Effect of clay content, homogenization RPM, pH, and ultrasonication on mechanical and barrier properties of fish gelatin/montmorillonite nanocomposite films

The effect of clay content, homogenization RPM, and pH on the mechanical and barrier properties of fish gelatin/nanoclay composite films was investigated. The addition of 5% nanoclay (w/w) increased the tensile strength from 30.31 ± 2.37 MPa to 40.71 ± 3.30 MPa. The 9 g clay/100 g gelatin film exhibited the largest improvements in oxygen and water barrier properties. Oxygen permeability decreased from 402.8 × 10−6 ± 0.7 × 10−6 g m/m2 day atm to 114.4 × 10−6 ± 16.2 × 10−6 g m/m2 day atm and the water vapor permeability decreased from 31.2 × 10−3 ± 1.6 × 10−3 ng m/m2 s Pa to 8.1 × 10−3 ± 0.1 × 10−3 ng m/m2 s Pa. The XRD and TEM observation suggested that the ultrasonication treatment (30 min at 40% output) resulted in exfoliation of the silicates.