Intercalation of epsilon-caprolactam ions into inorganic hosts

The intercalation reaction of E-caprolactam anion (epsilon-CL-) into hydrot alcite heated up to 500 degrees C to expel CO32- in its double hydroxide ga llery and also that of E-caprolactam cation (epsilon-CL+) into mica were su ccessfully performed in their aqueous solutions. The intercalation reaction of epsilon-CL- into 500 degrees C heated hydrotalcite was completed within 1 h at 60 degrees C, and the resultant intercalation compound had the inte rlayer spacing of 0.77 nm. The intercalation of epsilon-CL+ into mica, on t he other hand, proceeded rather slowly in two steps, which was due to the p resence of two species, Na+ and hydrated Nai in the mica gallery, and gave the intercalation compound with the interlayer spacing of 1.47 nm.