CdSe/polyvinyl alcohol nanocomposite films for packaging: thermal, mechanical, optical and physico-chemical properties

CdSe nanostructures, well-investigated for their optical properties, have been evaluated here as functional fillers in polyvinyl alcohol (PVA) films, for packaging applications. Polymer-nanocomposite films of PVA and CdSe nanoparticles (nanospheres and nanorods), were evaluated for their thermal, mechanical, optical and physico-chemical properties. Microemulsion-synthesized CdSe were loaded in PVA films by solution casting method. CdSe-PVA films were prepared at varying morphology (spherical to rod-like) of CdSe, by controlling the reaction time (0, 2, 4, 6 and 8 h) at 1% (by weight) loading. The effect of loading of CdSe was also studied at 0.1, 0.5, 1, 5, and 10% (by weight) for the reaction time of 4 h. CdSe nanoparticles were characterized by high-resolution transmission electron microscopy (HR-TEM) and X-ray diffractometry (XRD). The melting point and heat of fusion of CdSe-PVA films (for the reaction time of 4 h) exhibited the maximum values of 216.9 +/- 0.73 degrees C and 6.78 +/- 0.24 J/g, respectively, at 1% (by weight) of CdSe, as compared with 209.8 +/- 0.52 degrees C and 3.76 +/- 0.1 J/g for plain PVA film. The CdSe-PVA films with spherical CdSe showed the maximum enhancement of 118 and 87.4% for Young's modulus (MPa) and modulus of toughness (MPa), respectively as compared with PVA films. With increasing load of CdSe, the CdSe-PVA films showed an increase in the two moduli with maximum enhancement of 124 and 57 at 10% (by weight) of CdSe, as compared with PVA films. The optical, colorimetric, chemical resistance, UV-hindrance, water content and antibacterial properties of CdSe-PVA films were also investigated.