Effect of nano-SiO₂ on water vapor transmission rate of formed film of PVA- based composite coating-packaging material

Application of polyvinyl alcohol (PVA) in food packaging is greatly limited because of its hydrophilic property. PVA-based composite coating-packaging material was modified by adding nano-SiO2 in order to improve the efficiency of water vapor barrier. The individual and interactive effects of nano-SiO2, stearic acid, and glutaraldehyde on the water vapor transmission of formed film of composite coating-packaging material were investigated by response surface methodology. The results showed that the water vapor barrier performance of the PVA-based composite coating-packaging material could be effectively enhanced by modifying of nano-SiO2. The water vapor transmission ratio of formed film of optimize group (8.18 g/(m2·d)) was decreased by 26.61% (P<0.05) compared with the control group (no nano-SiO2). There were significant interactions between nano-SiO2 and stearic acid and between nano-SiO2 and glutaraldehyde for the effects on the water vapor transmission of formed film of composite coating-packaging material. With the increase of nano-SiO2 within the range below 0.05 g in 100 mL PVA solution (0.05 g/mL), the water vapor transmission rate of composite coating-packaging material was decreased and the water vapor barrier performance was improved with the increase of the proportion of stearic acid and glutaraldehyde .