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.