Emulsion Polymerization, Dispersion Polymerization Stabilized By Sulfonated Graphene, Sulfonated Carbon Nanotubes

Carbon nanotubes (CNTs), graphene and graphene oxide (GO) as new carbon materials have attracted widespread attention due to their unique structure and excellent properties. However, the poor dispersion and aggregation in a variety of solvents and polymers, which caused by the van der Waals forces, have restricted the wide application of these carbon materials. In this paper, the ability of GO lower the interfacial tension as surfactant and the effect of adding salt (NaCl) on particle adsorption at the oil-water interface were studied; the facile ways to the synthesis of carbon materials were explored:the functionalized, chemically modified CNTs and graphene were obtained by covalent functionalization method and used as the stabilizers for polymerization. Four sorts of GO/PS, Sulfonated graphene/PS (â… ), Sulfonated graphene/PS (â…¡) and Sulfonated MWNTs/PAM nanocomposites have been fabricated; the structures and morphologies of the nanocomposites were characterized; their potential applications were explored. In summary, we obtained the following results:1) The single-layer GO was synthesized using a modified Hummers method. A novel and more practical method was introduced to prepare Pickering emulsion stabilized by GO and salt (NaCl). The ability of GO lower the interfacial tension and the effects of adding salt (NaCl) concentration on particle adsorption at the oil-water interface were studied. After the Pickering emulsion polymerization, the GO/PS nanocomposites were prepared successfully and the morphologies of GO/PS nanocomposites were investigated by TEM and AFM.2) The Sulfonated graphene (â… ) was obtained via facile covalent functionalization with sulfanilic acid by condensation method. It was found that Pickering emulsion could be formed using the functionalized graphene as an effective stabilizer. After the Pickering emulsion polymerization of styrene, the Sulfonated graphene/PS nanocomposites (â… ) were prepared successfully. The morphologies of Sulfonated graphene/PS nanocomposites (â… ) were investigated by TEM and SEM. The results showed that the functionalized graphene could be homogeneously dispersed and incorporated into the PS microspheres.3) The Sulfonated graphene (â…¡) was prepared via reduction of GO followed by covalent functionalization with aryl diazonium salts for attachment of SO3H group and then postreduction with hydrazine. It is noteworthy that the functionalized graphene not only could be use as highly effective solid stabilizer for styrene-in-water Pickering emulsion, but also could be homogeneously dispersed into the production of polystyrene as nanofiller. The results showed that the Sulfonated graphene/PS nanocomposites (II) were prepared successfully and the mechanical, thermal and conductivity properties of polystyrene were remarkably improved at low loading of the functionalized graphene. 4) The Sulfonated MWNTs were prepared via covalent functionalization with aryl diazonium salts for attachment of SO3H group. The Sulfonated MWNTs/PAM nanocomposites were prepared successfully via dispersion polymerization using the functionalized carbon nanotubes as an efficient dispersant. The morphologies of the Sulfonated MWNTs/PAM nanocomposites were investigated by SEM and TEM. The results showed that the functionalized CNTs could be homogeneously dispersed into the PAM matrix. Furthermore, the nanocomposites can remarkably improve load-carrying capacity and anti-wear ability of base stock as a lubricant additive in water-based fluid.