Yazarlar
- Torğut, Gülben(3)
- Ayhan, Nagihan Karaaslan(2)
- Torgut, Gulben(2)
- Acikses, Aslisah(1)
- Aksoy, Yunus(1)
- Barim, Esra(1)
- Barım, Esra(1)
- Canpolat, Erdal(1)
- Dehghanpour, Heydar(1)
- Demirelli, Kadir(1)
- Doğan, Fatih(1)
- Gürler, Nedim(1)
- Hanay, Özge(1)
- Hasar, Halil(1)
- Maraşli, Muhammed(1)
- Subaşi, Serkan(1)
- Torgut, Gülben(1)
- Yegin, Mustafa(1)
- Çelik, Aytekin(1)
- İncesu, Rabia(1)
- Şahal, Hakan(1)
Yayınlar
- MakaleAçık Erişim2025Scopus SJRQ2Effect of Nano Titanium Dioxide on the Electrical and Thermal Properties of Poly(2,2,2-Trifluoroethyl Methacrylate) for Dielectric Materials
Barım, Esra; Torgut, Gülben
The increasing application areas of energy storage devices in recent years make it necessary to produce materials with sufficient efficiency. In this study, composites of poly(2,2,2-trifluoroethyl methacrylate) P(TFEM) homopolymer with nano titanium dioxide (TiO2 NPs) were prepared for applications of these devices requiring thermoelectric properties, and their thermal, dielectric, and electrical properties were investigated. Thermogravimetric analysis showed that TiO2 NPs in all composites limited the thermal diffusion of TiO2 NPs in the polymer matrix and increased the thermal stability of P(TFEM) from 341°C to 361.5°C. As dielectric properties, the dielectric constant (ε′), dielectric loss (ε″), AC conductivity (σac), and real (Z′) and imaginary (Z″) components of impedance of the composites containing TiO2 NPs were evaluated as functions of frequency and different weight percentages of TiO2 NPs. Increases in ε′ and ε″ at up to 15 wt% TiO2 NPs suggested increased dipole polarization. At 100 Hz, the ε″ value of P(TFEM) increased from 3.2 × 10−2 to 1.1 × 10−2, σac increased from 4.98 × 10−10 to 1.00 × 10−8, Z′ increased from 3.67 × 1010 to 8.66 × 1010, and Z″ increased from 2.09 × 108 to 4.42 × 108. Furthermore, ε′, ε″, and impedance decreased with increasing frequency for both P(TFEM) and TiO2 NPs composites, while σac increased with increasing frequency.
AtıfScopus3OpenAlex5
İncele - MakaleYalnız künye2025Scopus SJRQ2Response surface method (RSM) for optimization of electrical properties of polymer/CdS composites for dielectric capacitors
Torğut, Gülben; İncesu, Rabia
This paper aims to present the statistical evaluation of dielectric constant (έ) and conductivity (σ) performance of composites preparing Maleic Anhydride (MA) and Styrene (St) polymer with various amounts of Cadmium Sülfide (CdS) by analysis of variance (ANOVA) model. For this purpose, frequency, applied voltage and CdS amount at different weight percentages were selected as input factors while dielectric constant and conductivity of the composites were selected as the response. Analysis of input factors was performed, RSM method was designed and used for estimation of response factor. From the analysis results, we found that high values of dielectric constant and conductivity were strongly related to frequency and CdS amount. However, we found that applied voltage in the selected ranges did not have a significant effect on both factors. The structural properties of the composites were investigated by Fourier Transform Infrared Spectroscopy (FTIR). The surface morphology was investigated by Scanning Electron Microscopy (SEM). The presence of CdS in polymers has been proven by X-Ray Diffraction (XRD). The thermal properties of polymers were examined by thermogravimetric analysis (TGA).
