Enhancement of γ-radiation stability of polysulfone membrane matrix by reinforcement of hybrid nanomaterials of nanodiamond and ceria
For the first time, a hybrid nanoparticle system of nanodiamond (ND) and cerium oxide (ceria) is used as reinforcement materials in order to enhance the γ-radiation stability of polysulfone (Psf) host membrane matrix. Control Psf and Psf-(ND+Ce) hybrid membranes are synthesized and characterized, with the loading of each nanomaterial varying from 0.25 to 0.5 wt%. Membranes are put in γ-radiation for different doses (up to 1000 kGy) and the effect of radiation on the Psf matrix is evaluated. The gel permeation chromatography studies confirm that the average molecular weight of the hybrid membranes is restored to a reasonable extent, as against the control Psf membrane, which has reduced by 45% at 1000 kGy of radiation dose. The optimum loading of ND and ceria in the membrane matrix is found to be 0.5% each, which offers a remarkable ~10 times enhanced radiation stability, compared to the control Psf membrane, making it a novel membrane material for potential applications in radioactive environment. The enhanced stability of optimum hybrid membrane owes to the ability of ND and ceria in scavenging the secondary e-aq and OH• radicals, respectively, generated due to radiolysis of water, as confirmed by the free radical scavenging studies.