One-step fabrication of conductive poly(3,4-ethylenedioxythiophene) hollow spheres in the presence of poly(vinylpyrrolidone)

Poly(3,4-ethylenedioxythiophene) (PEDOT) hollow spheres with the size ranged from 130 to 820 nm and a conductivity of 8 × 10−2 S cm−1 were prepared simply and directly via a one-step self-assembly approach in the presence of poly(vinylpyrrolidone) (PVP) as a soft template. It was found that the formation probability of PEDOT hollow spheres depended on the concentration of PVP. Bulk quantities of PEDOT hollow spheres can be obtained readily under the optimal conditions such as the concentration of PVP > 0.175 mM and PVP/EDOT molar ratio <1.4. The electron-rich oxygen atoms on the lactam groups in PVP were proposed to act as the chemically active sites to anchor EDOT cation radicals by virtue of electrostatic interaction and cause the self-assembly of PEDOT hollow spheres. Our investigation for the formation mechanism of PEDOT hollow spheres may shed some light on preparing of other hollow materials by proper molecular design and experimental condition optimization.