gold nanoparticles

The stability conditions for mathematical models of carbon monoxide oxidation on the surface of gold nanoparticles are investigated.  The cases of reaction mechanisms of one-step and step-by-step transformation of reagents are consecutively considered.  Using the stability analysis by Lyapunov method, it is shown that models which take into account the possibility of structural changes of the catalyst surface can predict the occurrence of oscillatory mode in the system as a result of Hopf instability.

The obtaining of nanostructured gold in dimethylformamide solutions of HAuCl4 has been investigated. The morphology of gold deposited by chronoamperometry and pulse regime of deposition on the glassy carbon surface was studied. It is established, with growth of cathodic potential values at constant electrical mass the quantity of gold particles is increased and a tendency to agglomeration at stationary electrolysis is observed. Pulse electrodeposition mode allows to obtaining gold nanoparticles with relatively the same geometry and a uniform distribution over the surface. 

By means of molecular dynamics simulations we study formation of the wall-to-wall     percolation cluster in the solution of decorated nanoparticles in a pore. The model takes into account photo-switching between unpolar \trans\ and polar \cis-isomers of azobenzene. This leads to either colloidal dispersion of the particles or their aggregation     in a polar solvent. The dynamics of percolation cluster formation is analysed by applying a pulse-like illumination.