Characteristics of Novel Geopolymer Composites Synthesized from Red Mud and Diatomaceous Earth in Autoclave Conditions without Using Alkaline Activators

Abstract

The geopolymer-based materials have been studied and developed since the last decades of the 20th century and applied in many fields of life. The production of geopolymer also has many different levels of technology from low to high technology which depends on quality and the applied fields of products. The geopolymer composites are also considered as friendly environmentally products related to low energy consumption production technology; reuse industrial wastes as raw materials; low or even zero CO₂ emission; many better properties compared to the same traditional materials, and others. This investigation would like to introduce a novel type of geopolymer-based materials synthesized from red mud and diatomaceous earth in autoclave conditions without using alkaline activators. The geopolymer composites were fabricated in three various temperatures of 120^oC, 150^oC, and 200^oC and evaluated characteristics via the different analytical methods. The method of X ray diffraction (XRD) was used to evaluate phase transitions among raw materials (RM and DE) and the geopolymer composite materials. Characteristics of bondings in the materials were detected by using Fourier transform infrared spectroscopy (FTIR). The differential thermal analysis-thermogravimetric analysis (DTA-TG) is method used to look for the physico-chemical changes of the geopolymer composite materials exposed at high temperature. In addition, the geopolymer – based materials were observed morphologies and microstructures in its solid phase lattice matrixs using scanning electron microscope (SEM).