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- MakaleAçık Erişim2026Scopus SJRQ2Design of Fe–35Ni/PCL nanocomposites with coupled magnetic and shape memory properties
Kök, Mediha; Çirak, Z Deniz; Aydin, Handan; Coşkun, Meltem
In this study, poly(ϵ-caprolactone) (PCL)-based nanocomposite films reinforced with a Fe–35%Ni alloy, which possesses a low coefficient of thermal expansion and distinct magnetic properties, were produced. The composites were prepared using the solvent casting method, with the Fe–Ni alloy incorporated into the PCL matrix at different weight ratios (10%–50%). The structural, morphological, thermal, and magnetic properties of the resulting nanocomposites were comprehensively investigated using FTIR (Fourier transform infrared spectroscopy), XRD (X-ray diffraction), SEM (scanning electron microscopy/energy dispersive x-ray spectroscopy), differential scanning calorimetry, TGA (Thermogravimetric analysis) ve (vibrating sample Magnetometry). FTIR results indicated that the Fe–Ni addition does not form chemical bonds with the PCL matrix and that the composite structure is formed through physical interactions. XRD analyses confirmed that the semi-crystalline structure of PCL is preserved and that the Fe–Ni alloy exhibits a face-centered cubic (FCC) crystal structure. SEM images revealed that while a homogeneous distribution is achieved at low doping levels, partial agglomeration occurs at high levels. Thermal analyses showed that Fe–Ni particles increase the degree of crystallization through a nucleation effect and provide a significant increase in melting temperature and crystallinity values, particularly in the 10%–40% range. TGA results revealed that the thermal stability of the composites increased and their decomposition behavior became multi-stage. Magnetic measurements showed that the saturation magnetization increased significantly with increasing Fe–Ni content, and the composites acquired ferromagnetic character. Furthermore, it was determined that the developed composites exhibit distinct shape memory behavior and can return to their original form upon thermal stimulation. The findings indicate that Fe–35%Ni-doped PCL nanocomposites are a promising candidate for multifunctional applications due to their enhanced thermal, magnetic, and smart material properties.
- MakaleYalnız künye2020Scopus SJRQ1Structural and catalytic properties of Fe3O4doped Bi2S3novel magnetic nanocomposites: P-Nitrophenol case
Kurnaz Yetim, Nurdan; Aslan, Naim; Koç, Mumin Mehmet
Catalytic properties of Bi2S3 nanostructures, Fe3O4 nanoparticles and novel Bi2S3@Fe3O4 magnetic nanocomposites were investigated. Flower-like Bi2S3 nanostructures were produced using hydrothermal synthesis. Bi2S3 nanostructures were doped with Fe3O4 nanoparticles where Bi2S3@Fe3O4 novel magnetic nanocomposites was obtained. Structural characterization of the nanoflowers were performed using X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Microscopic characterization of the nanoflowers was performed using electron microscopy where scanning electron microscope (SEM) and transmission electron microscope (TEM) were used in the characterization which confirms the flower like structures. Vibrating sample magnetometry (VSM) confirmed the magnetic properties of the ferromagnetic characteristics of the magnetic nanocomposites. Optic properties of the nanoparticles were assessed using Ultraviolet - visible (UV-vis) spectroscopy. Band gap energies of the Bi2S3, Fe3O4 and Bi2S3@Fe3O4 were found to be 1.80 eV, 2.0 eV and 2.72 eV, respectively. Catalytic properties of the Bi2S3@Fe3O4 nanoparticles were confirmed using UV spectroscopy where reduction of p-nitrophenol to p-aminophenol was assessed in the presence of NaBH4. It was concluded that Bi2S3 nanostructures and Bi2S3@Fe3O4 nanocomposites showed better catalytic performance than that of Fe3O4 nanoparticles. Such a case was attributed to increased surface area - volume ratio. Results indicate that nanocomposites have the potential to be used in the wastewater treatment.
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