Nano-hybrid materials and nano-composite materials based on PVA

Abstract

Layered double hydroxides (LDHs) are a class of synthetic two-dimensional nano-structured anionic clays whose structure can be described as nano-layered ordered material. This study aims to use nano-layered materials as a host for Azo-compounds to form nano-hybrid materials and as filler for poly vinyl alcohol (PVA) to form nano-composite materials. A large anionic pigment (phenyl azobenzoic sodium salt; orange colour) has been intercalated into Zn-Al LDH and X-ray diffraction patterns showed that the interlayer spacing of Zn-Al LDH increased from 0.77 nm to 1.9-2.8 nm. Thermal analyses (TG and DTA) revealed the presence of a complex system of supra-molecular host-guest interactions. Nano-composite based on nano-hybrid Zn-Al-Azo LDH and PVA was prepared through intercalation reactions. It was characterised by X-ray diffraction, UV-Visible absorption spectra and thermal analyses. The results suggest that the nano-composites are formed via the re-aggregation of the delaminated LDH lamellar with the interlayer spacing 3 nm, and the thermal stability of the nano-composite improved compared with the original PVA.