Preparation and characterization of new Ca–Al–polycarboxylate layered double hydroxides

The synthesis and characterization of composite materials based on calcium–aluminum layered double hydroxides (Ca–Al-LDHs), intercalated with organic polycarboxylate (PC) polymers, is described. The PC polymers, which exhibit a “comb-like” architecture, contain ethylene oxide side chains of different lengths. They are intercalated between the cationic Ca–Al–OH-layers when tricalcium aluminate is rehydrated in the presence of PC polymers. The intercalation compounds are characterized by X-ray diffraction (XRD), elemental analysis, IR spectroscopy and TEM. The basal spacings of the PC-LDH composite materials, determined by XRD, are dependent on the number of the ethylene oxide units (EOUs) in the side chain. Accordingly, first TEM micrographs reveal approximately similar layer distances. Elemental analysis as well as IR-spectroscopy proves the existence of the intercalated organic material.