▎ 摘　　要

In the present study, a multifunctional composite nanopaper was developed on the basis of soy protein isolate (SPI) from the synergistic reinforcement of sheet-like graphene (RGO) and platelet-like starch nanocrystals (SNCs), providing a conductive function as well as enhanced mechanical and barrier properties. As a highly crystalline and rigid nanoparticle derived from a natural polymer, the introduction of SNCs 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 interactions from the surface groups, the effect of SNCs as a 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 simultaneous strengthening and toughening, water-vapor and oxygen permeability reduction, water absorption reduction, and solvent resistance, which may be a novel idea to solve the critical limitations of SPI-based materials in practical applications.