Synthesis and Properties of Al-δ Layered Sodium Disilicate with High Framework Stability

Abstract Al-δ layered sodium disilicate with high framework stability in hot water (60–80°C) has been successfully synthesized from the system of Na 2 O–Al 2 O 3 –SiO 2 –H 2 O. It was shown that the presence of aluminum can improve the purity of δ phase. After marinated in hot distilled water for 60minutes, Al-δ layered sodium disilicate still kept δ phase and had better Ca 2+ binding capacity and calcium binding rate. This property of Al-δ layered sodium disilicate may extend its application field. The samples were characterized by XRD, FT-IR, MAS NMR, Ca 2+ binding capacity and rate, The data of 27 Al MAS NMR and 29 Si MAS NMR showed that aluminum was incorporated essentially in tetrahedral framework position, and substitute for SiO 4 tetrahedron in sheet of δ layered sodium disilicate.