Ultrasonic-assisted synthesis and characterization of layered double hydroxides intercalated with bioactive N,N′-(pyromellitoyl)-bis-l-α-amino acids

Abstract

In this study Mg/Al layered double hydroxides (LDHs) and organo-modified chiral LDHs were synthesized in one step under green conditions. Co-precipitation reaction of the Al(NO₃)₃·9H₂O, Mg(NO₃)₂·6H₂O and different biocompatible N,N-(pyromellitoyl)-bis-L-amino acids was carried out in aqueous solution in a short time by an ultrasonic technique. Field emission scanning electron microscopy and transmission electron microscopy techniques showed that the resulting products have good crystallinity and uniform morphology. The presence of the bioactive surfactants in the interlayer space of LDH was confirmed by Fourier transform infrared spectroscopy, X-ray diffraction (XRD) and thermogravimetry analysis techniques. As expected, the positions of the basal reflections in the XRD patterns of modified samples are shifted to higher d value indicating the expansion of the interlayer distance. Thermal properties were investigated by the thermogravimetric analysis technique.