Multi-walled carbon nanotubes (MW-CNTs) were functionalized via covalent linkage of
perfluoropolyether (PFPE) radicals obtained by thermal decomposition of linear PFPE
peroxide, i.e. a macromolecular compound with a linear structure where (CF2CF2O),
(CF2O) and peroxidic units were randomly distributed along the polymer chain.
T O(CF2CF2O)m(CF2O)n(O)V T' + CF2O[(CF2CF2O)m (CF2O)n] T + V CF2O
The PFPE-functionalized MW-CNTs were characterized by X-ray photoelectron
spectroscopy (XPS), thermal gravimetric analysis (TGA), X-ray diffraction (XRD),
scanning electron microscopy (SEM), contact angle (CA) and surface area measurements.
The effects of the chemical treatment on the conductive properties of MW-CNTs were
studied by resistivity measurements at different applied pressures. Moreover, the amount
of PFPE chains linked on carbon nanotubes, the PFPE fluids obtained by homocoupling
side-reactions and the decomposed portion of PFPE were evaluated by mass balances.
After the introduction of PFPE chains on MW-CNTs surface, the water contact angle
measured on molded pellets of modified MW-CNTs significantly increased over 150\ub0.
This result revealed that the modification of MW-CNTs changed their wettability from a
hydrophilic behavior to superhydrophobic, because the low surface energy properties of
PFPE have been transferred to the MW-CNTs surface. From conductivity measurements
we concluded that the covalent linkage of PFPE chains weakly influenced on electrical
properties of conductive MW-CNTs. The experimental results indicated that
fucntionalization with PFPE peroxide is a suitable technique to modify and control
physical-chemical properties of MW-CNTs
