title: Gas-Barrier Hybrid Coatings by the Assembly of Novel Poly(vinyl alcohol) and Reduced Graphene Oxide Layers through Cross-Linking with Zirconium Adducts.
abstract: Gas-barrier materials obtained by coating poly(ethylene terephthalate) (PET) substrates have already been studied in the recent literature. However, because of the benefits of using cheaper, biodegradable, and nonpolar polymers, multilayered hybrid coatings consisting of alternate layers of reduced graphene oxide (rGO) nanosheets and a novel high amorphous vinyl alcohol (HAVOH) with zirconium (Zr) adducts as binders were successfully fabricated through a layer-by-layer (LbL) assembly approach. Atomic force microscopy analysis showed that rGO nanoplatelets were uniformly dispersed over the HAVOH polymer substrate. Scanning and transmission electron microscopies revealed that multilayer (HAVOH/Zr/rGO)n hybrid coatings exhibited a brick-wall structure with HAVOH and rGO as buildings blocks. It has been shown that 40 layers of HAVOH/Zr/rGO ultrathin films deposited on PET substrates lead to a decrease of 1 order of magnitude of oxygen permeability with respect to the pristine PET substrate. This is attributed to the effect of zirconium polymeric adducts, which enhance the assembling efficiency of rGO and compact the layers, as confirmed by NMR characterization, resulting in a significant increment of the oxygen-transport pathways. Because of their high barrier properties and high flexibility, these films are promising candidates in a variety of applications such as packaging, selective gas films, and protection of flexible electronics.
authors.affiliation: Institute of Polymers, Composites and Biomaterials, National Research Council , Piazzalle Fermi, 1-80055 Portici, Naples, Italy.|Xi'an Modern Chemistry Research Institute , Xi'an 710065, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Yan
authors.affiliation: Institute of Polymers, Composites and Biomaterials, National Research Council , Piazzalle Fermi, 1-80055 Portici, Naples, Italy.
authors.forename: Filomena
authors.initials: F
authors.lastname: Capezzuto
authors.affiliation: Institute of Polymers, Composites and Biomaterials, National Research Council , Piazzalle Fermi, 1-80055 Portici, Naples, Italy.
authors.forename: Giovanna G
authors.initials: GG
authors.lastname: Buonocore
authors.affiliation: Institute of Polymers, Composites and Biomaterials, National Research Council , Piazzalle Fermi, 1-80055 Portici, Naples, Italy.
authors.forename: Marino
authors.initials: M
authors.lastname: Lavorgna
authors.affiliation: State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute of Sichuan University , Chengdu 610065, China.
authors.forename: Hesheng
authors.initials: H
authors.lastname: Xia
authors.affiliation: Institute of Polymers, Composites and Biomaterials, National Research Council , Piazzalle Fermi, 1-80055 Portici, Naples, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Ambrosio
keywords: barrier properties; high amorphous poly(vinyl alcohol); layer-by-layer assembly; polymeric zirconium adducts; reduced graphene oxide