Humidity-sensitive and Conductive Nanopapers from Plant-derived Proteins with Synergistic Effect of Platelet-like Starch Nanocrystals and Sheet-like Graphene

In the present study, a multifunctional composite nanopaper was developed based on soy protein isolates (SPI) from the synergistic reinforcement of sheet-like graphene (RGO) and platelet-like starch nanocrystals (SNC), providing conductive function as well as enhanced mechanical and barrier properties. As a highly-crystalline and rigid nanoparticle derived from natural polymer, the introduction of SNC improved the dispersion of graphene nanoparticles at the relative ratio of 15/1 (SNC/RGO, w/w), and therefore promoted the electrical conductivity of the composite nanopapers under various humidity atmospheres. Because of hydrogen-bonding interaction from the surface groups, the effect of SNC as dispersing agent for RGO was investigated by rheological analysis of the composite suspensions and meanwhile directly observed by microscopy in the composite films. The proposed strategy of dual-enhanced fillers (with molecular interaction) in the composites can provide remarkable improvement of the properties, with ...