PELAPISAN MAGNETIT DENGAN SILIKA BERSUMBER ABU SEKAM PADI

ARIEF HAMDANY S, Prof. Nuryono, M.S.

2014 | Skripsi | KIMIA

Telah dilakukan penelitian tentang sintesis dan pelapisan magnetit (Fe3O4) dengan silika menggunakan larutan natrium silikat (Na2SiO3) yang berasal dari abu sekam padi. Penelitian ini bertujuan untuk menentukan metode sintesis magnetit yang memberikan kristalinitas tinggi dan mempelajari pengaruh pelapisan silika terhadap sifat magnetit. Magnetit disintesis melalui metode kopresipitasi dan non solven, pada rasio mol Fe2+/Fe3+ dalam reaksi 2:1. Pada penelitian ini dikaji pengaruh waktu pengaliran nitrogen, jenis pengendap yang digunakan, dan temperatur pemanasan magnetit hasil sintesis terhadap kristalinitasnya. Pelapisan dilakukan melalui metode sol-gel; 0,5 gram magnetit dicampurkan larutan natrium silikat 0,26 M dengan variasi volume 2, 4, 6, 8 dan 10 mL. Larutan sol tersebut ditambahkan HCl 1 M hingga pH 7 dan diperoleh akuagel yang selanjutnya dikeringkan. Karakterisasi magnetit terlapis dilakukan dengan Fourier Transform Infrared (FTIR) Spectrofotometer, X-ray Difractometer (XRD), Transmission Electron Microscope (TEM) dan Vibrating Sample Magnetometer (VSM), serta uji kestabilan magnetit terlapis terhadap asam. Hasil penelitian menunjukkan bahwa metode kopresipitasi, pengaliran nitrogen, ammonia sebagai pengendap dan temperatur pemanasan di bawah 250 oC menghasilkan kristalinitas magnetit yang paling tinggi. Pelapisan magnetit dengan silika mencapai kejenuhan pada penambahan volume 6 ml. Pelapisan magnetit dapat meningkatkan ukuran partikel dan kestabilan terhadap larutan asam. Uji kekuatan magnetisasi dengan VSM menghasilkan penurunan sifat magnetit setelah pelapisan silika. Kata kunci : magnetit, sol-gel, silika, natrium silikat, pelapisan.

Research on coating of magnetite (Fe3O4) with silica using a solution of sodium silicate (Na2SiO3) derived from rice husk ash has been carried out. This research was conducted to determine a method synthesis of magnetite giving high crystalline and to study the effect of silica coating on magnetite properties. Magnetite was synthesized by method of coprecipitation with solvent and free-solvent at the mol ratio of Fe2+: Fe3+ 2:1. The influence of nitrogen, type of agent precipitation was used, and the heating temperature on crystallinity of magnetite was examined. Coatings was conducted by sol-gel process; 0.5 g magnetite was mixed with sodium silicate solution 0,26 M at variationof volume 2, 4 , 6 , 8, and 10 mL. The sol solution was added with HCl 1 M in order to reach pH of 7 and the obtained aquagel was then dried. Characterization of magnetite coated was performed by Fourier Transform Infrared (FTIR) Spectrofotometer, X-ray Difractometer (XRD), Transmission Electron Microscope (TEM) and Vibrating Sample Magnetometer (VSM), as well as the test of stability coated magnetite against acid solution. The results showed that coprecipitation method, covering with nitrogen, ammonia as agent precipitation and temperature heating below 250 ° C resulted in highly crystalline magnetite. Coating magnetite with silica was reached maximum at the ratio of magnetit weight to sodium silicate solution volume 0.5 : 6. The coating magnetite increased the size of the particles and improves the stability in the acid solution. The strength magnetization magnetite was decreased after being coated with silica. Keywords : magnetite, sol-gel, silica, sodium silicate, coated.

Kata Kunci : magnetit, sol-gel, silika, natrium silikat, pelapisan