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- MakaleAçık Erişim2025Scopus SJRQ2Advanced synthesis and comprehensive characterization of nanoparticle-reinforced epoxy-based biocomposites derived from modified palm oil
Şahal, Hakan; Aydoğmuş, Ercan; Canpolat, Erdal; Kaya, Mehmet
In this research, new biocomposites were synthesized by two-step modification of palm oil (MPO). The raw material (MPOSA) was epoxidized in the first step and obtained by reacting with 4,4-diaminodiphenyl sulfone in the second step. Silicon carbide (SiC), MPOSA, bisphenol A diglycidyl ether, and epoxy resin were used to obtain the biocomposites. After this process, necessary physical tests and chemical analyses were performed. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM) analyses were used to characterize the biocomposites. The research included measurements of bulk density, Shore D hardness, thermal conductivity, and thermal stability of the biocomposite. The results indicated that MPOSA reinforcement decreased the bulk density of the biocomposite in proportion to the doping level, and Shore D hardness tests revealed a decrease in hardness with the addition of MPOSA. The increase in MPOSA reinforcement also led to a reduction in the thermal conductivity coefficient. In experimental studies, the optimum reinforcement ratio was determined as 1 wt.% nano-SiC, 10 wt.% glass fiber, and 10 wt.% MPOSA. Excessive MPOSA reinforcement adversely affected the matrix structure and pore distribution of the nanocomposite due to aggregation due to increased intermolecular interaction. Thermal decomposition results showed that MPOSA reinforcement reduced the activation energy of the nanocomposite. This study successfully developed an economical, environmentally friendly, and easily processed biocomposite and contributed to the development of functional and sustainable alternatives.
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İncele - MakaleAçık Erişim2024Scopus SJRQ2New sulfa drug derivatives and their zinc(II) complexes: synthesis, spectroscopic properties and in vitro cytotoxic activities
Şahal, Hakan; Öz, Samet; Keskin, Tuba; Tekin, Suat; Canpolat, Erdal; Kaya, Mehmet
Synthesis of four sulfa drug derivatives (L1–L4) and Zn(II) complexes derived from sulfonamide group antibiotic substances was carried out using the hydrothermal technique (HT) and their structures of the obtained compounds were explained using elemental analysis (EA), FT-IR and NMR (1H- and 13C-). Cytotoxic activities of four novel sulfa drug based-Schiff base compounds and their Zn(II) complexes were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay using MCF-7 (human breast cancer), Caco-2 (human colorectal adenocarcinoma), A2780 (human ovarian cancer) and LNCaP (human prostate adenocarcinoma) cell lines. LogIC50 values of all obtained compounds were computed with the Graphpad Prism 6 program after 24 h of treatment for MCF-7, Caco-2, A2780 and LNCaP cells. Comet assay experiments were performed using LogIC50 concentrations of all compounds to determine DNA damage. Based on the data obtained, all compounds significantly decreased MCF-7, Caco-2, A2780 and LNCaP cell viability compared to the control groups (p < 0.05).
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İncele - MakaleAçık Erişim2023Scopus SJRQ2Synthesis, structural characterizations and in vitro cytotoxic activities of new sulfonamide-based Schiff base derivatives
Şahal, Hakan; Öz, Samet; Tekin, Suat; Canpolat, Erdal
Synthesis of five different new compounds (1-5) were carried out. Their structures were characterized by spectroscopic methods such as Fourier transform infrared, Proton nuclear magnetic resonance, Carbon-13 nuclear magnetic resonance and Elemental analysis. Cytotoxic activities of five new sulfonamide based-Schiff base compounds were determined by MTT assay using A-2780 (human ovarian cancer) and MCF-7 (breast cancer) cell lines. LogIC50 values of the sulfonamide derivates compounds were calculated by Graphpad Prism 12 programme after a 24-hour treatment for A2780 and MCF-7 cells. Comet assay experiments were performed to determine DNA damage using LogIC50 concentrations of all compounds in A2780 and MCF-7 cells. All compounds significantly reduced A2780 and MCF-7 cell viability compared to control groups (p < 0.05). In addition, all compounds caused DNA damage in A2780 and MCF-7 cells (p < 0.05). These results show that the synthesized compounds exhibit cytotoxic effects against cancer cells and that the cause of cell death is due to DNA damage. Communicated by Ramaswamy H. Sarma.
