ABSTRACT
PbO (lead oxide) particles with different sizes were incorporated into polystyrene (PS) with various weight fractions (0, 10, 15, 25, 35%). These novel PS/PbO nano-composites were produced by roll mill mixing and compressing molding techniques and then investigated for radiation attenuation of X-rays (N-series/ISO 4037) typically used in radiology. Properties of the PbO particles were studied by X-ray diffraction (XRD). Filler dispersion and elemental composition of the prepared nano-composites were characterized using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS), revealing better filler distribution and fewer agglomerations with smaller PbO particle size. Linear and mass attenuation coefficients (µ and µm), total molecular and atomic cross-sections (σmol and σatm), as well as effective atomic number and electron density (Zeff and Neff), were calculated for the energy range N40 to N200. The influence of PbO weight percentage on the enhancement of the shielding parameters of the nano-composites was expected; however, the effect of PbO particle size was surprising. Linear and mass attenuation coefficients for PS/PbO composites increased gradually with increasing PbO concentrations, and composites with a small size of nanoparticles showed best performance. In addition, increasing PbO concentration raised the effective atomic number Zeff of the composite. Hence, the electron density Neff increased, which provided a higher total interaction cross-section of X-rays with the composites. Maximum radiation shielding was observed for PS/PbO(B). It is concluded that this material might be used in developping low-cost and lightweight X-ray shielding to be used in radiology.
