Intercalation of ε-caprolactam Ions into Inorganic Hosts

Abstract

The intercalation reaction of ε-caprolactam anion (ε–CL-) into hydrotalcite heated up to 500 °C to expel in its double hydroxide gallery and also that of ε-caprolactam cation (ε–CL+) into mica were successfully performed in their aqueous solutions. The intercalation reaction of ε–CL- into 500 °C heated hydrotalcite was completed within 1 h at 60 °C, and the resultant intercalation compound had the interlayer spacing of 0.77 nm. The intercalation of ε–CL+ into mica, on the other hand, proceeded rather slowly in two steps, which was due to the presence of two species, Na+ and hydrated Na+ in the mica gallery, and gave the intercalation compound with the interlayer spacing of 1.47 nm.