|Abstract:||In this bachelor's thesis, we researched the effects of the thickness of the silicate coating of synthesized NiCu nanoparticles on their magnetization, as well as the optimal conditions for the leaching of the silicate coating from NiCu nanoparticles.
We utilized several different methods to determine the chemical properties of the synthesized NiCu nanoparticles. In determining the composition of the nanoparticles, we used X-ray diffraction (XRD); for the measurement of the Curie temperature we used thermogravimetric analysis (TGA); we obtained the size values of the nanoparticles using X-ray diffraction, dynamic light scattering (DLS) and transmission electron microscopy (TEM), while the presence of the silicate coating was investigated using zeta potential, transmission electron microscopy and Fourier-transform infrared spectroscopy (FTIR). We also performed magnetic measurements, for which we used a vibrating-sample magnetometer (VSM), and calorimetric measurements.
For the leaching process, we used a NaOH solution, which also contained 3 % hydrazine. During the optimization of the leaching process, we changed the duration of the leaching and concentration of the NaOH. We managed to improve the conditions of the leaching process from 1 M NaOH, 24 h, with 3 % hydrazine, to 0,7 M NaOH, 8 h, with 3 % hydrazine. We also attempted leaching with 4 % tetramethylammonium hydroxide (TMAH), 4 h, but it was unsuccessful.
We were unable to determine the effects of the thickness of the silicate coating on the magnetization of synthesized NiCu nanoparticles, as the silica did not homogeneously spread across their surface but accumulated in larger clusters across the entire sample.
The synthesized NiCu nanoparticles were found to be heterogenous and suitable for use in magnetic hyperthermia, because of their average Curie temperature, magnetization, and size.|