SYNTHESIS OF CrNi NANOPARTICLES WITH MICROEMULSION METHOD

Namen diplomskega dela je bil sinteza nanodelcev CrNi z mikroemulzijsko metodo. V območju stabilnosti mikroemulzij v ternarnem diagramu (voda/CTAB, n-butanol/izooktan) smo izbrali dve točki z različnimi masnimi deleži (20/40/40 in 20/50/30) in v teh dveh točkah sintetizirali CrNi magnetne nanodelce z različnimi sestavami: Cr1-xNix (x=0.7, 0.8, 0.9), pri čemer smo kot reducent uporabili NaBH4. Delce smo najprej termično obdelali s pomočjo termoanaliznega sistema TGA-SDTA v N2 atmosferi pri 500 ° C z namenom njihove homogenizacije. Zaradi možne aplikacije v medicinske namene (magnetna hipertermija) smo želeli pridobiti delce z ustrezno Curiejevo temperaturo. Delce smo v ta namen še dodatno homogenizirali v cevni peči pri temperaturi 900°C, 12 ur, v redukcijski atmosferi (Ar/H2). S tem smo hkrati želeli preprečiti oksidacijo delcev. Vzorce smo kvalitativno analizirali z rentgensko praškovno difrakcijo (XRD). S pomočjo termogravimetrične analize (TGA) smo vzorce segreli na 500 °C in jim s prirejeno TGA aparaturo določili Curiejevo temperaturo (Tc).Diploma work focuses on synthesis of nanoparticles CrNi with microemulsion method. We prepared two different compositions of microemulsions in the region of microemulsion stability with mass % (20/40/40 and 20/50/30) in ternary water/CTAB, n-butanol/isooctane diagram. In those two compositions we synthesized CrNi magnetic nanoparticles of different alloy compositions: Cr1-xNix whereas (x = 07, 08 and 09). The reducing agent was NaBH4. The particles were first thermal treated with the TGA-SDTA thermoanalytical system in N2 at 500°C because of homogenization. Because of the application for medical purposes (magnetic hyperthermia) we tried to get the particles with appropriate Curie temperature. So, we additionally homogenised particles in a tube furnace at 900°C for 12 hours under reducing atmosphere (Ar/H2). With that, we tried to prevent the particles from oxidation. A qualitative analysis of the samples was carried out using the X-ray diffraction (XRD) and the Curie temperature measured with thermogravimetric analysis (TGA) which was also used to heat the samples to 500°C