Synthetic dyes are very important for textile dyeing, paper printing, color photography and petro... more Synthetic dyes are very important for textile dyeing, paper printing, color photography and petroleum products. Traditional methods of dye removal include biodegradation, precipitation, adsorption, chemical degradation, photo degradation, and chemical coagulation. Dye decolorization with enzymatic reaction is an important issue for several research field (chemistry, environment) In this study, minimum decolorization time of Remazol Brilliant Blue R dye with Horseradish peroxidase enzyme was calculated using with mathematical equation depending on experimental data. Dye decolorization was determined by monitoring the absorbance decrease at the specific maximum wavelength for dye. All experiments were carried out with different initial dye concentrations of Remazol Brilliant Blue R at 25 degrees C constant temperature for 30 minutes. The development of the least squares estimators for a nonlinear model brings about complications not encountered in the case of the linear model. Decolorization times for completely removal of dye were calculated according to equation. It was shown that mathematical equation was conformed exponential curve for dye degradation.
In this study, pistachio shell-polypropylene copolymer (PPc) biocomposites were prepared by using... more In this study, pistachio shell-polypropylene copolymer (PPc) biocomposites were prepared by using the melt compounding technique. Treated pistachio shell (TPS) (30%wt) was employed to increase mechanical and thermal properties of biocomposites. Maleation and filler pre-treatment processes improved the mechanical strength of the PPc-TPS composites. The UV additives, Chimassorb 944 (CHI) stabilizer, and the UV absorber Irganox 1010 (IRGV) were used to enhance oxidative and color stability of biocomposites after they were subjected to accelerated UV irradiation for 600 h. The mechanical properties of the UV additive containing composites were less affected after UV exposure. The oxidative induction time and discoloration analysis revealed that CHI and IRGV additives can be utilized in applications that require higher color stability while the former showed better performance for oxidative stability.
Journal of Thermoplastic Composite Materials, Apr 22, 2021
In this study, poly(lactic acid) (PLA)/pistachio shell (PS) biocomposites were fabricated by melt... more In this study, poly(lactic acid) (PLA)/pistachio shell (PS) biocomposites were fabricated by melt functionalization through a one-step compatibilization process in varying PS filler rates (0–30%). To enhance interfacial adhesion, alkaline-silane pre-treatment was applied to PS, and PLA was grafted with maleic anhydride (MA). The effect of filler ratio, pre-treatment, and maleation steps on the mechanical, thermal, and morphological properties of biocomposites was investigated. The tensile and flexural analysis showed that composites with optimum mechanical properties were obtained by blending 20% of pre-treated PS with maleated PLA. Mechanic and thermal analyses were performed to examine fiber/matrix surface compatibility. The mechanical analysis of biocomposites, such as tensile/flexural strength and modulus were determined with a universal testing machine. Thermal analysis and thermal degradation of biocomposites were determined by using Differential Scanning Calorimetry and TG/DTG. Morphological analysis performed by SEM proved that the composites prepared by maleated PLA and pre-treated PS showed better adhesion between the fiber and the matrix.
Applied Biochemistry and Biotechnology, Jul 27, 2013
In this study, covalent immobilization of the horseradish peroxidase (HRP) onto various polysulfo... more In this study, covalent immobilization of the horseradish peroxidase (HRP) onto various polysulfone supports was investigated. For this purpose, different polysulfones were methacrylated with methacryloyl chloride, and then, nonwoven fabric samples were coated by using solutions of these methacrylated polysulfones. Finally, support materials were immersed into aquatic solution of HRP enzyme for covalent immobilization. Structural analysis of enzyme immobilization onto various polysulfones was confirmed with Fourier transform infrared spectroscopy, atomic force microscopy, and proton nuclear magnetic resonance spectroscopy. Decolorization of textile diazo (Acid Black 1) and anthraquinone (Reactive Blue 19) dyes was investigated by UV-visible spectrophotometer. Covalently immobilized enzyme has been used seven times in freshly prepared dye solutions through 63 days. Dye decolorization performance of the immobilized systems was observed that still remained high (70%) after reusing three times. Enzyme activities of immobilized systems were determined and compared to free enzyme activity at different conditions (pH, temperature, thermal stability, storage stability). Enzyme activities of immobilized systems and free enzyme were also investigated at the different temperatures and effects of temperature and thermal resistance for different incubation time at 50 °C. In addition, storage activity of free and immobilized enzymes was determined at 4 °C at different incubation days.
