Chemical Force Microscopy on Single-Walled Carbon Nanotube Paper

Topographical and adhesive force measurements were acquired simultaneously on single-walled carbon nanotube (SWNT) paper using chemically modified atomic force microscopy probe tips. Gold-coated cantilever probe tips were chemically modified with a series of ω-substituted alkanethiols or para -substituted arylthiols. The observed adhesion forces were highly dependent on the contact area between the tip and paper, the type of thiol (alkane versus aryl), and the identity of the terminal group. The adhesion force per molecule interacting with the sidewall of single-walled carbon nanotubes was elucidated after correcting for variations in tip shape and sample topology.