ABSTRACT
Comparisons of the phase evolution processes of mullite precursors synthesized by different processing techniques were shown. Three basic reference studies were commonly used for the interpretation of phase transformation of mullite precursors in IR applications by Percival et al., Mackenzie, and Cameron. Ruscher et al. reproduced three types of precursors with tetraethyl orthosilicate and aluminum-sec-butylate as the starting materials as per Schneider et al. Researchers Okada, Hoshi, and Otsuka, Hirata et al., Colomban, Li and Thomson, Hyatt and Bansal, Suzuki et al., Sales and Alarcon, Ruscher et al., and Nieto et al. applied the IR technique as a tool to reveal the sequential phase evolution process of the monophasic/ Type I gel. The relation between the IR absorbances of 1130 cm-1 and 1170 cm-1 and the chemical composition of mullite over the range of 66 mol %–71 mol % of Al2O3 was first reported by Cameron. .
