Microstructure and transmission electron microscopy characterization of electroless Ni-B thin films deposited on MWCNTs

In this work we report on the Ni-B electroless coating of multiwall carbon nanotubes (MWCNTs). Characterization was carried out using scanning electron microscopy, high-resolution transmission electron microscopy, X-ray diffraction, Raman spectroscopy and thermogravimetric analysis. Prior to Ni-B coating MWCNTs were cleaned, sensitized and activated. Then the electroless coating was achieved by immersion for 1, 3 and 5 min. For immersion time of the 5 min the obtained coatings were homogeneous along the MWCNTs and without voids; the structure is mainly crystalline with some amorphous regions. This coating process was developed to give MWCNTs thermal stability on air and to change its superficial properties for several applications, mainly to be homogeneously mixed with liquid metals to increase their mechanic properties.