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Öğe Beneficial use of mussel shell as a bioadditive for TPU green composites by the valorization of an aqueous waste(Springernature, 2024) Sismanoglu, Sedef; Kanbur, Yasin; Popescu, Carmen-Mihaela; Kindzera, Diana; Tayfun, UmitScientific studies have focused on environmentally friendly solutions as effective as the reuse of crop products owing to plastic-waste problems in recent years. This issue is the main driving force for upcoming academic research attempts in waste valorization-related studies. Herein, we integrated an aqua-waste, mussel shell (MS), as a bioadditive form into green thermoplastic polyurethane (TPU) green composites. Tuning of the MS surface was performed to achieve strong adhesion between composite phases. The surface functionalities of MS powders were evaluated via infrared spectroscopy and scanning electron microscopy (SEM) images. Composite samples were prepared by melt-compounding followed by injection molding techniques. It was confirmed by morphological analysis that relatively better adhesion between the phases was achieved for composites involving surface-modified MS compared to unmodified MS. Tensile strength and Young's modulus of surface-modified MS-filled composites were found to be higher than those of unmodified MS, whereas the elongation at break shifted to lower values with MS inclusions. The shore hardness of TPU was remarkably improved after being incorporated with silane-treated MS (AS-MS). Stearic acid-treated MS (ST-MS) additions resulted in an enhancement in the thermal stability of the composites. Thermo-mechanical analysis showed that the storage moduli of composites were higher than those of unfilled TPU. ST-MS additions led to an increase in the characteristic glass transition temperature of TPU. Melt flow index (MFI) of neat TPU was highly improved after MS loading regardless of modification type. According to the wear test, surface modification of MS displayed a positive effect on the wear resistance of TPU. As the water absorption data of the composites were evaluated, the TPU/AS-MS composite yielded the lowest water absorption. The silane layer on MS inclusion promoted water repellency of composites due to the hydrophobicity of silane. The results of the biodegradation investigation demonstrated that adding unmodified and/or modified MS to the TPU matrix increased the biodegradation rate. The test results at the end of a 7-week period of biodegradation with a soft-rot fungus implied that the composite materials were more biodegradable than pure TPU. Silane modification of MS exhibited better performance in terms of the characterized properties of TPU-based composites.Öğe Binary biomaterials (inorganic material/natural resin): Synthesis, characterization and performance for adsorption of dyes(Scientific Publ-India, 2019) Duran, Hakan; Sismanoglu, Sedef; Sismanoglu, TubaThe sol-get method has been reported a useful techniques for synthesizing inorganic material HSS. In this study, the sol-gel process was used in two stages. In the first step, the hydrolysis of phenyltrimethoxysilane (PTMS) was carried out under acidic conditions. In the second step, the silane condensation proceeded under basic conditions and as a result the HSS were obtained. The obtaining HSS was treated with epichlorohydrin to carry out an epoxidation process (HSEPC). Then, HSEPC was functionalized by treatment with natural resin (gum arabic) and obtained HSEPCGUM. Gum arabic has GA-GP-GA-glycoprotein, hydroxyproline glucuronic acid and polysaccharides groups. Anionic and cationic dyes were adsorbed onto HSEPCGUM and values of absorbance was measurement by UV-Visible spectrophotometers. Adsorption isotherm experiments of adsorbed dyes on HSEPCGUM were performed at 35 degrees C with Freundlich, Langmuir and Dubinin-Radushkevich (DR) methods. Adsorption maximum capacity of HSEPCGUM (X-max) was obtained 100 mg/g for BB3. Before and after dye adsorption the structure characterization of adsorbent was done by SEM and FTIR analysis.