Fabrication of densely packed multi-walled carbon nanotube ultrathin films using a liquid–liquid interface

We describe the fabrication of a densely packed ultrathin film of multi-walled carbon nanotubes (MWCNTs) at a liquid–liquid interface. The MWCNTs, which were synthesized using an anodic aluminium oxide (AAO) film as a template, were dispersed in water. Then hexane was added to the dispersion to create the liquid–liquid interface. The MWCNTs were smoothly assembled at the interface to form an ultrathin film when ethanol was added to the MWCNT water dispersion/hexane solution. The ultrathin film can be transferred onto a solid substrate using the Langmuir–Blodgett deposition technique. With addition of 10 vol% ethanol to the solution, an ultrathin film of MWCNTs with coverage of about 70% was fabricated. The multilayer film was fabricated by repeated deposition of the ultrathin film.