Sürdürülebilir Kalkınma Amaçları

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• MakaleAçık Erişim2026Scopus SJRQ1/r/munzur/996
  Evaluation of electrical properties of poly(NIPA-co-St) composites containing neodymium and yttrium

  Cetinkaya, Ebru; Karaaslan Ayhan, Nagihan; Torgut, Gulben

  In this study, firstly, to obtain neodymium (Nd) and yttrium (Y)-containing composite materials, poly(N-isopropylacrylamide-copolymer-styrene) (poly(NIPA-co-St)) copolymer was synthesized by free radical polymerization method using N-isopropylacrylamide (NIPA) and styrene (St) monomers. Secondly, new composite materials were obtained by adding neodymium and yttrium to this copolymer at different weight ratios (10% and 20%). Structural and morphological characterizations of poly(NIPA-co-St) copolymer, poly(NIPA-co-St)-10%Nd, poly(NIPA-co-St)-20%Nd, poly(NIPA-co-St)-10%Y and poly(NIPA-co-St)-20%Y composite materials were carried out. The electrical properties of the copolymer and composite materials were evaluated by considering the frequency dependence of the dielectric constant (έ), dielectric loss (ε″) and electrical conductivity (σac) properties. At 100 Hz, the έ, ε″, and σac values of the copolymer were 5.12, 0.05, and 2.29 × 10−10 S/cm, respectively. With the addition of 10% Nd, the έ, ε″, and σac values at 100 Hz were calculated as 6.57, 0.10, and 1.79 × 10−9 S/cm, respectively, while with the addition of 20% Nd, these values were calculated as 8.39, 0.15, and 4.78 × 10−8 S/cm at 100 Hz. With the addition of 10% Y, the έ, ε″, and σac values at 100 Hz were calculated as 6.56, 0.053, and 1.81 × 10−9 S/cm, respectively, while with the addition of 20% Y, these values were calculated as 8.57, 0.0058, and 3.70 × 10−8 S/cm at 100 Hz. It can be stated that as the amount of Nd and Y additives to the poly(NIPA-co-St) copolymer increases, the έ, ε″, and σac values increase, indicating an improvement in electrical properties with the addition of Nd and Y elements.

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• MakaleAçık Erişim2026Scopus SJRQ1/r/munzur/603
  Removal of Reactive Blue 4 Dye from Aqueous Solution with Magnetic Fe3O4@Nd/Alg Beads

  Karaaslan Ayhan, Nagihan; Seker, Seda

  In this study, magnetic iron oxide@neodymium/alginate (Fe3O4@Nd/Alg) beads were prepared by ionic crosslinking with neodymium (Nd) ions, then subjected to heat treatment, and for the first time, effective removal of Reactive Blue 4 (RB 4) dye from aqueous solution was achieved with these beads. For this purpose, ideal adsorption conditions that significantly affect the removal of this dye were determined. The ideal adsorption conditions were determined as pH:5, contact time (t):60 min, amount of magnetic Fe3O4@Nd/Alg bead (m):10 mg, initial RB 4 dye concentration (C0):25 mg/L, temperature (T): 25 °C. Adsorption isotherm, kinetic and thermodynamic studies were carried out under the ideal adsorption conditions. The adsorption data was found to completely follow Langmuir model for RB 4 dye and the maximum adsorption capacity of RB 4 was found to be 263.16 mg/g. The adsorption kinetic data was found to be compatible with pseudo-second order and adsorption processes were explained by intraparticle diffusion. In adsorption thermodynamics studies, it has been determined that the nature of the adsorption reaction is spontaneous, endothermic and with increasing randomness. Furthermore, reuse studies of magnetic Fe3O4@Nd/Alg beads were carried out and it was determined that these beads could be used successfully up to 10 adsorption/desorption cycles.

