Morphological and rheological characterization of gold nanoparticles synthesized using Pluronic P103 as soft template

The synthesis of gold nanoparticles (Au-NPs), using Pluronic® P103 as soft template to design tuned hybrid gold/P103 nanomaterials, is reported here. The effect of the concentration of P103 and the synthesis temperature on the growth, size, and morphology of Au-NPs were studied. The rheological properties of these hybrid nanomaterials at different measured temperatures were studied as well. By increasing the concentration of P103, the micelles progressively grew due to an increase in the number of surface cavities. These cavities came together causing large nucleation centers and developing larger Au-NPs. The synthesis temperature was varied to induce significant dehydration of the P103 micelles. Below the cloud point temperature micelles underwent distinct changes related to spherical-to-polymer-like micelles transitions. Two nanostructures were formed: (1) small Au-NPs arranged on the surface of micelles, which acted as soft templates, and (2) large and independent Au-NPs. Above the cloud point temperature, Au-NPs were related to the shape and size of the P103 micellar aggregates. Rheological measurements showed that viscosity was sensitive to the concentration of P103. Also, it was demonstrated that synthesis temperature had a considerable influence on viscosity of the produced nanomaterials.