SINTESIS DAN KARAKTERISASI MATERIAL LEMPUNG MAGNETIK (MG/ALHYDROTALCITE- MAGNETIT)

Abstract

The study of onmagnetic clay’s synthesis and characterization, Mg/Al hydrotalcite-magnetite, in precipitation method has been done. This study aims to determine the material magnetism and stability characteristics  of  Mg/Al  hydrotalcite-magnetite  to  the  changing  in  pH  of medium. Synthesis of Mg/Al hydrotalcite - magnetite conducted in two phases namely the formation of magnetite phase and magnetic synthetic clay phase formation. At the stage of the magnetite phaseformation, magnetite with a molar ratio of Fe(III) : Fe(II) = 1:1 and 2:1 , synthesized  by  coprecipitation  method using  NaOH solution  at  pH13.  Then  part  of the magnetite  material  obtained,  were  characterized using  X  -  Ray  Diffraction  (XRD)  and Fourier  Transform  Infrared  (FTIR).  At  the stage of  the Mg/Al  hydrotalcite  -  magnetite formation, magnetite respectively were synthesized with the molar ratio of Fe(III) : Fe (II) = 1:1 and 2:1, further be precipitated with a solution of magnesium nitrate and aluminum nitrate in molar ratio Mg:Al = 2:1. In this stage the pH of medium been maintained at range of 10-13, and then carried out the hydrothermal treatment at a temperature of 110 ° C for 5 hours. After the precipitate is separated by using a centrifuge, the feculence bedried and the material obtained were characterized using XRD and FTIR. The results show synthesized magnetite with amolarratio of Fe(III): Fe(II) =1:1 had diffractogram, and IR spectra better than synthesized magnetite with the molar ratio of Fe(III): Fe(II) = 2 : 1. The same results were also obtained in the synthesis of Mg/Al hydrotalcite-magnetite, where the Mg/Al hydrotalcite-magnetite synthesized from magnetite with a molarratio ofFe(III): Fe(II) =1:1is betterthan theMg/Alhydrotalcite-magnetite synthesizedfrommagnetitewith amolarratio ofFe(III): Fe(II) =1:1. Magentism test for Mg/Alhydrotalcite-magnetite material shown that this material has capability for interacting with external magnetic field. Result of the Mg/Alhydrotalcite-magnetite’s stability test at pH range 2-14, shown that the Mg/Alhydrotalcite-magnetite is relatively stable at pH above 4 and relatively lessstable at pH below 4.