Dispersion of chiral amino acid organomodified Cloisite Na+ in poly(vinyl alcohol) matrix for designing of novel bionanocomposite films

In this study the inorganic nanolayers of Cloisite Na+ was modified with ammonium salt of L-valine amino acid (Val) and then it was dispersed in poly(vinyl alcohol) (PVA) matrix. The PVA/Cloisite Na+/Val bionanocomposites (BNC)s were prepared by solution intercalation technique using ultrasonic irradiation. The reaction between this novel organically modified Cloisite Na+ and PVA occurred by the hydrogen bonding and hydrophobic interactions. The basal spacing of the Cloisite Na+/Val was studied by X-ray diffraction. The thermal stability and optical clarity of PVA and PVA/Cloisite Na+/Val are also studied by thermogravimetric analysis (TGA) and UV-visible transmission spectra, respectively. TGA results show that using Cloisite Na+/Val in the PVA matrix improved the thermal stability property of the resulting BNC films. The morphological image of synthesized materials was studied by scanning electron microscopy. and transmission electron microscopy. The nanocomposite structure study specified a coexistence of exfoliated and intercalated Cloisite Na+/Val layers in the PVA matrix. (C) 2011 Elsevier B.V. All rights reserved.