The mechanism of defect formation in the structure of pyrolyzed polyacrylonitrile

The paper considers the mechanism of formation of a vacancy defect (pore) in the structure of pyrolyzed polyacrylonitrile. The energy of defect formation, the binding energy of a porous structure are calculated. Theoretical calculations were performed within the framework of the molecular cluster model using the MNDO method. A vacancy defect (the so-called V defect) changes the local geometry of the polymer layer and, consequently, the electronic states. The surface of the material with vacancies consists of carbon hexagons and the emerging penta- and heptagons (topological defects), which leads to deformation of the polymer surface.