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Biomimetic Nanoreactors via in situ Synthesis of Atomically-Thin Gold Sheets and Platinum Nanoclusters
M. McTaggart, C. Malardier-Jugroot, M. Jugroot
Royal Military College of Canada, CA
Keywords: biomimetics, catalysis, gold nanocrystals, self-assembly, supramolecular materials
Summary:
We present the synthesis and activity of broadly stable polymer-metal nanoreactors capable of confinement-enhanced catalysis. Poly(styrene-alt-maleic acid), SMA, is known to self-assemble in water into highly organized supramolecular nanostructures containing confined polar and non-polar reaction spaces. Spontaneous polymerization of pyrrole, a desirable process not typically possible, was discovered to occur under confinement in SMA. The polymer's nanoarchitecture was also found to direct the reduction of hydrophobic salt precursors into atomically-thin gold sheets and monodisperse platinum nanoclusters under ambient conditions. The addition of platinum nanoclusters into the confined reaction space catalyzed polypyrrole synthesis, mimicking the active centres and confinement effects of unsupported bioreactors. Generalization of the nanocrystal synthesis method to gold led to the production of atomically-thin gold nanosheets. UV/vis spectroscopy, transmission electron spectroscopy, and small-angle neutron scattering reveal that the gold and platinum nanocatalysts are produced and remain within respective hydrophilic and hydrophobic confined spaces. Evidence of electronic communication between the platinum and gold systems across the polymer membrane allows for the co-ordination of reactions in the separate polar and non-polar reaction sites such as coupled oxidation and reduction between otherwise immiscible chemicals.
