In the past decades, there has been increasing interest in using colloidal particles in water (i.e., polymer latexes) to create nanocomposites. Numerous examples of hybrid polymerorganic or polymer-inorganic nanomaterials have been demonstrated, where the polymeric phase is combined with metal oxides, semiconductors, as well as various types of one- or two-dimensional materials such as cellulose nanocrystals (CNCs), carbon nanotubes (CNTs) or clay minerals. Among the various types of particles, those composed of a polymer core surrounded by a shell of conductive graphenic fillers, have attracted particular attention. Indeed, such armored morphology guarantees electrical percolation of the conductive filler upon film formation leading to high conductivity values for very low filler volume fractions. In an ideal situation, the conductive particles can also act as Pickering stabilizers, dispensing with the use of organic surfactants. Most current methods for forming graphene-based colloidal nanocomposites rely on the use of GO as the latter can be easily dispersed in water and functionalized to promote its interaction with the polymer matrix. However, GO is electrically insulating and thermally unstable. Consequently, at least partial reduction is required to restore electrical conductivity, leaving behind some structural defects, affecting therefore the electrical and thermal properties.
The main goal of this PhD thesis is to synthesize graphene-based colloidal nanocomposites with armored morphology to produce conductive film materials. Exfoliated graphene sheets stabilized with functional molecular or colloidal polyelectrolytes, will be incorporated into polymer latexes to form armored particles, resulting after casting in film materials with controlled microstructure and consequently both high electrical and mechanical properties.