleri, yanma süreçlerinden kaynaklanan emisyonları azaltmak için alternatif bir yöntem olarak kullanılmaktadır. Metanol ilavesinin n-heptan oksidasyonuna etkileri 2.10 eşdeğerilk oranında, bir boyutlu, atmosferik basınç, laminer, önceden karıştırılmış, yakıt bakımından zengin alev için araştırılmıştır. Detaylı Kimyasal Kinetik Modelleme yaklaşımı, n-heptan ve n-heptan/metanol karışımının yanma özellikleri hakkında bilgi edinmek için kullanılmıştır. Detaylı kimyasal kinetik mekanizmada, n-heptan oksidasyonunu (polisiklik aromatik hidrokarbonların (PAH) oluşumu ile birlikte) ve metanol oksidasyonunu içeren literatürdeki iki farklı mekanizma kullanıldı. Geliştirilen Detaylı kimyasal Kinetik Mekanizma, 4480 reaksiyon ve 945 bileşikten oluşmaktadır. Modelin doğrulanması, literatürdeki farklı yanma sistemleri (laminer, önceden karıştırılmış, alev ve hızlı sıkıştırma makinesi) için mevcut deneysel veriler kullanılarak yapılmıştır. Geliştirilen ayrıntılı kimyasal kinetik model, n-heptan ve n-heptan/metanol alevlerinin yanması için reaksiyon hassasiyeti, üretim hızı ve reaksiyon yolu analizleri kullanılarak incelenmiştir. Düşük moleküler ağırlıklı kararlı bileşiklerin, tek halka aromatiklerin ve PAH’ların alev içerisindeki konsantrasyon (mol fraksiyon) profilleri model tarafından tahmin edilmiştir. n-Heptan/Metanol alevi için detaylı mekanizmanın bileşiklerin mol fraksiyonu tahminleri ile deneysel veriler arasında uyum vardır. Hem deneysel hem de modelleme sonuçlarına göre kararlı yapıdaki düşük moleküler ağırlıklı öncül bileşiklerin, aromatikler ve PAH'ların mol fraksiyonları, n-heptan alevine eklenen metanol katkısı ile azaldı. Asetilen, propargil radikali ve vinilasetilen, ilk aromatik halkanın ve PAH bileşiklerinin oluşumu için önemli öncül olarak bulunmuştur. Ayrıca, indirgenmiş mekanizma, yönlendirilmiş ilişki grafiği yöntemi kullanılarak üretildi. Geliştirilen İndirgendirmiş Mekanizma, 1113 reaksiyon ve 156 bileşikten oluşmaktadır. İndirgendirmiş Mekanizma, n-heptan/metanol alevi sırasında oluşan bileşiklerin mol fraksiyonu tahminleri açısından Detaylı Mekanizma ile iyi bir uyum göstermiştir.