Öğe Comparison of effective removal of cationic malachite green dye from waste water with three different adsorbents: date palm, date palm biochar and phosphated biochar(Taylor & Francis Ltd, 2023) Sismanoglu, Sedef; Shakir, Safa Abdulmahdi; Kol, Hamiyet Sahin; Hani, Yahia Bani; Aghlara, Elham; Akalin, Mehmet KuddusiAdsorbents obtained from agricultural wastes attract attention because they are both effective, inexpensive and environmentally friendly. In this study, it was studied on the removal of malachite green (MG) from aqueous solutions by using date palm fronds (DPF), which are agricultural wastes, date biochar (DPC) obtained by pyrolysis and phosphated date biochar with the help of microwave pyrolysis (DPMW) as three different adsorbents. Characterisation of adsorbents was made by FTIR/ATR, SEM, TGA. According to the results of TGA, it was observed that thermal strengths decreased after adsorption. Adsorption studies were carried out at 25 degrees C in isothermal environment at the pH of the natural dye solution. Adsorption data of date palm, biochar and phosphated biochar were evaluated according to Freundlich, Langmuir, Temkin, Dubinin-Radushkevich (D-R), Flory-Huggings (F-H) and Fowler-Frumkin-Guggenheim (FFG) isotherm models. Maximum adsorption capacities (qmax) according to Langmuir isotherm were found as 334 mg/g, 125 mg/g and 32 mg/g for date palm, biochar and phosphated biochar, respectively. The heat of adsorption calculated using the Temkin and Fowler - Frumkin-Guggenheim (FFG) isotherms is exothermic for date palm and biochar, while it is endothermic for phosphated biochar. It was observed that the adsorption mechanism energy E calculated in D-R and the B values calculated in Temkin were compatible and the adsorption was physical. According to these results, the most effective adsorbent for the removal of malachite green from aqueous solutions is biochar, which is the pyrolysis product, while phosphated biochar is not very suitable.Öğe Effect of alkali and silane surface treatments on the mechanical and physical behaviors of date palm seed-filled thermoplastic polyurethane eco-composites(Sage Publications Ltd, 2022) Sismanoglu, Sedef; Tayfun, Umit; Kanbur, YasinIn this study, eco-grade thermoplastic polyurethane (TPU), which includes 46% renewable content, was reinforced with date palm seed (DPS). Alkali and silane surface treatments were applied to DPS to increase the compatibility between DPS and TPU matrix. The oil of DPS was removed before treatments and surface functionalities of modified and pristine DPS samples were examined by Fourier transform infrared spectroscopy. Composites were fabricated using melt blending method and injection molding processes. Test samples of composites were characterized using tensile test, hardness test, water absorption study, dynamic mechanical analysis (DMA), melt flow index (MFI) test, thermogravimetric analysis, and scanning electron microscopy (SEM). According to test results, silane treatment led to remarkable improvement for mechanical performance of composites attributed to improvement of compatibility and interface adhesion between DPS and TPU. DMA results implied that higher storage modulus and glass transition temperature were achieved for treated DPS-containing composites compared to pristine DPS filled ones. Thermal stability of flexible segment of TPU increased with the addition of DPS regardless of surface treatment. Additionally, DPS loadings caused significant increase in MFI value of unfilled TPU. Silane-treated DPS-containing composite yielded the lowest water uptake value among samples due to the hydrophobicity of silane layer. Enrichment of interface adhesion of DPS to TPU matrix was confirmed by SEM micrographs of composites. Silane-treated DPS-containing composite displayed higher results among produced composites since the increase in interfacial interactions with TPU was achieved by silane treatment for DPS surface.Öğe Effect of silane-modification of diatomite on its composites with thermoplastic polyurethane(Elsevier Science Sa, 2020) Kucuk, Fatma; Sismanoglu, Sedef; Kanbur, Yasin; Tayfun, UmitDiatomite (KG) surface was modified by four different silane coupling agents having amino, epoxy, triamine and octyl functional groups for enhancement of interfacial adhesion between thermoplastic polyurethane (TPU) and diatomite. EDX and FTIR spectroscopy techniques were used to evaluate the surface functionalities of modified and neat KG samples. TPU/KG composites were fabricated using melt-compounding process. Mechanical, thermo-mechanical, thermal, melt-flow and morphological properties of composites were reported. Mechanical