Theoretical Investigation on the Thermal Stability of Hollow Gold Nanoparticles

Abstract

The thermal stability of hollow gold nanoparticles has been studied by molecular dynamics (MD) simulations. On the basis of the MD simulation results, the hollow nanoparticles have been classified into three categories, namely, stable, half-stable, and unstable systems. The stability of hollow nanoparticles strongly depends on the wall thickness and the aspect ratio, defined as the outer radius over the wall thickness. These features can be further presented in a two-dimensional phase space according to a large number of simulations. By using this stability diagram, the collapsing mechanism has been proposed.

Size Dependent Properties of Hollow Gold Nanoparticles: A Theoretical Investigation

“…This trend is observed in MD simulations as shown in Fig. 3 and in agreement with the other theoretical calculations obtained by Jiang et al [7]. Figure 3a shows the predicted results due to different aspect ratios up to 5.…”

“…Jiang et al [7] have created the diagram of the twodimensional phase space of the thermal stability using MD simulations at a temperature of 300 K. During the relaxation process, the HGNPs are classified into three categories, i.e., unstable, half-stable, and stable systems. There is no unstable system when the wall thickness is larger than 2.0 nm.…”

“…Jiang et al [7] noted that when the wall is thicker than 2.5, the system moves from the stable region to the half stationary part in the two-dimensional phase space of the thermal stability. They have predicted, when the wall thickness is constant, that the larger hollow nanoparticle becomes more unstable structure.…”

“…It may be noted that modulating and controlling of these parameters are also dependent on the method used for the synthesis of the nanoparticles. However, another significant phenomenon is possible to observe that the hollow nanostructures similar to nanovoids and nanocavities may become shrinkage or collapse at elevated temperatures which strongly affect their physical and chemical properties [5][6][7]. * e-mail: serapd@trakya.edu.tr; dserap@yahoo.com…”

“…Schwarz and Safran reported first the size dependent material properties of multiwall HNPs [12]. Jiang and coworkers have investigated the thermal stability of hollow gold nanoparticles (HGNPs) with core-shell structured using MD simulations to obtain the stability diagram based on the aspect ratio (the ratio of outer radius over shell thickness) and collapsing mechanism [6,7].…”