Chemical Engineering / Kimya Mühendisliği
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Book Part A Study on Absorption and Reflection of Infrared Light by the Uncoated and Al Coated Surfaces of Polymer Films Techniques(Apple Academic Press, 2014) Arkış, Esen; Balköse, DevrimPolymer films coated with a thin layer of aluminum or aluminum oxide are extensively used in food packing as heat shields. The infrared rays were not transmitted through the films and were reflected protecting the contents from the harmful effects of infrared light. The quantitative measurement of the film thickness and infrared light reflection and absorption capacities of aluminum coated films used as packing materials were possible using infrared spectroscopy. © 2015 by Apple Academic Press, Inc.Book Part Calcium Soap Lubricants(CRC Press, 2015) İzer, Alaz; Kahyaoğlu, Tuğçe Nefise; Balköse, DevrimThe reparation and characterization of calcium stearate (CaSt2) and a lubricant by using calcium stearate were aimed at in this study. Calcium stearate powder was prepared from sodium stearate and calcium chloride by precipitation from aqueous solutions. CaSt2 and the Light Neutral Base oil were mixed together to obtain lubricating oil. It was found that CaSt2 had a melting temperature of 142.8 °C and in base oil it had a lower melting point, above 128 °C. It was dispersed as lamellar micelles as the optical micrographs had shown. From rate of settling the size of dispersed particles were found to be 1.88 µm and 0.11 µm for lubricants having 1% and 2% CaSt2, respectively. The friction coefficient and wear scar diameter of base oil 0.099 and 1402 nm were reduced to 0.0730 and 627.61 nm respectively for the lubricant having 1% CaSt2. Lower wear scar diameter (540 nm) was obtained for lubricant with 2% CaSt2. CaSt2 improved the lubricating property of the base oil but did not improve its oxidative and thermal stability. © 2015 by Apple Academic Press, Inc.Research Project Süperkritik Akışkan Ekstraksiyonu ile Bor Minerallerinden Borik Asit Üretimi(2014) Gönen, Mehmet; Akçil, Ata Utku; Pamukoğlu, Muhammet Yunus; Balköse, DevrimSüpekritik etanol ile tinkal mineralinden %32 verimle borik asit ayrıştırılmış; süperkritik karbondioksit ile su ortamında kolemanit mineralinden %98 verimle borik asit ekstraklanmıştır. Proje doğal kaynaklarımızdan temel bor kimyasalı, borik asit, üretiminde atmosferde sera gazı etkisi oluşturan CO2?nin kullanılması yönüyle önemlidir. Baca gazları içindeki CO2 kolemanit reaksiyonu sonucunda kararlı bir bileşik olan kalsite (CaCO3) dönüşmektedir. Bu proses kolemanit mineralinden borik asit üretiminin yanında CO2 tutulumu da sağladığından dolayı sürdürülebilir ve çevreci bir prosestir. SüperPro Designer programı ile hem geleneksel (kolemanit-H2SO4) hemde geliştirilen (kolemanit-süperkritik CO2) prosesler için proses dizayn yapılmış ve prosesler teknik ve ekonomik açıdan karşılaştırılmıştır.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.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 Water Sorption of Polyvinyl Chloride-Luffa Cylindrica Composites(Taylor & Francis, 2014) Demir, Hasan; Balköse, DevrimNatural Luffa Cylindrica fibers were modified with 0.1M sodium hydroxide (NaOH) for removing lignin and hemicellulose. Natural and modified Luffa fibers were characterized by using IR spectroscopy. Composites were produced with PVC plastisol and natural Luffa fiber. Natural Luffa fiber is a highly hydrophilic substance. This feature increased the water sorption capacity of the composites. Flexible PVC-luffa cylindrica composites had higher liquid water sorption capacity (0.3-0.6%) compared to that of flexible PVC (0.1%). There was no volume change of composites due to liquid water sorption.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 Part Citation - Scopus: 1Metal Soap Greases(Apple Academic Press, 2013) Arkı, Esen; Balköse, DevrimMetal soaps are transition metal salts of the fatty acids and the alkaline earth. Although, the alkali salts of the fatty acids such as sodium and potassium are water soluble, metal soap is water insoluble but more soluble in nonpolar organic solvents [1]. Some commercially important metal soap include those of Alluminum, barium, cadmium, calcium, cobalt, copper, iron, lead, lithium, magnesium, manganese, potassium, nickel, zinc, and zirconium. Significant application areas for metal soaps include lubricants and heat stabilizers in plastics as well as driers in paint, varnishes, and printing inks. Other uses are as processing aids in rubber, fuel and lubricant additives, catalysts, gel thickeners, emulsifiers, water repellents, and fungicides [2]. © 2013 by Apple Academic Press, Inc.Book Part Calcium Soap Lubricants(Apple Academic Press, 2015) İzer, Alaz; Kahyaoğlu, Tuğçe Nefise; Balköse, DevrimThe reparation and characterization of calcium stearate (CaSt2) and a lubricant by using calcium stearate were aimed at in this study. Calcium stearate powder was prepared from sodium stearate and calcium chloride by precipitation from aqueous solutions. CaSt2 and the Light Neutral Base oil were mixed together to obtain lubricating oil. It was found that CaSt2 had a melting temperature of 142.8 °C and in base oil it had a lower melting point, above 128 °C. It was dispersed as lamellar micelles as the optical micrographs had shown. From rate of settling the size of dispersed particles were found to be 1.88 ?m and 0.11 ?m for lubricants having 1% and 2% CaSt2, respectively. The friction coefficient and wear scar diameter of base oil 0.099 and 1402 nm were reduced to 0.0730 and 627.61 nm respectively for the lubricant having 1% CaSt2. Lower wear scar diameter (540 nm) was obtained for lubricant with 2% CaSt2. CaSt2 improved the lubricating property of the base oil but did not improve its oxidative and thermal stability. © 2015 by Apple Academic Press, Inc.Book Part Citation - Scopus: 2Influence of Filler Surface Modification on the Properties of Pp Composites(Wiley, 2015) Balköse, DevrimThis chapter reviews the fillers have been grouped as silica, glass, silicates, magnesium hydroxide and eggshell, cellulose and carbon, and their surface modification techniques. It explains the effects of the surface modification of fillers on the properties of composite materials having polypropylene as the matrix. The surface modification of fillers affects the properties of the polypropylene matrix composites in different aspects depending on the types of the filler and the modifications. The polypropylene phase was also functionalized by treating PP with MA or ammines. The properties most affected are the tensile strength, Young modulus, and elongation at break of the composites. If crosslinking occurs between the filler and functionalized PP, the tensile strength increases and elongation at break decreases owing to decrease in mobility. PP crystallite formation at the interface also increases the adhesion between filler and matrix. © 2015 Wiley-VCH Verlag GmbH & Co. KGaA. All rights reserved.