Thesis (Master)--Izmir Institute of Technology, Chemical Engineering, Izmir, 2019, Includes bibliographical references (leaves: 55-58), Text in English; Abstract: Turkish and English, The textile wastewater contains a significant level of organic dyes and inorganic salts. Separation of a vast amount of organic dyes and inorganic salts is important not only to comply with strict regulations but also to recover dyes for reuse during the process. Nanofiltration is proposed as a cost-effective alternative solution for dye and salt separation compared to traditional techniques. The main objective of this thesis is to develop a polyamideimide based positively charged nanofiltration membranes with high permeability, and high selectivity for separation of dyes and salts in textile wastewater treatment. Polyamide-imide (PAI) is an excellent choice for membrane production because of its superior processability, good mechanical features, and high chemical and thermal resistance. Its imide groups are crosslinked with polyethyleneimine (PEI), which is a suitable material to obtain a positively charged surface. In this study, support membranes of various pore sizes were produced by changing the composition of the coagulation bath and casting solution during the phase inversion method. Then, the optimum support membrane was in-situ modified with the alginate and coordinated with the metal ions for high permeability and high selectivity. The influences of the metal concentration and reaction time on the membrane performances were examined. It has been demonstrated that resulted nanofiltration membrane has high solute permeability (>22 L / m2 h bar), high dye rejection (~ 95 %) and low salt rejection (~ 11 %). Moreover, this membrane was tested in the treatment of real textile wastewater samples. Salts in wastewater permeated, while high amounts of dye were rejected., Tekstil atık suları önemli miktarda organik boya ve inorganik tuz içerir. Organik boya ve inorganik tuzun ayrılması, yalnızca yasal düzenlemelere uymak için değil, aynı zamanda işlem sırasında tekrar kullanılmak üzere boyaları geri kazanmak için de önemlidir. Nanofiltrasyon, geleneksel tekniklere kıyasla boya ve tuz ayırma için uygun maliyetli bir alternatif çözüm olarak önerilmiştir. Bu tezin temel amacı, tekstil atıksu arıtımında boya ve tuzların ayrılması için yüksek geçirgenliğe ve yüksek seçiciliğe sahip bir poliamid-imid (PAI) bazlı nanofiltrasyon membranı geliştirmektir. PAI, üstün işlenebilirlik, yüksek mekanik özelliği ile , yüksek kimyasal ve termal direnci nedeniyle membran üretimi için mükemmel bir seçimdir. Imid grupları, pozitif yüklü bir membran elde etmek için uygun bir malzeme olan polietilenimin (PEI) ile çapraz bağ yapabilir. Bu çalışmada, faz inversiyon yöntemi kullanılarak, koagülasyon banyosunun ve döküm çözeltisinin bileşiminin değiştirilmesi suretiyle çeşitli gözenek boyutlarında destek membranları üretilmiştir. Optimize edilen destek membranı aljinat ile modifiye edilmiş, ardından yüksek geçirgenlik ve yüksek seçicilik için metal iyonlarıyla koordine edilmiştir. Metal konsantrasyonunun ve reaksiyon süresinin membran performansına olan etkileri incelenmiştir. Elde edilen nanofiltrasyon membranının yüksek geçirgenliğe (> 22 L /m2 h bar), yüksek boya reddine (~ % 95) ve düşük tuz reddine (~ % 11) sahip olduğu gösterilmiştir. Ayrıca, bu membran, gerçek tekstil atıksu numunelerinin arıtılmasında test edilmiştir. Sonuç olarak, tuzların membrandan geçtiği boya ve renkli bileşiklerin ise önemli oranda membran tarafından tutulduğu belirlenmiştir. Elde edilen membranlar Taramalı Elektron Mikroskobu (SEM), Enerji Dağılımlı X-Ray Analizi (EDX), Zeta Potansiyeli, Atomsal Kuvvet Mikroskopisi ve Temas Açısı ölçümü ile karakterize edilmiştir.

This study reports levels of indoor environmental quality variables before and after installation of heat recovery ventilation in a primary school located in an urban area in Izmir, Turkey. A CO2-based modeling was performed to determine the required flow rates that would comply with an international ventilation standard, followed by computational fluid dynamics modeling for best airflow distribution in a classroom. Temperature, CO2, PM2.5, and total volatile organic compounds were found at undesired levels, among which relative humidity, CO2, and PM2.5 were improved after the intervention. Reductions in the mean and maximum concentrations were 29% and 68% for CO2 and 29% and 46% for PM2.5. This intervention study was a part of the city-wide main project that aimed to increase awareness of the students and their families, teachers, and staff regarding importance of indoor environmental quality in both at school and home due to its possible effects on children's health and academic performance, one of the major challenges of today's societies all around the globe., Mechanical Engineering Chamber of Izmir; HVAC industry; Ministry of Education-Izmir Directorate

