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    Öğe
    Influence of silane coating and graphene oxide integration on the magnetothermal Behaviors of La1-xSrxMnO3 nanoparticles
    (Elsevier, 2025) Sert, Buse; Kaya, Gul; Cicek, Sinem; Harputlu, Ersan; Simsek, Telem; Tekgul, Atakan; Unlu, C. Gokhan
    In this study, La1-xSrxMnO3 (x = 0.27, 0.3, 0.33) magnetic nanoparticles (MNPs) were synthesized and then these nanoparticles synthesized in the core-shell structure were coated with silane for potential magnetic hyperthermia applications. In order to provide support material for the coated magnetic nanoparticles, silane-coated hybrid magnetic nanoparticles were obtained by producing graphene oxide (GO) nanoflakes. The structural and magnetic properties and magnetothermal properties of these structures were investigated. It was observed that the structure of the silane-coated magnetic nanoparticles remained intact and did not show any degradation compared to the uncoated materials. In addition, the highest saturation magnetization (MS) value was observed in the sample doped with x = 0.30. This value indicated that the heating power would be higher than the other doped samples in the specific absorption ratio (SAR) measurements. In this context, the heating amount in the silane-coated samples showed a slight decrease compared to the uncoated samples. Despite the decrease in the SAR values of the integrated samples by incorporating GO into the coated MNPs, it is anticipated that effective results will be obtained for practical applications with the advantage of increasing the thermal conductivity of GO.
  • [ X ]
    Öğe
    Investigating the effect of coating and synthesis parameters on La1-xSrxMnO3 based core-shell magnetic nanoparticles
    (Elsevier, 2025) Sert, Buse; Kaya, Gul; Tataroglu, Aleyna Akcay; Harputlu, Ersan; Simsek, Telem; Tekguel, Atakan; Unlu, C. Gokhan
    Magnetic nanoparticles are an important class of functional materials that have unique magnetic properties due to their reduced size (<100 nm) and have the potential for use in many fields. In the preparation of magnetic nanoparticles, factors such as intrinsic magnetic properties, surface coating, size and shape of the particles, surface charge and stability are very important. In this regard, carefully determining the synthesis parameters of magnetic nanoparticles and particle coating materials is of critical importance in the application area chosen for the material. In this study, La1-xSrxMnO3 (x = 0.27, 0.30, 0.33) magnetic nanoparticles (MNPs), carbon-coated magnetic nanoparticles in core-shell structure (C@MNP) and their derivatives integrated into graphene oxide (GO-C@MNP) were synthesized and their properties were investigated in detail for their use in possible future application studies. The crystal structure of perovskite compounds with Pbnm symmetry remains unchanged after carbon coating but shrinks in volume due to its amorphous structure. The magnetic behavior of the uncoated and coated materials is almost identical, but the Curie temperature of the compounds shifts to a higher temperature. In the specific absorption ratio (SAR) measurements performed, it was found that the best SAR value for carbon-coated MNPs was 12.9 W/g at x = 0.27. By integrating the MNPs into graphene oxide, heat is easily distributed regionally, and this shows that the structures can be ideal candidates for applications such as hyperthermia, drug carriers, tissue repair, and cellular therapy including cell labeling and targeting. Perovskite-structured manganite materials were selected for their suitability in controlled production, where the Curie temperature can be tuned near the therapeutic temperature by adjusting the doping levels, making them ideal for magnetic hyperthermia applications. In this study, for the first time, the nanoparticle surfaces were coated with carbon, which was chosen not only due to carbon's non-magnetic nature but also because it provides an ideal platform for future combined biomedical applications such as drug delivery systems.