KAJIAN SIFAT KEMAGNETAN PADA NANOPARTIKEL MAGNESIUM FERRITE (MgFe2O4) YANG DIENKAPSULASI DENGAN POLYETHYLENE GLYCOL (PEG-4000) DAN SILIKA; STUDY OF MAGNETIC PROPERTIES OF POLYETHYLENE GLYCOL (PEG-4000) AND SILICA ENCAPSULATED MAGNESIUM FERRITE (MgFe2O4) NANOPARTICLES

Puspitarum, Deska L, Edi Suharyadi

2015 | Disertasi | FMIPA

The Magnesium ferrite (MgFe2O4) magnetic nanoparticles have been successfully encapsulated by varying the concentration of PEG-4000 and silica which are used as a material for encapsulation with using co-precipitation method. X-ray Diffraction (XRD) analysis showed the new phase appearance ?-Fe2O3 which crystal structure is rhombohedral and ? ? FeO(OH) with paramagnetic characteristic of MgFe2O4 postencapsulted by PEG-4000. MgFe2O4’s particle size pre-encapsulated was 10.49 ± 0.03 nm, became 5.24 ± 0.02 nm after PEG-4000 encapsulation and 18.79 ± 0.06 nm after silica encapsulation. Encapsulation of silica has showed a new diffraction peak (222) because silica is crystal. Transmission Electron Microscopy (TEM) morphology analysis on PEG-4000 encapsulated nanoparticles showed that the particles become more round, more dispersive, and less aglomerated. The result of Fourier Transform Infra Red (FTIR) analysis showed that MgFe2O4 (PEG-4000 encapsulation) wavenumbers were shifted as 2885,51 cm-1 became 2924,09 ± 0,5 cm- 1 in C-H bond (a formed bond of PEG-4000) and shifted as 316,33 cm-1 became 300,9 ± 0,5 cm-1 in M-O bond (a uniform pattern of MgFe2O4). Magnetic material has been encapsulated by silica which is shown by wavenumber 455,2 cm-1 in Si-OSi bonding analysis. The analysis result of MgFe2O4 magnetic properties with Vibrating Sample Magnetometer (VSM) showed that coersivity of MgFe2O4 was 120,7 Oe, and then decrease after encapsulation to 40,9 Oe and 34,7 Oe for encapsulation with PEG-4000 and silica, respectively.

Kata Kunci : co-precipitation; MgFe2O4; encapsulation; PEG-4000; silica