Thermal transformation of a kaolinite-poly(acrylamide) intercalation compound

The thermal transformation of a kaolinite-poly(acrylamide) (PAAm) intercalation compound has been investigated. Acrylamide molecules were intercalated between the layers of kaolinite and were subsequently polymerized by heat treatment at 300°C for 1 h. The kaolinite-PAAm intercalation compound was heated in the range 460-620°C under a nitrogen atmosphere. XRD analysis revealed that carbonaceous materials remained between the layers in this temperature range. The ²⁹Si and ²⁷Al NMR spectra of the kaolinite-PAAm compounds heated above 500°C showed that the structural change of aluminosilicate layers was relatively suppressed compared with that of kaolinite itself, indicating that the carbonaceous materials hindered the transformation of aluminosilicate layers. This new finding provides a method for controlling the skeletal transformation of inorganic layered materials upon thermal treatment.