Lightweight green composite of bacterial cellulose/tungsten oxide nanowires for attenuation of gamma radiation

Abstract Polymeric composites are recently recommended for substituting the traditional radiation shielding non-eco-friendly lead-based materials. Sustainable polymer cellulose has been studied for shielding against multiple types of radiation, but the bacterial cellulose (BC) has not received the same attention for this application although of its extraordinary physico-chemical properties such as the high crystallinity and the entangled nanofibrous structure which secure high robustness, high reactive surface area, porosity, in addition to its green footprints. Herein, we examined the potentiality of BC composites in the attenuation of gamma radiation by combining it with multiple proportions of tungsten oxide nanowires (WO 3 NWs). The synthesized WO 3 NWs underwent TEM, Zeta potential, and Zeta sizing analyses, while other structural characterization has been conducted on the BC/WO 3 NWs composites including FTIR, XRD, SEM, EDX, contact angle, TGA, where these investigations declared the compositing between the BC and WO 3 NWs. WO 3 showed their diversified sized nanowires shape under the SEM and the TEM detector, with negative surface charge (-22 mV) revealed by Zeta potential. EDX analysis of the BC/WO 3 NWs elucidated the inclusion of tungsten metal, while the contact angle analysis indicated decreased hydrophilicity degree for the BC/WO 3 NWs comparing to the pristine BC. The TGA analysis pinpointed that the BC/WO 3 NWs composite showed thermostability till T = 247 °C, before the structure start collapsing. Afterward, four BC/WO 3 NWs constructs of multiple weight percentages were tested for their gamma radiation shielding, where the examined composite exhibited an attenuation capability directly proportional to the WO 3 NWs loading whenever the photon energy was below about 250 keV. Above this photon energy, no obvious shielding impact for the BC/WO 3 NWs composite was observed, regardless of the dopant concentration. This suggests the potential of the BC/WO 3 NWs in attenuation of gamma radiation at low energy range and proposes reinforcing the composite composition to extend the scale of its shielding capacity for higher energy range.