Interlayer Surface Modification of Layered Perovskite HLaNb2O7·xH2O with Diol Compounds Possessing Ethylene Oxide Chains

Abstract

Grafting reactions between an n-decoxy derivative of ion-exchangeable layered perovskite HLaNb2O7·xH2O and polyethylene glycols (PEGs) with various molecular masses were investigated. X-ray diffraction analysis showed that a reflection corresponding to the interlayer distance of the n-decoxy derivative of HLaNb2O7·xH2O (2.73 nm) disappeared and that new diffraction lines ascribable to smaller interlayer distances, which increased with increases in the molecular mass of PEGs, appeared. The solid-state 13C CP/MAS NMR spectra of the products indicated that ethylene oxide chains were covalently bound to the interlayer surface of HLaNb2O7∙xH2O. The signal assignable the carbons bound to OH groups suggests that the grafting reactions for the formation of Nb-O-C bonds typically involve one of the terminal OH groups in PEGs.