Characterization of allophane from gamalama volcanic soil, North Maluku, Indonesia

Abstract

Extraction of allophane particles from Gamalama volcanic soil have been performed and characterized by using FTIR, XRD, SEM-EDX and TEM. Gamalama volcanic soil sample was dried in air for 5 days and crushed into 200 mesh particle size. The sample is then treated with 10 % H2O2 and dispered at pH 10 by addition of 2 M NaOH. Colloid layer about 10 cm from the surface of the solution was taken after decanted for 10-20 h. Allophane were collected by centrifuge. The FTIR spectra shows peaks which are vibration characteristic of alluminosilicate. X-ray diffraction result proved that allophane is non-crystalline aluminosilicate mineral. TEM result has confirmed that the resulted allophane is spherule with diameter about 4 nm. The nature of allophane to form globular aggregates has confirmed by SEM. In the isolated allophane, Si/Al ratio is 1.45.