AtıfScopus1WoS2OpenAlex2
İncele - MakaleAçık Erişim2024Scopus SJRQ2Photoresponse, thermal and electrical behaviors of MXene-based polysulfone nanocomposite
Demirelli, Kadir; Barim, Esra; Çelik, Aytekin; Yegin, Mustafa; Aksoy, Yunus; Hanay, Özge; Hasar, Halil
The Ti3C2Tx MXene nanosheet was prepared by 40% (v/v) hydrofluoric acid etching at 20 °C for 48 h and delamination of bulk MAX Ti3AlC2 precursor material. A 2D nanomaterial MXene Ti3C2Tx as a nanofiller was introduced to polysulfone (PSulfone) matrix. MXene and PSulfone/MXene nanocomposite systems were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscope, Fourier-transform infrared and thermogravimetric analysis instruments. Dielectric and electrical characterization of PSulfone/MXene nanocomposite was carried out. The electrical resistance of Ti3C2Tx MXene from measurement current (I)–voltage (V) was measured as 116 Ω. Pure PSulfone matrix exhibits typical insulator behavior, and MXene exhibits a good conductor behavior. But, when MXene was added to the pure PSulfone matrix, the resistance of the MXene/PSulfone nanocomposite increased moderately compared to that of pure MXene. In spite of the excess of surface functional groups, MXene showed surprisingly good electron transport across the surface, while in the case of PSulfone/MXene nanocomposite, the insulating behavior of PSulfone significantly reduced the electron transport of MXene. The semiconductor behavior of PSulfone/Ti3C2Tx MXene nanocomposite indicates that MXene provides efficient charge carrier transfer in the nanocomposite system. By comparing the TGA results between the PSulfone and different weight ratios of PSulfone/Ti3C2Tx MXene nanocomposites, it was determined that MXene nanosheets had a significant effect in slightly accelerating the thermal degradation of PSulfone. Optical conductivity was investigated by preparing a film of PSulfone/MXene nanocomposite on an interdigital contact. It was observed that the optical current values changed depending on the increasing illumination intensity. Considering current–voltage measurements, the photocurrent generation potential of PSulfone/MXene nanocomposite shows that it can be used in photodevice production.
AtıfScopus24OpenAlex27İncele - MakaleAçık Erişim2024Scopus SJRQ3Structural, Dielectric, and Electrical Properties of Chitosan Composites Doped with Silver for Electrochemical Applications
Ayhan, Nagihan Karaaslan; Torgut, Gulben
In this study, chitosan-silver (Chs-Ag) composites containing Ag in different concentrations (0.01–0.08 M) were prepared. The characterization and structure studies of the composites containing 0.01, 0.02, 0.04, and 0.08 M Ag were carried out, and then the dielectric properties of these composites were examined. The composites were characterized by Fourier transform infrared spectrophotometer (FTIR), scanning electron microscopy and energy dispersive spectroscopy (SEM-EDS), and thermogravimetric analysis (TGA). The dielectric and electrical properties of these composites were investigated depending on the frequency at room temperature, and these properties were determined using an impedance analyzer. Spectroscopy revealed that the dielectric constant (ε′), dielectric loss (ε′′), and real (Z′) and imaginary (Z″) components of impedance are found to decrease with increased frequency for both Chs and Chs-Ag (0.01M–0.08 M) composites. On the contrary, the AC conductivity (σac) of samples increased with increasing frequency. ε′ and ε′′ values of Chs were lower than when the Ag was added. The AC conductivity was improved by the addition of silver particles. The results show that the dielectric and electrical properties of Chs-Ag samples were improved by using Ag as filler.
