Reaction Monitoring of Cementing Materials through Multivariate Techniques Applied to In Situ Synchrotron X-Ray Diffraction Data

In this work, methods for on-line monitoring of the setting reaction of magnesium potassium phosphate ceramic (MKPC) were developed. To this aim, multivariate statistical techniques combined with in-situ synchrotron X-ray powder diffraction (XRPD) enabled a fast, real time and reliable analysis of the phenomena occurring even in complex systems as investigated here. Thus, Multivariate Curve Resolution - Alternating Least Squares (MCR-ALS) was employed together with Evolving Factor Analysis (EFA). Comparison with conventional methods for describing reaction kinetic, namely, integrated area of selected diffraction peak for the crystalline phases, show that compounds involved in the process can be correctly distinguished and the main reaction steps, such as reactants consumption, occurrence of intermediate amorphous phase and finally MKPC formation can be clearly identified.