An effect of Fe atom clusters doped CNTs on resistivity of PTFE dielectrics

Polymers are of interest for use on spacecraft surfaces as dielectrics and electrical insulators, and polytetrafluoroethylene (PTFE) is a polymer with mechanical advantages, but low conductivity. Fe-doped carbon nanotubes (CNT) can be added to the polymer matrix and may improve their electrical properties. This work measures the volume and surface resistivity for PTFE and PTFE + Fe-doped CNT test specimens using the Keithley 6517B Electrometer/High Resistance Meter system, by determining current levels through the samples as a function of applied voltage. The system noise current was measured and averaged to be 4.83×10⁻¹⁵ Amps. The results obtained show that both volume and surface resistivities of pristine PTFE increase with increasing voltage. The volume resistivity is higher if compared to the surface resistivity at the same voltage. The conductivities of PTFE + Fe doped CNTs composites are higher as compared to the pristine PTFE, which can be contributed to the Fe-doped CNTs. The conductivity of the PTFE + Fe doped CNTs composite material increases with the concentration of the Fe-doped CNTs.