Multiwalled carbon nanotube reinforced fibers electrospun from regenerated silk fibroin aqueous solutions

摘要

Nanocomposite fibers of Bombyx mori silk and multiwalled carbon nanotubes (MWNTs) were successfully prepared by electrospinning process from aqueous solutions, which blended with a dispersion of MWNTs in water. Scanning electron microscopy (SEM), Raman spectroscopy, wide angle X-ray diffraction (WAXD), and tensile testing were used to characterize the morphology, structure, and mechanical properties of the nanocomposite fibers with different weight fractions of MWNTs of 0, 0.25%, 0.5%, 1% and 1.5%. SEM showed that the reinforced fibers were ribbon-like and smaller than the un-reinforced fibers in cross sectional area. Raman spectroscopy demonstrated that MWNTs were well embedded in the RSF fibers, and indicated that the nanocomposite fibers had more β-sheet content than the pure RSF electrospun fibers. WAXD result proved that the electrospun silk fibers with MWNTs had higher crystallinity than the fibers without MWNTs. The mechanical properties of the RSF electrospun fibers were improved drastically by incorporating MWNTs. Compared with the pure RSF electrospun fibers, the composite fiber mats with 1% MWNTs exhibited a 2.8-fold increase in breaking strength, a 4.4-fold increase in Young's modulus and a 2.1-fold increase in breaking energy.