Self assembling and crosslinking of polyelectrolyte multilayer films of chitosan and alginate studied by QCM and IR spectroscopy.

The formation of novel biocompatible multilayer films based on the alternate deposition of CHI and ALG was investigated for the first time by QCM-D and FTIR-ATR. A linear increase of the thickness was found during the film build-up. GLUT was used to crosslink the films terminated with either CHI or ALG. A change in the QCM-D signal was observed just in the first case, indicating that crosslinking only takes place in the top CHI layer. The evolution of the dissipation factor during crosslinking was modelled with a first-order kinetics; this reaction was found to be faster for chitosan terminated films with a lower number of multilayers. It was also found that more robust films could be produced by crosslinking the intermediate CHI layers during the build-up.