Mechanical properties of individual electrospun polymer-nanotube composite nanofibers

Singlewalled carbon nanotube/polyvinylalcohol composite nanofibers were electro-spun onto a silicon surface pre-patterned with trenches. These nanofibers were prepared with different loadings of SWCNTs and had radii between 20 and 40 nm. Individual fiber sections were pinned across the trenches and laterally loaded by an AFM tip to yield mechanical response curves. A simple model was exploited to extract the tensile mechanical properties from the lateral force-displacement data. Depending on the fiber composition, the tensile modulus was found to be between 3 and 85 GPa. In addition we have prepared fibers with tensile strength of up to 2.6 GPa. Such optimised fibers break at strains of ∼4% and exhibit toughness of up to 27 MJ/m³.