Carbon nanotube imprinting on a polymer surface

Imprinting of multi-walled carbon nanotubes (CNTs) on the surface of a polymer sheet was demonstrated using interphase CNT transfer from one polymer to another. A pure polycarbonate (PC) sheet was placed on top of a sheet of a polypropylene (PP)/CNT composite and annealed at either 200 or 300 °C. It was found that CNTs move from the PP/CNT composite to the PC during annealing. The sheets of PP/CNT and PC were easily separated because of the large interfacial tension between PP and PC. The formation of a thin CNT-rich layer on the surface of the separated PC sheet produces electrical conductivity. Consequently, a conductive sheet is obtained with 2 wt.% of CNTs only in the thin surface layer. Since the CNT transfer is attributed to Brownian motion, the annealing conditions such as temperature and time are responsible for the diffusion. The polymer species decides the ability of the CNTs to transfer.