Yazarlar

• Andaç, O.(2)
• Karadag, A.(2)
• Korkmaz, S. Aslan(2)
• Aydin, Handan(1)
• Coşkun, Meltem(1)
• Deniz Çirak, Zehra(1)
• Gürbüz, N.(1)
• Korkmaz, N.(1)
• Kök, Mediha(1)
• Topcu, Y.(1)
• Topkaya, R.(1)
• Yerli, Y.(1)
• Özdemir, I.(1)

• MakaleAçık Erişim2026Scopus SJRQ3/r/munzur/1322
  Functional magnetic polymer nanocomposites: Fe2O3/Fe3O4-enhanced PCL-PVA materials

  Deniz Çirak, Zehra; Aydin, Handan; Coşkun, Meltem; Kök, Mediha

  In this study, magnetic polymer nanocomposites based on PCL/PVA PCL(Polycaprolactone)-PVA(Polyvinyl alcohol) (80/20) reinforced with Fe2O3 and Fe3O4 nanoparticles were successfully produced, and their thermal, structural, morphological, and magnetic properties were comparatively investigated. The systematic evaluation of the effects of Fe2O3 and Fe3O4 additions on the same biodegradable polymer matrix at 20% and 40% loading levels constitutes the main novelty of this study. The nanocomposites were characterized using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and physical property measurement system (PPMS) analyses. The TGA results demonstrated that the decomposition onset temperature increased with the addition of nanoparticles and, particularly in the composite with 40% Fe3O4 content, the residual mass reached 15.81%, indicating a significant improvement in thermal stability. DSC analyses showed that the melting peak temperature increased at high loading levels and that Fe2O3 loading supported crystallization more than Fe3O4. FTIR and XRD results confirmed that the nanoparticles dispersed successfully in the polymer matrix without forming chemical bonds and provided strong interfacial interactions. The SEM images revealed a homogeneous distribution at low loading levels, while significant agglomeration formed at high Fe3O4 content. Magnetic measurements indicated that the pure PCL/PVA blend exhibited diamagnetic behavior, Fe2O3-containing composites displayed hard ferromagnetic behavior, and Fe3O4-containing composites exhibited soft ferromagnetic behavior. The highest saturation magnetization of 10.4 emu/g was obtained in the composite with 40% Fe3O4 content. The findings indicate that Fe2O3- and Fe3O4-doped PCL/PVA nanocomposites are functional materials with high potential for applications in sensors, actuators, magnetically controlled systems, and biomedical applications.

  İncele
• MakaleYalnız künye2013Scopus SJRQ2/r/munzur/4254
  Five complexes containing N,N-bis(2-hydroxyethyl)-ethylenediamine with tetracyanidopalladate(II): synthesis, crystal structures, thermal, magnetic, and catalytic properties

  Korkmaz, S. Aslan; Karadag, A.; Korkmaz, N.; Andaç, O.; Gürbüz, N.; Özdemir, I.; Topkaya, R.

  Five cyanide complexes, [Ni(N-bishydeten)Pd(CN)(4)] (1), [Cu(N-bishydeten)Pd(-CN)(2)(CN)(2)](n) (2), [Cu(N-bishydeten)(2)][Pd(CN)(4)] (3), [Zn(N-bishydeten)Pd(CN)(4)] (4), and [Cd(N-bishydeten)(2)][Pd(CN)(4)] (5) (N-bishydeten = N,N-bis(2-hydroxyethyl)-ethylenediamine), have been synthesized and characterized using various techniques. Different structures were formed when the M:L ratio was varied in copper complexes. The single-crystal X-ray diffraction analysis reveals that 2, a 1-D cyanide-bridged complex with 2,2-CT-type zigzag chain, was obtained by using 1:1M:L ratio whereas 3 was formed as a complex salt in a molar ratio of 1:2. The thermal stabilities determined from DTG(max) values of the first decomposition stages change in the order 1>5>4>3>2. Although an EPR signal was not observed for 1, the g parameters obtained from the EPR spectra of 2 and 3 indicate that Cu-II ions are located in tetragonally distorted octahedral sites (D-4h), and the ground state of the unpaired electron is (B-2(1g)). The magnetic behavior indicates a very small antiferromagnetic interaction below 10K for 1-3. In 3, there is a temperature-independent paramagnetism () due to the orbital moments of the d electrons. 1-3 were tested as catalysts in Suzuki and Heck coupling reactions.

  AtıfWoS16·OpenAlex15

  İncele
• MakaleYalnız künye2012Scopus SJRQ2/r/munzur/4419
  Cyano-complexes and salts with tetracyanonickellateII and N,N-bis(2-hydroxyethyl)-ethylenediamine: synthesis, IR spectra, magnetic properties, thermal analyses, and crystal structures

  Karadag, A.; Korkmaz, S. Aslan; Andaç, O.; Yerli, Y.; Topcu, Y.

  Four cyano complexes, [Ni(N-bishydeten)Ni(CN)(4)](n) (c1), [Cu(N-bishydeten)(2)][Ni(CN)(4)] (c2), [Zn-2(N-bishydeten)(2)Ni(CN)(4)](n) (c3), and [Cd(N-bishydeten)(2)][Ni(CN)(4)] (c4), have been synthesized and characterized by FT-IR, elemental, and thermal analyses. The structures of c2 and c4 were determined by single-crystal X-ray diffraction studies; both structures contain isolated cations and anions. The c2 consists of [Cu(N-bishydeten)(2)](2+) with octahedrally coordinated Cu-II and diamagnetic [Ni(CN)(4)](2-), but c4 consists of [Cd(N-bishydeten)(2)](2+), in which Cd-II is eight coordinate with two tetradentate N-bishydeten and diamagnetic [Ni(CN)(4)](2-). The value of the shape measure S (degrees) indicates that the coordination geometry around Cd-II lies along D-2d [dodecahedron; (dd)], C-2v [bicapped trigonal prism; (btp)], and D-4d [square antiprism; (sap)] but close to D-2d and D-4d. Variable temperature magnetic susceptibility measurements of c1 and c2 show the presence of little antiferromagnetic interaction below 20 K. Thermal analyses reveal that first neutral N-bishydeten and then cyano ligands were liberated from the complexes.

  AtıfWoS19·OpenAlex16

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