Novel Neutron Shielding Alginate Based Aerogel with Extremely Low Flammability

Novel low-density neutron shielding materials were fabricated by incorporating boron compounds into aerogel via a freeze-drying method. The microstructure was investigated with scanning electron microscopy (SEM). The results revealed a mostly layered structure of both boron-containing aerogels and the control. The aerogel composites have mechanical properties comparable with rigid polyurethane (PU) foam. The obtained composites have a good neutron shielding effect, with shielding efficiency up to 99% (0.283 g/cm2). The neutron shielding efficiency is mainly determined by B content, which is also influenced by the components of the composites. Combustion parameters, including heat release rate (HRR), fire growth rate (FIGRA), total heat release (THR), and total smoke release (TSR), all indicate extremely low fire risk of the neutron shielding materials. The facile fabrication of the low-density boron-containing material makes it promising in neutron shielding applications.