Oxidative Layer-By-Layer Multilayers Based on Metal Coordination: Influence of Intervening Graphene Oxide Layers

Mikko Salomäki, Jussi Kauppila, Jouko Kankare, Jukka Lukkari

    Research output: Contribution to journalArticleScientificpeer-review

    2 Citations (Scopus)

    Abstract

    Layer-by-layer (LbL) fabricated oxidative multilayers consisting of successive layers of inorganic polyphosphate (PP) and Ce(IV) can electrolessly form thin conducting polymer films on their surface. We describe the effect of substituting every second PP layer in the (PP/Ce) multilayers for graphene oxide (GO) as a means of modifying the structure and mechanical properties of these (GO/Ce/PP/Ce) films and enhancing their growth. Both types of LbL films are based on reversible coordinative bonding between the metal ions and the oxygen-bearing groups in PP and GO, instead of purely electrostatic interactions. The GO incorporation leads to the doubling of the areal mass density and to a dry film thickness close to 300 nm after 4 (GO/Ce/PP/Ce) tetralayers. The film roughness increases significantly with thickness. The (PP/Ce) films are soft materials with approximately equal shear storage and loss moduli, but the incorporation of GO doubles the storage modulus. PP displays a marked terminating layer effect and practically eliminates mechanical losses, making the (GO/Ce/PP/Ce) films almost pure soft elastomers. The smoothness of the (PP/Ce) films and the PP-termination effects are attributed to the reversible coordinative bonding. The (GO/Ce/PP/Ce) films oxidize pyrrole and 3,4-ethylenedioxythiophene (EDOT) and form polypyrrole and PEDOT films on their surfaces. These polymer films are considerably thicker than those formed using the (PP/Ce) multilayers with the same nominal amount of cerium layers. The GO sheets interfere with the polymerization reaction and make its kinetics biphasic. The (GO/Ce) multilayers without PP are brittle and thin.
    Original languageUndefined/Unknown
    Pages (from-to)13171–13182
    Number of pages12
    JournalLangmuir
    Volume34
    Issue number44
    DOIs
    Publication statusPublished - 2018
    MoE publication typeA1 Journal article-refereed

    Keywords

    • Chemistry and Materials Science

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