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.