Abstract:

The preparation of nano-Fe3+-TiO2 modified PVA/shellac composite film was optimized in the present study. Nano-
Fe3+-TiO2 particles were used to modify polyvinyl alcohol (PVA) solution, and succinylated monoglycerides (SMG) was used
to emulsify and stabilize PVA/shellac solution, and then the solution was dried to form a film. By using the concentration
of nano-Fe3+-TiO2, shellac and SMG as the experimental factors and moisture permeability as the response variables, we
optimized the film formation process by response surface methodology. Antibacterial properties of composite films were
investigated. The results showed that shellac and nano-Fe3+-TiO2 modified PVA could significantly reduce the water vapor
transmission rate of the PVA-based film material (P < 0.05). Shellac concentration had significant interaction effects on
the water vapor transmission rate with nano-Fe3+-TiO2 and SMG concentration (P < 0.05). The optimal concentrations of
Fe3+-TiO2 nanoparticles, shellac and SMG were 9.18, 1.33, and 0.92 g/100 mL, respectively. These results indicated that
appropriate proportion of different components could achieve the lowest water vapor transmission rate for the composite
film. Under visible light irradiation, the composite film produced by the optimized process conditions had high antibacterial
properties, and the viable cell numbers of Salmonella and Listeria were reduced by 1.8 (lg(CFU/mL)) and 1.6 (lg(CFU/mL))
after photocatalysis for 180 min, respectively, compared with single PVA films.

Key words: nano-Fe3+-TiO2, polyvinyl alcohol (PVA), shellac, water vapor transmission, photocatalytic antibacterial property