Tuning aggregation and charge transfer of poly(3-hexylthiopene) nanoparticles by graphene oxide

Resumen del trabajo presentado a la International Conference on Carbon Nanoscience and Nanotechnology (NanoteC), celebrada en Nantes (Francia) del 30 de agosto al 2 de septiembre de 2017.Nanoparticles derived from conjugated polymers have attracted widespread attention for a number of reasons such as their easy synthesis, tuneable properties, less toxicity and environmentally friendly processing conditions for device fabrication. Besides, their properties can be enhanced by preparing composites with carbon nanomaterials. Poly-3-hexyl thiophene (P3HT), the archetype of conducting polymers, is characterized by the presence of quasi-crystalline domains (i.e. H, J or H-J aggregates) defining the electro-optical properties. However, reliable control of these nanoscale aggregates plays an essential role to tune charge transport and charge separation properties. In this work, we report the self-assembly of novel conjugated polymer nanoparticle/graphene oxide (P3HTNPs/GO) composites using a re-precipitation technique. The resulting composites are stable in aqueous dispersions and can be processed directly instead of usual hazardous chlorinated solvents. Photophysical studies reveals that the internal aggregate structure of the P3HTNPs is affected by GO and can be tuned by varying the amount of GO. Meanwhile, Raman spectroscopy and cyclic voltammetry reveal that the observed changes in the P3HTNP aggregate structure of the P3HTNPs/GO composite are accompanied by a charge transfer process taking place at the interface between P3HTNPs and the GO sheets. Our synthesis approach leading to novel P3HTNPs/GO composites with tuneable electro-optical properties and environmental-friendly processing characteristics thus may provide a base for the development of further functional nanomaterials for variety of applications for photovoltaic or sensing applications.EU H2020 MSC ITN 642742. MINECO (ENE2016-79282-C5-1-R). DGA-T66-GCNN.Peer reviewe