title: Biopolymeric nanocomposites with enhanced interphases.
abstract: Ultrathin and robust nanocomposite membranes were fabricated by incorporating graphene oxide (GO) sheets into a silk fibroin (SF) matrix by a dynamic spin-assisted layer-by-layer assembly (dSA-LbL). We observed that in contrast to traditional SA-LbL reported earlier fast solution removal during dropping of solution on constantly spinning substrates resulted in largely unfolded biomacromolecules with enhanced surface interactions and suppressed nanofibril formation. The resulting laminated nanocomposites possess outstanding mechanical properties, significantly exceeding those previously reported for conventional LbL films with similar composition. The tensile modulus reached extremely high values of 170 GPa, which have never been reported for graphene oxide-based nanocomposites, the ultimate strength was close to 300 MPa, and the toughness was above 3.4 MJ m(-3). The failure modes observed for these membranes suggested the self-reinforcing mechanism of adjacent graphene oxide sheets with strong 2 nm thick silk interphase composed mostly from individual backbones. This interphase reinforcement leads to the effective load transfer between the graphene oxide components in reinforced laminated nanocomposite materials with excellent mechanical strength that surpasses those known today for conventional flexible laminated carbon nanocomposites from graphene oxide and biopolymer components.
authors.affiliation: School of Optoelectronic Information, University of Electronic Science and Technology of China , Chengdu, Sichuan 610054, P. R. China.|School of Materials Science and Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332-0245, United States.
authors.forename: Yi
authors.initials: Y
authors.lastname: Yin
authors.affiliation: School of Materials Science and Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332-0245, United States.
authors.forename: Kesong
authors.initials: K
authors.lastname: Hu
authors.affiliation: School of Materials Science and Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332-0245, United States.
authors.forename: Anise M
authors.initials: AM
authors.lastname: Grant
authors.affiliation: School of Materials Science and Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332-0245, United States.|Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, College of Chemistry and Chemical Engineering, Hubei University , Wuhan, Hubei 430062, P. R. China.
authors.forename: Yuhong
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: School of Materials Science and Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332-0245, United States.
authors.forename: Vladimir V
authors.initials: VV
authors.lastname: Tsukruk
mesh_terms: D001704:Biopolymers / Q000737:chemistry*; D005349:Fibroins / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry; D053761:Nanocomposites / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry; D013499:Surface Properties
chemical_list: D001704:Biopolymers; D010087:Oxides; D006108:Graphite; D005349:Fibroins