Neutral-cluster implantation in polymers by computer experiments

In this work, we perform atomistic model potential molecular dynamics simulations by means of state-of-the art force-fields to study the implantation of a single Au nanocluster on a polydimethylsiloxane substrate. All the simulations have been performed on realistic substrate models containing up to ∼4.6 × 106 of atoms having depths up to ∼90 nm and lateral dimensions up to ∼25 nm. We consider both entangled-melt and cross-linked polydimethylsiloxane amorphous structures. We show that even a single cluster impact on the polydimethylsiloxane substrate remarkably changes the polymer local temperature and pressure. Moreover, we observe the presence of craters created on the polymer surface having lateral dimensions comparable to the cluster radius and depths strongly dependent on the implantation energy. Present simulations suggest that the substrate morphology is largely affected by the cluster impact and that most-likely such modifications favour the penetration of the next impinging clusters.