This
report demonstrates the facile fabrication of conductive,
high-strength, all-carbon “buckyfilms”, which spontaneously
delaminate from their depositing substrates. Electrophoretic deposition
(EPD) is a scalable technique that has been underutilized in the fabrication
of freestanding, bulk carbon nanotube (CNT) materials. Here, Derjaguin–Landau–Verwey–Overbeek
(DLVO) theory is applied to understand and optimize the deposition
process of oxidized multiwall carbon nanotubes. As a result, unprecedented
deposition rates of 0.3 mg/(cm2 min) and film thicknesses
of >40 μm were achieved. The deposited films are electrochemically
reduced to achieve enhanced electrical conductivities (55 S/cm), demonstrating
a freestanding carbon nanotube analogue to reduced graphene oxide.
Examination of the films using electron microscopy revealed a densely
packed structure (1.61 g/cm3) and cross-linking effects,
which produce tensile strengths (>60 MPa) comparable to CNT–epoxy
composites and many common structural polymers. These lightweight,
flexible films and the versatile, scalable method used to produce
them represent promising new technologies for flexible electronics.