Biopolymeric nanocomposites with enhanced interphases.

Area of Science:

• Materials Science
• Nanotechnology
• Biomaterials Engineering

Background:

• Conventional layer-by-layer assembly (LbL) methods often result in limited mechanical properties for nanocomposite films.
• Silk fibroin (SF) is a promising biopolymer for creating advanced materials.
• Graphene oxide (GO) offers unique properties but requires effective integration into matrices.

Purpose of the Study:

• To fabricate ultrathin and robust nanocomposite membranes using graphene oxide (GO) and silk fibroin (SF).
• To investigate the effect of dynamic spin-assisted layer-by-layer assembly (dSA-LbL) on material properties.
• To achieve superior mechanical performance in GO-based nanocomposites.

Main Methods:

• Fabrication of nanocomposite membranes via dynamic spin-assisted layer-by-layer assembly (dSA-LbL).
• Incorporation of graphene oxide (GO) sheets into a silk fibroin (SF) matrix.
• Analysis of biomacromolecule conformation and nanofibril formation during assembly.

Main Results:

• Dynamic spin-assisted assembly led to unfolded biomacromolecules and suppressed nanofibril formation.
• The resulting laminated nanocomposites exhibited exceptional mechanical properties: tensile modulus of 170 GPa, ultimate strength near 300 MPa, and toughness above 3.4 MJ m(-3).
• Failure analysis indicated a self-reinforcing mechanism driven by GO sheets and a 2 nm SF interphase.

Conclusions:

• The dSA-LbL method significantly enhances the mechanical properties of GO-SF nanocomposites.
• The observed interphase reinforcement facilitates effective load transfer, leading to superior strength.
• These findings present a new pathway for developing high-performance flexible laminated nanocomposites.