  The functionalized graphene sheets (FGS)-polyacrylamide (PAM) composite films
have been prepared by solution cast technique. The FGS have been synthesized by
thermal exfoliation of graphite oxide. Several composites with different weight
% (between 0 to 25 wt %) of FGS loading in PAM have been prepared and
characterized by XRD, SEM, TEM and FTIR spectroscopy. FTIR analysis revealed
the existence of the amide linkage (-NHC= O) between the polymer chain and
oxygenated graphene sheets. The electrical and mechanical properties of FGS-PAM
composite films have been studied by employing low temperature dc electrical
conductivity measurement and nanoindentation technique. A significant increase
in both electrical conductivity and mechanical properties (hardness and elastic
modulus) is observed at 15 wt% loading of FGS in PAM. As the FGS loading
increases from 0 to 25 wt% the conductivity of composite film increases by
seven orders of magnitude (~5.55x10-7 to 1.42 S/cm). The hardness and elastic
modulus of FGS (~15 wt%)PAM film increased four and five fold, respectively as
compared to that of PAM film. To our knowledge studies on FGS-PAM composites
and also improvement of both the electrical and mechanical properties have not
yet been made.
