2.3.6. Scanning electron microscopy (SEM)The morphological examination of films was performed byscanning electron microscopy (SEM) (VEGA II, TESCAN, CzechRepublic). Strips of dry films were immersed in liquid nitrogen andcryo-fractured manually. Then, the specimens were stuck onto acylindrical aluminum stub by a double-sided tape. The stubs withthe film were sputtered with a thin layer of gold in an ion sputtercoater (K-450X, EMITECH, England) and placed into a scanning elec-tron microscope to see the cross-section morphology of the films.Also the surface of the films was investigated.