Influence of vacuum ultraviolet on changes in Fourier-transform infrared spectra, electrical and hydrophobic properties of a composite based on polyimide track membranes filled with silica

Vacuum ultraviolet radiation is a part of ultraviolet radiation with a very short wavelength and is a component of cosmic radiation. Composite materials based on polyimide have great potential for protection against cosmic radiation. The paper presents the results of studies on the effect of vacuum ultraviolet radiation on a polyimide film, a polyimide track membrane and a composite material based on a polyimide track membrane filled with silicon dioxide nanofibers. Mass losses, dielectric properties, Fourier-transform infrared spectra and wettability of the studied samples before and after vacuum ultraviolet irradiation were studied. It was found that the lowest mass losses during vacuum ultraviolet irradiation are observed in a composite material based on a polyimide track membrane filled with SiO2; the dielectric constant of the composite film after vacuum ultraviolet irradiation increased by 65.8%. It was established that the effect of vacuum ultraviolet irradiation on the films under study is accompanied by the destruction of a small amount of the following bonds: C=O, C–O, C–C and C–N. At the same time, vacuum ultraviolet caused the least damage to the developed composite material. Analysis of the contact angle of the studied samples showed that the surface of the polyimide film, polyimide track membrane, composite material remained hydrophilic. No changes were detected in the structure of the film surface.