Highly Ductile Multilayered Films by Layer-by-Layer Assembly of Oppositely Charged Polyurethanes for Biomedical Applications

Multilayered thin films prepared with the layer-by-layer (LBL) assembly technique are typically brittle composites, while many applications such as flexible electronics or biomedical devices would greatly benefit from ductile, and tough nanostructured coatings, Here we present the preparation or highly ductile multilayered Films via LBL assembly or oppositely charged polyurethanes. Free-standing films were found to be robust, strong, and tough with ultimate strains as high as 680% and toughness of similar to 30 MJ/m(3). These results are at least 2 orders of magnitude greater than most LBL materials presented until today. In addition to enhanced ductility, the films showed First-order biocompatibility with animal and human cells. Multilayered structures incorporating polyurethanes open up a new research avenue into the preparation or multifunctional nanostructured Films with great potential in biomedical applications.