Admixture Effects on Nucleation of Ettringite in Supersaturated Solutions

Abstract

This study investigated the influence of sodium tartrate and sodium carbonate on the homogeneous nucleation of ettringite in supersaturated solutions. Nucleation kinetics were monitored through conductivity measurements and interpreted using classical nucleation theory (CNT). Sodium tartrate prolonged the induction time of ettringite nucleation and showed a strong concentration‐dependent retardation effect. No significant synergistic effect was observed for combined addition of sodium tartrate and sodium carbonate. SEM and XRD analyses confirmed the formation of ettringite and revealed that sample collection procedures influenced the observed crystal morphology. The study further demonstrates the strong sensitivity of nucleation experiments to heterogeneous nucleation effects induced by reactor surfaces, electrode surfaces, and sample preparation methods.