  Quasi all water soluble composites use graphene oxide (GO) or reduced
graphene oxide (rGO) as graphene based additives despite the long and harsh
conditions required for their preparation. Herein, polyvinyl alcohol (PVA)
films containing few layer graphene (FLG) are prepared by the co-mixing of
aqueous colloids and casting, where the FLG colloid is first obtained via an
effcient, rapid, simple, and bio-compatible exfoliation method providing access
to relatively large FLG flakes. The enhanced mechanical, electrical
conductivity, and O2 barrier properties of the films are investigated and
discussed together with the structure of the films. In four different series of
the composites, the best Young modulus is measured for the films containing
around 1% of FLG. The most significant enhancement is obtained for the series
with the largest FLG sheets contrary to the elongation at break which is well
improved for the series with the lowest FLG sheets. Relatively high one-side
electrical conductivity and low percolation threshold are achieved when
compared to GO(rGO) composites (almost 10-3 S.cm-1 for 3% of FLG and transport
at 0.5% FLG), while the conductivity is affected by the formation of a
macroscopic branched FLG network. The composites demonstrate a reduction of O2
transmission rate up to 60%.
