  Self-assembled hierarchical solid surfaces are very interesting for wetting
phenomena, as observed in a variety of natural and artificial surfaces. Here,
we report single-walled (SWCNT) and multi-walled carbon nanotube (MWCNT) thin
films realized by a simple, rapid, reproducible, and inexpensive filtration
process from an aqueous dispersion, that was deposited at room temperature by a
dry-transfer printing method on glass. Furthermore, the investigation of carbon
nanotube films through scanning electron microscopy (SEM) reveals the
multi-scale hierarchical morphology of the self-assembled carbon nanotube
random networks. Moreover, contact angle measurements show that hierarchical
SWCNT/MWCNT composite surfaces exhibit a higher hydrophobicity (contact angles
of up to 137{\deg}) than bare SWCNT (110{\deg}) and MWCNT (97{\deg}) coatings,
thereby confirming the enhancement produced by the surface hierarchical
morphology.
