Background: The atomic force microscope (AFM) technique has proven to be a useful and
versatile tool for the surface characterization of various materials. AFM is capable of providing three
dimensional representations of surfaces down to the sub-nanometer scale resolution, with even atomic
resolution. The aims of this mini review are to briefly illustrate our personal experience in AFM application
for characterizing plasma-treated surface growth on different substrates, such as fluorocarbon
(CFx) nano-structured films, polyethylene oxide (PEO) substrates and plasma deposited acrilic acid
(pdAA) coatings, and nanocomposite materials, such as polydimethylsiloxane-gold (PDMS-Au) and
chitosan-Au (CTO-Au), including the characterization of nanoparticle powder.
Methods: The CFx films were obtained by plasma enhanced-chemical vapor deposition in the non-contact AFM mode
and pdAA coatings by radiofrequency glow discharges fed with AA vapors and analyzed in the contact AFM mode. Coating
morphology was analized by X-Ray photoelectron microscopy (XPS) and water contact angle (WCA). The AFM images
of PDMS-Au and CTO-Au nanocomposites was also acquired and analyzed for their topography.
Results: The surface topography, the root-mean square (RMS) surface roughness and the mean surface height of CFx
coatings plasma-polymerised on polyethyleneterephthalate (PET) substrates were evaluated by AFM as a function of the
deposition time, and AFM images obtained were used to gain detailed topographical information of the single nanostructure.
By comparing the AFM images of pure PDMS with those of PDMS-Au it was possible to observe the topography of
nanofillers embedded in a polymeric matrix or generated on a polymeric surface and also other main differences between
the two materials.
Conclusion: The AFM technique was shown to be a versatile and promising tool for the morphological characterization
of growth of plasma-treated surfaces, such as CFx nano-structured films, PEO substrates and pdAA coatings, and for the
topographical characterization of nanocomposite materials such as PDMs-Au and CTO-Au. Finally, AFM can be used as
a simple method able to characterize the topography of as-received nanofillers, based on the attachment of the nanopowders
on a bi-adhesive tape and on 3D image processing.