Energy / Environment 3


Dr Anthony M Granville


Figure 1. Schematic design for the polydopamine coating on a substrate material

Mussels and other bivalves excrete a natural polymeric adhesive shown to be water insoluble, tough, and nontoxic.  This material can be synthetically manufactured using dopamine as the monomeric material in a rather simple, weakly basic, aqueous solution.  The dopamine compound will cyclise to form an indole intermediate before crosslinking to form the desired polymer.  When a substrate is immersed in the aqueous solutions system, the polydopamine will form a homogeneous coating on the substrate surface (Figure 1).  This paves the way for simple, benign coatings of a controlled thickness to be used for drug delivery, surface modification, and metal binding for electronic applications.

Unfortunately, no research work has been done to investigate the universality of this reaction scheme.  What other monomers, structurally similar to dihydroxyindoles (the generally accepted active monomer molecule for the polymerisation) can also be used in this reaction?


Figure 2. Reaction scheme for the synthesis of poly(dihydroxybenzimidazole) and its similarity to polydopamine

As a means of answering this basic question, we began researching the synthesis, and subsequent polymerisation, of 5,6-dihydroxybenzimidazole (DHBI).  Polybenzimidazoles are renowned for their high temperature properties as well as their ability to be used as proton exchange membranes when doped with acids.  However, these materials are generally made through a highly industrially unfriendly process, using toxic organic solvents to dissolve and cast the polymers when formed.  The ability to generate these materials using a facile, room temperature, aqueous system akin to the polydopamine process would represent a significant paradigm shift and the potential to increase the usefulness of these materials in the energy storage and transfer realms.  Currently, our labs is developing this project further and patent filings in this area have been done and can be investigated further through contacting NSInnovations at UNSW.




  • Expanding the mussel-inspired self-polymerization system beyond dopamine – the aqueous polymerization of 5,6-dihydroxy-1H-benzimidazole, K. W. Fan, P. Ellersdorfer, A. M. Granville, Nature Mat., 2014, submitted.
  • Incorporation of 5-Hydroxyindazole into the Self-Polymerization of Dopamine for Novel Copolymer Synthesis, M. B. Peterson, S. P. Le-Masurier, K. Lim, J. Hook, P. Martens, A. M. Granville, Macromol. Rapid Commun. 2014, 35(3), 291 - 297.