NOVEL APPLICATIONS OF METAL-GEOPOLYMERS

摘要

Geopolymers are generally XRD-amorphous materials; however recent research has proved that they contain nanometer particles probably with zeolitic structure. It has also been confirmed in our investigation that sodium in metakaolin-based geopolymer could be easily exchanged for other cations such as ammonium, cobalt, copper etc. Moreover, according to UV-VIS spectra of Co-geopolymer, it has been proven that the local arrangements of Co~(2+)- extraframework ions in cationic positions correspond to those known in high-silica zeolites, such as mordenite, ZSM-5 or beta. A similar high level of ion exchange with various ions of transition metals has also been reached for metakaolin-slag-based geopolymers. Accordingly, it could be truly expected that these metal-exchanging geopolymers would show similar properties and potential applications as zeolites, while keeping the advantages of the geopolymers, such as simple synthesis procedure, easy molding into complicated shapes or forming thin highly adhesive layers. These novel applications, such as heterogeneous catalysis for environmental applications and active antibacterial thin coating of metal-geopolymers will be presented and discussed.