tests revealed that tensile strength and hardness of TPU extended to higher levels while its flexibility was retained after KG additions. Epoxy-silane modified KG exhibited the highest results in the case of mechanical properties. Glass transition temperature of TPU shifted to higher values by the additions of modified KG. Thermal stability of TPU raised by KG inclusions regardless of modification type. Modified KG containing composites yield lower MFI values with respect to neat KG. Enhancement of interfacial adhesion between TPU and KG phases was confirmed by SEM micrographs of composites in which silane-modified KG surfaces were covered by TPU matrix. Silane modifiers involving amine and epoxy groups led to significant improvement in properties of KG-filled TPU composites. Epoxy-based silane displayed the highest performances thanks to strong interfacial interactions between epoxy functional group and isocyanate segment of TPU.Öğe Effective Removal of Cationic Dyes from Aqueous Solutions by Using Black Cumin (Nigella sativa) Seed Pulp and Biochar(North Carolina State Univ Dept Wood & Paper Sci, 2023) Sismanoglu, Sedef; Akalin, Mehmet Kuddusi; Akalin, Gulen Oytun; Topak, FatimaBlack cumin seed pulp (C), as well as biochar (CC) produced via pyrolysis of black cumin seed pulp were used to remove methylene violet 2B (MV) and basic yellow 28 (BY28) from aqueous solution. Adsorption isotherms and kinetics were applied at 10, 25, and 35 degrees C. The adsorption of methylene violet 2B and basic yellow 28 on the black cumin seed pulp and biochar surface was exothermic; the heat of adsorption values were lower CC were 212.8, 625, 164, and 909 mg g-1 at 25 degrees C, respectively. The adsorption of black cumin seed pulp and biochar data were examined with Flory-Huggins (F-H) isotherm models. The kinetics of the adsorption were fitted to the pseudo first-order and pseudo second order equations. The pseudo second order equation gave a better fit than the pseudo first-order equation.Öğe Effective use of olive pulp as biomass additive for eco-grade TPU-based composites using functional surface modifiers(Springer Heidelberg, 2023) Sismanoglu, Sedef; Tayfun, Umit; Popescu, Carmen-Mihaela; Kanbur, YasinOlive pulp, which is formed 80% in the olive oil extraction process, attracts the attention of researchers with the zero waste project in Turkey. Our study aims to prove that olive pulp is not only a waste and can be used as a resource when used correctly as a filler in composite materials to provide not only durable but also shorter biodegradation times for polymer-based composite materials. The surface modification process with 3 different silanes containing epoxy, vinyl, and amino groups was applied to the surface of olive pulp (OP) to solve the problem of surface incompatibility with eco-grade thermoplastic polyurethane (TPU) matrix. The oil portion of OP was removed before silane treatments. Surface functions and thermal properties of both modified and unmodified OP powder samples were evaluated by FTIR, SEM, and TGA techniques, respectively. TPU/OP composites were fabricated using melt-compounding process, and mechanical, thermomechanical, thermal, melt flow, wear, biodegradation, and morphological properties of composites were reported. According to test results, TPU/VS-OP (vinyl silanized olive pulp) composite showed the highest hardness and wear resistance values among all composites. Additionally, silane modifications led to remarkable improvements for mechanical, thermal, thermomechanical, and melt flow properties of composites thanks to the enhancement of compatibility and interface adhesion between OP and TPU phases. It seems that VS-OP containing composite sample displayed the highest results in most of the examined results. It has been shown that the addition of unmodified and modified OP filler to TPU caused to level of the biodegradation of pure TPU, and as a result, environmentally friendly composites have been produced.