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Abadiah, Nur Millaty (2020) Pengaruh Doping M (M = Fe, Cr, Ti) terhadap Struktur Kristal, Sifat Optik, dan Aktivitas Antibakteri Magnetik Cair MFe2O4. Sarjana thesis, Universitas Brawijaya.

Indonesian Abstract

Secara teoritis, magnetit memiliki sifat magnetik dan struktur kristal yang memungkinkan adanya modifikasi melalui doping logam transisi. Penelitian ini ditujukan untuk menginvestigasi struktur nano magnetik cair (ferofluida) MFe2O4, dengan M berupa Fe, Ti, dan Cr. Partikel nano MFe2O4 disintesis melalui metode kopresipitasi. Kristalinitas dan fase diinvestigasi menggunakan instrumen XRD. Data difraksi menunjukkan fase Fe3O4, namun terdapat pergeseran posisi puncak difraksi sebagai kontribusi adanya doping ion-ion Ti2+ dan Cr3+. Lebih jauh lagi, perubahan parameter kisi, volume kristal, dan ukuran partikel sampel juga teramati. Ukuran partikel untuk Fe3O4, Fe2TiO4, dan Fe2CrO4 masing-masing adalah 10,2; 13,4; dan 6,9 nm. Gugus fungsi dari ferofluida Fe2MO4 dikarakterisasi menggunakan FTIR dan diperoleh pergeseran stretching band Fe-O dikarenakan modifikasi pada struktur. Selain itu, analisa FTIR digunakan pula sebagai referensi untuk konfirmasi gugus fungsi ferofluida Fe2MO4. Koleksi data absorbansi kemudian dilakukan melalui karakterisasi menggunakan instrumen UV-Vis, dan terdapat transfer muatan intervalensi pada panjang gelombang yang mendekati infra-merah, mengindikasikan bahwa terdapat elemen Fe dan interaksi antarmuka partikel nano yang meningkatkan absorpsi maksimum pada rentang 400–550 nm. Lebih lanjut, berdasarkan data absorbansi, terkomputasi kesenjangan energi (energy gap) dalam rentang 2.20– 2.24 eV. Menariknya, analisa dari hasil uji antibakteri melalui metode dilusi menunjukkan bahwa modifikasi struktur memainkan peran penting dalam meningkatkan aktivitas antibakteri ferofluida MFe2O4 melalui penurunan presentasi koloni bakteri yang bertahan hidup.

English Abstract

Theoretically, magnetite has magnetic properties and a crystal structure that allows modification through transition metal doping. This research was intended to investigate the nanostructure of MFe2O4 magnetic fluids (ferrofluids), wherein M was Fe, Ti, and Cr. The Fe2MO4 nanoparticles were synthesized through the coprecipitation method, and their crystallinity and phase were investigated using the XRD instrument. The diffraction data showed the Fe3O4 phase, but there was a shift in the peak position of the diffraction as a doping contribution of Ti2+ and Cr3+ ions. Furthermore, the changes in lattice parameters, crystal volume, and particle size of the samples were also observed. The particle sizes of the Fe3O4, Fe2TiO4, and Fe2CrO4 were 10.2, 13.4, and 6.9 nm, respectively. The functional groups of the Fe2MO4 ferrofluids were characterized using FTIR and obtained a shift in the Fe-O stretching band due to the structural modification. In addition, the FTIR analysis was also maintained as a reference to confirm the functional groups of the Fe2MO4 ferrofluids. The absorbance data collection was then carried out through characterization using UV-Vis instrument, and there was an intervalence charge transfer detected at a wavelength near infra-red indicating the presence of Fe element and interface interactions of the nanoparticles, which increase maximum absorption in the range of 400–550 nm. Furthermore, based on the absorbance data, the energy gap was computed in the range of 2.20–2.24 eV. Interestingly, analysis of the results of the antibacterial test through the dilution method showed that the structural modification played an essential role in increasing the antibacterial activity of the MFe2O4 ferrofluids through the decreasing survival of bacterial colonies.

Other Language Abstract

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Item Type: Thesis (Sarjana)
Identification Number: 0520090203
Uncontrolled Keywords: -
Subjects: 500 Natural sciences and mathematics > 538 Magnetism > 538.4 Magnetic substances and their characteristic phenomena
Divisions: Fakultas Matematika dan Ilmu Pengetahuan Alam > Fisika
Depositing User: ismanto
URI: http://repository.ub.ac.id/id/eprint/183066
Text
0520090203 - NUR MILLATY ABADIAH.pdf

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