Electrospun Polyvinyl Butyral Nanofibers Loaded with Bismuth Oxide Nanoparticles for X-ray Shielding

The combination of electrospun nanofibers and nanoparticles is opening up potential in the field of nanocomposite materials. This paper presents a composite electrospun nanofibrous material for X-ray shielding purposes consisting of a polyvinyl butyral polymer matrix and bismuth oxide nanoparticles. The organic–inorganic composite nanofibers considered in this paper, produced via the ex situ approach, attained a high content of nanoparticles of up to 95 wt %. The high content of nanoparticles inside the composite nanofibers was acquired via the application of the highly productive needleless electrospinning method. The resulting material is flexible and has a high drape and good air and steam permeability. The content of particles in the nanofibers was proved by the thermogravimetric analysis, and the homogeneous distribution of particles inside the nanofibers and within a whole nanofibrous layer was demonstrated via energy dispersive spectroscopy-scanning electron microscopy. In addition, samples of the composite electrospun nanofibers were tested for cytotoxicity, which revealed that the nanofibers were cytocompatible in all concentrations. The radiation attenuation properties of the samples were investigated via X-ray and γ-ray spectral measurements at a narrow beam geometry. The principal experimentally determined quantity for the tested samples was X- and γ-ray attenuation for the considerable energies of the spectra. The mass attenuation coefficients were calculated for the final composite electrospun material, which was supplemented by a composite nanofibrous material covering layer. With respect to photon energies higher than 40 keV, the attenuation coefficients were observed to be comparable with a commercially produced anti-radiation vest, which had a similar mass density as both the final composite electrospun material and the covering layer. Monte Carlo (MC) simulations in the FLUKA code were conducted to determine the photon attenuation for the respective energies in the tested samples. The results were compared to those determined experimentally, and the MC model was verified.