In case of increasing the concentration of nano ZnO as 0.1, 0.3,
0.5% in chitosan film the WVP values decreased from 1.23, 1.08 to
0.69 mg/cm2 /h, respectively, this is because, nano ZnO exhibit high barrier property as well as it gets well dispersed into the chitosan matrix so that it will reduce the hydrogen bonding interaction