AtıfScopus3WoS3OpenAlex4İncele - MakaleYalnız künye2023Scopus SJRQ1Improving dielectric properties, electrical conductivity, and thermal properties of biodegradable polymer composites prepared with lanthanum
Torgut, Gulben; Ayhan, Nagihan Karaaslan; Acikses, Aslisah
The precipitation method was adapted to synthesize the poly(ε-caprolactone-copolymer- ethylene oxide) (ε-CL-co-EO) composite with the salt of lanthanum (La), a rare earth element. This salt was incorporated into the polymer of different weight percentages to study how it affects the thermal and dielectric properties of the polymer. The resulting products were characterized by Fourier Transform Infrared Spectroscopy, X-ray diffractometry (XRD), Scanning electron microscopy (SEM) and thermogravimetric analysis. XRD and SEM data show that the polymer mixes homogeneously with the metal salt. Thermal degradation data show that the thermal stability of composites synthesized with La is lower than that of pure polymer. The dielectric properties and A.C conductivity measurements of the composites were investigated by using impedance analyzer in the frequency range (100 Hz to 20 kHz) at room temperature. The electrical property results of (ε-CL-co-EO)/La composites displayed that dielectric constant (έ), dielectric loss (ε"), tan delta (tan δ) and A.C electrical conductivity (σac) increase with increasing La content. The largest conductivity of (ε-CL-co-EO)/La composite filled with 20 wt% La was 8.80 × 10−8 S/cm, which was 162% times pure (ε-CL-co-EO). In addition, impedance (IZI) of composites was evaluated from the dielectric data. This procedure is eco-friendly and easy to handle, which provides a promising route to polymer composites in the application of the conductivity field.
AtıfScopus6WoS6OpenAlex7İncele - MakaleAçık Erişim2022Characterization of carbon fiber reinforced conductive mortars filled with recycled ferrochrome slag aggregates
Doğan, Fatih; Dehghanpour, Heydar; Subaşi, Serkan; Maraşli, Muhammed
Recently, it has been known that carbon fiber, a conductive fiber, is used in different mixture designs and the development of electrically conductive cementitious materials. Howev-er, the evaluation of ferrochrome slag as a recycled aggregate in the mixture of these special concretes has still not been investigated. In this study, electrically conductive mortars were produced using 100% recycled ferrochrome slag aggregate with a particle size of less than 1 mm as filling material and using carbon fiber in 4 different ratios, 0%, 0.5%, 0.75%, and 1%. To investigate the electrical conductivity properties, the resistivity values of the samples were measured at five different times within 2–180 days. In addition, 28-day compressive strength, flexural strength, dynamic resonance, ultrasonic pulse velocity, Leeb hardness, scanning elec-tron microscope, and X-Ray Diffraction tests were performed on all samples. The results were compared with the literature, proving that ferrochrome slag could be used as a reasonable aggregate in conductive mortars. The age effect was minimal in CF-added mixtures. With the addition of 1% CF, the resistivity values decreased approximately 40 times compared to the ref-erence. Moreover, SEM analyses of the CF-0.75 sample showed that the CFs adhered to form a conductive network between the components in the ferrochrome-filled compact structure.
AtıfScopus10TR Dizin5
İncele - MakaleYalnız künye2022Scopus SJRQ2Physicomechanical, thermal and dielectric properties of eco-friendly starch-microcrystalline cellulose-clay nanocomposite films for food packaging and electrical applications
Gürler, Nedim; Torğut, Gülben
Potato starch (PS) films reinforced with microcrystalline cellulose (MCC) were prepared with casting solution, and the effect of montmorillonite (MMT) clay in different proportions (1, 3, 5 and 10 wt%) using nanofiller was established. The films were investigated by Fourier transform ınfrared (FTIR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), tensile strength, opacity, colour, water vapour permeability and solubility. Tensile strength for nanocomposite films depending on the clay content was increased significantly from 0.64 to 1.89 MPa. The water vapour permeability of nanocomposite films was improved compared to the PSMCC blend without MMT. Also, dielectric properties and electrical conductivity of films were studied. The dielectric permittivity (έ), the dielectric loss (ε˝) and the electrical conductivity (σ) increased with increasing MMT content at frequencies between 100 Hz to 10 kHz. This nanocomposite with improved functional properties could be used in potential food packaging materials and electrical applications.
AtıfScopus21WoS19İncele - 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