Characteristics And Mineral Content of Lampung Tengah Ironsands

Characteristics and Mineral Content of Lampung Tengah Ironsands. This study is carried out to investigate the characteristics and mineral content of ironsands from Bekri, Lampung Tengah Regency by using precipitation method. The research was conducted in Physics Laboratory of Institut Teknologi Sumatera from June to September 2018. Mineral content of sand is analayzed with X-Ray Diffractometer. The extraction was varied in temperature and stirring time. The temperature is varied in 80oC, 120oC, dan 160oC and yields different size; 33.76 nm, 11.84 nm and 11.14 nm. Meanwhile, the extraction is varied for 2 hours, 4 hours and 6 hours stirring and yields particle with 43.12 nm, 11.14 nm and 11.32 size. Mineral content of ironsands in Lampung Tengah are dominated by Ilmenite and Potassium Chloride

SINTESIS KOMPOSIT Fe3O4/SiO2/TiO2 BERBASIS LIMBAH AMPAS TEBU DI WILAYAH BANDAR LAMPUNG DENGAN KOMBINASI METODE KOPRESIPITASI & SOL GEL UNTUK APLIKASI FOTOKATALIS

Telah dilakukan sintesis komposit Fe3O4/SiO2/TiO2 berbasis limbah ampas dengan kombinasi metode kopresipitasi dan sol gel. Proses sintesis terdiri dari 3 tahap, yaitu (1) preparasi nanopartikel Fe3O4 dengan metode kopresipitasi, (2) sintesis SiO2 dari limbah ampas tebu dengan metode sol gel, dan tahap akhir sintesis komposit Fe3O4/SiO2/TiO2. Karakterisasi X-ray Diffraction (XRD) menunjukkan struktur kristal dari komposit dan analisis gugus fungsi ditunjukkan dengan  Fourier Transform Infrared (FTIR) yang menunjukkan bahwa komposit telah berhasil disintesis. Aktivitas fotokatalis dari komposit diujikan  dengan pendegradasian zat warna Methylene Blue (MB) di bawah sinar matahari (visible light) selama 5 jam. Hasilnya menunjukkan bahwa komposit mempunyai aktivitas fotokatalis dan kemampuan degradasi MB yang lebih efektif dibandingkan dengan TiO2 murni.

KARAKTERISASI DAN SIFAT KEMAGNETAN PASIR BESI di WILAYAH LAMPUNG TENGAH

Karakterisasi dan pengujian sifat kemagnetan pasir besi ekstraksi di Wilayah Lampung Tengah telah dilakukan. Penelitian ini bertujuan untuk mengetahui kandungan mineral dan sifat kemagnetan dari pasir besi di daerah Bekri Kabupaten Lampung Tengah dengan menggunakan metode presipitasi basa. Penelitian ini dilakukan di Laboratorium Fisika, Institut Teknologi Sumatera pada bulan Juni hingga September 2018. Kandungan mineral pasir dianalisis menggunakan X-Ray Diffractometer (XRD). Hasil analisis ekstraksi pasir besi dengan variasi suhu 80oC, 120oC, dan 160oC berturut-turut berukuran 33.76 nm, 11.84 nm dan 11.14 nm. Sedangkan hasil analisis ekstraksi pasir besi dengan lama pengadukan yaitu 2 jam, 4 jam, dan 6 jam  berturut-turut memiliki ukuran partikel 43.12 nm, 11.14 nm, dan 11.32 nm. Hasil analisis kandungan mineral pasir besi di wilayah Lampung Tengah didominasi oleh Ilmenite dan Potassium Chloride. Kurva histerisis Vibrating Sample Magnetometer (VSM) menunjukkan bahwa pasir besi ekstraksi dari Lampung Tengah merupakan material antiferomagnetik dengan nilai magnetisasi saturasi maksimum (Ms) sebesar 5.78 memu (mili emu), magnetisasi remanen (Mr) 1.13 memu dan nilai medan koersivitas sebesar 851.68 Oe

New design of a commercial chip-based GMR sensor with magnetite nanoparticles for biosensing applications

The availability of rapid and low-cost instruments to detect magnetic nanoparticles (MNPs) concentrations is vital in giant magnetoresistance (GMR)-based biosensors. This paper reports a new setup for a simple GMR sensor using the commercial chip AAL024 as a transducer. It was combined with a basic differential amplifier and microcontroller to acquire digital output voltages for the detection of green-synthesized (GS)-Fe3O4 MNPs as a label and streptavidin-coated MNPs in biosensor applications. As a characteristic feature of Fe3O4, the GS-Fe3O4 MNPs displayed a cubic inverse spinel structure. The average GS-Fe3O4 particle size was 11 nm and they exhibited soft ferromagnetic behavior with a saturation magnetization (MS) of 55.5 emu/g. Owing to the presence of phytochemical components in the Moringa oleifera (MO) extract, the MS of GS-Fe3O4 was lower than that of Fe3O4. To study sensor performance, the detection of the GS-Fe3O4 MNP labels and streptavidin-coated MNPs assay was investigated. Using the microcontroller as the supply voltage for the AAL024 and an analog-to-digital converter simplified data collection and made any additional measuring instruments unnecessary. The sensor showed promising performance with the GS-Fe3O4 MNP label and streptavidin assay owing to the linear correspondence between the signal and concentration of the MNP label. A small limit-of-detection of 4 mg/mL was achieved for GS-Fe3O4. The sensitivity of GS-Fe3O4 and streptavidin were 2.79 and 1.80 mV/(mg/mL), respectively. Moreover, the excellent stability and reproducibility of the sensor were confirmed by the stable signal for over 30 s with relative signal deviation (RSD) ranges of 2–20% and 2–10% for MNPs and streptavidin, respectively

Optical, microstructural, and magnetic hyperthermia properties of green-synthesized Fe3O4/carbon dots nanocomposites utilizing Moringa oleifera extract and watermelon rinds

Cancer therapy with targeted-localized heating is one of the breakthroughs in the biomedical field. The incorporation of magnetic nanoparticles and fluorescent nanoparticles was one of the crucial issues for magnetic hyperthermia applications. This research investigates the magnetic hyperthermia properties of green-synthesized Fe3O4/CDs. Fe3O4 nanoparticles were synthesized using the coprecipitation method with Moringa oleifera leaf extract as a reducing agent and stabilizer. In contrast, CDs were synthesized using a hydrothermal method with watermelon rind waste as a carbon source. X-ray diffraction analysis confirmed the presence of cubic inverse spinel and a reduction in crystallite size with increasing CDs concentration. Transmission electron microscopy revealed particle size distributions of 9.7 nm for Fe3O4 and 7.5 nm for Fe3O4/CDs. Scanning electron microscopy showed that CDs were distributed on the surface of Fe3O4. The detection of characteristic FeO, CC, CO, and CO-C bonds indicated the presence of CDs on the surface of Fe3O4. Ultraviolet-visible spectroscopy spectra absorption peaks at 282 nm for CDs and 193 nm for Fe3O4. Photoluminescence spectra indicated shifts from 509 to 505 nm in excitation wavelength for both CDs and Fe3O4/CDs, situated within the green region of visible light. The vibrating sample magnetometer revealed that the nanocomposites displayed characteristics of soft ferromagnetic materials. Furthermore, the specific absorption rate (SAR) value of Fe3O4/CDs was found to be dependent on magnetization. The SAR value of Fe3O4/CDs decreased as the concentration of CDs increased, and the frequency and strength of the AMF increased. Therefore, these results can promote Fe3O4/CDs nanocomposites as a promising candidate for magnetic hyperthermia applications