Electrospun and in situ self-polymerization of polyacrylonitrile containing gadolinium nanofibers for thermal neutron protection

In this work, the polyacrylonitrile containing gadolinium nanofibers for thermal neutron protection were successfully fabricated by electrospunning and followed by in situ self-polymerization. Scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) results show that there are no beads on the smooth surface of the nanofibers and gadolinium elements are uniformly dispersed in the matrix. The thermal analysis and FTIR results prove that gadolinium methacrylate is induced in situ self-polymerization during the heat treatment. The leaching rate of Gd3+ decreases from 79.97% to 10.74% tested by low-field nuclear magnetic resonance (LF-NMR) method after the self-polymerization of gadolinium methacrylate in the matrix when the nanofibers were immersed in water for 7 days. The thermal neutron shielding analysis calculated by MCNP program shows that above 99% thermal neutrons are absorbed when traveling through the 2-mm-thick polyacrylonitrile containing gadolinium nanofibers.