Abstract

Simon Sembiring¹,Agus Riyanto¹, Wasinton Simanjuntak² and Rudy Situmeang²

DOI : http://dx.doi.org/10.13005/ojc/330427

This study acquires the potential of rice husk silica for production forsterite precursors using sol-gel method. The samples preparation were conducted by mixing magnesium oxide sol from Mg(NO₃)₂.6.12H₂O with silica sol extracted from rice husk, with three different composition ratios of MgO to SiO₂ are 1:1, 2:3 and 3:2 by weight and sintered at 900^oC. The samples were characterized using Fourier transform infrared (FTIR) spectroscopy, x-ray diffraction (XRD),differential thermal analysis (DTA), followed by scanning electron microscopy (SEM). The FTIR results showed the presence of Si-O-Si, Mg-O and Mg-O-Si functional groups, which were associated with forsterite, enstatite, cristobalite and periclase, according to the XRD analysis. The formation of forsterite (Mg₂SiO₄) is composition-dependent as revealed the increase of forsterite intensity after sintered at 900^oC in ratio 3:2. The surface morphology of non-sintered samples shows that particle and grain size were larger than particle and grain size of sintered samples. Also, SEM analysis of sintered samples clearly shows the presence of regular particle size with smaller grain size was found in ratio of MgO to SiO₂ is 3:2. DTA analysis revealed that the formation of forsterite increased with increasing temperature. In addition, the electrical resistivities of the samples were found in the range of 0.75 x 10¹³ to 3.30 x 10¹³W-cm, demonstrating that the samples exhibit good potential as isolator.

Forsterite; rice husk; sintering; structure; microstructure

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