Fabrication of high conductivity dual multi-porous poly (l-lactic acid)/polypyrrole composite micro/nanofiber film

Dual multi-porous PLLA (poly(l-lactic acid))/H2SO4-doped PPy (polypyrrole) composite micro/nano fiber films were fabricated by combining electrospinning with in situ polymerization. The morphologies and structures of the resulting samples were analyzed by scanning electron microscopy (SEM). It was found that the composite micro/nano fibers exhibited a core–shell structure and the composite fiber film had a dual multi-pore structure composed of pores both in the fibers and among the fibers. Semiconductor parameter analyzer was used to characterize the electrical properties of the samples. It was interesting to find that all the PLLA/H2SO4-doped PPy composite micro/nano fiber films had higher conductivity than H2SO4-doped PPy particles when the polymerization time up to 180 min. Effects of the pyrrole synthesis conditions on the pore size and the conductivity of PLLA/PPy composite fiber film were assessed. By optimizing the polymerization conditions, the max conductivity of this composite fiber film was about 179.0 S cm−1 with a pore size of about 250 μm. The possible mechanism of PLLA/H2SO4-doped PPy composite micro/nano fiber films had much higher conductivity than H2SO4-doped PPy particles was discussed.

► PLLA/H2SO4-doped PPy composite micro/nano fibers dual multi-pore membranes with high conductivity were fabricated by combining electrospinning with in situ polymerization.These composite fibers have a core–shell structure, the PPy is the core and the PLLA/PPy is the shell.
► The size and shape of the pores in this PPy composite fiber membrane can be tuned by polymerization parameters. The largest size of the pores is about 250 μm.
► The conductivity of this composite fiber membrane can be adjusted by polymerization parameters. The highest conductivity is 179.0 S cm−1. The PLLA fibers act as the template in the pyrrole polymerization process and contributed to the increase of the conductivity.