Journal of the Turkish Chemical Society, Section A: Chemistry, Jun 5, 2015
Cevre kirliligi ve su kirliligi canlilarin yasam alanlarini ve kalitesini olumsuz etkileyen konul... more Cevre kirliligi ve su kirliligi canlilarin yasam alanlarini ve kalitesini olumsuz etkileyen konulardan birisidir. Su kirliligini olusturan endustriyel atik sular icerisinde tekstil atik sulari icerdikleri cok cesitli kimyasallar ve boyalar nedeniyle dikkat cekmektedirler. Bazik boyalar tekstil endustrisinde ozellikle elyaflarin boyanmasinda kullanilmaktadir. Atik sularin cevre kirleticilerinden boyalardan temizlenmesinde polimerlerden de yararlanilmaktadir. Atik sulardan boyalarin giderilmesinde ana basliklar olarak fiziksel, kimyasal ve biyolojik yontemler atik suyun turune gore tercih edilmektedir. Bu yontemler icerisinde flokulasyon, koagulasyon, oksidasyon, ozonlama, membran ile ayirma, adsorpsiyon ve anaerobik aritma isletmelere gore farkli olmakla birlikte kullanilmaktadir [1-3]. Bu calismada, Basic Yellow 28 katyonik boyasi ticari olarak uretilen perflorkarbon esasli polimer ile farkli kosullarda giderildi. Basic Blue 28 boyasinin perflorkarbon esasli ticari polimer ile pH: 7.0 ve 45 oC’de 100 dakika sonunda % 100’e yakin renksizlestirilmistir (Sekil 1).
To achieve increased flow and reduce fouling, polymeric membranes can be functionalized with hydr... more To achieve increased flow and reduce fouling, polymeric membranes can be functionalized with hydrophilic groups such as sulfone, amines, and others. This research has aimed at the sulfonation of Polysulfone (PSU) with various agents and at varying substitution degrees to change its hydrophobic character. PSU was also blended with Poly(lactic acid) (PLA), which is a more hydrophilic polymer. The phase inversion method was used to make PSU, PLA, sulfonated PSU, and PSU/PLA blend-based membranes. Sulfonation degrees of sulfonated PSU membranes were assessed using FT-IR, mechanical characteristics of membranes were determined, and thermal properties of membranes were clarified using DSC and TGA techniques. Hydrophilic natures and membrane alterations were investigated, as well as contact angle and water uptake measures. Among three distinct sulfonation agents (trimethylsilyl chlorosulfonate (TMSCS), sulfuric acid, and chlorosulfonic acid) employed to produce a 20% sulfonation degree of ...
Synthetic dyes are very important for textile dyeing, paper printing, color photography and petro... more Synthetic dyes are very important for textile dyeing, paper printing, color photography and petroleum products. Traditional methods of dye removal include biodegradation, precipitation, adsorption, chemical degradation, photo degradation, and chemical coagulation. Dye decolorization with enzymatic reaction is an important issue for several research field (chemistry, environment) In this study, minimum decolorization time of Remazol Brilliant Blue R dye with Horseradish peroxidase enzyme was calculated using with mathematical equation depending on experimental data. Dye decolorization was determined by monitoring the absorbance decrease at the specific maximum wavelength for dye. All experiments were carried out with different initial dye concentrations of Remazol Brilliant Blue R at 25 degrees C constant temperature for 30 minutes. The development of the least squares estimators for a nonlinear model brings about complications not encountered in the case of the linear model. Decolorization times for completely removal of dye were calculated according to equation. It was shown that mathematical equation was conformed exponential curve for dye degradation.
In this study, pistachio shell-polypropylene copolymer (PPc) biocomposites were prepared by using... more In this study, pistachio shell-polypropylene copolymer (PPc) biocomposites were prepared by using the melt compounding technique. Treated pistachio shell (TPS) (30%wt) was employed to increase mechanical and thermal properties of biocomposites. Maleation and filler pre-treatment processes improved the mechanical strength of the PPc-TPS composites. The UV additives, Chimassorb 944 (CHI) stabilizer, and the UV absorber Irganox 1010 (IRGV) were used to enhance oxidative and color stability of biocomposites after they were subjected to accelerated UV irradiation for 600 h. The mechanical properties of the UV additive containing composites were less affected after UV exposure. The oxidative induction time and discoloration analysis revealed that CHI and IRGV additives can be utilized in applications that require higher color stability while the former showed better performance for oxidative stability.
