A small-angle neutron scattering and rheology study of the composite of chitosan and gelatin

The composite chitosan/gelatin solutions and films formed from these solutions were studied by rheological measurements, SANS and tensile tests. The relationship between the inter-molecule interactions with microstructure, rheological behaviour of a solution and eventually the mechanical performance of formed films was established. It was found that the complex formed between chitosan and gelatin was mainly through hydrogen bond but the size of the structure was also affected by electrostatic repulsions. The local structure (correlation length) and the global structure (large inhomogeneous structure size) in the composite solutions were found to be highly correlated to each other. It was also found that the interactions between these two polymers in solution were closely related to the mechanical properties of the formed films. This work will enable one to design films with desired mechanical properties through the combination of different polymers at optimum weight ratios.