WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7150
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Article Effects of Span 60 Template and Freeze Drying on Zinc Borate Produced From Zinc Nitrate Hexahydrate and Borax Decahydrate(Taylor and Francis Ltd., 2022) Alp, Burcu; Gönen, Mehmet; Atakul Savrık, Sevdiye; Balköse, DevrimZinc borate is an important additive to polymers and lubricants. The process variables such as reactant concentration, presence of template in precipitating medium and drying method determine the composition and particle size of zinc borates. In the present study, zinc borate precipitate obtained by mixing aqueous zinc nitrate and borax decahydrate solutions was dried either by conventional method or by freeze drying. The products were well characterized by advanced methods. Zinc borate from 1 mol dm(-3) reactants had (2.1 +/- 0.5)x(2.5 +/- 0.5)x(1.3 +/- 0.2) mu m and (0.5 +/- 0.1)x(1.3 +/- 0.1)x(0.028 +/- 0.01) mu m dimensions by conventional and freeze drying respectively. Individual particles smaller in size is obtained since the particles are not agglomerated due to absence of surface tension of liquid water for case of freeze drying. Planar particles agglomerated into 20 to 60 mu m crystals in the presence of template Span 60 in 1 mol dm(-3) reactants for conventional drying. Nano zinc borate particles with primary particle size of (46 +/- 9) nm were obtained by decreasing the reactant concentration to 0.1 mol dm(-3). The primary particle size was decreased to (40 +/- 3) nm by addition of Span 60 to dilute solutions. However zinc borate nanoparticles obtained from dilute solutions adhered to each other forming agglomerates during conventional drying. Their freeze drying would allow formation of a freely flowing nano powder.Article Citation - WoS: 14Supercritical Ethanol Drying of Zinc Borates of 2zno Center Dot 3b(2)o(3)center Dot 3h(2)o and Zno Center Dot B2o3 Center Dot 2h(2)o(Elsevier Ltd., 2011) Gönen, Mehmet; Balköse, Devrim; Ülkü, SemraSupercritical ethanol (SCE) drying of zinc borates was investigated to obtain dry zinc borate nanoparticles and to elucidate possible chemical interactions between zinc borates and ethanol. Commercial and synthesized 2ZnO center dot 3B(2)O(3)center dot 3H(2)O and ZnO center dot B2O3 center dot 2H(2)O samples were dried by both conventional and SCE drying methods and the products were compared. Zinc borates were characterized using X-ray powder diffraction (XRD), thermo gravimetric analysis (TGA), Fourier transform infrared (FTIR) analysis, transmission electron microscopy (TEM), scanning electron microscopy (SEM) and helium pycnometer. Zn and B contents of samples were also determined by analytical titration. It was found that zinc borate of ZnO center dot B2O3 center dot 2H(2)O decomposed completely into zinc oxide and boric acid. However, zinc borate having oxide formula of 2ZnO center dot 3B(2)O(3)center dot 3H(2)O decomposed partially to form anhydrous zinc borate, zinc oxide, water and boric acid during the SCE drying carried out at 250 degrees C and 6.5 MPa. Boric acid and water were extracted from both of zinc borates by supercritical ethanol. The extraction of boric acid by ethanol in the SCE drying of zinc borates is an important result which can be utilized in the production of boric acid from water insoluble natural minerals, e.g. colemanite. The boric acid-ethanol solution could be directly utilized in the synthesis of ethyl borate. (C) 2011 Elsevier B.V. All rights reserved.Article Citation - WoS: 4Citation - Scopus: 4Characterization of a Pearlescent Biaxially Oriented Multilayer Polypropylene Film(Lviv Polytechnic National University, 2015) Arkış, Esen; Çetinkaya, Hayrullah; Kurtuluş, Işıl; Ulucan, Utku; Aytaç, Arda; Balcı, Beste; Balköse, DevrimThe morphology, composition, optical, thermal and mechanical properties of a commercial pearlescent and multilayer biaxially oriented polypropylene (BOPP) films were determined. The structure and orientation of BOPP films were confirmed by FTIR spectroscopy, X-ray diffraction and EDX analysis. The films surface roughness was determined by AFM method. The tensile strength of the films was determined in machine and transverse directions.Conference Object Heavy Metal Removal Using Natural Zeolite Packed Ion Exchange Column(American Chemical Society, 2008) Balköse, Devrim; Ülkü, Semra[No abstract available]Book Part Key Engineering Materials Volume I: Current State of the Art on Novel Materials(Taylor and Francis Ltd., 2014) Balköse, Devrim; Horak, Daniel; Soltes, Ladislav[No abstract available]Book Part Aluminium-Coated Polymer Films as Infrared Light Shields for Food Packing(Taylor and Francis Ltd., 2015) Arkış, Esen; Balköse, Devrim[No abstract available]Book Part Citation - WoS: 1Preparation, Characterization, and Applications of Magnesium Stearate, Cobalt Stearate, and Copper Stearate(Taylor and Francis Ltd., 2014) Gönen, Mehmet; Egbuchunam, Theresa