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• MakaleAçık Erişim2025Scopus SJRQ3/r/munzur/1701
  Cu, Fe, Mn AND Zn CONTENTS IN PROPOLIS SAMPLES FROM MALATYA, TÜRKİYE AND HEALTH RISK ASSESSMENT; [MALATYA, TÜRKİYE ARI PROPOLİSİNDEKİ CU, FE, MN VE ZN İÇERİKLERİ VE SAĞLIK RİSK DEĞERLENDİRMESİ]

  Karaaslan Ayhan, Nagihan

  In this study, copper (Cu), iron (Fe), manganese (Mn) and zinc (Zn) contents of propolis samples obtained from five different districts of Malatya, Türkiye were investigated. Element contents were determined using flame atomic absorption spectrometry (FAAS). The concentration ranges of propolis samples taken from five different districts of Malatya province varied between 1.24 ± 0.06 mg/kg and 6.28 ± 0.02 mg/kg for Cu, 206.28 ± 21.50 mg/kg and 663.08 ± 55.24 mg/kg for Fe, 15.40 ± 0.17 mg/kg and 27.11 ± 1.83 for Mn, 39.36 ± 1.82 mg/kg and 52.57 ± 2.13 mg/kg for Zn. The results obtained for each district and element were evaluated in detail considering the estimated daily intake (EDI), recommended dietary allowance (RDA), provisional maximum tolerable daily intake (PMTDI) of these elements for adults. Moreover, hazard coefficient (HQ) was calculated for risk assessment and it was determined that HQ values for the studied elements in bee propolis from all districts were below 1.

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• MakaleYalnız künye2024Scopus SJRQ3/r/munzur/2189
  Development of a novel rare earth element doped chitosan-graft-poly(hydroxyethyl methacrylate) composite for biomedical applications: synthesis, characterization, drug delivery, and antibacterial properties

  Gürler, N.; Torǧut, G.; Yazdıç, F.C.; Karaman, A.; Karaaslan Ayhan, N.

  The films of chitosan-graft-poly(hydroxyethyl methacrylate) polymer (Ch—g-poly(HEMA)) doped with the rare earth element (REE) lanthanum (La content of 0, 0.2, 0.4, and 0.8 wt.%) were fabricated. The films were characterized by attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDS), thermogravimetric analysis (TGA), and powder X-ray diffraction (XRD) analysis. The films obtained were loaded with a model drug tetracycline by freezing/thawing method. The cumulative drug release properties of tetracycline were investigated. The release of tetracycline from the polymer matrix was carried out in phosphate-buffered saline (PBS) buffer (pH 7.4) at 37 °C. It was found that the REE-doped composite films had a retarding effect on tetracycline drug release compared to that of the undoped film. All tested composites regardless of the REE dopant content were found to be active against three Gram-positive and three Gram-negative bacterial strains used to assess the antimicrobial properties of the polymer composites. These findings demonstrated that lanthanum and tetracycline have a high affinity for the Ch—g-poly(HEMA) polymer and suggested a synergistic effect in the polymer—lanthanum—tetracycline system. The La3+-doped Ch—g-poly(HEMA) composite film can be used as drug carrier system in the biomedical field.

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• MakaleAçık Erişim2024Scopus SJRQ3/r/munzur/1565
  Structural, 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.

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• Derleme MakaleAçık Erişim2021/r/munzur/6632
  Rare Earth Element Doped ZnO Thin Films and Applications

  Ayhan, Nagihan Karaaslan; İpek, Yeliz

  In this review, general information has been given about the recent studies on thin film coating techniques, zinc oxide (ZnO) thin films and zinc oxide films doped with rare earth elements (REE). As a thin film coating method, the sol‒gel method is widely used due to its economical nature. However, it has been seen that the magnteron sputter technique is also very popular due to its ease of application. Zinc oxide is a semiconductor with a wide band gap and is easy to produce and to supply. In addition, it does not have negative effects on the environment and human health. All these properties have led to intensive studies on zinc oxide. Due to its optical and electrical properties, it has found many different uses such as solar cells, light emitting diodes, gas sensors and flat panel displays. Recently, various studies have been carried out to improve the properties of zinc oxide and to create new areas of use by doping with rare earth elements.

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