In this paper, a novel hybrid process for the treatment of microcrystalline cellulose (MCC) under hot-compressed water was investigated by applying constant direct current on the reaction medium. Constant current range from 1A to 2A was applied through a cylindrical anode made of titanium to the reactor wall. Reactions were conducted using a specially designed batch reactor (450 mL) made of SUS 316 stainless steel for 30–120 min of reaction time at temperature range of 170–230 °C. As a proton donor H2SO4 was used at concentrations of 1–50 mM. Main hydrolysis products of MCC degradation in HCW were detected as glucose, fructose, levulinic acid, 5-HMF, and furfural. For the quantification of these products, High Performance Liquid Chromatography (HPLC) and Gas Chromatography with Mass Spectroscopy (GC–MS) were used. A ½ fractional factorial design with 2-level of four factors; reaction time, temperature, H2SO4 concentration and applied current with 3 center points were built and responses were statistically analyzed. Response surface methodology was used for process optimization and it was found that introduction of 1A current at 200 °C to the reaction medium increased Total Organic Carbon (TOC) and cellulose conversions to 62 and 81 %, respectively. Moreover, application of current diminished the necessary reaction temperature and time to obtain high TOC and cellulose conversion values and hence decreased the energy required for cellulose hydrolysis to value added chemicals. Applied current had diverse effect on levulinic acid concentration (29.9 %) in the liquid product (230 °C, 120 min., 2 A, 50 mM H2SO4). © 2016, Springer Science+Business Media Dordrecht., Marie Curie Career Integration Grants (FP7-PEOPLE-CIG) PCIG11-GA-2012-321741

The effect of acidic or basic pre-treatment on the adsorption capacity of CO2 on coals was investigated. Argonne Premium Pocahontas No. 3, Upper Freeport, Pittsburgh No. 8, Lewiston–Stockton, Blind Canyon, Illinois No. 6, Wyodak, and Beulah–Zap coals were washed in weak solutions of H2SO4 and NaOH to the pH values of 10, 7, and 2, after an initial washing in acidic water. Attempts to treat the Wyodak and Beulah–Zap coals were unsuccessful because the base treatment after the initial acid treatment resulted in a suspension which could be separated neither via filtration through a 45 μm filter nor centrifugation. Equilibration took several days in some cases, although the as-received coal had been ground to 150 μm. Acid washing preferentially removed Ca (calcite) and Mg. Aluminosilicate clays were not notably removed. Iron was removed in significant amounts only after base treatment, possibly after it was converted to hematite. The adsorption capacity of CO2 on the acid treated coals was higher than both the base treated and untreated coals. The difference in adsorption capacities for acid and base treated coals was related to the pore sizes and mineral matter removal from the coals, where the calculated average pore size was higher for acid treated coals than for the base treated coals. It is concluded that the pH decrease due to CO2 dissolution in cleat water is favored in coal seam sequestration, which resulted in an increase in storage capacity of coals.

The effect of calcium hydroxide (Ca(OH)2) on the stability of calcium carbonate (CaCO3) particles was investigated with respect to the surface potential and particle size. Both CaCO3 and Ca(OH)2 were dissolved in ultrapure water at concentrations up to 100 mM. The solubility limits were about 18 mM for Ca(OH)2 and about 0.13 mM for CaCO3 at 23 °C in water. Dissolution of commercial CaCO3 in 10 mM of Ca(OH)2 solution and dissolution of Ca(OH)2 in 10 mM of CaCO3 slurry were also studied at similar conditions. Conductivity, pH, zeta potential, and average particle sizes were measured for each solution. The morphological characteristics of the particles were analyzed by the SEM images. It was found that the zeta potential of CaCO3 particles was greater than + 30 mV when they were placed in the Ca(OH)2 solution compared to a zeta potential value of - 10 mV in water. It was concluded that the Ca(OH)2 solution is a stabilizer for the CaCO3 particles., Scientific and Technological Research Council of Turkey (TUBITAK MAG 110M104)