Self-assembly of single-walled carbon nanotubes into a sheet by drop drying

The formation of a thin film at the free surface of a drying drop of single-walled carbon nanotubes (SWNT)-F68, was demonstrated. The phenomenon of crusting at the free surface due to solvent mass transfer across an interface could be employed to fabricate thin crusts and coatings of SWNTs on substrates. Evaporation proceeded at a slower rate through a porous mesh-like crust, and loss of volume enclosed leads to the surface undulation. The results show that the loss of the solvent decreases the volume enclosed by the thin crust and thus inverting the crust resulting into formation of an undulation similar to a collapsing dome.