Fluorinated carbon nanofiber/polyimide composites: Electrical, mechanical, and hydrophobic properties

The poor multifunction of polyimide (PI) based composites and the weak dispersion of nanofillers in PI matrix greatly limits their broad industrial application. In this paper, fluorine element doping carbon nanofiber (FCNF) was designed, and the FCNF can disperse and embed into the PI matrix commendably, compared with pure PI, even at a very low contents of FCNF (1 wt%), the FCNF/PI composite can endow the PI matrix with a dramatic increment on mechanical strength (77.9%), volume resistivity (77.9%), and hydrophobic properties (35.0%), this can be attributed to the doping of F element in carbon nanofiber, the uniform dispersion of FCNF in composite and strong interfacial interaction between FCNF and the matrix. Meanwhile, TEM and XPS results further proved the doping of fluorine element, and the SEM results also confirmed the uniform distribution of FCNF in the FCNF/PI composites. Moreover, the interface existence the FCNF/PI composite was proved by the synchrotron radiation small angle x-ray scattering (SAXS) experiments. This method provides a novel route for improving the electrical, mechanical, and hydrophobic of PI based composites and a new thought to carry out the application of the FCNF as an advanced nano-material.