Pengaruh Konsentrasi NaOH Pada Ekstrak Nanosilika Berbasis Batu Apung

Abstract

The investigation of effect NaOH in extracting nanosilika from pumice has been carried out. The aim of research is to study the effect of variation NaOH against the amount and chemical compositions of nanosilica extract results. The extraction process is carried out with NaOH, H₂SO₄ and HCl. Variations of NaOH used are 2,0 M, 2,5 M, 3,0 M, 3,5 M and 4,0 M. Pumice powder was calcined at 500C for 4 hours and nanosilica powder was calcined at 800C for 5,5 hours. Nanosilica was characterized by X-Ray Flouresence (XRF), X-Ray Diffractometer (XRD) and Transmission Electron Microscopy (TEM). The results of extraction increases with increasing of NaOH concentration. XRF analysis shows that the highest amorphous nanosilica was obtained in nanosilica of NaOH 3,0 M. Difractogram XRD shows that pumice powder formed anorthite and albite phase and nanosilika 3,0 M NaOH has amorphous phase. Based on TEM result, the particle size of amorphous nanosilica NaOH 3,0 M is in the range of 8,8-19,5 nm and the average of particle size is (14,8 3,07) nm.