FTIR and XRD characterization of kaolin geopolymer based on solids-to-liquid and alkaline activator ratios

Abstract

This paper covers the results of X-ray powder diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) in assessing the phase identification and functional group of kaolin geopolymer based on the different solids-to-liquid and alkaline activator ratios. The XRD results showed the kaolinite and zeolite peaks decreased in intensities with increasing ageing days and large part of unreacted materials remained in the system. Nevertheless, FTIR results proved that the geopolymer bonding (Si-O-Al) increased with the ageing day. Both XRD and FTIR analysis showed that the presence of zeolite crystalline phases were not beneficial for the strength development and strength increased as the zeolite phase decreased.