Öğe The facile production of Fe2O3-biochar electrocatalyst for methanol oxidation reaction(Pergamon-Elsevier Science Ltd, 2024) Mert, Mehmet Erman; Hani, Yahia Bani; Akalin, Mehmet Kuddusi; Sismanoglu, Sedef; Aksaray, Goncaguel; Mert, Basak Dogru; Kol, Hamiyet SahinIn this study, the facile-green method was applied for the production of electroactive composite anode material. For this purpose, biochar was produced via pyrolysis of Pinus nigra (PN) sawdust in a stainless-steel reactor at 300, 400 and 500 degrees C with 10 degrees C/min heating rate. The Fe2O3 particles were fabricated via the green synthesis method. The Fe2O3-biochar electrocatalyst was operated on Ni foam electrode and the potential application as an anode for methanol fuel cell was investigated in an alkaline medium. Field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), X-ray diffraction analysis (XRD), Brunauer-Emmett-Teller analysis (BET), and attenuated total reflectance Fourier transform infrared spectroscopy (FTIR/ATR) were used to characterize the morphology of the electrocatalyst samples. The electrochemical measurements of electrocatalyst samples were achieved via cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), linear sweep voltammetry (LSV) and chronoamperometry (CA). The enlarged surface area of biochar enabled the formation of more electroactive sites for methanol electrooxidation and favorable structures of biochar could support to increased electrocatalytic activity of catalysts for methanol oxidation and produce favorable matrices for Fe2O3 loading. The obtained results demonstrate that the electrooxidation of methanol occurred at 0.36 V. The favorable structures of biochar acted as a support, enhancing the electrocatalytic activity of Fe2O3 for methanol oxidation. The electrocatalyst demonstrated remarkable activity with almost 4 A g-1 current density at 0.55 V. The Rct values were 0.73 omega and 0.45 omega at 0.55 V, for Ni foam and Ni foam/Fe2O3-biochar, respectively. Long-term measurements demonstrated that the Ni foam/Fe2O3-biochar catalysts was remarkably stable, with a 4 % difference in current before and after the CA analysis.Öğe Investigation by UV spectrophotometry of removal of para-nitrophenol on raney alloy(Elsevier Science Bv, 2018) Sismanoglu, SedefIn present work, the sonochemical degradation of para nitrophenol (PNP) on raney alloy is described. Solutions of PNP at initial concentrations of 40, 50 and 75 ppm were prepared. 50%Al-50%Ni raney alloy (100 mg) was suspended in deionized water and sonicated for 15 min. Then, PNP (40, 50, 75 ppm) was added to the pre-activated alloy. The reaction mixture was sonicated for 15, 30 and 45 min at 30 degrees C. After sonication at different times, the concentration of para nitrophenol in the solution was determined by UV-visible spectrophotometer. For 40 ppm and the percentage of removal of para nitrophenol by Ni-Al alloy was found to be 95% after 30 min. (C) 2018 Elsevier B.V. All rights reserved.Öğe Investigation of the effect of surface modification types on the tribological performance of cow bone powder reinforced polymer materials(Wiley, 2023) Kilincarslan, Sena Kabave; Cetin, M. Huseyin; Kanbur, Yasin; Sismanoglu, Sedef; Polat, RefikThis study investigated the production, characterization, mechanical and tribo-logical performance of surface-modified cow bone powder-reinforced composites. The primary goal was to increase the tribological and mechanical performance of sustainable and cleanly produced composite materials. It was determined that the surface-modified bone powder reinforcement increased the mechanical, thermal, and wear resistance of the polymer. The best surface modification method was determined as silanization. It reduced the friction coefficient and weight loss by 16.60% and 40.0%, respectively, according to the main factor analysis. In addition, it increased the glass transition temperature by 45.54%, crystallization by 2.93%, hardness by 2.70%, and tensile strength by 9.26% compared to the unmodified bone powder reinforcement.Öğe Optimization of mechanical, thermo-mechanical, melt-flow and thermal performance of TPU green composites by diatomaceous earth content(Elsevier, 2021) Kucuk, Fatma; Sismanoglu, Sedef; Kanbur, Yasin; Tayfun, UmitIn the present paper the effect of the diatomite, also known as diatomaceous earth and kiesel guhr (KG), content on mechanical, thermo-mechanical, melt-flow and thermal performance of thermoplastic polyurethane-based composites was investigated. Composites were fabricated by melt blending method with 10, 20, 30 and 40% filling ratios of KG. and injection molded test samples were characterized using tensile, hardness, dynamic mechanical analysis (DMA), melt