AtıfScopus5WoS5OpenAlex5İncele - MakaleAçık Erişim2023Scopus SJRQ3Synthesis, Characterization, Antimicrobial and Time Killing Activities of New SulfaDerived Schiff Bases Coordinated with Cu(II)
İdil, Önder; Şahal, Hakan; Canpolat, Erdal; Özkan, Mustafa
Synthesis of three Schiff bases of 5-bromo-3-nitro salicylaldehyde containing different sulfonamide group antibiotic compounds and their Cu(II) complexes was carried out. Structures of all compounds were characterized with spectroscopic methods, including Fourier transform infrared, proton nuclear magnetic resonance, and elemental analysis. The in vitro antimicrobial activity of ligands and complexes against Gramnegative and Gram-positive bacteria and the yeast Candida albicans was evaluated. It was determined that the ligand and complexes showed outstanding antimicrobial activity against almost all of the microorganisms tested. It has been observed that the newly synthesized complexes have more antimicrobial effects than the corresponding ligands. It has been determined that the newly synthesized complexes have more antimicrobial effects than the others (E. coli, L. monocytogenes, and C. albicans), especially on Staphylococcus aureus and Pseudomonas aeruginosa.
AtıfScopus4WoS3OpenAlex2İncele - MakaleAçık Erişim2023Scopus SJRQ4Cu(II) Complexes of New Sulfa Drug Schiff Base Ligands: Synthesis, Structural Characterization, Antimicrobial Activities, and Time-Killing Kinetics
Şahal, Hakan; İdil, Önder; Canpolat, Erdal; Özkan, Mustafa
Abstract: Synthesis of three different new sulfonamide compounds (L1–L3) and their Cu(II) complexes were carried out. Their structures were characterized by spectroscopic methods such as Fourier transform infrared, Proton nuclear magnetic resonance and elemental analysis. Cu(II) complexes were screened for Gram-positive, Gram-negative bacteria and against yeast using the microdilution method. In particular, CuL2 was found to have significant antimicrobial effects on Gram (–), Gram (+) and eukaryotic yeast. The results showed that CuL2 exhibited better antimicrobial activity than other complexes. Depending on the antimicrobial activity results, time killing experiments of CuL2, the most effective complex, were performed.
AtıfScopus3WoS2OpenAlex2İncele - MakaleAçık Erişim2022Scopus SJRQ2Optimization of Electrical Conductivity of SA-graphene Nanocomposites Using Response Surface Methodology
Şahal, Hakan; Torğut, Gülben; Canpolat, Erdal
Synthesis and characterization of 4-{(E)-[(5-bromo-2-hydroxyphenyl)methylidene]amino}-N-carbamimidoylbenzene-1-sulfonamide(SA) and its composites with graphene(SA-GF) were performed. Compound SA and SA-GF were characterized by FTIR and 1H NMR. The GF dispersion in the composites was analyzed by means of scanning electron microscopy(SEM) for morphology. Thermal properties of SA and nanocomposites were investigated using differential thermal analysis(DTA) and thermogravimetric analysis(TGA). The optimum electrical conductivity of the new sulfonamide-based Schiff base was determined to be 1.78×10−5 S/cm at a frequency of 9923 Hz, an applied voltage of −19 V, a mass fraction of 9.38% for graphene loading using a central composite design in the response surface methodology. The significance of the selected parameters(frequency, voltage and GF amount) in the model was determined by the analysis of variance(ANOVA). The results showed that frequency and graphene loading represent important model terms and have considerable effects on the conductivity of SA.
AtıfScopus3WoS3OpenAlex2İncele - MakaleAçık Erişim2019Scopus SJRQ1A study on the technological pedagogical contextual knowledge of science teacher candidates across different years of study
Karakaya Cirit, Didem; Canpolat, Erdal
This case study survey investigates the Technological Pedagogical Contextual Knowledge (TPCK) of Science Teacher Candidates (STC) across different years of study in the Topic of Renewable Energy (TRE). In line with the transformative model, the study treats TRE-TPCK as a new knowledge domain emerging from the interaction between content, technology, pedagogy and contextual knowledge. Participants were 36 Science Education students who were in their 1st, 2nd, 3rd and 4th years of study during the 2014–2015 academic year. Teacher candidates’ TPCK was identified through semi-structured interviews based on (1) Vignettes, (2) Anecdotes from a teacher named Zeynep and the (3) Content Presentation Technique (CPT). The data were analyzed by using the content analysis technique. The findings showed that the TRE-TPCK of teacher candidates across different years of study was at a similar and less-than-ideal level. STCs in different years of study mostly disregarded the macro and meso contexts when teaching the topic of renewable energy and were partially competent in the sub-meso, micro and sub-micro contexts. They particularly lacked technology-integrated evaluation knowledge when teaching TRE.
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