Journal of Thermoplastic Composite Materials, Apr 22, 2021
In this study, poly(lactic acid) (PLA)/pistachio shell (PS) biocomposites were fabricated by melt... more In this study, poly(lactic acid) (PLA)/pistachio shell (PS) biocomposites were fabricated by melt functionalization through a one-step compatibilization process in varying PS filler rates (0–30%). To enhance interfacial adhesion, alkaline-silane pre-treatment was applied to PS, and PLA was grafted with maleic anhydride (MA). The effect of filler ratio, pre-treatment, and maleation steps on the mechanical, thermal, and morphological properties of biocomposites was investigated. The tensile and flexural analysis showed that composites with optimum mechanical properties were obtained by blending 20% of pre-treated PS with maleated PLA. Mechanic and thermal analyses were performed to examine fiber/matrix surface compatibility. The mechanical analysis of biocomposites, such as tensile/flexural strength and modulus were determined with a universal testing machine. Thermal analysis and thermal degradation of biocomposites were determined by using Differential Scanning Calorimetry and TG/DTG. Morphological analysis performed by SEM proved that the composites prepared by maleated PLA and pre-treated PS showed better adhesion between the fiber and the matrix.
Applied Biochemistry and Biotechnology, Jul 27, 2013
In this study, covalent immobilization of the horseradish peroxidase (HRP) onto various polysulfo... more In this study, covalent immobilization of the horseradish peroxidase (HRP) onto various polysulfone supports was investigated. For this purpose, different polysulfones were methacrylated with methacryloyl chloride, and then, nonwoven fabric samples were coated by using solutions of these methacrylated polysulfones. Finally, support materials were immersed into aquatic solution of HRP enzyme for covalent immobilization. Structural analysis of enzyme immobilization onto various polysulfones was confirmed with Fourier transform infrared spectroscopy, atomic force microscopy, and proton nuclear magnetic resonance spectroscopy. Decolorization of textile diazo (Acid Black 1) and anthraquinone (Reactive Blue 19) dyes was investigated by UV-visible spectrophotometer. Covalently immobilized enzyme has been used seven times in freshly prepared dye solutions through 63 days. Dye decolorization performance of the immobilized systems was observed that still remained high (70%) after reusing three times. Enzyme activities of immobilized systems were determined and compared to free enzyme activity at different conditions (pH, temperature, thermal stability, storage stability). Enzyme activities of immobilized systems and free enzyme were also investigated at the different temperatures and effects of temperature and thermal resistance for different incubation time at 50 °C. In addition, storage activity of free and immobilized enzymes was determined at 4 °C at different incubation days.
Journal of the Turkish Chemical Society, Section A: Chemistry, Jun 5, 2015
Cevre kirliligi ve su kirliligi canlilarin yasam alanlarini ve kalitesini olumsuz etkileyen konul... more Cevre kirliligi ve su kirliligi canlilarin yasam alanlarini ve kalitesini olumsuz etkileyen konulardan birisidir. Su kirliligini olusturan endustriyel atik sular icerisinde tekstil atik sulari icerdikleri cok cesitli kimyasallar ve boyalar nedeniyle dikkat cekmektedirler. Bazik boyalar tekstil endustrisinde ozellikle elyaflarin boyanmasinda kullanilmaktadir. Atik sularin cevre kirleticilerinden boyalardan temizlenmesinde polimerlerden de yararlanilmaktadir. Atik sulardan boyalarin giderilmesinde ana basliklar olarak fiziksel, kimyasal ve biyolojik yontemler atik suyun turune gore tercih edilmektedir. Bu yontemler icerisinde flokulasyon, koagulasyon, oksidasyon, ozonlama, membran ile ayirma, adsorpsiyon ve anaerobik aritma isletmelere gore farkli olmakla birlikte kullanilmaktadir [1-3]. Bu calismada, Basic Yellow 28 katyonik boyasi ticari olarak uretilen perflorkarbon esasli polimer ile farkli kosullarda giderildi. Basic Blue 28 boyasinin perflorkarbon esasli ticari polimer ile pH: 7.0 ve 45 oC’de 100 dakika sonunda % 100’e yakin renksizlestirilmistir (Sekil 1).
To achieve increased flow and reduce fouling, polymeric membranes can be functionalized with hydr... more To achieve increased flow and reduce fouling, polymeric membranes can be functionalized with hydrophilic groups such as sulfone, amines, and others. This research has aimed at the sulfonation of Polysulfone (PSU) with various agents and at varying substitution degrees to change its hydrophobic character. PSU was also blended with Poly(lactic acid) (PLA), which is a more hydrophilic polymer. The phase inversion method was used to make PSU, PLA, sulfonated PSU, and PSU/PLA blend-based membranes. Sulfonation degrees of sulfonated PSU membranes were assessed using FT-IR, mechanical characteristics of membranes were determined, and thermal properties of membranes were clarified using DSC and TGA techniques. Hydrophilic natures and membrane alterations were investigated, as well as contact angle and water uptake measures. Among three distinct sulfonation agents (trimethylsilyl chlorosulfonate (TMSCS), sulfuric acid, and chlorosulfonic acid) employed to produce a 20% sulfonation degree of ...
Uploads
Papers by mithat çelebi