flow index (MFI), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM) analysis. According to test results, KG inclusions effect mechanical, thermal and morphological properties of composites positively up to 30% KG content. Further addition of KG caused remarkable reductions in related properties. Tensile strength of unfilled TPU exhibited increasing trend and elongation showed no obvious difference after KG loadings. TPU/KG composites yield relatively higher MFI values with respect to unfilled TPU. Glass transition temperature of TPU shifted to 6 points higher value by the help of KG incorporation. TGA findings revealed that KG additions caused improvement for thermal stability of TPU. Homogeneous dispersion of KG particles for their lower content, whereas agglomorate formations for higher loading level of KG were confirmed by SEM micrographs. TPU composite containing 10% KG showed the highest results among samples.Öğe Removal of Basic Blue 3 from the Aqueous Solution with Ternary Polymer Nanocomposite: Swelling, Kinetics, Isotherms and Error Function(Chem Soc Pakistan, 2017) Karakus, Selcan; Sismanoglu, Sedef; Akdut, Gizem; Urk, Oyku; Tan, Ezgi; Sismanoglu, Tuba; Kilislioglu, AybenTernary nanocomposite (Gum Arabic / PVA / Alginate) adsorbent was prepared by a cost effective method for dyes removal, because gum arabic and alginate are the cheapest materials. Gum arabic is a natural gum. Alginate that has long carboxylate functional group is a biosorbent. In this study, Gum arabic/PVA/Alginate was prepared that this absorbent has the high specific surface area. BET was measured as 12.93 m(2)/g. Swelling of adsorbent was determined at different pH. For the maximum swelling ratio was obtained at pH 6.88 congruent to 7, adsorption experiments were studied by the batch method. Freundlich, BET and Langmuir isotherm methods were applied at different concentrations and constant temperature 25 degrees C. Finally, the adsorption capacity of the nanocomposite was calculated as 200 mgg(-1). The different adsorption kinetic models were studied at temperature from 25 degrees C to 45 degrees C and different concentrations. The thermodynamic parameters as Delta H degrees, Delta G degrees, and Delta S degrees were calculated.Öğe Reuse of black cumin biomass into beneficial additive for thermoplastic polyurethane-based green composites with silane modifiers(Springer Heidelberg, 2023) Sismanoglu, Sedef; Tayfun, Umit; Gradinariu, Petronela; Popescu, Carmen-Mihaela; Kanbur, YasinRich in protein, carbohydrates, and lignocellulosic, black cumin is a plant that is used in the treatment of many diseases and has antioxidant and anti-tumor properties. Apart from its use in medicine, black cumin is used as a filler in the production of new and eco-friendly eco-composites to reduce the environmental pollution caused by petroleum-based classical polymer composite materials. In this study, bio-based thermoplastic polyurethane (TPU) polymer was used as a matrix and black cumin unmodified and modified with 3 different functionalized group silanes, was added as a filler and mixed in a twin-screw extruder, and biocomposite materials in the form of dog-bones were produced by injection molding. Black cumin powders were analyzed by Fourier-transform infrared-attenuated total reflection (FTIR/ATR), field effect scanning electron microscopy (FESEM), and thermogravimetric analysis (TGA), while the mechanical, tribological, morphological, thermal, thermo-mechanical, melt flow index, and biological properties of the produced biocomposites were characterized. According to the results obtained, it was seen that surface treatment of the black cumin with silane both improved the biodegradability and other properties of eco-composites. Among thermoplastic polyurethane-based eco-composites, surface modification of black cumin with 3-aminopropyltriethoxysilane had the lowest water absorption capacity of 8% and also the highest abrasion resistance and an improvement of 88.5%. It was observed that the eco-composite containing octyldecyl-modified black cumin had the lowest MFI value of 26, the best biodegradability among the surface-modified eco-composites, the tensile strength of 14.5 MPa, and the highest value compared to other eco-composites. Epoxy-silane modifier yields optimum results in terms of thermal and thermo-mechanical analysis.
