Influence of Graphene Oxide Incorporation and Chemical Cross-Linking on Structure and Mechanical Properties of Layer-by-Layer Assembled Poly(VinylAlcohol)-Laponite Free-Standing Films

摘要

Functional fillers in multilayered films provide opportunity in tailoring the mechanical properties through chemical cross-linking. In this study, Laponite-graphene oxide co-dispersion was used to incorporate graphene oxide (GO) easily into polyvinyl alcohol (PVA)/Laponite layer-by-layer (LBL) films. The LBL films were found to be uniform and the layer thickness increased linearly with number of depositions. The process was extended to a large number of depositions to investigate the macroscopic mechanical properties of the freestanding films. The LBL films showed remarkable improvements in mechanical properties as compared to neat PVA film. The GO-incorporated LBL films displayed higher enhancements in the tensile strength, ductility, and toughness as compared to that of PVA/Laponite LBL films, upon chemical cross-linking. This suggests the advantageous effects of GO incorporation. Interestingly, cross-linking of LBL films for longer time period (>1 h) and higher temperature (similar to 80 degrees C) was not found to be much beneficial. (C) 2016 Wiley Periodicals, Inc.