Zinc Ion Exchanged Geopolymer Derived from Sodium Geopolymer and Comparison of Their Thermal Behavior


Kara İ.

14th International Conference on Ceramic Materials and Components for Energy and Environmental Systems, Budapest, Hungary, 18 - 22 August 2024

  • Publication Type: Conference Paper / Summary Text
  • City: Budapest
  • Country: Hungary
  • Anadolu University Affiliated: Yes

Abstract

In this study, sodium based geopolymer with about 1:1:2 NaO:Al2O3:SiO2 molar ratio was synthesized by using metakaolin and sodium hydroxide solution. The synthesized geopolymer was subjected to an ion exchange process in an aqueous solution containing zinc ions. Almost complete ion exchange took place between Na2+ and Zn2+. Thermal behavior of the sodium geopolymer and the Zn-exchanged geopolymer was followed by optical dilatometer and TG-DTA analysis. The sodium geopolymer crystallizes to nepheline at the early stages of sintering, which precludes further densification. On the other hand, the Zn-exchanged geopolymer starts sintering at about 50 °C lower temperature and sinters to a nearly full density before gahnite crystallization takes place. The dense Zn-exchanged geopolymer body contains extensive gahnite crystallization with sizes finer than 30 nm embedded in an amorphous matrix.