Novel PTFE/CNT composite nanofiber membranes with enhanced mechanical, crystalline, conductive, and dielectric properties fabricated by emulsion electrospinning and sintering

Polytetrafluoroethylene/multiwalled carbon nanotubes (PTFE/CNT) nanofiber membranes were prepared by emulsion electrospinning and high temperature sintering. Compared with pure PTFE nanofiber membranes, at low CNT content, the mechanical properties of PTFE/CNT nanofiber membranes were improved. For example, the tensile strength of PTFE/CNT (0.5 wt%) composite nanofiber membranes increased from 2.5 MPa to 5.92 MPa, and the elongation at break increased from 123% to 330%. The conductivity of PTFE/CNT (5 wt%) nanofiber membranes reached 1.5 S/m. Meanwhile, the dielectric constant and dielectric loss of PTFE/CNT (5 wt%) nanofiber membranes are 58.46 and 2372.3 respectively. The PTFE/CNT (1 wt%) composite nanofiber membrane displayed an optimal reflection loss of −53.2 dB with a thickness of 2.0 mm. After adding CNT, water contact angle value was slightly reduced from 135° of pure PTFE to 133.55°, but still has good hydrophobicity. What's more, the obtained PTFE/CNT nanofiber membranes also showed good thermal properties and permeability as well as oil absorption characteristics, endowing it many great potential applications, such as electromagnetic wave absorption, electronic packaging, and oil-water separation and so on.