The synergetic effect of chiral organoclay and surface modified-Al2O3 nanoparticles on thermal and physical properties of poly(vinyl alcohol) based nanocomposite films

In the present investigation, poly(vinyl alcohol) (PVA)/organoclay/surface modified Al2O3 nanocomposites (POANC)s of different compositions were prepared by solution intercalation method. The nanocomposite films were obtained by mixing a colloidal solution consisting of surface modified Al2O3 nanoparticles (1, 3 and 6 wt%) with a water solution of PVA and organoclay (10 wt%) via ultrasound-assisted technique. Field emission scanning electron microscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy, thermogravimetric analysis (TGA), and UV-vis spectroscopy were utilized to characterize the morphology and properties of the POANCs. TGA and UV-vis results indicated that the thermal stability was enhanced distinctly, without a sacrifice in optical clarity. The improvement in the thermal properties of the hybrid materials was due to strong hydrogen bonding between O-H groups of PVA, free acid functionalized groups of organoclay and the oxygen atoms of Al2O3 nanoparticles. TEM and FE-SEM results also showed that the organoclay and Al2O3 were dispersed homogeneously in PVA matrix. (C) 2012 Elsevier B.V. All rights reserved.