Development and Assessment of Computational Models Detailing the Influence of Extra‐Framework Cations on the Local Structure, Stability and Structure‐Property Relationships in Geopolymers

Abstract

AbstractThis study presents density functional theory based computational analysis of geopolymeric materials of varied Si:Al ratios and extra‐framework cations. Due to the absence of crystallinity and long‐range order in geopolymers, no standard molecular models are present for quantum chemical analysis of these materials. Therefore, computationally feasible molecular models conforming to experimental reports and constraints are developed that accounted for all combinatorially possible local structures in the material. The computational analysis conclusively proved the effect of Si:Al ratio and the identity of the extra‐framework cation on the stability of the material with Si:Al = 2:1 decorated with Ca2 + ions exhibiting the highest stability. No significant effect of local structure is observed on the stability of the systems. Insights into the stability and adsorption property are developed on the basis of partial charge distribution thereby providing the details on the effects of constituent elements on the structure‐property relationships in geopolymers.