Graphene oxide as a surfactant in the nanostructuring of a conduction polymer: Effect on the electronic structure, chain orientation, and charge transfer dynamics

• Published in: Organic electronics 2019-12, Vol.75, p.105440, Article 105440
• Main Authors: de Matos, Carolina F., Holakoei, Soheila, Yamamoto, Natasha D., Rocco, Maria Luiza M., Zarbin, Aldo J.G., Roman, Lucimara S.
• Format: Article
• Language: English
• Subjects: Conduction polymer; Graphene oxide; Nanostructuring; Pickering emulsion
• ISSN: 1566-1199; 1878-5530
• DOI: 10.1016/j.orgel.2019.105440

The search for new structures, new synthetic paths, and new processing technologies is crucial for the future of electronic devices. In this context, this work reports a novel and simple miniemulsion-way to achieve nanostructured polymers in aqueous solution using graphene oxide (GO) as a surfactant for electronic applications. The materials were prepared using the Pickering emulsion concepts, where the graphene oxide colloidal dispersion was sonicated along with toluene solutions of the organic semiconductive polymer poly[2,7-(9,9-bis(2-ethylhexyl)-dibenzosilole)-alt-4,7-bis(thiophen-2-yl) benzo-2,1,3-thiadiazole] (PSiF-DBT). We have investigated various PSiF: GO ratios as well as the effect of the pH on the thin film preparation, by the liquid-liquid interfacial method. Scanning and transmission electron microscopy (SEM and TEM) and atomic force microscopy (AFM) images showed that the morphology of the films is strongly dependent on both the amount of the polymer and the pH. Infrared spectroscopy suggests the anchoring of Si atoms from the PSiF-DBT in some oxygenated groups of graphene oxide, explaining better the angle-resolved near-edge X-ray absorption fine structure (NEXAFS) results, that indicate an upright-standing molecular orientation for the thiophene units and a lying-down orientation for the benzothiadiazole units. UV–Vis molecular absorption and resonant Auger spectroscopies indicated that the charge transfer is faster the higher are the ratio of PSiF: GO in the film. [Display omitted] •Innovative method to prepare polymeric nanoparticles using graphene oxide as surfactant.•Polymer concentration and pH influences the morphology and the electronic properties.•Simpler synthesis, ability to modulate the morphology and electronic structure.•Charge transfer by controlling the synthesis variables.•Thin film deposition via liquid-liquid interfacial method at ambient conditions.