Formation of a kaolinite-serine intercalation compound via exchange of the pre-intercalated transition molecules in kaolinite with serine

A kaolinite-serine intercalation compound was formed via the guest displacement method. The results show that serine can be intercalated into kaolinite to form kaolinite-serine by exchanging it with the guest molecules of ethylene glycol or water in the interlayer instead of inserting it directly into kaolinite. The activation energy Ea for releasing the pre-intercalated molecule before intercalation controlled the degree of serine insertion into kaolinite based on N = 0.9 − A exp (− Ea/RT). This value was 6.95 kJ/mol for ethylene glycol and 21.2 kJ/mol for water as transition molecules. The intercalation degree of the former was 45%, and that of the latter was 85%, which was ~ 1.8 times the value of the former. The kaolinite-serine intercalation compound is expected to be applied in the pharmaceutical and cosmetics fields.181