Abstract:
Research on analysis of rice husk content of Siam Unus with various NaOH
concentrations (1.0 M; 1.5 M; 2.0 M; 2.5 M; 3.0 M) has been done. This study aims to
obtain data on the effect of variations in NaOH concentration on the purity of the silica
extract from Siam Unus rice husks and silica characterization of Siam Unus rice husks
using Fourier Transform Infra-Red (FTIR) and X-ray fluorescence spectrometry (XRF).
The results showed that the combustion of rice husks at 200 °C as optimum temperature
for 1 hour followed by combustion at 600 °C for 4 hours produces grayish-white rice
husks with a yield is 20.70%. Silica functional group characterization showed that
silanol (Si-OH) and siloxane (Si-O-Si) as dominant functional groups. The result of
composition characterization using XRF showed that SiO2 as the dominant compound
with the highest percentage of SiO2 is 1.5 M NaOH extract at 42.80%.
Keywords: Siam Unus rice husk ash, extraction, silica, FTIR, XRF
