The swelling behaviour can affect the mechanical properties of the composite film and altering their ability to recover adsorbed substances. These problems are particularly important in the case of porous polymers. Therefore, several researchers have tried to improve the swelling properties by reducing the hydrophilic properties of gelatine and chitosan with adding reinforcing fillers. In this paper, the addition of the hydrophobic properties of pith and cortex of Napier grass in the chitosan/gelatin composite film will be investigated. The composite films were prepared via solution casting method will be evaluated based on the swelling behaviour in the alkali, neutral and acid solution. The result shows that type of reinforcement material and aqueous media used would affect the swelling behaviour of composite film. The results also suggest that the chitosan/gelatin composite films with incorporated cortex of Napier grass are the most water-resistant in neutral followed with acid and alkali.
