The approaches to modeling of self-healing for polydimethylsiloxanes after electrical breakdown

A new approach is proposed for analyzing the efficiency of self-healing of polydimethylsiloxane polymers with bubble-shaped defects that occur after low-power electrical breakdown in polydimethylsiloxane samples. The rheological characteristics of the samples were close to those of amorphous gel-like materials with fairly high transparency. Simulation modeling of the bubble-shaped defect disappearance process was performed, taking into account the dissolution of gases (hydrogen, oxygen, nitrogen, carbon monoxide) in the sample and the effect of surface tension forces on the defect boundary. It is shown that, for small sample sizes, hydrogen and carbon monoxide that occur as a result of electrical breakdown are quickly replaced by nitrogen and oxygen dissolved in the sample due to contact with the atmosphere. It has been established that efficient self-healing of a polydimethylsiloxane sample after a low-power electrical breakdown is possible only with the simultaneous action of both surface tension and good gas solubility in the sample. Based on the simulation model, a method for analyzing the efficiency of self-healing of the continuity of a polymer material medium is proposed. The method is based on comparing the rate of change in the shape and volume of bubble-shaped defects after an electrical breakdown and the rate of change in mechanical defects. This information can be obtained by analyzing photographs of defects taken in light transmitted through the defect. The mechanical nature of the defects is used as a reference level relative to which the effect of electrical breakdown can be analyzed. The considered method allows one to easily perform direct measurements of the dynamics of defect change and is therefore especially effective in collecting statistical data on the self-healing of transparent amorphous materials.