Insights into the Rupture Surface Formation in Self-Healing Polydimethylsiloxane with Ni(II) Complexes by Molecular Dynamic Methods

Forecasting and theoretical evaluation of the self-healing ability of a material requires an analysis of the structural features on the boundary of phase interfaces formed upon material destruction under mechanical stress. In our study, the structural organization of surfaces arising upon mechanical rupture was analyzed using the structural models of Ni(II)pyridinedicarboxamide and polydimethylsiloxane copolymer, Ni-PDC-APDMS, constructed by molecular dynamics methods (MD). A novel protocol of the rupture gradually forming under the action of stretching strains was presented. The suggested approach for identifying the surface of the walls for copolymer rupture is based on analysis of changes in the substance density along the direction of the stretching strain. It was shown that with an increase of Ni(II) in the composition of the Ni-PDC-APDMS material, its rupture resistance increases. The less Ni(II) in the copolymer, the more water molecules that are concentrated on the walls of the forming rupture. We believe that considering the structure and composition factors of the rupture surface will help in studying the self-healing processes of metal-complex polymers.