Nanosphere composite materials are often synthesized using layer-by-layer deposition (LbL) of cationic and anionic organic polymers. We investigate the synthesis and characterization of multilayer-coated gold nanoparticles (AuNPs) with alternating organic and inorganic layers. Rather than using an organic polyanion polymer, we employ polyoxometalates (POMs) as our anionic layer in the synthesis of novel nanospheres. These well-defined anionic metal-oxygen clusters maintain their structural integrity in acidic environments and during multi-redox reactions, making them a promising candidate for use in electrocatalysis applications. We are currently layering bare AuNPs with Poly(allylamine) (PolyA) as the organic cationic polymer and silicotungstic acid (STA) as our inorganic anionic layer. Additionally, we are also investigating another POM, phosphomolybdic acid (PMA), as our inorganic layer. We have deposited two sets of PolyA/STA layers in water which we confirmed using UV-visible spectroscopy (UV-vis), Zeta potential, dynamic light scattering (DLS) and inductively coupled plasma optical emission spectroscopy. UV-vis and DLS data show an increase in hydrated diameter and Zeta potential shows an alternating positive or negative charge after the deposition of each layer to the gold core. However, this method yielded high levels of aggregation. Using an acidic solvent and controlling the mixing process decreases aggregation and increased electrostatic interactions evident by a blue shift in wavelength absorbances and an increase in charge variation with each layer.

Synthesis of polymer/polyoxometalate multilayered gold nanoparticles

255th National Meeting (2018)

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