The Intercalation of n-Alkylamines into Layered Transition Metal Phosphates-Solvent Effect

Abstract

Abstract The intercalation of n-alkylamines (carbon number 1–18) into γ-titanium phosphate and γ-zirconium phosphate was examined in aqueous, methanol, and benzene solutions. The interlayer spacings increased with an increase in the carbon number of alkylamines, showing the formation of bilayers of alkylamines in a similar manner to that in previous reports. The intercalation reaction depended on the solvents used to dissolve the alkylamines. For example, an anomaly was observed regarding intercalation in ethanol solutions. The interlayer spacings decreased when the carbon number exceeded 14–16, indicating a distortion or the monolayer formation of alkylamines. The rate of intercalation was also seriously affected by the kind of solvents. Intercalation occurred almost instantaneously in aqueous solutions. The rate of the intercalation reaction was generally faster in benzene solutions than that in ethanol solutions. The formation of bilayers was also more perfect in benzene solutions, and resulting interlayer spacings were slightly larger than those prepared in ethanol solutions. The anomaly in ethanol was attributed to a disturbance due to the cointercalation of methanol molecules. The solvent effect was also accountable due to the dielectric constant, or dipole moment, of solvents.