SKRIPSI Jurusan Fisika - Fakultas MIPA UM, 2017

Ukuran Huruf:  Kecil  Sedang  Besar

Synthesis and Characterization of Ferrofluids ZnxFe3-xO4 from Iron Sand for Antibacterial Application

Defi Yuliantika

Abstrak


ABSTRAK

 

ZnxFe3-xO4 ferrofluids are superparamagnetic liquid contained Zn doped Fe3O4 nanoparticles in aqueous coloidal based of water as a carrier liquid and TMAH as a surfactant. Fe3O4 nanoparticles denoted as [Fe3+]A[Fe2+Fe3+]B was a superparamagnetic due to particle size in single domain, < 20 nm.. Fe3O4 have insignificant saturation magnetization caused by antiparallel spin magnetic of Fe3+ in tetrahedral (A) and octahedral (B) site. In this research. Fe3O4 from iron sand doped with ammount of Zn in attempt to enhance ionic interaction between A and B site cation in spinel structure, improve the corresponding magnetic properties and other physics properties.

In this study, ZnxFe3-xO4 with varried ammount of Zn dopan denoted as x = 0.1; 0.2; and 0.4 have been succesfull synthesized by coprecipitation- sonochemical methods. The prepared ZnxFe3-xO4 nanoparticles were characterized by Transmission Electron Microscopy (TEM), X-ray Diffractometer (XRD),  Fourier Transformation Infrared (FTIR), Vibrating Sample Magnetometer (VSM), and UV-Vis Spectrophotometry to analized morphology and size distribution, crystal structure, functional group of molecules, magnetization, and band gap values. Moreover, antibacterial activity of ZnxFe3-xO4 ferrofluids against E. coli and B. subtilis studied by broth dilution method.

The result of TEM test confirmed that Fe3O4 have spheris shape with homogen size distribution and less agglomeration. ZnxFe3-xO4 was single domain particles and have cubic spinel invers structure when x < 0.3 indicated by XRD analysis. ZnxFe3-xO4 nanoparticles shows characteristic of superparamagnetic with increasing Zn content, remanent magnerization and coercivity were approximately tend to zero and have maximum saturation magnetization of 43 emu/g. Direct band gap value of the samples were carried out by means of Tauc plot is 2.24 eV for Zn0.2Fe2.8O4 and 2.54 for Zn0.4Fe2.6O4. Based on Antibacterial assay, the antibacterial activity of ZnxFe3-xO4 ferrofluids against E. coli was significally higher than that observed against B. subtilis. ZnxFe3-xO4 ferrofluids show great potential for antibacterial application.