posted on 2021-09-16, 17:08authored byBich Ngoc Tran, Stuart C. Thickett, Vipul Agarwal, Per B. Zetterlund
Electrically
conductive polymer nanocomposite films comprising
reduced graphene oxide (rGO) have been prepared using aqueous emulsion-based
techniques with a specific focus on the effects of the polymer matrix.
Polymer matrices with glass transition temperatures in a suitable
range were selected such that film formation can occur at ambient
temperature via drop-casting of the as-obtained nanocomposite latexes.
The monomers methyl methacrylate (MMA), benzyl methacrylate (BzMA),
and styrene (St) were each copolymerized with n-butyl
acrylate (nBA) using radical polymerization implemented
as miniemulsion polymerization or soap-free emulsion polymerization.
Thermal annealing of the films converted GO to rGO, thus imparting
electrical conductivity. In agreement with theoretical calculations
related to the propensity of GO sheets to operate as Pickering stabilizers
based on polarity and interfacial tension, nanocomposites with higher
electrical conductivity resulted for monomers of lower polarity such
as nBA/St and nBA/BzMA compared
to the more polar system nBA/MMA. Incorporation of
GO resulted in higher Young’s modulus and more brittle materials
regardless of the polymer matrix. The results demonstrate that relatively
subtle changes in the nature of the polymer matrix can have significant
effects on nanocomposite properties.