Improving Mechanical and Morphological Characteristics Pva/Sio₂ Nanocomposites for Food Packing Applications

This study deals with using nano-SiO₂ to enhance the characteristics of PVA for food packing applications. Thin-film of Polyvinyl alcohol (PVA)/nano-silica (nano-SiO₂) was prepared by adding different weights of silica (0, 5, 7, 9) wt. %. Differential scanning calorimetry, atomic force microscopy (AFM), FTIR, and mechanical properties such as tensile strength, modulus, elongation at break, and micro-hardness used to examine the characteristics of PVA/nano-SiO₂ films. The results revealed a dramatic improvement in the PVA/nano-SiO₂ mechanical properties, increasing nano-SiO₂ content to 7 wt %, the value of tensile strength increasing from 62 MPa to 143 MPa. While increasing SiO₂ content to 9 wt.%, the tensile strength decreased to 65 MPa. The study also showed that the value of elongation at break and modulus of elasticity of film increment with increases in the nano-SiO₂ content. There was also an increase in the crystallinity from 0.97 (for pure PVA) to 1.154 at 7wt. % nano-SiO₂. Crystallinity, however, decreased to 0.012 with the increase of SiO₂ to 9 wt. %. FTIR results revealed that there was physical interaction between nano-SiO₂ and PVA. AFM result showed less roughness at 7wt. % from nano-SiO₂. Generally, the results showed that the concentration of 7% of the nano –SiO₂ in thin films resulted in a significant improvement in the mechanical properties of the films. These findings suggest that nano-SiO₂ can be useful as food packaging material to maintain food quality.