Nanoscale insight into the exfoliation mechanism of graphene with organic dyes: Effect of charge, dipole and molecular structure

Andrea Schlierf, Huafeng Yang, Elias Gebremedhn, Emanuele Treossi, Luca Ortolani, Liping Chen, Andrea Minoia, Vittorio Morandi, Paolo Samorì, Cinzia Casiraghi, David Beljonne, Vincenzo Palermo

    Research output: Contribution to journalArticlepeer-review

    Abstract

    We study the mechanism of surface adsorption of organic dyes on graphene, and successive exfoliation in water of these dye-functionalized graphene sheets. A systematic, comparative study is performed on pyrenes functionalized with an increasing number of sulfonic groups. By combining experimental and modeling investigations, we find an unambiguous correlation between the graphene-dye interaction energy, the molecular structure and the amount of graphene flakes solubilized. The results obtained indicate that the molecular dipole is not important per se, but because it facilitates adsorption on graphene by a "sliding" mechanism of the molecule into the solvent layer, facilitating the lateral displacement of the water molecules collocated between the aromatic cores of the dye and graphene. While a large dipole and molecular asymmetry promote the adsorption of the molecule on graphene, the stability and pH response of the suspensions obtained depend on colloidal stabilization, with no significant influence of molecular charging and dipole. This journal is © 2013 The Royal Society of Chemistry.
    Original languageEnglish
    Pages (from-to)4205-4216
    Number of pages11
    JournalNanoscale
    Volume5
    Issue number10
    DOIs
    Publication statusPublished - 21 May 2013

    Fingerprint

    Dive into the research topics of 'Nanoscale insight into the exfoliation mechanism of graphene with organic dyes: Effect of charge, dipole and molecular structure'. Together they form a unique fingerprint.

    Cite this