Background:
Chitosan-multiwall carbon nanotubes (CS-MWCNTs) nanocomposites are
an attractive material due to their biocompatibility and possibility to produce nanocomposites with
high conductivities and high mechanical properties. Both electrical and mechanical properties depend
upon the method of MWCNT chemical oxidation; this oxidation affects the interaction of CS
side groups with MWCNT’s surface groups. However, in the literature, there are no reports on how
different methods of MWCNT oxidation will affect the electrical and mechanical properties of related
nanocomposites.
Objective:
The objective of this work is to probe CS-MWCNT nanocomposite’s electrical and mechanical
properties by taking advantage of the presence of interfacial layer and its dependence on the
methods of MWCNTs chemical oxidation routes.
Methods:
Nanocomposites are prepared with non-functionalized MWCNT and functionalized
MWCNTs obtained by chemical oxidation treatments in HNO3 in H2SO4/NHO3 mixtures and commercially
carboxyl-terminated MWCNTs, respectively. Properties of MWCNTs and nanocomposites
were evaluated using SEM, FTIR, Raman, TGA, XRD, impedance and mechanical measurements.
Results:
It was shown that different chemical oxidation routes produce MWCNTs with a different
number of carboxylic groups and defects which influence the interaction between MWCNTs with CS
matrix and thickness of the interfacial layer between MWCNTs and CS matrix. Additionally, it was
shown that the formation of the interfacial layer dominates on the dispersion of MWCNTs and
affects on the electrical and mechanical percolation effects.
Conclusion:
It was shown that contrary to many studies previously reported, good dispersion of
MWCNT does not guarantee obtained nanocomposites with the best electrical and mechanical properties.
Microstructure and mechanical properties of zinc matrix composites reinforced with copper coated multiwall carbon nanotubes