O.; Balköse, Devrim; İnal, Fikret; Ülkü, Semra[No abstract available]Book Part Control of the Particle Size and Purity of Nano Zinc Oxide(Taylor & Francis, 2014) Özmıhçı Ömürlü, Filiz; Balköse, DevrimEffects of template, mechanical mixing and/or ultrasound mixing on the size of the ZnO crystals obtained by precipitation at 30 °C from aqueous zinc chloride and potassium hydroxide solutions were investigated by 2k factorial design. Precipitation method is employed to synthesize nano zinc oxide particles. Monodisperse nano ZnO having 29 nm particle size was produced by adding triethyl amine and applying simultaneously mechanical and ultrasound mixing. The surface area and the density of the powder were 21 m2/g and 4.8 g/cm3. It contains 5.2% impurities present as CO3-2 and bound OH- groups. Volumetric resistivity was found as 1.3 × 107ohm cm. Absorption spectrum of the powder showed absorption peak at 353 nm. The room temperature fluorescence spectrum of the powder revealed a strong and sharp UV emission band at 391 nm due to free exciton or bound exciton of ZnO and a weak and broad violet emission band at 405 nm due to zinc vacancies.Book Citation - Scopus: 5Aluminium-Coated Polymer Films as Infrared Light Shields for Food Packing(Apple Academic Press, 2014) Hamrang, Abbas; Balköse, Devrim; Zaikov, Gennadij Efremovich; Haghi, A. K.This book covers a broad range of polymeric materials and provides industry professionals and researchers in polymer science and technology with a single, comprehensive book summarizing all aspects involved in the functional materials production chain. This volume presents the latest developments and trends in advanced polymer materials and structures. It discusses the developments of advanced polymers and respective tools to characterize and predict the material properties and behavior. This book has an important role in advancing polymer materials in macro and nanoscale. Its aim is to provide original, theoretical, and important experimental results that use non-routine methodologies. It also includes chapters on novel applications of more familiar experimental techniques and analyses of composite problems that indicate the need for new experimental approaches. This new book: • Provides a collection of articles that highlight some important areas of current interest in key polymeric materials and technology. • Gives an up-to-date and thorough exposition of the present state of the art of key polymeric materials and technology. • Describes the types of techniques now available to the engineers and technicians and discusses their capabilities, limitations, and applications. • Provides a balance between materials science and chemical aspects, basic and applied research. • Focuses on topics with more advanced methods. • Emphasizes precise mathematical development and actual experimental details. • Explains modification methods for changing of different materials properties. © 2020 Elsevier B.V., All rights reserved.Article Citation - WoS: 5Citation - Scopus: 7Effect of the Zeolite Filler on the Thermal Degradation Kinetics of Polypropylene(Scibulcom Ltd., 2006) Tıhmınlıoğlu, Funda; Pehlivan, Hilal; Balköse, Devrim; Ülkü, SemraIn this study, the thermal degradation behaviour of polypropylene (PP) and polypropylene-zeolite composites was investigated. Clinoptilolite, a natural zeolitic tuff, was used as the filling material into the composites. Effect of both pure clinoptilolite and silver ion exchanged form of clinoptilolite addition on the thermal degradation kinetics of polypropylene composites was studied by using differential scanning calorimetry (DSC) and thermal gravimetry analysis (TGA) techniques. Polymer degradation was evaluated by using DSC with heating rates of 5, 10, and 20 degrees C/ min from room temperature up to 500 degrees C. Silver concentration (4.36, 27.85 and 183.8 mg Ag/g zeolite) was the selected parameter under consideration. From the DSC curves, it was observed that the heat of degradation values of the composites containing 2-6% silver exchanged zeolites (321-390 kJ/kg) were larger compared to that of the pure PP free of silver and zeolite (258 kJ/kg). From the DSC results it was confirmed that PP-zeolite composites can be used at higher temperatures compared to the pure PP polymer because of its higher thermal stability. The thermal decomposition activation energies of the composites were calculated by using both the Kissenger and Ozawa models. The values predicted from these two equations were in close agreement. From the TGA curves, it was found that zeolite addition into the PP matrix speeds down the decomposition reaction, however, silver exchanged zeolite addition into the matrix accelerates the reaction. The higher the silver concentration, the lower the thermal decomposition activation energies were obtained. As a result, PP was found to be much more susceptible to thermal decomposition in the presence of silver exchanged zeolite.