Functional magnetic polymer nanocomposites: Fe 2 O 3 /Fe 3 O 4
Zehra Deniz Çirak, Handan Aydin, Meltem Coşkun, Mediha KökAbstract
In this study, magnetic polymer nanocomposites based on PCL/PVA PCL(Polycaprolactone)-PVA(Polyvinyl alcohol) (80/20) reinforced with Fe 2 O 3 and Fe 3 O 4 nanoparticles were successfully produced, and their thermal, structural, morphological, and magnetic properties were comparatively investigated. The systematic evaluation of the effects of Fe 2 O 3 and Fe 3 O 4 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 % Fe 3 O 4 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 Fe 2 O 3 loading supported crystallization more than Fe 3 O 4 . 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 Fe 3 O 4 content. Magnetic measurements indicated that the pure PCL/PVA blend exhibited diamagnetic behavior, Fe 2 O 3 -containing composites displayed hard ferromagnetic behavior, and Fe 3 O 4 -containing composites exhibited soft ferromagnetic behavior. The highest saturation magnetization of 10.4 emu/g was obtained in the composite with 40 % Fe 3 O 4 content. The findings indicate that Fe 2 O 3 - and Fe 3 O 4 -doped PCL/PVA nanocomposites are functional materials with high potential for applications in sensors, actuators, magnetically controlled systems, and biomedical applications.